Merge remote-tracking branch 'spi/topic/master' into spi-next

9 files changed, 1201 insertions, 674 deletions

diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 4b1d6e74c744f..1f6e86f787efd 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -1,17 +1,23 @@
 SPI (Serial Peripheral Interface) busses
 
-SPI busses can be described with a node for the SPI master device
-and a set of child nodes for each SPI slave on the bus.  For this
-discussion, it is assumed that the system's SPI controller is in
-SPI master mode.  This binding does not describe SPI controllers
-in slave mode.
+SPI busses can be described with a node for the SPI controller device
+and a set of child nodes for each SPI slave on the bus.  The system's SPI
+controller may be described for use in SPI master mode or in SPI slave mode,
+but not for both at the same time.
 
-The SPI master node requires the following properties:
+The SPI controller node requires the following properties:
+- compatible      - Name of SPI bus controller following generic names
+		    recommended practice.
+
+In master mode, the SPI controller node requires the following additional
+properties:
 - #address-cells  - number of cells required to define a chip select
 		address on the SPI bus.
 - #size-cells     - should be zero.
-- compatible      - name of SPI bus controller following generic names
-		recommended practice.
+
+In slave mode, the SPI controller node requires one additional property:
+- spi-slave       - Empty property.
+
 No other properties are required in the SPI bus node.  It is assumed
 that a driver for an SPI bus device will understand that it is an SPI bus.
 However, the binding does not attempt to define the specific method for
@@ -21,7 +27,7 @@ assumption that board specific platform code will be used to manage
 chip selects.  Individual drivers can define additional properties to
 support describing the chip select layout.
 
-Optional properties:
+Optional properties (master mode only):
 - cs-gpios	  - gpios chip select.
 - num-cs	  - total number of chipselects.
 
@@ -41,28 +47,36 @@ cs1 : native
 cs2 : &gpio1 1 0
 cs3 : &gpio1 2 0
 
-SPI slave nodes must be children of the SPI master node and can
-contain the following properties.
-- reg             - (required) chip select address of device.
-- compatible      - (required) name of SPI device following generic names
-		recommended practice.
-- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz.
-- spi-cpol        - (optional) Empty property indicating device requires
-		inverse clock polarity (CPOL) mode.
-- spi-cpha        - (optional) Empty property indicating device requires
-		shifted clock phase (CPHA) mode.
-- spi-cs-high     - (optional) Empty property indicating device requires
-		chip select active high.
-- spi-3wire       - (optional) Empty property indicating device requires
-		3-wire mode.
-- spi-lsb-first   - (optional) Empty property indicating device requires
-		LSB first mode.
-- spi-tx-bus-width - (optional) The bus width (number of data wires) that is
-                      used for MOSI. Defaults to 1 if not present.
-- spi-rx-bus-width - (optional) The bus width (number of data wires) that is
-                      used for MISO. Defaults to 1 if not present.
-- spi-rx-delay-us  - (optional) Microsecond delay after a read transfer.
-- spi-tx-delay-us  - (optional) Microsecond delay after a write transfer.
+
+SPI slave nodes must be children of the SPI controller node.
+
+In master mode, one or more slave nodes (up to the number of chip selects) can
+be present.  Required properties are:
+- compatible      - Name of SPI device following generic names recommended
+		    practice.
+- reg             - Chip select address of device.
+- spi-max-frequency - Maximum SPI clocking speed of device in Hz.
+
+In slave mode, the (single) slave node is optional.
+If present, it must be called "slave".  Required properties are:
+- compatible      - Name of SPI device following generic names recommended
+		    practice.
+
+All slave nodes can contain the following optional properties:
+- spi-cpol        - Empty property indicating device requires inverse clock
+		    polarity (CPOL) mode.
+- spi-cpha        - Empty property indicating device requires shifted clock
+		    phase (CPHA) mode.
+- spi-cs-high     - Empty property indicating device requires chip select
+		    active high.
+- spi-3wire       - Empty property indicating device requires 3-wire mode.
+- spi-lsb-first   - Empty property indicating device requires LSB first mode.
+- spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI.
+		    Defaults to 1 if not present.
+- spi-rx-bus-width - The bus width (number of data wires) that is used for MISO.
+		    Defaults to 1 if not present.
+- spi-rx-delay-us - Microsecond delay after a read transfer.
+- spi-tx-delay-us - Microsecond delay after a write transfer.
 
 Some SPI controllers and devices support Dual and Quad SPI transfer mode.
 It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index d1824b399b2d1..1721c1b570c32 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -62,8 +62,8 @@ chips described as using "three wire" signaling: SCK, data, nCSx.
 (That data line is sometimes called MOMI or SISO.)
 
 Microcontrollers often support both master and slave sides of the SPI
-protocol.  This document (and Linux) currently only supports the master
-side of SPI interactions.
+protocol.  This document (and Linux) supports both the master and slave
+sides of SPI interactions.
 
 
 Who uses it?  On what kinds of systems?
@@ -154,9 +154,8 @@ control audio interfaces, present touchscreen sensors as input interfaces,
 or monitor temperature and voltage levels during industrial processing.
 And those might all be sharing the same controller driver.
 
-A "struct spi_device" encapsulates the master-side interface between
-those two types of driver.  At this writing, Linux has no slave side
-programming interface.
+A "struct spi_device" encapsulates the controller-side interface between
+those two types of drivers.
 
 There is a minimal core of SPI programming interfaces, focussing on
 using the driver model to connect controller and protocol drivers using
@@ -177,10 +176,24 @@ shows up in sysfs in several locations:
    /sys/bus/spi/drivers/D ... driver for one or more spi*.* devices
 
    /sys/class/spi_master/spiB ... symlink (or actual device node) to
-	a logical node which could hold class related state for the
-	controller managing bus "B".  All spiB.* devices share one
+	a logical node which could hold class related state for the SPI
+	master controller managing bus "B".  All spiB.* devices share one
 	physical SPI bus segment, with SCLK, MOSI, and MISO.
 
+   /sys/devices/.../CTLR/slave ... virtual file for (un)registering the
+	slave device for an SPI slave controller.
+	Writing the driver name of an SPI slave handler to this file
+	registers the slave device; writing "(null)" unregisters the slave
+	device.
+	Reading from this file shows the name of the slave device ("(null)"
+	if not registered).
+
+   /sys/class/spi_slave/spiB ... symlink (or actual device node) to
+	a logical node which could hold class related state for the SPI
+	slave controller on bus "B".  When registered, a single spiB.*
+	device is present here, possible sharing the physical SPI bus
+	segment with other SPI slave devices.
+
 Note that the actual location of the controller's class state depends
 on whether you enabled CONFIG_SYSFS_DEPRECATED or not.  At this time,
 the only class-specific state is the bus number ("B" in "spiB"), so
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 0978833620364..82cd818aa0629 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -785,6 +785,30 @@ config SPI_TLE62X0
 
 endif # SPI_MASTER
 
-# (slave support would go here)
+#
+# SLAVE side ... listening to other SPI masters
+#
+
+config SPI_SLAVE
+	bool "SPI slave protocol handlers"
+	help
+	  If your system has a slave-capable SPI controller, you can enable
+	  slave protocol handlers.
+
+if SPI_SLAVE
+
+config SPI_SLAVE_TIME
+	tristate "SPI slave handler reporting boot up time"
+	help
+	  SPI slave handler responding with the time of reception of the last
+	  SPI message.
+
+config SPI_SLAVE_SYSTEM_CONTROL
+	tristate "SPI slave handler controlling system state"
+	help
+	  SPI slave handler to allow remote control of system reboot, power
+	  off, halt, and suspend.
+
+endif # SPI_SLAVE
 
 endif # SPI
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index b375a7a892160..1d7923e8c63bc 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -105,3 +105,7 @@ obj-$(CONFIG_SPI_XILINX)		+= spi-xilinx.o
 obj-$(CONFIG_SPI_XLP)			+= spi-xlp.o
 obj-$(CONFIG_SPI_XTENSA_XTFPGA)		+= spi-xtensa-xtfpga.o
 obj-$(CONFIG_SPI_ZYNQMP_GQSPI)		+= spi-zynqmp-gqspi.o
+
+# SPI slave protocol handlers
+obj-$(CONFIG_SPI_SLAVE_TIME)		+= spi-slave-time.o
+obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL)	+= spi-slave-system-control.o
diff --git a/drivers/spi/spi-slave-system-control.c b/drivers/spi/spi-slave-system-control.c
new file mode 100644
index 0000000000000..c0257e937995e
--- /dev/null
+++ b/drivers/spi/spi-slave-system-control.c
@@ -0,0 +1,154 @@
+/*
+ * SPI slave handler controlling system state
+ *
+ * This SPI slave handler allows remote control of system reboot, power off,
+ * halt, and suspend.
+ *
+ * Copyright (C) 2016-2017 Glider bvba
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
+ * system):
+ *
+ *   # reboot='\x7c\x50'
+ *   # poweroff='\x71\x3f'
+ *   # halt='\x38\x76'
+ *   # suspend='\x1b\x1b'
+ *   # spidev_test -D /dev/spidev2.0 -p $suspend # or $reboot, $poweroff, $halt
+ */
+
+#include <linux/completion.h>
+#include <linux/module.h>
+#include <linux/reboot.h>
+#include <linux/suspend.h>
+#include <linux/spi/spi.h>
+
+/*
+ * The numbers are chosen to display something human-readable on two 7-segment
+ * displays connected to two 74HC595 shift registers
+ */
+#define CMD_REBOOT	0x7c50	/* rb */
+#define CMD_POWEROFF	0x713f	/* OF */
+#define CMD_HALT	0x3876	/* HL */
+#define CMD_SUSPEND	0x1b1b	/* ZZ */
+
+struct spi_slave_system_control_priv {
+	struct spi_device *spi;
+	struct completion finished;
+	struct spi_transfer xfer;
+	struct spi_message msg;
+	__be16 cmd;
+};
+
+static
+int spi_slave_system_control_submit(struct spi_slave_system_control_priv *priv);
+
+static void spi_slave_system_control_complete(void *arg)
+{
+	struct spi_slave_system_control_priv *priv = arg;
+	u16 cmd;
+	int ret;
+
+	if (priv->msg.status)
+		goto terminate;
+
+	cmd = be16_to_cpu(priv->cmd);
+	switch (cmd) {
+	case CMD_REBOOT:
+		dev_info(&priv->spi->dev, "Rebooting system...\n");
+		kernel_restart(NULL);
+
+	case CMD_POWEROFF:
+		dev_info(&priv->spi->dev, "Powering off system...\n");
+		kernel_power_off();
+		break;
+
+	case CMD_HALT:
+		dev_info(&priv->spi->dev, "Halting system...\n");
+		kernel_halt();
+		break;
+
+	case CMD_SUSPEND:
+		dev_info(&priv->spi->dev, "Suspending system...\n");
+		pm_suspend(PM_SUSPEND_MEM);
+		break;
+
+	default:
+		dev_warn(&priv->spi->dev, "Unknown command 0x%x\n", cmd);
+		break;
+	}
+
+	ret = spi_slave_system_control_submit(priv);
+	if (ret)
+		goto terminate;
+
+	return;
+
+terminate:
+	dev_info(&priv->spi->dev, "Terminating\n");
+	complete(&priv->finished);
+}
+
+static
+int spi_slave_system_control_submit(struct spi_slave_system_control_priv *priv)
+{
+	int ret;
+
+	spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
+
+	priv->msg.complete = spi_slave_system_control_complete;
+	priv->msg.context = priv;
+
+	ret = spi_async(priv->spi, &priv->msg);
+	if (ret)
+		dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
+
+	return ret;
+}
+
+static int spi_slave_system_control_probe(struct spi_device *spi)
+{
+	struct spi_slave_system_control_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->spi = spi;
+	init_completion(&priv->finished);
+	priv->xfer.rx_buf = &priv->cmd;
+	priv->xfer.len = sizeof(priv->cmd);
+
+	ret = spi_slave_system_control_submit(priv);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, priv);
+	return 0;
+}
+
+static int spi_slave_system_control_remove(struct spi_device *spi)
+{
+	struct spi_slave_system_control_priv *priv = spi_get_drvdata(spi);
+
+	spi_slave_abort(spi);
+	wait_for_completion(&priv->finished);
+	return 0;
+}
+
+static struct spi_driver spi_slave_system_control_driver = {
+	.driver = {
+		.name	= "spi-slave-system-control",
+	},
+	.probe		= spi_slave_system_control_probe,
+	.remove		= spi_slave_system_control_remove,
+};
+module_spi_driver(spi_slave_system_control_driver);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
+MODULE_DESCRIPTION("SPI slave handler controlling system state");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/spi/spi-slave-time.c b/drivers/spi/spi-slave-time.c
new file mode 100644
index 0000000000000..f2e07a392d686
--- /dev/null
+++ b/drivers/spi/spi-slave-time.c
@@ -0,0 +1,129 @@
+/*
+ * SPI slave handler reporting uptime at reception of previous SPI message
+ *
+ * This SPI slave handler sends the time of reception of the last SPI message
+ * as two 32-bit unsigned integers in binary format and in network byte order,
+ * representing the number of seconds and fractional seconds (in microseconds)
+ * since boot up.
+ *
+ * Copyright (C) 2016-2017 Glider bvba
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
+ * system):
+ *
+ *   # spidev_test -D /dev/spidev2.0 -p dummy-8B
+ *   spi mode: 0x0
+ *   bits per word: 8
+ *   max speed: 500000 Hz (500 KHz)
+ *   RX | 00 00 04 6D 00 09 5B BB ...
+ *		^^^^^    ^^^^^^^^
+ *		seconds  microseconds
+ */
+
+#include <linux/completion.h>
+#include <linux/module.h>
+#include <linux/sched/clock.h>
+#include <linux/spi/spi.h>
+
+
+struct spi_slave_time_priv {
+	struct spi_device *spi;
+	struct completion finished;
+	struct spi_transfer xfer;
+	struct spi_message msg;
+	__be32 buf[2];
+};
+
+static int spi_slave_time_submit(struct spi_slave_time_priv *priv);
+
+static void spi_slave_time_complete(void *arg)
+{
+	struct spi_slave_time_priv *priv = arg;
+	int ret;
+
+	ret = priv->msg.status;
+	if (ret)
+		goto terminate;
+
+	ret = spi_slave_time_submit(priv);
+	if (ret)
+		goto terminate;
+
+	return;
+
+terminate:
+	dev_info(&priv->spi->dev, "Terminating\n");
+	complete(&priv->finished);
+}
+
+static int spi_slave_time_submit(struct spi_slave_time_priv *priv)
+{
+	u32 rem_us;
+	int ret;
+	u64 ts;
+
+	ts = local_clock();
+	rem_us = do_div(ts, 1000000000) / 1000;
+
+	priv->buf[0] = cpu_to_be32(ts);
+	priv->buf[1] = cpu_to_be32(rem_us);
+
+	spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
+
+	priv->msg.complete = spi_slave_time_complete;
+	priv->msg.context = priv;
+
+	ret = spi_async(priv->spi, &priv->msg);
+	if (ret)
+		dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
+
+	return ret;
+}
+
+static int spi_slave_time_probe(struct spi_device *spi)
+{
+	struct spi_slave_time_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->spi = spi;
+	init_completion(&priv->finished);
+	priv->xfer.tx_buf = priv->buf;
+	priv->xfer.len = sizeof(priv->buf);
+
+	ret = spi_slave_time_submit(priv);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, priv);
+	return 0;
+}
+
+static int spi_slave_time_remove(struct spi_device *spi)
+{
+	struct spi_slave_time_priv *priv = spi_get_drvdata(spi);
+
+	spi_slave_abort(spi);
+	wait_for_completion(&priv->finished);
+	return 0;
+}
+
+static struct spi_driver spi_slave_time_driver = {
+	.driver = {
+		.name	= "spi-slave-time",
+	},
+	.probe		= spi_slave_time_probe,
+	.remove		= spi_slave_time_remove,
+};
+module_spi_driver(spi_slave_time_driver);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
+MODULE_DESCRIPTION("SPI slave reporting uptime at previous SPI message");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6f87fec409b5f..4fcbb0aa71d36 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -48,11 +48,11 @@ static void spidev_release(struct device *dev)
 {
 	struct spi_device	*spi = to_spi_device(dev);
 
-	/* spi masters may cleanup for released devices */
-	if (spi->master->cleanup)
-		spi->master->cleanup(spi);
+	/* spi controllers may cleanup for released devices */
+	if (spi->controller->cleanup)
+		spi->controller->cleanup(spi);
 
-	spi_master_put(spi->master);
+	spi_controller_put(spi->controller);
 	kfree(spi);
 }
 
@@ -71,17 +71,17 @@ modalias_show(struct device *dev, struct device_attribute *a, char *buf)
 static DEVICE_ATTR_RO(modalias);
 
 #define SPI_STATISTICS_ATTRS(field, file)				\
-static ssize_t spi_master_##field##_show(struct device *dev,		\
-					 struct device_attribute *attr,	\
-					 char *buf)			\
+static ssize_t spi_controller_##field##_show(struct device *dev,	\
+					     struct device_attribute *attr, \
+					     char *buf)			\
 {									\
-	struct spi_master *master = container_of(dev,			\
-						 struct spi_master, dev); \
-	return spi_statistics_##field##_show(&master->statistics, buf);	\
+	struct spi_controller *ctlr = container_of(dev,			\
+					 struct spi_controller, dev);	\
+	return spi_statistics_##field##_show(&ctlr->statistics, buf);	\
 }									\
-static struct device_attribute dev_attr_spi_master_##field = {		\
+static struct device_attribute dev_attr_spi_controller_##field = {	\
 	.attr = { .name = file, .mode = 0444 },				\
-	.show = spi_master_##field##_show,				\
+	.show = spi_controller_##field##_show,				\
 };									\
 static ssize_t spi_device_##field##_show(struct device *dev,		\
 					 struct device_attribute *attr,	\
@@ -201,51 +201,51 @@ static const struct attribute_group *spi_dev_groups[] = {
 	NULL,
 };
 
-static struct attribute *spi_master_statistics_attrs[] = {
-	&dev_attr_spi_master_messages.attr,
-	&dev_attr_spi_master_transfers.attr,
-	&dev_attr_spi_master_errors.attr,
-	&dev_attr_spi_master_timedout.attr,
-	&dev_attr_spi_master_spi_sync.attr,
-	&dev_attr_spi_master_spi_sync_immediate.attr,
-	&dev_attr_spi_master_spi_async.attr,
-	&dev_attr_spi_master_bytes.attr,
-	&dev_attr_spi_master_bytes_rx.attr,
-	&dev_attr_spi_master_bytes_tx.attr,
-	&dev_attr_spi_master_transfer_bytes_histo0.attr,
-	&dev_attr_spi_master_transfer_bytes_histo1.attr,
-	&dev_attr_spi_master_transfer_bytes_histo2.attr,
-	&dev_attr_spi_master_transfer_bytes_histo3.attr,
-	&dev_attr_spi_master_transfer_bytes_histo4.attr,
-	&dev_attr_spi_master_transfer_bytes_histo5.attr,
-	&dev_attr_spi_master_transfer_bytes_histo6.attr,
-	&dev_attr_spi_master_transfer_bytes_histo7.attr,
-	&dev_attr_spi_master_transfer_bytes_histo8.attr,
-	&dev_attr_spi_master_transfer_bytes_histo9.attr,
-	&dev_attr_spi_master_transfer_bytes_histo10.attr,
-	&dev_attr_spi_master_transfer_bytes_histo11.attr,
-	&dev_attr_spi_master_transfer_bytes_histo12.attr,
-	&dev_attr_spi_master_transfer_bytes_histo13.attr,
-	&dev_attr_spi_master_transfer_bytes_histo14.attr,
-	&dev_attr_spi_master_transfer_bytes_histo15.attr,
-	&dev_attr_spi_master_transfer_bytes_histo16.attr,
-	&dev_attr_spi_master_transfers_split_maxsize.attr,
+static struct attribute *spi_controller_statistics_attrs[] = {
+	&dev_attr_spi_controller_messages.attr,
+	&dev_attr_spi_controller_transfers.attr,
+	&dev_attr_spi_controller_errors.attr,
+	&dev_attr_spi_controller_timedout.attr,
+	&dev_attr_spi_controller_spi_sync.attr,
+	&dev_attr_spi_controller_spi_sync_immediate.attr,
+	&dev_attr_spi_controller_spi_async.attr,
+	&dev_attr_spi_controller_bytes.attr,
+	&dev_attr_spi_controller_bytes_rx.attr,
+	&dev_attr_spi_controller_bytes_tx.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo0.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo1.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo2.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo3.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo4.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo5.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo6.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo7.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo8.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo9.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo10.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo11.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo12.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo13.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo14.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo15.attr,
+	&dev_attr_spi_controller_transfer_bytes_histo16.attr,
+	&dev_attr_spi_controller_transfers_split_maxsize.attr,
 	NULL,
 };
 
-static const struct attribute_group spi_master_statistics_group = {
+static const struct attribute_group spi_controller_statistics_group = {
 	.name  = "statistics",
-	.attrs  = spi_master_statistics_attrs,
+	.attrs  = spi_controller_statistics_attrs,
 };
 
 static const struct attribute_group *spi_master_groups[] = {
-	&spi_master_statistics_group,
+	&spi_controller_statistics_group,
 	NULL,
 };
 
 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
 				       struct spi_transfer *xfer,
-				       struct spi_master *master)
+				       struct spi_controller *ctlr)
 {
 	unsigned long flags;
 	int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
@@ -260,10 +260,10 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
 
 	stats->bytes += xfer->len;
 	if ((xfer->tx_buf) &&
-	    (xfer->tx_buf != master->dummy_tx))
+	    (xfer->tx_buf != ctlr->dummy_tx))
 		stats->bytes_tx += xfer->len;
 	if ((xfer->rx_buf) &&
-	    (xfer->rx_buf != master->dummy_rx))
+	    (xfer->rx_buf != ctlr->dummy_rx))
 		stats->bytes_rx += xfer->len;
 
 	spin_unlock_irqrestore(&stats->lock, flags);
@@ -405,7 +405,7 @@ EXPORT_SYMBOL_GPL(__spi_register_driver);
 /*-------------------------------------------------------------------------*/
 
 /* SPI devices should normally not be created by SPI device drivers; that
- * would make them board-specific.  Similarly with SPI master drivers.
+ * would make them board-specific.  Similarly with SPI controller drivers.
  * Device registration normally goes into like arch/.../mach.../board-YYY.c
  * with other readonly (flashable) information about mainboard devices.
  */
@@ -416,17 +416,17 @@ struct boardinfo {
 };
 
 static LIST_HEAD(board_list);
-static LIST_HEAD(spi_master_list);
+static LIST_HEAD(spi_controller_list);
 
 /*
  * Used to protect add/del opertion for board_info list and
- * spi_master list, and their matching process
+ * spi_controller list, and their matching process
  */
 static DEFINE_MUTEX(board_lock);
 
 /**
  * spi_alloc_device - Allocate a new SPI device
- * @master: Controller to which device is connected
+ * @ctlr: Controller to which device is connected
  * Context: can sleep
  *
  * Allows a driver to allocate and initialize a spi_device without
@@ -435,27 +435,27 @@ static DEFINE_MUTEX(board_lock);
  * spi_add_device() on it.
  *
  * Caller is responsible to call spi_add_device() on the returned
- * spi_device structure to add it to the SPI master.  If the caller
+ * spi_device structure to add it to the SPI controller.  If the caller
  * needs to discard the spi_device without adding it, then it should
  * call spi_dev_put() on it.
  *
  * Return: a pointer to the new device, or NULL.
  */
-struct spi_device *spi_alloc_device(struct spi_master *master)
+struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
 {
 	struct spi_device	*spi;
 
-	if (!spi_master_get(master))
+	if (!spi_controller_get(ctlr))
 		return NULL;
 
 	spi = kzalloc(sizeof(*spi), GFP_KERNEL);
 	if (!spi) {
-		spi_master_put(master);
+		spi_controller_put(ctlr);
 		return NULL;
 	}
 
-	spi->master = master;
-	spi->dev.parent = &master->dev;
+	spi->master = spi->controller = ctlr;
+	spi->dev.parent = &ctlr->dev;
 	spi->dev.bus = &spi_bus_type;
 	spi->dev.release = spidev_release;
 	spi->cs_gpio = -ENOENT;
@@ -476,7 +476,7 @@ static void spi_dev_set_name(struct spi_device *spi)
 		return;
 	}
 
-	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
+	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
 		     spi->chip_select);
 }
 
@@ -485,7 +485,7 @@ static int spi_dev_check(struct device *dev, void *data)
 	struct spi_device *spi = to_spi_device(dev);
 	struct spi_device *new_spi = data;
 
-	if (spi->master == new_spi->master &&
+	if (spi->controller == new_spi->controller &&
 	    spi->chip_select == new_spi->chip_select)
 		return -EBUSY;
 	return 0;
@@ -503,15 +503,14 @@ static int spi_dev_check(struct device *dev, void *data)
 int spi_add_device(struct spi_device *spi)
 {
 	static DEFINE_MUTEX(spi_add_lock);
-	struct spi_master *master = spi->master;
-	struct device *dev = master->dev.parent;
+	struct spi_controller *ctlr = spi->controller;
+	struct device *dev = ctlr->dev.parent;
 	int status;
 
 	/* Chipselects are numbered 0..max; validate. */
-	if (spi->chip_select >= master->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n",
-			spi->chip_select,
-			master->num_chipselect);
+	if (spi->chip_select >= ctlr->num_chipselect) {
+		dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
+			ctlr->num_chipselect);
 		return -EINVAL;
 	}
 
@@ -531,8 +530,8 @@ int spi_add_device(struct spi_device *spi)
 		goto done;
 	}
 
-	if (master->cs_gpios)
-		spi->cs_gpio = master->cs_gpios[spi->chip_select];
+	if (ctlr->cs_gpios)
+		spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
 
 	/* Drivers may modify this initial i/o setup, but will
 	 * normally rely on the device being setup.  Devices
@@ -561,7 +560,7 @@ EXPORT_SYMBOL_GPL(spi_add_device);
 
 /**
  * spi_new_device - instantiate one new SPI device
- * @master: Controller to which device is connected
+ * @ctlr: Controller to which device is connected
  * @chip: Describes the SPI device
  * Context: can sleep
  *
@@ -573,7 +572,7 @@ EXPORT_SYMBOL_GPL(spi_add_device);
  *
  * Return: the new device, or NULL.
  */
-struct spi_device *spi_new_device(struct spi_master *master,
+struct spi_device *spi_new_device(struct spi_controller *ctlr,
 				  struct spi_board_info *chip)
 {
 	struct spi_device	*proxy;
@@ -586,7 +585,7 @@ struct spi_device *spi_new_device(struct spi_master *master,
 	 * suggests syslogged diagnostics are best here (ugh).
 	 */
 
-	proxy = spi_alloc_device(master);
+	proxy = spi_alloc_device(ctlr);
 	if (!proxy)
 		return NULL;
 
@@ -604,7 +603,7 @@ struct spi_device *spi_new_device(struct spi_master *master,
 	if (chip->properties) {
 		status = device_add_properties(&proxy->dev, chip->properties);
 		if (status) {
-			dev_err(&master->dev,
+			dev_err(&ctlr->dev,
 				"failed to add properties to '%s': %d\n",
 				chip->modalias, status);
 			goto err_dev_put;
@@ -631,7 +630,7 @@ EXPORT_SYMBOL_GPL(spi_new_device);
  * @spi: spi_device to unregister
  *
  * Start making the passed SPI device vanish. Normally this would be handled
- * by spi_unregister_master().
+ * by spi_unregister_controller().
  */
 void spi_unregister_device(struct spi_device *spi)
 {
@@ -648,17 +647,17 @@ void spi_unregister_device(struct spi_device *spi)
 }
 EXPORT_SYMBOL_GPL(spi_unregister_device);
 
-static void spi_match_master_to_boardinfo(struct spi_master *master,
-				struct spi_board_info *bi)
+static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
+					      struct spi_board_info *bi)
 {
 	struct spi_device *dev;
 
-	if (master->bus_num != bi->bus_num)
+	if (ctlr->bus_num != bi->bus_num)
 		return;
 
-	dev = spi_new_device(master, bi);
+	dev = spi_new_device(ctlr, bi);
 	if (!dev)
-		dev_err(master->dev.parent, "can't create new device for %s\n",
+		dev_err(ctlr->dev.parent, "can't create new device for %s\n",
 			bi->modalias);
 }
 
@@ -697,7 +696,7 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n)
 		return -ENOMEM;
 
 	for (i = 0; i < n; i++, bi++, info++) {
-		struct spi_master *master;
+		struct spi_controller *ctlr;
 
 		memcpy(&bi->board_info, info, sizeof(*info));
 		if (info->properties) {
@@ -709,8 +708,9 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n)
 
 		mutex_lock(&board_lock);
 		list_add_tail(&bi->list, &board_list);
-		list_for_each_entry(master, &spi_master_list, list)
-			spi_match_master_to_boardinfo(master, &bi->board_info);
+		list_for_each_entry(ctlr, &spi_controller_list, list)
+			spi_match_controller_to_boardinfo(ctlr,
+							  &bi->board_info);
 		mutex_unlock(&board_lock);
 	}
 
@@ -727,16 +727,16 @@ static void spi_set_cs(struct spi_device *spi, bool enable)
 	if (gpio_is_valid(spi->cs_gpio)) {
 		gpio_set_value(spi->cs_gpio, !enable);
 		/* Some SPI masters need both GPIO CS & slave_select */
-		if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
-		    spi->master->set_cs)
-			spi->master->set_cs(spi, !enable);
-	} else if (spi->master->set_cs) {
-		spi->master->set_cs(spi, !enable);
+		if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
+		    spi->controller->set_cs)
+			spi->controller->set_cs(spi, !enable);
+	} else if (spi->controller->set_cs) {
+		spi->controller->set_cs(spi, !enable);
 	}
 }
 
 #ifdef CONFIG_HAS_DMA
-static int spi_map_buf(struct spi_master *master, struct device *dev,
+static int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
 		       struct sg_table *sgt, void *buf, size_t len,
 		       enum dma_data_direction dir)
 {
@@ -761,7 +761,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 		desc_len = min_t(int, max_seg_size, PAGE_SIZE);
 		sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
 	} else if (virt_addr_valid(buf)) {
-		desc_len = min_t(int, max_seg_size, master->max_dma_len);
+		desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
 		sgs = DIV_ROUND_UP(len, desc_len);
 	} else {
 		return -EINVAL;
@@ -811,7 +811,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 	return 0;
 }
 
-static void spi_unmap_buf(struct spi_master *master, struct device *dev,
+static void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
 			  struct sg_table *sgt, enum dma_data_direction dir)
 {
 	if (sgt->orig_nents) {
@@ -820,31 +820,31 @@ static void spi_unmap_buf(struct spi_master *master, struct device *dev,
 	}
 }
 
-static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
+static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 {
 	struct device *tx_dev, *rx_dev;
 	struct spi_transfer *xfer;
 	int ret;
 
-	if (!master->can_dma)
+	if (!ctlr->can_dma)
 		return 0;
 
-	if (master->dma_tx)
-		tx_dev = master->dma_tx->device->dev;
+	if (ctlr->dma_tx)
+		tx_dev = ctlr->dma_tx->device->dev;
 	else
-		tx_dev = master->dev.parent;
+		tx_dev = ctlr->dev.parent;
 
-	if (master->dma_rx)
-		rx_dev = master->dma_rx->device->dev;
+	if (ctlr->dma_rx)
+		rx_dev = ctlr->dma_rx->device->dev;
 	else
-		rx_dev = master->dev.parent;
+		rx_dev = ctlr->dev.parent;
 
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-		if (!master->can_dma(master, msg->spi, xfer))
+		if (!ctlr->can_dma(ctlr, msg->spi, xfer))
 			continue;
 
 		if (xfer->tx_buf != NULL) {
-			ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
+			ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
 					  (void *)xfer->tx_buf, xfer->len,
 					  DMA_TO_DEVICE);
 			if (ret != 0)
@@ -852,79 +852,78 @@ static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
 		}
 
 		if (xfer->rx_buf != NULL) {
-			ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
+			ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
 					  xfer->rx_buf, xfer->len,
 					  DMA_FROM_DEVICE);
 			if (ret != 0) {
-				spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
+				spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
 					      DMA_TO_DEVICE);
 				return ret;
 			}
 		}
 	}
 
-	master->cur_msg_mapped = true;
+	ctlr->cur_msg_mapped = true;
 
 	return 0;
 }
 
-static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
+static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
 {
 	struct spi_transfer *xfer;
 	struct device *tx_dev, *rx_dev;
 
-	if (!master->cur_msg_mapped || !master->can_dma)
+	if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
 		return 0;
 
-	if (master->dma_tx)
-		tx_dev = master->dma_tx->device->dev;
+	if (ctlr->dma_tx)
+		tx_dev = ctlr->dma_tx->device->dev;
 	else
-		tx_dev = master->dev.parent;
+		tx_dev = ctlr->dev.parent;
 
-	if (master->dma_rx)
-		rx_dev = master->dma_rx->device->dev;
+	if (ctlr->dma_rx)
+		rx_dev = ctlr->dma_rx->device->dev;
 	else
-		rx_dev = master->dev.parent;
+		rx_dev = ctlr->dev.parent;
 
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-		if (!master->can_dma(master, msg->spi, xfer))
+		if (!ctlr->can_dma(ctlr, msg->spi, xfer))
 			continue;
 
-		spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
-		spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
+		spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
+		spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
 	}
 
 	return 0;
 }
 #else /* !CONFIG_HAS_DMA */
-static inline int spi_map_buf(struct spi_master *master,
-			      struct device *dev, struct sg_table *sgt,
-			      void *buf, size_t len,
+static inline int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
+			      struct sg_table *sgt, void *buf, size_t len,
 			      enum dma_data_direction dir)
 {
 	return -EINVAL;
 }
 
-static inline void spi_unmap_buf(struct spi_master *master,
+static inline void spi_unmap_buf(struct spi_controller *ctlr,
 				 struct device *dev, struct sg_table *sgt,
 				 enum dma_data_direction dir)
 {
 }
 
-static inline int __spi_map_msg(struct spi_master *master,
+static inline int __spi_map_msg(struct spi_controller *ctlr,
 				struct spi_message *msg)
 {
 	return 0;
 }
 
-static inline int __spi_unmap_msg(struct spi_master *master,
+static inline int __spi_unmap_msg(struct spi_controller *ctlr,
 				  struct spi_message *msg)
 {
 	return 0;
 }
 #endif /* !CONFIG_HAS_DMA */
 
-static inline int spi_unmap_msg(struct spi_master *master,
+static inline int spi_unmap_msg(struct spi_controller *ctlr,
 				struct spi_message *msg)
 {
 	struct spi_transfer *xfer;
@@ -934,63 +933,63 @@ static inline int spi_unmap_msg(struct spi_master *master,
 		 * Restore the original value of tx_buf or rx_buf if they are
 		 * NULL.
 		 */
-		if (xfer->tx_buf == master->dummy_tx)
+		if (xfer->tx_buf == ctlr->dummy_tx)
 			xfer->tx_buf = NULL;
-		if (xfer->rx_buf == master->dummy_rx)
+		if (xfer->rx_buf == ctlr->dummy_rx)
 			xfer->rx_buf = NULL;
 	}
 
-	return __spi_unmap_msg(master, msg);
+	return __spi_unmap_msg(ctlr, msg);
 }
 
-static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
+static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 {
 	struct spi_transfer *xfer;
 	void *tmp;
 	unsigned int max_tx, max_rx;
 
-	if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
+	if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
 		max_tx = 0;
 		max_rx = 0;
 
 		list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-			if ((master->flags & SPI_MASTER_MUST_TX) &&
+			if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
 			    !xfer->tx_buf)
 				max_tx = max(xfer->len, max_tx);
-			if ((master->flags & SPI_MASTER_MUST_RX) &&
+			if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
 			    !xfer->rx_buf)
 				max_rx = max(xfer->len, max_rx);
 		}
 
 		if (max_tx) {
-			tmp = krealloc(master->dummy_tx, max_tx,
+			tmp = krealloc(ctlr->dummy_tx, max_tx,
 				       GFP_KERNEL | GFP_DMA);
 			if (!tmp)
 				return -ENOMEM;
-			master->dummy_tx = tmp;
+			ctlr->dummy_tx = tmp;
 			memset(tmp, 0, max_tx);
 		}
 
 		if (max_rx) {
-			tmp = krealloc(master->dummy_rx, max_rx,
+			tmp = krealloc(ctlr->dummy_rx, max_rx,
 				       GFP_KERNEL | GFP_DMA);
 			if (!tmp)
 				return -ENOMEM;
-			master->dummy_rx = tmp;
+			ctlr->dummy_rx = tmp;
 		}
 
 		if (max_tx || max_rx) {
 			list_for_each_entry(xfer, &msg->transfers,
 					    transfer_list) {
 				if (!xfer->tx_buf)
-					xfer->tx_buf = master->dummy_tx;
+					xfer->tx_buf = ctlr->dummy_tx;
 				if (!xfer->rx_buf)
-					xfer->rx_buf = master->dummy_rx;
+					xfer->rx_buf = ctlr->dummy_rx;
 			}
 		}
 	}
 
-	return __spi_map_msg(master, msg);
+	return __spi_map_msg(ctlr, msg);
 }
 
 /*
@@ -1000,14 +999,14 @@ static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
  * drivers which implement a transfer_one() operation.  It provides
  * standard handling of delays and chip select management.
  */
-static int spi_transfer_one_message(struct spi_master *master,
+static int spi_transfer_one_message(struct spi_controller *ctlr,
 				    struct spi_message *msg)
 {
 	struct spi_transfer *xfer;
 	bool keep_cs = false;
 	int ret = 0;
 	unsigned long long ms = 1;
-	struct spi_statistics *statm = &master->statistics;
+	struct spi_statistics *statm = &ctlr->statistics;
 	struct spi_statistics *stats = &msg->spi->statistics;
 
 	spi_set_cs(msg->spi, true);
@@ -1018,13 +1017,13 @@ static int spi_transfer_one_message(struct spi_master *master,
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 		trace_spi_transfer_start(msg, xfer);
 
-		spi_statistics_add_transfer_stats(statm, xfer, master);
-		spi_statistics_add_transfer_stats(stats, xfer, master);
+		spi_statistics_add_transfer_stats(statm, xfer, ctlr);
+		spi_statistics_add_transfer_stats(stats, xfer, ctlr);
 
 		if (xfer->tx_buf || xfer->rx_buf) {
-			reinit_completion(&master->xfer_completion);
+			reinit_completion(&ctlr->xfer_completion);
 
-			ret = master->transfer_one(master, msg->spi, xfer);
+			ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
 			if (ret < 0) {
 				SPI_STATISTICS_INCREMENT_FIELD(statm,
 							       errors);
@@ -1044,7 +1043,7 @@ static int spi_transfer_one_message(struct spi_master *master,
 				if (ms > UINT_MAX)
 					ms = UINT_MAX;
 
-				ms = wait_for_completion_timeout(&master->xfer_completion,
+				ms = wait_for_completion_timeout(&ctlr->xfer_completion,
 								 msecs_to_jiffies(ms));
 			}
 
@@ -1099,33 +1098,33 @@ out:
 	if (msg->status == -EINPROGRESS)
 		msg->status = ret;
 
-	if (msg->status && master->handle_err)
-		master->handle_err(master, msg);
+	if (msg->status && ctlr->handle_err)
+		ctlr->handle_err(ctlr, msg);
 
-	spi_res_release(master, msg);
+	spi_res_release(ctlr, msg);
 
-	spi_finalize_current_message(master);
+	spi_finalize_current_message(ctlr);
 
 	return ret;
 }
 
 /**
  * spi_finalize_current_transfer - report completion of a transfer
- * @master: the master reporting completion
+ * @ctlr: the controller reporting completion
  *
  * Called by SPI drivers using the core transfer_one_message()
  * implementation to notify it that the current interrupt driven
  * transfer has finished and the next one may be scheduled.
  */
-void spi_finalize_current_transfer(struct spi_master *master)
+void spi_finalize_current_transfer(struct spi_controller *ctlr)
 {
-	complete(&master->xfer_completion);
+	complete(&ctlr->xfer_completion);
 }
 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
 
 /**
  * __spi_pump_messages - function which processes spi message queue
- * @master: master to process queue for
+ * @ctlr: controller to process queue for
  * @in_kthread: true if we are in the context of the message pump thread
  *
  * This function checks if there is any spi message in the queue that
@@ -1136,136 +1135,136 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
  * inside spi_sync(); the queue extraction handling at the top of the
  * function should deal with this safely.
  */
-static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
+static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
 {
 	unsigned long flags;
 	bool was_busy = false;
 	int ret;
 
 	/* Lock queue */
-	spin_lock_irqsave(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
 
 	/* Make sure we are not already running a message */
-	if (master->cur_msg) {
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+	if (ctlr->cur_msg) {
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return;
 	}
 
 	/* If another context is idling the device then defer */
-	if (master->idling) {
-		kthread_queue_work(&master->kworker, &master->pump_messages);
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+	if (ctlr->idling) {
+		kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return;
 	}
 
 	/* Check if the queue is idle */
-	if (list_empty(&master->queue) || !master->running) {
-		if (!master->busy) {
-			spin_unlock_irqrestore(&master->queue_lock, flags);
+	if (list_empty(&ctlr->queue) || !ctlr->running) {
+		if (!ctlr->busy) {
+			spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 			return;
 		}
 
 		/* Only do teardown in the thread */
 		if (!in_kthread) {
-			kthread_queue_work(&master->kworker,
-					   &master->pump_messages);
-			spin_unlock_irqrestore(&master->queue_lock, flags);
+			kthread_queue_work(&ctlr->kworker,
+					   &ctlr->pump_messages);
+			spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 			return;
 		}
 
-		master->busy = false;
-		master->idling = true;
-		spin_unlock_irqrestore(&master->queue_lock, flags);
-
-		kfree(master->dummy_rx);
-		master->dummy_rx = NULL;
-		kfree(master->dummy_tx);
-		master->dummy_tx = NULL;
-		if (master->unprepare_transfer_hardware &&
-		    master->unprepare_transfer_hardware(master))
-			dev_err(&master->dev,
+		ctlr->busy = false;
+		ctlr->idling = true;
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+		kfree(ctlr->dummy_rx);
+		ctlr->dummy_rx = NULL;
+		kfree(ctlr->dummy_tx);
+		ctlr->dummy_tx = NULL;
+		if (ctlr->unprepare_transfer_hardware &&
+		    ctlr->unprepare_transfer_hardware(ctlr))
+			dev_err(&ctlr->dev,
 				"failed to unprepare transfer hardware\n");
-		if (master->auto_runtime_pm) {
-			pm_runtime_mark_last_busy(master->dev.parent);
-			pm_runtime_put_autosuspend(master->dev.parent);
+		if (ctlr->auto_runtime_pm) {
+			pm_runtime_mark_last_busy(ctlr->dev.parent);
+			pm_runtime_put_autosuspend(ctlr->dev.parent);
 		}
-		trace_spi_master_idle(master);
+		trace_spi_controller_idle(ctlr);
 
-		spin_lock_irqsave(&master->queue_lock, flags);
-		master->idling = false;
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+		spin_lock_irqsave(&ctlr->queue_lock, flags);
+		ctlr->idling = false;
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return;
 	}
 
 	/* Extract head of queue */
-	master->cur_msg =
-		list_first_entry(&master->queue, struct spi_message, queue);
+	ctlr->cur_msg =
+		list_first_entry(&ctlr->queue, struct spi_message, queue);
 
-	list_del_init(&master->cur_msg->queue);
-	if (master->busy)
+	list_del_init(&ctlr->cur_msg->queue);
+	if (ctlr->busy)
 		was_busy = true;
 	else
-		master->busy = true;
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+		ctlr->busy = true;
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
-	mutex_lock(&master->io_mutex);
+	mutex_lock(&ctlr->io_mutex);
 
-	if (!was_busy && master->auto_runtime_pm) {
-		ret = pm_runtime_get_sync(master->dev.parent);
+	if (!was_busy && ctlr->auto_runtime_pm) {
+		ret = pm_runtime_get_sync(ctlr->dev.parent);
 		if (ret < 0) {
-			dev_err(&master->dev, "Failed to power device: %d\n",
+			dev_err(&ctlr->dev, "Failed to power device: %d\n",
 				ret);
-			mutex_unlock(&master->io_mutex);
+			mutex_unlock(&ctlr->io_mutex);
 			return;
 		}
 	}
 
 	if (!was_busy)
-		trace_spi_master_busy(master);
+		trace_spi_controller_busy(ctlr);
 
-	if (!was_busy && master->prepare_transfer_hardware) {
-		ret = master->prepare_transfer_hardware(master);
+	if (!was_busy && ctlr->prepare_transfer_hardware) {
+		ret = ctlr->prepare_transfer_hardware(ctlr);
 		if (ret) {
-			dev_err(&master->dev,
+			dev_err(&ctlr->dev,
 				"failed to prepare transfer hardware\n");
 
-			if (master->auto_runtime_pm)
-				pm_runtime_put(master->dev.parent);
-			mutex_unlock(&master->io_mutex);
+			if (ctlr->auto_runtime_pm)
+				pm_runtime_put(ctlr->dev.parent);
+			mutex_unlock(&ctlr->io_mutex);
 			return;
 		}
 	}
 
-	trace_spi_message_start(master->cur_msg);
+	trace_spi_message_start(ctlr->cur_msg);
 
-	if (master->prepare_message) {
-		ret = master->prepare_message(master, master->cur_msg);
+	if (ctlr->prepare_message) {
+		ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
 		if (ret) {
-			dev_err(&master->dev,
-				"failed to prepare message: %d\n", ret);
-			master->cur_msg->status = ret;
-			spi_finalize_current_message(master);
+			dev_err(&ctlr->dev, "failed to prepare message: %d\n",
+				ret);
+			ctlr->cur_msg->status = ret;
+			spi_finalize_current_message(ctlr);
 			goto out;
 		}
-		master->cur_msg_prepared = true;
+		ctlr->cur_msg_prepared = true;
 	}
 
-	ret = spi_map_msg(master, master->cur_msg);
+	ret = spi_map_msg(ctlr, ctlr->cur_msg);
 	if (ret) {
-		master->cur_msg->status = ret;
-		spi_finalize_current_message(master);
+		ctlr->cur_msg->status = ret;
+		spi_finalize_current_message(ctlr);
 		goto out;
 	}
 
-	ret = master->transfer_one_message(master, master->cur_msg);
+	ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
 	if (ret) {
-		dev_err(&master->dev,
+		dev_err(&ctlr->dev,
 			"failed to transfer one message from queue\n");
 		goto out;
 	}
 
 out:
-	mutex_unlock(&master->io_mutex);
+	mutex_unlock(&ctlr->io_mutex);
 
 	/* Prod the scheduler in case transfer_one() was busy waiting */
 	if (!ret)
@@ -1274,44 +1273,43 @@ out:
 
 /**
  * spi_pump_messages - kthread work function which processes spi message queue
- * @work: pointer to kthread work struct contained in the master struct
+ * @work: pointer to kthread work struct contained in the controller struct
  */
 static void spi_pump_messages(struct kthread_work *work)
 {
-	struct spi_master *master =
-		container_of(work, struct spi_master, pump_messages);
+	struct spi_controller *ctlr =
+		container_of(work, struct spi_controller, pump_messages);
 
-	__spi_pump_messages(master, true);
+	__spi_pump_messages(ctlr, true);
 }
 
-static int spi_init_queue(struct spi_master *master)
+static int spi_init_queue(struct spi_controller *ctlr)
 {
 	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
 
-	master->running = false;
-	master->busy = false;
+	ctlr->running = false;
+	ctlr->busy = false;
 
-	kthread_init_worker(&master->kworker);
-	master->kworker_task = kthread_run(kthread_worker_fn,
-					   &master->kworker, "%s",
-					   dev_name(&master->dev));
-	if (IS_ERR(master->kworker_task)) {
-		dev_err(&master->dev, "failed to create message pump task\n");
-		return PTR_ERR(master->kworker_task);
+	kthread_init_worker(&ctlr->kworker);
+	ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
+					 "%s", dev_name(&ctlr->dev));
+	if (IS_ERR(ctlr->kworker_task)) {
+		dev_err(&ctlr->dev, "failed to create message pump task\n");
+		return PTR_ERR(ctlr->kworker_task);
 	}
-	kthread_init_work(&master->pump_messages, spi_pump_messages);
+	kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
 
 	/*
-	 * Master config will indicate if this controller should run the
+	 * Controller config will indicate if this controller should run the
 	 * message pump with high (realtime) priority to reduce the transfer
 	 * latency on the bus by minimising the delay between a transfer
 	 * request and the scheduling of the message pump thread. Without this
 	 * setting the message pump thread will remain at default priority.
 	 */
-	if (master->rt) {
-		dev_info(&master->dev,
+	if (ctlr->rt) {
+		dev_info(&ctlr->dev,
 			"will run message pump with realtime priority\n");
-		sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
+		sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, &param);
 	}
 
 	return 0;
@@ -1320,23 +1318,23 @@ static int spi_init_queue(struct spi_master *master)
 /**
  * spi_get_next_queued_message() - called by driver to check for queued
  * messages
- * @master: the master to check for queued messages
+ * @ctlr: the controller to check for queued messages
  *
  * If there are more messages in the queue, the next message is returned from
  * this call.
  *
  * Return: the next message in the queue, else NULL if the queue is empty.
  */
-struct spi_message *spi_get_next_queued_message(struct spi_master *master)
+struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
 {
 	struct spi_message *next;
 	unsigned long flags;
 
 	/* get a pointer to the next message, if any */
-	spin_lock_irqsave(&master->queue_lock, flags);
-	next = list_first_entry_or_null(&master->queue, struct spi_message,
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
+	next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
 					queue);
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
 	return next;
 }
@@ -1344,36 +1342,36 @@ EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
 
 /**
  * spi_finalize_current_message() - the current message is complete
- * @master: the master to return the message to
+ * @ctlr: the controller to return the message to
  *
  * Called by the driver to notify the core that the message in the front of the
  * queue is complete and can be removed from the queue.
  */
-void spi_finalize_current_message(struct spi_master *master)
+void spi_finalize_current_message(struct spi_controller *ctlr)
 {
 	struct spi_message *mesg;
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&master->queue_lock, flags);
-	mesg = master->cur_msg;
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
+	mesg = ctlr->cur_msg;
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
-	spi_unmap_msg(master, mesg);
+	spi_unmap_msg(ctlr, mesg);
 
-	if (master->cur_msg_prepared && master->unprepare_message) {
-		ret = master->unprepare_message(master, mesg);
+	if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
+		ret = ctlr->unprepare_message(ctlr, mesg);
 		if (ret) {
-			dev_err(&master->dev,
-				"failed to unprepare message: %d\n", ret);
+			dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
+				ret);
 		}
 	}
 
-	spin_lock_irqsave(&master->queue_lock, flags);
-	master->cur_msg = NULL;
-	master->cur_msg_prepared = false;
-	kthread_queue_work(&master->kworker, &master->pump_messages);
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
+	ctlr->cur_msg = NULL;
+	ctlr->cur_msg_prepared = false;
+	kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
 	trace_spi_message_done(mesg);
 
@@ -1383,66 +1381,65 @@ void spi_finalize_current_message(struct spi_master *master)
 }
 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
 
-static int spi_start_queue(struct spi_master *master)
+static int spi_start_queue(struct spi_controller *ctlr)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
 
-	if (master->running || master->busy) {
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+	if (ctlr->running || ctlr->busy) {
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return -EBUSY;
 	}
 
-	master->running = true;
-	master->cur_msg = NULL;
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	ctlr->running = true;
+	ctlr->cur_msg = NULL;
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
-	kthread_queue_work(&master->kworker, &master->pump_messages);
+	kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
 
 	return 0;
 }
 
-static int spi_stop_queue(struct spi_master *master)
+static int spi_stop_queue(struct spi_controller *ctlr)
 {
 	unsigned long flags;
 	unsigned limit = 500;
 	int ret = 0;
 
-	spin_lock_irqsave(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
 
 	/*
 	 * This is a bit lame, but is optimized for the common execution path.
-	 * A wait_queue on the master->busy could be used, but then the common
+	 * A wait_queue on the ctlr->busy could be used, but then the common
 	 * execution path (pump_messages) would be required to call wake_up or
 	 * friends on every SPI message. Do this instead.
 	 */
-	while ((!list_empty(&master->queue) || master->busy) && limit--) {
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+	while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		usleep_range(10000, 11000);
-		spin_lock_irqsave(&master->queue_lock, flags);
+		spin_lock_irqsave(&ctlr->queue_lock, flags);
 	}
 
-	if (!list_empty(&master->queue) || master->busy)
+	if (!list_empty(&ctlr->queue) || ctlr->busy)
 		ret = -EBUSY;
 	else
-		master->running = false;
+		ctlr->running = false;
 
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
 	if (ret) {
-		dev_warn(&master->dev,
-			 "could not stop message queue\n");
+		dev_warn(&ctlr->dev, "could not stop message queue\n");
 		return ret;
 	}
 	return ret;
 }
 
-static int spi_destroy_queue(struct spi_master *master)
+static int spi_destroy_queue(struct spi_controller *ctlr)
 {
 	int ret;
 
-	ret = spi_stop_queue(master);
+	ret = spi_stop_queue(ctlr);
 
 	/*
 	 * kthread_flush_worker will block until all work is done.
@@ -1451,12 +1448,12 @@ static int spi_destroy_queue(struct spi_master *master)
 	 * return anyway.
 	 */
 	if (ret) {
-		dev_err(&master->dev, "problem destroying queue\n");
+		dev_err(&ctlr->dev, "problem destroying queue\n");
 		return ret;
 	}
 
-	kthread_flush_worker(&master->kworker);
-	kthread_stop(master->kworker_task);
+	kthread_flush_worker(&ctlr->kworker);
+	kthread_stop(ctlr->kworker_task);
 
 	return 0;
 }
@@ -1465,23 +1462,23 @@ static int __spi_queued_transfer(struct spi_device *spi,
 				 struct spi_message *msg,
 				 bool need_pump)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	unsigned long flags;
 
-	spin_lock_irqsave(&master->queue_lock, flags);
+	spin_lock_irqsave(&ctlr->queue_lock, flags);
 
-	if (!master->running) {
-		spin_unlock_irqrestore(&master->queue_lock, flags);
+	if (!ctlr->running) {
+		spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 		return -ESHUTDOWN;
 	}
 	msg->actual_length = 0;
 	msg->status = -EINPROGRESS;
 
-	list_add_tail(&msg->queue, &master->queue);
-	if (!master->busy && need_pump)
-		kthread_queue_work(&master->kworker, &master->pump_messages);
+	list_add_tail(&msg->queue, &ctlr->queue);
+	if (!ctlr->busy && need_pump)
+		kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
 
-	spin_unlock_irqrestore(&master->queue_lock, flags);
+	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 	return 0;
 }
 
@@ -1497,31 +1494,31 @@ static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
 	return __spi_queued_transfer(spi, msg, true);
 }
 
-static int spi_master_initialize_queue(struct spi_master *master)
+static int spi_controller_initialize_queue(struct spi_controller *ctlr)
 {
 	int ret;
 
-	master->transfer = spi_queued_transfer;
-	if (!master->transfer_one_message)
-		master->transfer_one_message = spi_transfer_one_message;
+	ctlr->transfer = spi_queued_transfer;
+	if (!ctlr->transfer_one_message)
+		ctlr->transfer_one_message = spi_transfer_one_message;
 
 	/* Initialize and start queue */
-	ret = spi_init_queue(master);
+	ret = spi_init_queue(ctlr);
 	if (ret) {
-		dev_err(&master->dev, "problem initializing queue\n");
+		dev_err(&ctlr->dev, "problem initializing queue\n");
 		goto err_init_queue;
 	}
-	master->queued = true;
-	ret = spi_start_queue(master);
+	ctlr->queued = true;
+	ret = spi_start_queue(ctlr);
 	if (ret) {
-		dev_err(&master->dev, "problem starting queue\n");
+		dev_err(&ctlr->dev, "problem starting queue\n");
 		goto err_start_queue;
 	}
 
 	return 0;
 
 err_start_queue:
-	spi_destroy_queue(master);
+	spi_destroy_queue(ctlr);
 err_init_queue:
 	return ret;
 }
@@ -1529,21 +1526,12 @@ err_init_queue:
 /*-------------------------------------------------------------------------*/
 
 #if defined(CONFIG_OF)
-static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
+static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 			   struct device_node *nc)
 {
 	u32 value;
 	int rc;
 
-	/* Device address */
-	rc = of_property_read_u32(nc, "reg", &value);
-	if (rc) {
-		dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
-			nc->full_name, rc);
-		return rc;
-	}
-	spi->chip_select = value;
-
 	/* Mode (clock phase/polarity/etc.) */
 	if (of_find_property(nc, "spi-cpha", NULL))
 		spi->mode |= SPI_CPHA;
@@ -1568,7 +1556,7 @@ static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
 			spi->mode |= SPI_TX_QUAD;
 			break;
 		default:
-			dev_warn(&master->dev,
+			dev_warn(&ctlr->dev,
 				"spi-tx-bus-width %d not supported\n",
 				value);
 			break;
@@ -1586,17 +1574,36 @@ static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
 			spi->mode |= SPI_RX_QUAD;
 			break;
 		default:
-			dev_warn(&master->dev,
+			dev_warn(&ctlr->dev,
 				"spi-rx-bus-width %d not supported\n",
 				value);
 			break;
 		}
 	}
 
+	if (spi_controller_is_slave(ctlr)) {
+		if (strcmp(nc->name, "slave")) {
+			dev_err(&ctlr->dev, "%s is not called 'slave'\n",
+				nc->full_name);
+			return -EINVAL;
+		}
+		return 0;
+	}
+
+	/* Device address */
+	rc = of_property_read_u32(nc, "reg", &value);
+	if (rc) {
+		dev_err(&ctlr->dev, "%s has no valid 'reg' property (%d)\n",
+			nc->full_name, rc);
+		return rc;
+	}
+	spi->chip_select = value;
+
 	/* Device speed */
 	rc = of_property_read_u32(nc, "spi-max-frequency", &value);
 	if (rc) {
-		dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
+		dev_err(&ctlr->dev,
+			"%s has no valid 'spi-max-frequency' property (%d)\n",
 			nc->full_name, rc);
 		return rc;
 	}
@@ -1606,15 +1613,15 @@ static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
 }
 
 static struct spi_device *
-of_register_spi_device(struct spi_master *master, struct device_node *nc)
+of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
 {
 	struct spi_device *spi;
 	int rc;
 
 	/* Alloc an spi_device */
-	spi = spi_alloc_device(master);
+	spi = spi_alloc_device(ctlr);
 	if (!spi) {
-		dev_err(&master->dev, "spi_device alloc error for %s\n",
+		dev_err(&ctlr->dev, "spi_device alloc error for %s\n",
 			nc->full_name);
 		rc = -ENOMEM;
 		goto err_out;
@@ -1624,12 +1631,12 @@ of_register_spi_device(struct spi_master *master, struct device_node *nc)
 	rc = of_modalias_node(nc, spi->modalias,
 				sizeof(spi->modalias));
 	if (rc < 0) {
-		dev_err(&master->dev, "cannot find modalias for %s\n",
+		dev_err(&ctlr->dev, "cannot find modalias for %s\n",
 			nc->full_name);
 		goto err_out;
 	}
 
-	rc = of_spi_parse_dt(master, spi, nc);
+	rc = of_spi_parse_dt(ctlr, spi, nc);
 	if (rc)
 		goto err_out;
 
@@ -1640,7 +1647,7 @@ of_register_spi_device(struct spi_master *master, struct device_node *nc)
 	/* Register the new device */
 	rc = spi_add_device(spi);
 	if (rc) {
-		dev_err(&master->dev, "spi_device register error %s\n",
+		dev_err(&ctlr->dev, "spi_device register error %s\n",
 			nc->full_name);
 		goto err_of_node_put;
 	}
@@ -1656,39 +1663,40 @@ err_out:
 
 /**
  * of_register_spi_devices() - Register child devices onto the SPI bus
- * @master:	Pointer to spi_master device
+ * @ctlr:	Pointer to spi_controller device
  *
- * Registers an spi_device for each child node of master node which has a 'reg'
- * property.
+ * Registers an spi_device for each child node of controller node which
+ * represents a valid SPI slave.
  */
-static void of_register_spi_devices(struct spi_master *master)
+static void of_register_spi_devices(struct spi_controller *ctlr)
 {
 	struct spi_device *spi;
 	struct device_node *nc;
 
-	if (!master->dev.of_node)
+	if (!ctlr->dev.of_node)
 		return;
 
-	for_each_available_child_of_node(master->dev.of_node, nc) {
+	for_each_available_child_of_node(ctlr->dev.of_node, nc) {
 		if (of_node_test_and_set_flag(nc, OF_POPULATED))
 			continue;
-		spi = of_register_spi_device(master, nc);
+		spi = of_register_spi_device(ctlr, nc);
 		if (IS_ERR(spi)) {
-			dev_warn(&master->dev, "Failed to create SPI device for %s\n",
-				nc->full_name);
+			dev_warn(&ctlr->dev,
+				 "Failed to create SPI device for %s\n",
+				 nc->full_name);
 			of_node_clear_flag(nc, OF_POPULATED);
 		}
 	}
 }
 #else
-static void of_register_spi_devices(struct spi_master *master) { }
+static void of_register_spi_devices(struct spi_controller *ctlr) { }
 #endif
 
 #ifdef CONFIG_ACPI
 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
 {
 	struct spi_device *spi = data;
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 
 	if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
 		struct acpi_resource_spi_serialbus *sb;
@@ -1702,8 +1710,8 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
 			 * 0 .. max - 1 so we need to ask the driver to
 			 * translate between the two schemes.
 			 */
-			if (master->fw_translate_cs) {
-				int cs = master->fw_translate_cs(master,
+			if (ctlr->fw_translate_cs) {
+				int cs = ctlr->fw_translate_cs(ctlr,
 						sb->device_selection);
 				if (cs < 0)
 					return cs;
@@ -1732,7 +1740,7 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
 	return 1;
 }
 
-static acpi_status acpi_register_spi_device(struct spi_master *master,
+static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
 					    struct acpi_device *adev)
 {
 	struct list_head resource_list;
@@ -1743,9 +1751,9 @@ static acpi_status acpi_register_spi_device(struct spi_master *master,
 	    acpi_device_enumerated(adev))
 		return AE_OK;
 
-	spi = spi_alloc_device(master);
+	spi = spi_alloc_device(ctlr);
 	if (!spi) {
-		dev_err(&master->dev, "failed to allocate SPI device for %s\n",
+		dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
 			dev_name(&adev->dev));
 		return AE_NO_MEMORY;
 	}
@@ -1774,7 +1782,7 @@ static acpi_status acpi_register_spi_device(struct spi_master *master,
 	adev->power.flags.ignore_parent = true;
 	if (spi_add_device(spi)) {
 		adev->power.flags.ignore_parent = false;
-		dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
+		dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
 			dev_name(&adev->dev));
 		spi_dev_put(spi);
 	}
@@ -1785,104 +1793,211 @@ static acpi_status acpi_register_spi_device(struct spi_master *master,
 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
 				       void *data, void **return_value)
 {
-	struct spi_master *master = data;
+	struct spi_controller *ctlr = data;
 	struct acpi_device *adev;
 
 	if (acpi_bus_get_device(handle, &adev))
 		return AE_OK;
 
-	return acpi_register_spi_device(master, adev);
+	return acpi_register_spi_device(ctlr, adev);
 }
 
-static void acpi_register_spi_devices(struct spi_master *master)
+static void acpi_register_spi_devices(struct spi_controller *ctlr)
 {
 	acpi_status status;
 	acpi_handle handle;
 
-	handle = ACPI_HANDLE(master->dev.parent);
+	handle = ACPI_HANDLE(ctlr->dev.parent);
 	if (!handle)
 		return;
 
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
-				     acpi_spi_add_device, NULL,
-				     master, NULL);
+				     acpi_spi_add_device, NULL, ctlr, NULL);
 	if (ACPI_FAILURE(status))
-		dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
+		dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
 }
 #else
-static inline void acpi_register_spi_devices(struct spi_master *master) {}
+static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
 #endif /* CONFIG_ACPI */
 
-static void spi_master_release(struct device *dev)
+static void spi_controller_release(struct device *dev)
 {
-	struct spi_master *master;
+	struct spi_controller *ctlr;
 
-	master = container_of(dev, struct spi_master, dev);
-	kfree(master);
+	ctlr = container_of(dev, struct spi_controller, dev);
+	kfree(ctlr);
 }
 
 static struct class spi_master_class = {
 	.name		= "spi_master",
 	.owner		= THIS_MODULE,
-	.dev_release	= spi_master_release,
+	.dev_release	= spi_controller_release,
 	.dev_groups	= spi_master_groups,
 };
 
+#ifdef CONFIG_SPI_SLAVE
+/**
+ * spi_slave_abort - abort the ongoing transfer request on an SPI slave
+ *		     controller
+ * @spi: device used for the current transfer
+ */
+int spi_slave_abort(struct spi_device *spi)
+{
+	struct spi_controller *ctlr = spi->controller;
+
+	if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
+		return ctlr->slave_abort(ctlr);
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(spi_slave_abort);
+
+static int match_true(struct device *dev, void *data)
+{
+	return 1;
+}
+
+static ssize_t spi_slave_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+						   dev);
+	struct device *child;
+
+	child = device_find_child(&ctlr->dev, NULL, match_true);
+	return sprintf(buf, "%s\n",
+		       child ? to_spi_device(child)->modalias : NULL);
+}
+
+static ssize_t spi_slave_store(struct device *dev,
+			       struct device_attribute *attr, const char *buf,
+			       size_t count)
+{
+	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+						   dev);
+	struct spi_device *spi;
+	struct device *child;
+	char name[32];
+	int rc;
+
+	rc = sscanf(buf, "%31s", name);
+	if (rc != 1 || !name[0])
+		return -EINVAL;
+
+	child = device_find_child(&ctlr->dev, NULL, match_true);
+	if (child) {
+		/* Remove registered slave */
+		device_unregister(child);
+		put_device(child);
+	}
+
+	if (strcmp(name, "(null)")) {
+		/* Register new slave */
+		spi = spi_alloc_device(ctlr);
+		if (!spi)
+			return -ENOMEM;
+
+		strlcpy(spi->modalias, name, sizeof(spi->modalias));
+
+		rc = spi_add_device(spi);
+		if (rc) {
+			spi_dev_put(spi);
+			return rc;
+		}
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
+
+static struct attribute *spi_slave_attrs[] = {
+	&dev_attr_slave.attr,
+	NULL,
+};
+
+static const struct attribute_group spi_slave_group = {
+	.attrs = spi_slave_attrs,
+};
+
+static const struct attribute_group *spi_slave_groups[] = {
+	&spi_controller_statistics_group,
+	&spi_slave_group,
+	NULL,
+};
+
+static struct class spi_slave_class = {
+	.name		= "spi_slave",
+	.owner		= THIS_MODULE,
+	.dev_release	= spi_controller_release,
+	.dev_groups	= spi_slave_groups,
+};
+#else
+extern struct class spi_slave_class;	/* dummy */
+#endif
 
 /**
- * spi_alloc_master - allocate SPI master controller
+ * __spi_alloc_controller - allocate an SPI master or slave controller
  * @dev: the controller, possibly using the platform_bus
  * @size: how much zeroed driver-private data to allocate; the pointer to this
  *	memory is in the driver_data field of the returned device,
- *	accessible with spi_master_get_devdata().
+ *	accessible with spi_controller_get_devdata().
+ * @slave: flag indicating whether to allocate an SPI master (false) or SPI
+ *	slave (true) controller
  * Context: can sleep
  *
- * This call is used only by SPI master controller drivers, which are the
+ * This call is used only by SPI controller drivers, which are the
  * only ones directly touching chip registers.  It's how they allocate
- * an spi_master structure, prior to calling spi_register_master().
+ * an spi_controller structure, prior to calling spi_register_controller().
  *
  * This must be called from context that can sleep.
  *
- * The caller is responsible for assigning the bus number and initializing
- * the master's methods before calling spi_register_master(); and (after errors
- * adding the device) calling spi_master_put() to prevent a memory leak.
+ * The caller is responsible for assigning the bus number and initializing the
+ * controller's methods before calling spi_register_controller(); and (after
+ * errors adding the device) calling spi_controller_put() to prevent a memory
+ * leak.
  *
- * Return: the SPI master structure on success, else NULL.
+ * Return: the SPI controller structure on success, else NULL.
  */
-struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
+struct spi_controller *__spi_alloc_controller(struct device *dev,
+					      unsigned int size, bool slave)
 {
-	struct spi_master	*master;
+	struct spi_controller	*ctlr;
 
 	if (!dev)
 		return NULL;
 
-	master = kzalloc(size + sizeof(*master), GFP_KERNEL);
-	if (!master)
+	ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
+	if (!ctlr)
 		return NULL;
 
-	device_initialize(&master->dev);
-	master->bus_num = -1;
-	master->num_chipselect = 1;
-	master->dev.class = &spi_master_class;
-	master->dev.parent = dev;
-	pm_suspend_ignore_children(&master->dev, true);
-	spi_master_set_devdata(master, &master[1]);
+	device_initialize(&ctlr->dev);
+	ctlr->bus_num = -1;
+	ctlr->num_chipselect = 1;
+	ctlr->slave = slave;
+	if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
+		ctlr->dev.class = &spi_slave_class;
+	else
+		ctlr->dev.class = &spi_master_class;
+	ctlr->dev.parent = dev;
+	pm_suspend_ignore_children(&ctlr->dev, true);
+	spi_controller_set_devdata(ctlr, &ctlr[1]);
 
-	return master;
+	return ctlr;
 }
-EXPORT_SYMBOL_GPL(spi_alloc_master);
+EXPORT_SYMBOL_GPL(__spi_alloc_controller);
 
 #ifdef CONFIG_OF
-static int of_spi_register_master(struct spi_master *master)
+static int of_spi_register_master(struct spi_controller *ctlr)
 {
 	int nb, i, *cs;
-	struct device_node *np = master->dev.of_node;
+	struct device_node *np = ctlr->dev.of_node;
 
 	if (!np)
 		return 0;
 
 	nb = of_gpio_named_count(np, "cs-gpios");
-	master->num_chipselect = max_t(int, nb, master->num_chipselect);
+	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
 
 	/* Return error only for an incorrectly formed cs-gpios property */
 	if (nb == 0 || nb == -ENOENT)
@@ -1890,15 +2005,14 @@ static int of_spi_register_master(struct spi_master *master)
 	else if (nb < 0)
 		return nb;
 
-	cs = devm_kzalloc(&master->dev,
-			  sizeof(int) * master->num_chipselect,
+	cs = devm_kzalloc(&ctlr->dev, sizeof(int) * ctlr->num_chipselect,
 			  GFP_KERNEL);
-	master->cs_gpios = cs;
+	ctlr->cs_gpios = cs;
 
-	if (!master->cs_gpios)
+	if (!ctlr->cs_gpios)
 		return -ENOMEM;
 
-	for (i = 0; i < master->num_chipselect; i++)
+	for (i = 0; i < ctlr->num_chipselect; i++)
 		cs[i] = -ENOENT;
 
 	for (i = 0; i < nb; i++)
@@ -1907,20 +2021,21 @@ static int of_spi_register_master(struct spi_master *master)
 	return 0;
 }
 #else
-static int of_spi_register_master(struct spi_master *master)
+static int of_spi_register_master(struct spi_controller *ctlr)
 {
 	return 0;
 }
 #endif
 
 /**
- * spi_register_master - register SPI master controller
- * @master: initialized master, originally from spi_alloc_master()
+ * spi_register_controller - register SPI master or slave controller
+ * @ctlr: initialized master, originally from spi_alloc_master() or
+ *	spi_alloc_slave()
  * Context: can sleep
  *
- * SPI master controllers connect to their drivers using some non-SPI bus,
+ * SPI controllers connect to their drivers using some non-SPI bus,
  * such as the platform bus.  The final stage of probe() in that code
- * includes calling spi_register_master() to hook up to this SPI bus glue.
+ * includes calling spi_register_controller() to hook up to this SPI bus glue.
  *
  * SPI controllers use board specific (often SOC specific) bus numbers,
  * and board-specific addressing for SPI devices combines those numbers
@@ -1929,16 +2044,16 @@ static int of_spi_register_master(struct spi_master *master)
  * chip is at which address.
  *
  * This must be called from context that can sleep.  It returns zero on
- * success, else a negative error code (dropping the master's refcount).
+ * success, else a negative error code (dropping the controller's refcount).
  * After a successful return, the caller is responsible for calling
- * spi_unregister_master().
+ * spi_unregister_controller().
  *
  * Return: zero on success, else a negative error code.
  */
-int spi_register_master(struct spi_master *master)
+int spi_register_controller(struct spi_controller *ctlr)
 {
 	static atomic_t		dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
-	struct device		*dev = master->dev.parent;
+	struct device		*dev = ctlr->dev.parent;
 	struct boardinfo	*bi;
 	int			status = -ENODEV;
 	int			dynamic = 0;
@@ -1946,103 +2061,109 @@ int spi_register_master(struct spi_master *master)
 	if (!dev)
 		return -ENODEV;
 
-	status = of_spi_register_master(master);
-	if (status)
-		return status;
+	if (!spi_controller_is_slave(ctlr)) {
+		status = of_spi_register_master(ctlr);
+		if (status)
+			return status;
+	}
 
 	/* even if it's just one always-selected device, there must
 	 * be at least one chipselect
 	 */
-	if (master->num_chipselect == 0)
+	if (ctlr->num_chipselect == 0)
 		return -EINVAL;
 
-	if ((master->bus_num < 0) && master->dev.of_node)
-		master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
+	if ((ctlr->bus_num < 0) && ctlr->dev.of_node)
+		ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi");
 
 	/* convention:  dynamically assigned bus IDs count down from the max */
-	if (master->bus_num < 0) {
+	if (ctlr->bus_num < 0) {
 		/* FIXME switch to an IDR based scheme, something like
 		 * I2C now uses, so we can't run out of "dynamic" IDs
 		 */
-		master->bus_num = atomic_dec_return(&dyn_bus_id);
+		ctlr->bus_num = atomic_dec_return(&dyn_bus_id);
 		dynamic = 1;
 	}
 
-	INIT_LIST_HEAD(&master->queue);
-	spin_lock_init(&master->queue_lock);
-	spin_lock_init(&master->bus_lock_spinlock);
-	mutex_init(&master->bus_lock_mutex);
-	mutex_init(&master->io_mutex);
-	master->bus_lock_flag = 0;
-	init_completion(&master->xfer_completion);
-	if (!master->max_dma_len)
-		master->max_dma_len = INT_MAX;
+	INIT_LIST_HEAD(&ctlr->queue);
+	spin_lock_init(&ctlr->queue_lock);
+	spin_lock_init(&ctlr->bus_lock_spinlock);
+	mutex_init(&ctlr->bus_lock_mutex);
+	mutex_init(&ctlr->io_mutex);
+	ctlr->bus_lock_flag = 0;
+	init_completion(&ctlr->xfer_completion);
+	if (!ctlr->max_dma_len)
+		ctlr->max_dma_len = INT_MAX;
 
 	/* register the device, then userspace will see it.
 	 * registration fails if the bus ID is in use.
 	 */
-	dev_set_name(&master->dev, "spi%u", master->bus_num);
-	status = device_add(&master->dev);
+	dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
+	status = device_add(&ctlr->dev);
 	if (status < 0)
 		goto done;
-	dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
-			dynamic ? " (dynamic)" : "");
+	dev_dbg(dev, "registered %s %s%s\n",
+			spi_controller_is_slave(ctlr) ? "slave" : "master",
+			dev_name(&ctlr->dev), dynamic ? " (dynamic)" : "");
 
 	/* If we're using a queued driver, start the queue */
-	if (master->transfer)
-		dev_info(dev, "master is unqueued, this is deprecated\n");
+	if (ctlr->transfer)
+		dev_info(dev, "controller is unqueued, this is deprecated\n");
 	else {
-		status = spi_master_initialize_queue(master);
+		status = spi_controller_initialize_queue(ctlr);
 		if (status) {
-			device_del(&master->dev);
+			device_del(&ctlr->dev);
 			goto done;
 		}
 	}
 	/* add statistics */
-	spin_lock_init(&master->statistics.lock);
+	spin_lock_init(&ctlr->statistics.lock);
 
 	mutex_lock(&board_lock);
-	list_add_tail(&master->list, &spi_master_list);
+	list_add_tail(&ctlr->list, &spi_controller_list);
 	list_for_each_entry(bi, &board_list, list)
-		spi_match_master_to_boardinfo(master, &bi->board_info);
+		spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
 	mutex_unlock(&board_lock);
 
 	/* Register devices from the device tree and ACPI */
-	of_register_spi_devices(master);
-	acpi_register_spi_devices(master);
+	of_register_spi_devices(ctlr);
+	acpi_register_spi_devices(ctlr);
 done:
 	return status;
 }
-EXPORT_SYMBOL_GPL(spi_register_master);
+EXPORT_SYMBOL_GPL(spi_register_controller);
 
 static void devm_spi_unregister(struct device *dev, void *res)
 {
-	spi_unregister_master(*(struct spi_master **)res);
+	spi_unregister_controller(*(struct spi_controller **)res);
 }
 
 /**
- * devm_spi_register_master - register managed SPI master controller
- * @dev:    device managing SPI master
- * @master: initialized master, originally from spi_alloc_master()
+ * devm_spi_register_controller - register managed SPI master or slave
+ *	controller
+ * @dev:    device managing SPI controller
+ * @ctlr: initialized controller, originally from spi_alloc_master() or
+ *	spi_alloc_slave()
  * Context: can sleep
  *
- * Register a SPI device as with spi_register_master() which will
+ * Register a SPI device as with spi_register_controller() which will
  * automatically be unregister
  *
  * Return: zero on success, else a negative error code.
  */
-int devm_spi_register_master(struct device *dev, struct spi_master *master)
+int devm_spi_register_controller(struct device *dev,
+				 struct spi_controller *ctlr)
 {
-	struct spi_master **ptr;
+	struct spi_controller **ptr;
 	int ret;
 
 	ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
 		return -ENOMEM;
 
-	ret = spi_register_master(master);
+	ret = spi_register_controller(ctlr);
 	if (!ret) {
-		*ptr = master;
+		*ptr = ctlr;
 		devres_add(dev, ptr);
 	} else {
 		devres_free(ptr);
@@ -2050,7 +2171,7 @@ int devm_spi_register_master(struct device *dev, struct spi_master *master)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(devm_spi_register_master);
+EXPORT_SYMBOL_GPL(devm_spi_register_controller);
 
 static int __unregister(struct device *dev, void *null)
 {
@@ -2059,71 +2180,71 @@ static int __unregister(struct device *dev, void *null)
 }
 
 /**
- * spi_unregister_master - unregister SPI master controller
- * @master: the master being unregistered
+ * spi_unregister_controller - unregister SPI master or slave controller
+ * @ctlr: the controller being unregistered
  * Context: can sleep
  *
- * This call is used only by SPI master controller drivers, which are the
+ * This call is used only by SPI controller drivers, which are the
  * only ones directly touching chip registers.
  *
  * This must be called from context that can sleep.
  */
-void spi_unregister_master(struct spi_master *master)
+void spi_unregister_controller(struct spi_controller *ctlr)
 {
 	int dummy;
 
-	if (master->queued) {
-		if (spi_destroy_queue(master))
-			dev_err(&master->dev, "queue remove failed\n");
+	if (ctlr->queued) {
+		if (spi_destroy_queue(ctlr))
+			dev_err(&ctlr->dev, "queue remove failed\n");
 	}
 
 	mutex_lock(&board_lock);
-	list_del(&master->list);
+	list_del(&ctlr->list);
 	mutex_unlock(&board_lock);
 
-	dummy = device_for_each_child(&master->dev, NULL, __unregister);
-	device_unregister(&master->dev);
+	dummy = device_for_each_child(&ctlr->dev, NULL, __unregister);
+	device_unregister(&ctlr->dev);
 }
-EXPORT_SYMBOL_GPL(spi_unregister_master);
+EXPORT_SYMBOL_GPL(spi_unregister_controller);
 
-int spi_master_suspend(struct spi_master *master)
+int spi_controller_suspend(struct spi_controller *ctlr)
 {
 	int ret;
 
-	/* Basically no-ops for non-queued masters */
-	if (!master->queued)
+	/* Basically no-ops for non-queued controllers */
+	if (!ctlr->queued)
 		return 0;
 
-	ret = spi_stop_queue(master);
+	ret = spi_stop_queue(ctlr);
 	if (ret)
-		dev_err(&master->dev, "queue stop failed\n");
+		dev_err(&ctlr->dev, "queue stop failed\n");
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(spi_master_suspend);
+EXPORT_SYMBOL_GPL(spi_controller_suspend);
 
-int spi_master_resume(struct spi_master *master)
+int spi_controller_resume(struct spi_controller *ctlr)
 {
 	int ret;
 
-	if (!master->queued)
+	if (!ctlr->queued)
 		return 0;
 
-	ret = spi_start_queue(master);
+	ret = spi_start_queue(ctlr);
 	if (ret)
-		dev_err(&master->dev, "queue restart failed\n");
+		dev_err(&ctlr->dev, "queue restart failed\n");
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(spi_master_resume);
+EXPORT_SYMBOL_GPL(spi_controller_resume);
 
-static int __spi_master_match(struct device *dev, const void *data)
+static int __spi_controller_match(struct device *dev, const void *data)
 {
-	struct spi_master *m;
+	struct spi_controller *ctlr;
 	const u16 *bus_num = data;
 
-	m = container_of(dev, struct spi_master, dev);
-	return m->bus_num == *bus_num;
+	ctlr = container_of(dev, struct spi_controller, dev);
+	return ctlr->bus_num == *bus_num;
 }
 
 /**
@@ -2133,22 +2254,22 @@ static int __spi_master_match(struct device *dev, const void *data)
  *
  * This call may be used with devices that are registered after
  * arch init time.  It returns a refcounted pointer to the relevant
- * spi_master (which the caller must release), or NULL if there is
+ * spi_controller (which the caller must release), or NULL if there is
  * no such master registered.
  *
  * Return: the SPI master structure on success, else NULL.
  */
-struct spi_master *spi_busnum_to_master(u16 bus_num)
+struct spi_controller *spi_busnum_to_master(u16 bus_num)
 {
 	struct device		*dev;
-	struct spi_master	*master = NULL;
+	struct spi_controller	*ctlr = NULL;
 
 	dev = class_find_device(&spi_master_class, NULL, &bus_num,
-				__spi_master_match);
+				__spi_controller_match);
 	if (dev)
-		master = container_of(dev, struct spi_master, dev);
+		ctlr = container_of(dev, struct spi_controller, dev);
 	/* reference got in class_find_device */
-	return master;
+	return ctlr;
 }
 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
 
@@ -2168,7 +2289,7 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master);
  * Return: the pointer to the allocated data
  *
  * This may get enhanced in the future to allocate from a memory pool
- * of the @spi_device or @spi_master to avoid repeated allocations.
+ * of the @spi_device or @spi_controller to avoid repeated allocations.
  */
 void *spi_res_alloc(struct spi_device *spi,
 		    spi_res_release_t release,
@@ -2220,11 +2341,10 @@ EXPORT_SYMBOL_GPL(spi_res_add);
 
 /**
  * spi_res_release - release all spi resources for this message
- * @master:  the @spi_master
+ * @ctlr:  the @spi_controller
  * @message: the @spi_message
  */
-void spi_res_release(struct spi_master *master,
-		     struct spi_message *message)
+void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
 {
 	struct spi_res *res;
 
@@ -2233,7 +2353,7 @@ void spi_res_release(struct spi_master *master,
 				      struct spi_res, entry);
 
 		if (res->release)
-			res->release(master, message, res->data);
+			res->release(ctlr, message, res->data);
 
 		list_del(&res->entry);
 
@@ -2246,7 +2366,7 @@ EXPORT_SYMBOL_GPL(spi_res_release);
 
 /* Core methods for spi_message alterations */
 
-static void __spi_replace_transfers_release(struct spi_master *master,
+static void __spi_replace_transfers_release(struct spi_controller *ctlr,
 					    struct spi_message *msg,
 					    void *res)
 {
@@ -2255,7 +2375,7 @@ static void __spi_replace_transfers_release(struct spi_master *master,
 
 	/* call extra callback if requested */
 	if (rxfer->release)
-		rxfer->release(master, msg, res);
+		rxfer->release(ctlr, msg, res);
 
 	/* insert replaced transfers back into the message */
 	list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
@@ -2375,7 +2495,7 @@ struct spi_replaced_transfers *spi_replace_transfers(
 }
 EXPORT_SYMBOL_GPL(spi_replace_transfers);
 
-static int __spi_split_transfer_maxsize(struct spi_master *master,
+static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
 					struct spi_message *msg,
 					struct spi_transfer **xferp,
 					size_t maxsize,
@@ -2437,7 +2557,7 @@ static int __spi_split_transfer_maxsize(struct spi_master *master,
 	*xferp = &xfers[count - 1];
 
 	/* increment statistics counters */
-	SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
+	SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
 				       transfers_split_maxsize);
 	SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
 				       transfers_split_maxsize);
@@ -2449,14 +2569,14 @@ static int __spi_split_transfer_maxsize(struct spi_master *master,
  * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
  *                              when an individual transfer exceeds a
  *                              certain size
- * @master:    the @spi_master for this transfer
+ * @ctlr:    the @spi_controller for this transfer
  * @msg:   the @spi_message to transform
  * @maxsize:  the maximum when to apply this
  * @gfp: GFP allocation flags
  *
  * Return: status of transformation
  */
-int spi_split_transfers_maxsize(struct spi_master *master,
+int spi_split_transfers_maxsize(struct spi_controller *ctlr,
 				struct spi_message *msg,
 				size_t maxsize,
 				gfp_t gfp)
@@ -2472,8 +2592,8 @@ int spi_split_transfers_maxsize(struct spi_master *master,
 	 */
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 		if (xfer->len > maxsize) {
-			ret = __spi_split_transfer_maxsize(
-				master, msg, &xfer, maxsize, gfp);
+			ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
+							   maxsize, gfp);
 			if (ret)
 				return ret;
 		}
@@ -2485,18 +2605,18 @@ EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
 
 /*-------------------------------------------------------------------------*/
 
-/* Core methods for SPI master protocol drivers.  Some of the
+/* Core methods for SPI controller protocol drivers.  Some of the
  * other core methods are currently defined as inline functions.
  */
 
-static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
+static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
+					u8 bits_per_word)
 {
-	if (master->bits_per_word_mask) {
+	if (ctlr->bits_per_word_mask) {
 		/* Only 32 bits fit in the mask */
 		if (bits_per_word > 32)
 			return -EINVAL;
-		if (!(master->bits_per_word_mask &
-				SPI_BPW_MASK(bits_per_word)))
+		if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
 			return -EINVAL;
 	}
 
@@ -2542,9 +2662,9 @@ int spi_setup(struct spi_device *spi)
 		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
 		return -EINVAL;
 	/* help drivers fail *cleanly* when they need options
-	 * that aren't supported with their current master
+	 * that aren't supported with their current controller
 	 */
-	bad_bits = spi->mode & ~spi->master->mode_bits;
+	bad_bits = spi->mode & ~spi->controller->mode_bits;
 	ugly_bits = bad_bits &
 		    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
 	if (ugly_bits) {
@@ -2563,15 +2683,16 @@ int spi_setup(struct spi_device *spi)
 	if (!spi->bits_per_word)
 		spi->bits_per_word = 8;
 
-	status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
+	status = __spi_validate_bits_per_word(spi->controller,
+					      spi->bits_per_word);
 	if (status)
 		return status;
 
 	if (!spi->max_speed_hz)
-		spi->max_speed_hz = spi->master->max_speed_hz;
+		spi->max_speed_hz = spi->controller->max_speed_hz;
 
-	if (spi->master->setup)
-		status = spi->master->setup(spi);
+	if (spi->controller->setup)
+		status = spi->controller->setup(spi);
 
 	spi_set_cs(spi, false);
 
@@ -2590,7 +2711,7 @@ EXPORT_SYMBOL_GPL(spi_setup);
 
 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	struct spi_transfer *xfer;
 	int w_size;
 
@@ -2602,16 +2723,16 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 	 * either MOSI or MISO is missing.  They can also be caused by
 	 * software limitations.
 	 */
-	if ((master->flags & SPI_MASTER_HALF_DUPLEX)
-			|| (spi->mode & SPI_3WIRE)) {
-		unsigned flags = master->flags;
+	if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
+	    (spi->mode & SPI_3WIRE)) {
+		unsigned flags = ctlr->flags;
 
 		list_for_each_entry(xfer, &message->transfers, transfer_list) {
 			if (xfer->rx_buf && xfer->tx_buf)
 				return -EINVAL;
-			if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
+			if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
 				return -EINVAL;
-			if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
+			if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
 				return -EINVAL;
 		}
 	}
@@ -2631,13 +2752,12 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 		if (!xfer->speed_hz)
 			xfer->speed_hz = spi->max_speed_hz;
 		if (!xfer->speed_hz)
-			xfer->speed_hz = master->max_speed_hz;
+			xfer->speed_hz = ctlr->max_speed_hz;
 
-		if (master->max_speed_hz &&
-		    xfer->speed_hz > master->max_speed_hz)
-			xfer->speed_hz = master->max_speed_hz;
+		if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
+			xfer->speed_hz = ctlr->max_speed_hz;
 
-		if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
+		if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
 			return -EINVAL;
 
 		/*
@@ -2655,8 +2775,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 		if (xfer->len % w_size)
 			return -EINVAL;
 
-		if (xfer->speed_hz && master->min_speed_hz &&
-		    xfer->speed_hz < master->min_speed_hz)
+		if (xfer->speed_hz && ctlr->min_speed_hz &&
+		    xfer->speed_hz < ctlr->min_speed_hz)
 			return -EINVAL;
 
 		if (xfer->tx_buf && !xfer->tx_nbits)
@@ -2701,16 +2821,16 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 
 static int __spi_async(struct spi_device *spi, struct spi_message *message)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 
 	message->spi = spi;
 
-	SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
+	SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
 	SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
 
 	trace_spi_message_submit(message);
 
-	return master->transfer(spi, message);
+	return ctlr->transfer(spi, message);
 }
 
 /**
@@ -2746,7 +2866,7 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
  */
 int spi_async(struct spi_device *spi, struct spi_message *message)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	int ret;
 	unsigned long flags;
 
@@ -2754,14 +2874,14 @@ int spi_async(struct spi_device *spi, struct spi_message *message)
 	if (ret != 0)
 		return ret;
 
-	spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
 
-	if (master->bus_lock_flag)
+	if (ctlr->bus_lock_flag)
 		ret = -EBUSY;
 	else
 		ret = __spi_async(spi, message);
 
-	spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
 
 	return ret;
 }
@@ -2800,7 +2920,7 @@ EXPORT_SYMBOL_GPL(spi_async);
  */
 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	int ret;
 	unsigned long flags;
 
@@ -2808,11 +2928,11 @@ int spi_async_locked(struct spi_device *spi, struct spi_message *message)
 	if (ret != 0)
 		return ret;
 
-	spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
 
 	ret = __spi_async(spi, message);
 
-	spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
 
 	return ret;
 
@@ -2824,7 +2944,7 @@ int spi_flash_read(struct spi_device *spi,
 		   struct spi_flash_read_message *msg)
 
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *master = spi->controller;
 	struct device *rx_dev = NULL;
 	int ret;
 
@@ -2878,7 +2998,7 @@ EXPORT_SYMBOL_GPL(spi_flash_read);
 
 /*-------------------------------------------------------------------------*/
 
-/* Utility methods for SPI master protocol drivers, layered on
+/* Utility methods for SPI protocol drivers, layered on
  * top of the core.  Some other utility methods are defined as
  * inline functions.
  */
@@ -2892,7 +3012,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
 	int status;
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	unsigned long flags;
 
 	status = __spi_validate(spi, message);
@@ -2903,7 +3023,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
 	message->context = &done;
 	message->spi = spi;
 
-	SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
+	SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
 	SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
 
 	/* If we're not using the legacy transfer method then we will
@@ -2911,14 +3031,14 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
 	 * This code would be less tricky if we could remove the
 	 * support for driver implemented message queues.
 	 */
-	if (master->transfer == spi_queued_transfer) {
-		spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+	if (ctlr->transfer == spi_queued_transfer) {
+		spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
 
 		trace_spi_message_submit(message);
 
 		status = __spi_queued_transfer(spi, message, false);
 
-		spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+		spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
 	} else {
 		status = spi_async_locked(spi, message);
 	}
@@ -2927,12 +3047,12 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message)
 		/* Push out the messages in the calling context if we
 		 * can.
 		 */
-		if (master->transfer == spi_queued_transfer) {
-			SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
+		if (ctlr->transfer == spi_queued_transfer) {
+			SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
 						       spi_sync_immediate);
 			SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
 						       spi_sync_immediate);
-			__spi_pump_messages(master, false);
+			__spi_pump_messages(ctlr, false);
 		}
 
 		wait_for_completion(&done);
@@ -2967,9 +3087,9 @@ int spi_sync(struct spi_device *spi, struct spi_message *message)
 {
 	int ret;
 
-	mutex_lock(&spi->master->bus_lock_mutex);
+	mutex_lock(&spi->controller->bus_lock_mutex);
 	ret = __spi_sync(spi, message);
-	mutex_unlock(&spi->master->bus_lock_mutex);
+	mutex_unlock(&spi->controller->bus_lock_mutex);
 
 	return ret;
 }
@@ -2999,7 +3119,7 @@ EXPORT_SYMBOL_GPL(spi_sync_locked);
 
 /**
  * spi_bus_lock - obtain a lock for exclusive SPI bus usage
- * @master: SPI bus master that should be locked for exclusive bus access
+ * @ctlr: SPI bus master that should be locked for exclusive bus access
  * Context: can sleep
  *
  * This call may only be used from a context that may sleep.  The sleep
@@ -3012,15 +3132,15 @@ EXPORT_SYMBOL_GPL(spi_sync_locked);
  *
  * Return: always zero.
  */
-int spi_bus_lock(struct spi_master *master)
+int spi_bus_lock(struct spi_controller *ctlr)
 {
 	unsigned long flags;
 
-	mutex_lock(&master->bus_lock_mutex);
+	mutex_lock(&ctlr->bus_lock_mutex);
 
-	spin_lock_irqsave(&master->bus_lock_spinlock, flags);
-	master->bus_lock_flag = 1;
-	spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
+	ctlr->bus_lock_flag = 1;
+	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
 
 	/* mutex remains locked until spi_bus_unlock is called */
 
@@ -3030,7 +3150,7 @@ EXPORT_SYMBOL_GPL(spi_bus_lock);
 
 /**
  * spi_bus_unlock - release the lock for exclusive SPI bus usage
- * @master: SPI bus master that was locked for exclusive bus access
+ * @ctlr: SPI bus master that was locked for exclusive bus access
  * Context: can sleep
  *
  * This call may only be used from a context that may sleep.  The sleep
@@ -3041,11 +3161,11 @@ EXPORT_SYMBOL_GPL(spi_bus_lock);
  *
  * Return: always zero.
  */
-int spi_bus_unlock(struct spi_master *master)
+int spi_bus_unlock(struct spi_controller *ctlr)
 {
-	master->bus_lock_flag = 0;
+	ctlr->bus_lock_flag = 0;
 
-	mutex_unlock(&master->bus_lock_mutex);
+	mutex_unlock(&ctlr->bus_lock_mutex);
 
 	return 0;
 }
@@ -3147,45 +3267,48 @@ static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
 	return dev ? to_spi_device(dev) : NULL;
 }
 
-static int __spi_of_master_match(struct device *dev, const void *data)
+static int __spi_of_controller_match(struct device *dev, const void *data)
 {
 	return dev->of_node == data;
 }
 
-/* the spi masters are not using spi_bus, so we find it with another way */
-static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
+/* the spi controllers are not using spi_bus, so we find it with another way */
+static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
 {
 	struct device *dev;
 
 	dev = class_find_device(&spi_master_class, NULL, node,
-				__spi_of_master_match);
+				__spi_of_controller_match);
+	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
+		dev = class_find_device(&spi_slave_class, NULL, node,
+					__spi_of_controller_match);
 	if (!dev)
 		return NULL;
 
 	/* reference got in class_find_device */
-	return container_of(dev, struct spi_master, dev);
+	return container_of(dev, struct spi_controller, dev);
 }
 
 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
 			 void *arg)
 {
 	struct of_reconfig_data *rd = arg;
-	struct spi_master *master;
+	struct spi_controller *ctlr;
 	struct spi_device *spi;
 
 	switch (of_reconfig_get_state_change(action, arg)) {
 	case OF_RECONFIG_CHANGE_ADD:
-		master = of_find_spi_master_by_node(rd->dn->parent);
-		if (master == NULL)
+		ctlr = of_find_spi_controller_by_node(rd->dn->parent);
+		if (ctlr == NULL)
 			return NOTIFY_OK;	/* not for us */
 
 		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
-			put_device(&master->dev);
+			put_device(&ctlr->dev);
 			return NOTIFY_OK;
 		}
 
-		spi = of_register_spi_device(master, rd->dn);
-		put_device(&master->dev);
+		spi = of_register_spi_device(ctlr, rd->dn);
+		put_device(&ctlr->dev);
 
 		if (IS_ERR(spi)) {
 			pr_err("%s: failed to create for '%s'\n",
@@ -3224,7 +3347,7 @@ extern struct notifier_block spi_of_notifier;
 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
 
 #if IS_ENABLED(CONFIG_ACPI)
-static int spi_acpi_master_match(struct device *dev, const void *data)
+static int spi_acpi_controller_match(struct device *dev, const void *data)
 {
 	return ACPI_COMPANION(dev->parent) == data;
 }
@@ -3234,16 +3357,19 @@ static int spi_acpi_device_match(struct device *dev, void *data)
 	return ACPI_COMPANION(dev) == data;
 }
 
-static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
+static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
 {
 	struct device *dev;
 
 	dev = class_find_device(&spi_master_class, NULL, adev,
-				spi_acpi_master_match);
+				spi_acpi_controller_match);
+	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
+		dev = class_find_device(&spi_slave_class, NULL, adev,
+					spi_acpi_controller_match);
 	if (!dev)
 		return NULL;
 
-	return container_of(dev, struct spi_master, dev);
+	return container_of(dev, struct spi_controller, dev);
 }
 
 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
@@ -3259,17 +3385,17 @@ static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
 			   void *arg)
 {
 	struct acpi_device *adev = arg;
-	struct spi_master *master;
+	struct spi_controller *ctlr;
 	struct spi_device *spi;
 
 	switch (value) {
 	case ACPI_RECONFIG_DEVICE_ADD:
-		master = acpi_spi_find_master_by_adev(adev->parent);
-		if (!master)
+		ctlr = acpi_spi_find_controller_by_adev(adev->parent);
+		if (!ctlr)
 			break;
 
-		acpi_register_spi_device(master, adev);
-		put_device(&master->dev);
+		acpi_register_spi_device(ctlr, adev);
+		put_device(&ctlr->dev);
 		break;
 	case ACPI_RECONFIG_DEVICE_REMOVE:
 		if (!acpi_device_enumerated(adev))
@@ -3312,6 +3438,12 @@ static int __init spi_init(void)
 	if (status < 0)
 		goto err2;
 
+	if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
+		status = class_register(&spi_slave_class);
+		if (status < 0)
+			goto err3;
+	}
+
 	if (IS_ENABLED(CONFIG_OF_DYNAMIC))
 		WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
 	if (IS_ENABLED(CONFIG_ACPI))
@@ -3319,6 +3451,8 @@ static int __init spi_init(void)
 
 	return 0;
 
+err3:
+	class_unregister(&spi_master_class);
 err2:
 	bus_unregister(&spi_bus_type);
 err1:
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 935bd2854ff19..7b2170bfd6e7d 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -24,13 +24,13 @@
 
 struct dma_chan;
 struct property_entry;
-struct spi_master;
+struct spi_controller;
 struct spi_transfer;
 struct spi_flash_read_message;
 
 /*
- * INTERFACES between SPI master-side drivers and SPI infrastructure.
- * (There's no SPI slave support for Linux yet...)
+ * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
+ * and SPI infrastructure.
  */
 extern struct bus_type spi_bus_type;
 
@@ -84,7 +84,7 @@ struct spi_statistics {
 
 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
 				       struct spi_transfer *xfer,
-				       struct spi_master *master);
+				       struct spi_controller *ctlr);
 
 #define SPI_STATISTICS_ADD_TO_FIELD(stats, field, count)	\
 	do {							\
@@ -98,13 +98,14 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
 	SPI_STATISTICS_ADD_TO_FIELD(stats, field, 1)
 
 /**
- * struct spi_device - Master side proxy for an SPI slave device
+ * struct spi_device - Controller side proxy for an SPI slave device
  * @dev: Driver model representation of the device.
- * @master: SPI controller used with the device.
+ * @controller: SPI controller used with the device.
+ * @master: Copy of controller, for backwards compatibility.
  * @max_speed_hz: Maximum clock rate to be used with this chip
  *	(on this board); may be changed by the device's driver.
  *	The spi_transfer.speed_hz can override this for each transfer.
- * @chip_select: Chipselect, distinguishing chips handled by @master.
+ * @chip_select: Chipselect, distinguishing chips handled by @controller.
  * @mode: The spi mode defines how data is clocked out and in.
  *	This may be changed by the device's driver.
  *	The "active low" default for chipselect mode can be overridden
@@ -140,7 +141,8 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
  */
 struct spi_device {
 	struct device		dev;
-	struct spi_master	*master;
+	struct spi_controller	*controller;
+	struct spi_controller	*master;	/* compatibility layer */
 	u32			max_speed_hz;
 	u8			chip_select;
 	u8			bits_per_word;
@@ -198,7 +200,7 @@ static inline void spi_dev_put(struct spi_device *spi)
 		put_device(&spi->dev);
 }
 
-/* ctldata is for the bus_master driver's runtime state */
+/* ctldata is for the bus_controller driver's runtime state */
 static inline void *spi_get_ctldata(struct spi_device *spi)
 {
 	return spi->controller_state;
@@ -292,9 +294,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
 			spi_unregister_driver)
 
 /**
- * struct spi_master - interface to SPI master controller
+ * struct spi_controller - interface to SPI master or slave controller
  * @dev: device interface to this driver
- * @list: link with the global spi_master list
+ * @list: link with the global spi_controller list
  * @bus_num: board-specific (and often SOC-specific) identifier for a
  *	given SPI controller.
  * @num_chipselect: chipselects are used to distinguish individual
@@ -311,6 +313,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @min_speed_hz: Lowest supported transfer speed
  * @max_speed_hz: Highest supported transfer speed
  * @flags: other constraints relevant to this driver
+ * @slave: indicates that this is an SPI slave controller
  * @max_transfer_size: function that returns the max transfer size for
  *	a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
  * @max_message_size: function that returns the max message size for
@@ -326,8 +329,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	the device whose settings are being modified.
  * @transfer: adds a message to the controller's transfer queue.
  * @cleanup: frees controller-specific state
- * @can_dma: determine whether this master supports DMA
- * @queued: whether this master is providing an internal message queue
+ * @can_dma: determine whether this controller supports DMA
+ * @queued: whether this controller is providing an internal message queue
  * @kworker: thread struct for message pump
  * @kworker_task: pointer to task for message pump kworker thread
  * @pump_messages: work struct for scheduling work to the message pump
@@ -374,6 +377,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @handle_err: the subsystem calls the driver to handle an error that occurs
  *		in the generic implementation of transfer_one_message().
  * @unprepare_message: undo any work done by prepare_message().
+ * @slave_abort: abort the ongoing transfer request on an SPI slave controller
  * @spi_flash_read: to support spi-controller hardwares that provide
  *                  accelerated interface to read from flash devices.
  * @spi_flash_can_dma: analogous to can_dma() interface, but for
@@ -382,7 +386,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *	number. Any individual value may be -ENOENT for CS lines that
  *	are not GPIOs (driven by the SPI controller itself).
- * @statistics: statistics for the spi_master
+ * @statistics: statistics for the spi_controller
  * @dma_tx: DMA transmit channel
  * @dma_rx: DMA receive channel
  * @dummy_rx: dummy receive buffer for full-duplex devices
@@ -391,7 +395,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	what Linux expects, this optional hook can be used to translate
  *	between the two.
  *
- * Each SPI master controller can communicate with one or more @spi_device
+ * Each SPI controller can communicate with one or more @spi_device
  * children.  These make a small bus, sharing MOSI, MISO and SCK signals
  * but not chip select signals.  Each device may be configured to use a
  * different clock rate, since those shared signals are ignored unless
@@ -402,7 +406,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * an SPI slave device.  For each such message it queues, it calls the
  * message's completion function when the transaction completes.
  */
-struct spi_master {
+struct spi_controller {
 	struct device	dev;
 
 	struct list_head list;
@@ -440,12 +444,16 @@ struct spi_master {
 
 	/* other constraints relevant to this driver */
 	u16			flags;
-#define SPI_MASTER_HALF_DUPLEX	BIT(0)		/* can't do full duplex */
-#define SPI_MASTER_NO_RX	BIT(1)		/* can't do buffer read */
-#define SPI_MASTER_NO_TX	BIT(2)		/* can't do buffer write */
-#define SPI_MASTER_MUST_RX      BIT(3)		/* requires rx */
-#define SPI_MASTER_MUST_TX      BIT(4)		/* requires tx */
-#define SPI_MASTER_GPIO_SS      BIT(5)		/* GPIO CS must select slave */
+#define SPI_CONTROLLER_HALF_DUPLEX	BIT(0)	/* can't do full duplex */
+#define SPI_CONTROLLER_NO_RX		BIT(1)	/* can't do buffer read */
+#define SPI_CONTROLLER_NO_TX		BIT(2)	/* can't do buffer write */
+#define SPI_CONTROLLER_MUST_RX		BIT(3)	/* requires rx */
+#define SPI_CONTROLLER_MUST_TX		BIT(4)	/* requires tx */
+
+#define SPI_MASTER_GPIO_SS		BIT(5)	/* GPIO CS must select slave */
+
+	/* flag indicating this is an SPI slave controller */
+	bool			slave;
 
 	/*
 	 * on some hardware transfer / message size may be constrained
@@ -480,8 +488,8 @@ struct spi_master {
 	 *   any other request management
 	 * + To a given spi_device, message queueing is pure fifo
 	 *
-	 * + The master's main job is to process its message queue,
-	 *   selecting a chip then transferring data
+	 * + The controller's main job is to process its message queue,
+	 *   selecting a chip (for masters), then transferring data
 	 * + If there are multiple spi_device children, the i/o queue
 	 *   arbitration algorithm is unspecified (round robin, fifo,
 	 *   priority, reservations, preemption, etc)
@@ -494,7 +502,7 @@ struct spi_master {
 	int			(*transfer)(struct spi_device *spi,
 						struct spi_message *mesg);
 
-	/* called on release() to free memory provided by spi_master */
+	/* called on release() to free memory provided by spi_controller */
 	void			(*cleanup)(struct spi_device *spi);
 
 	/*
@@ -504,13 +512,13 @@ struct spi_master {
 	 * not modify or store xfer and dma_tx and dma_rx must be set
 	 * while the device is prepared.
 	 */
-	bool			(*can_dma)(struct spi_master *master,
+	bool			(*can_dma)(struct spi_controller *ctlr,
 					   struct spi_device *spi,
 					   struct spi_transfer *xfer);
 
 	/*
 	 * These hooks are for drivers that want to use the generic
-	 * master transfer queueing mechanism. If these are used, the
+	 * controller transfer queueing mechanism. If these are used, the
 	 * transfer() function above must NOT be specified by the driver.
 	 * Over time we expect SPI drivers to be phased over to this API.
 	 */
@@ -531,14 +539,15 @@ struct spi_master {
 	struct completion               xfer_completion;
 	size_t				max_dma_len;
 
-	int (*prepare_transfer_hardware)(struct spi_master *master);
-	int (*transfer_one_message)(struct spi_master *master,
+	int (*prepare_transfer_hardware)(struct spi_controller *ctlr);
+	int (*transfer_one_message)(struct spi_controller *ctlr,
 				    struct spi_message *mesg);
-	int (*unprepare_transfer_hardware)(struct spi_master *master);
-	int (*prepare_message)(struct spi_master *master,
+	int (*unprepare_transfer_hardware)(struct spi_controller *ctlr);
+	int (*prepare_message)(struct spi_controller *ctlr,
 			       struct spi_message *message);
-	int (*unprepare_message)(struct spi_master *master,
+	int (*unprepare_message)(struct spi_controller *ctlr,
 				 struct spi_message *message);
+	int (*slave_abort)(struct spi_controller *ctlr);
 	int (*spi_flash_read)(struct  spi_device *spi,
 			      struct spi_flash_read_message *msg);
 	bool (*spi_flash_can_dma)(struct spi_device *spi,
@@ -550,9 +559,9 @@ struct spi_master {
 	 * of transfer_one_message() provied by the core.
 	 */
 	void (*set_cs)(struct spi_device *spi, bool enable);
-	int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
+	int (*transfer_one)(struct spi_controller *ctlr, struct spi_device *spi,
 			    struct spi_transfer *transfer);
-	void (*handle_err)(struct spi_master *master,
+	void (*handle_err)(struct spi_controller *ctlr,
 			   struct spi_message *message);
 
 	/* gpio chip select */
@@ -569,57 +578,78 @@ struct spi_master {
 	void			*dummy_rx;
 	void			*dummy_tx;
 
-	int (*fw_translate_cs)(struct spi_master *master, unsigned cs);
+	int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs);
 };
 
-static inline void *spi_master_get_devdata(struct spi_master *master)
+static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)
 {
-	return dev_get_drvdata(&master->dev);
+	return dev_get_drvdata(&ctlr->dev);
 }
 
-static inline void spi_master_set_devdata(struct spi_master *master, void *data)
+static inline void spi_controller_set_devdata(struct spi_controller *ctlr,
+					      void *data)
 {
-	dev_set_drvdata(&master->dev, data);
+	dev_set_drvdata(&ctlr->dev, data);
 }
 
-static inline struct spi_master *spi_master_get(struct spi_master *master)
+static inline struct spi_controller *spi_controller_get(struct spi_controller *ctlr)
 {
-	if (!master || !get_device(&master->dev))
+	if (!ctlr || !get_device(&ctlr->dev))
 		return NULL;
-	return master;
+	return ctlr;
+}
+
+static inline void spi_controller_put(struct spi_controller *ctlr)
+{
+	if (ctlr)
+		put_device(&ctlr->dev);
 }
 
-static inline void spi_master_put(struct spi_master *master)
+static inline bool spi_controller_is_slave(struct spi_controller *ctlr)
 {
-	if (master)
-		put_device(&master->dev);
+	return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
 }
 
 /* PM calls that need to be issued by the driver */
-extern int spi_master_suspend(struct spi_master *master);
-extern int spi_master_resume(struct spi_master *master);
+extern int spi_controller_suspend(struct spi_controller *ctlr);
+extern int spi_controller_resume(struct spi_controller *ctlr);
 
 /* Calls the driver make to interact with the message queue */
-extern struct spi_message *spi_get_next_queued_message(struct spi_master *master);
-extern void spi_finalize_current_message(struct spi_master *master);
-extern void spi_finalize_current_transfer(struct spi_master *master);
+extern struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr);
+extern void spi_finalize_current_message(struct spi_controller *ctlr);
+extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
 
-/* the spi driver core manages memory for the spi_master classdev */
-extern struct spi_master *
-spi_alloc_master(struct device *host, unsigned size);
+/* the spi driver core manages memory for the spi_controller classdev */
+extern struct spi_controller *__spi_alloc_controller(struct device *host,
+						unsigned int size, bool slave);
 
-extern int spi_register_master(struct spi_master *master);
-extern int devm_spi_register_master(struct device *dev,
-				    struct spi_master *master);
-extern void spi_unregister_master(struct spi_master *master);
+static inline struct spi_controller *spi_alloc_master(struct device *host,
+						      unsigned int size)
+{
+	return __spi_alloc_controller(host, size, false);
+}
 
-extern struct spi_master *spi_busnum_to_master(u16 busnum);
+static inline struct spi_controller *spi_alloc_slave(struct device *host,
+						     unsigned int size)
+{
+	if (!IS_ENABLED(CONFIG_SPI_SLAVE))
+		return NULL;
+
+	return __spi_alloc_controller(host, size, true);
+}
+
+extern int spi_register_controller(struct spi_controller *ctlr);
+extern int devm_spi_register_controller(struct device *dev,
+					struct spi_controller *ctlr);
+extern void spi_unregister_controller(struct spi_controller *ctlr);
+
+extern struct spi_controller *spi_busnum_to_master(u16 busnum);
 
 /*
  * SPI resource management while processing a SPI message
  */
 
-typedef void (*spi_res_release_t)(struct spi_master *master,
+typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
 				  struct spi_message *msg,
 				  void *res);
 
@@ -644,7 +674,7 @@ extern void *spi_res_alloc(struct spi_device *spi,
 extern void spi_res_add(struct spi_message *message, void *res);
 extern void spi_res_free(void *res);
 
-extern void spi_res_release(struct spi_master *master,
+extern void spi_res_release(struct spi_controller *ctlr,
 			    struct spi_message *message);
 
 /*---------------------------------------------------------------------------*/
@@ -828,7 +858,7 @@ struct spi_message {
 
 	/* for optional use by whatever driver currently owns the
 	 * spi_message ...  between calls to spi_async and then later
-	 * complete(), that's the spi_master controller driver.
+	 * complete(), that's the spi_controller controller driver.
 	 */
 	struct list_head	queue;
 	void			*state;
@@ -912,25 +942,27 @@ extern int spi_setup(struct spi_device *spi);
 extern int spi_async(struct spi_device *spi, struct spi_message *message);
 extern int spi_async_locked(struct spi_device *spi,
 			    struct spi_message *message);
+extern int spi_slave_abort(struct spi_device *spi);
 
 static inline size_t
 spi_max_message_size(struct spi_device *spi)
 {
-	struct spi_master *master = spi->master;
-	if (!master->max_message_size)
+	struct spi_controller *ctlr = spi->controller;
+
+	if (!ctlr->max_message_size)
 		return SIZE_MAX;
-	return master->max_message_size(spi);
+	return ctlr->max_message_size(spi);
 }
 
 static inline size_t
 spi_max_transfer_size(struct spi_device *spi)
 {
-	struct spi_master *master = spi->master;
+	struct spi_controller *ctlr = spi->controller;
 	size_t tr_max = SIZE_MAX;
 	size_t msg_max = spi_max_message_size(spi);
 
-	if (master->max_transfer_size)
-		tr_max = master->max_transfer_size(spi);
+	if (ctlr->max_transfer_size)
+		tr_max = ctlr->max_transfer_size(spi);
 
 	/* transfer size limit must not be greater than messsage size limit */
 	return min(tr_max, msg_max);
@@ -941,7 +973,7 @@ spi_max_transfer_size(struct spi_device *spi)
 /* SPI transfer replacement methods which make use of spi_res */
 
 struct spi_replaced_transfers;
-typedef void (*spi_replaced_release_t)(struct spi_master *master,
+typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
 				       struct spi_message *msg,
 				       struct spi_replaced_transfers *res);
 /**
@@ -985,7 +1017,7 @@ extern struct spi_replaced_transfers *spi_replace_transfers(
 
 /* SPI transfer transformation methods */
 
-extern int spi_split_transfers_maxsize(struct spi_master *master,
+extern int spi_split_transfers_maxsize(struct spi_controller *ctlr,
 				       struct spi_message *msg,
 				       size_t maxsize,
 				       gfp_t gfp);
@@ -999,8 +1031,8 @@ extern int spi_split_transfers_maxsize(struct spi_master *master,
 
 extern int spi_sync(struct spi_device *spi, struct spi_message *message);
 extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
-extern int spi_bus_lock(struct spi_master *master);
-extern int spi_bus_unlock(struct spi_master *master);
+extern int spi_bus_lock(struct spi_controller *ctlr);
+extern int spi_bus_unlock(struct spi_controller *ctlr);
 
 /**
  * spi_sync_transfer - synchronous SPI data transfer
@@ -1185,9 +1217,9 @@ struct spi_flash_read_message {
 /* SPI core interface for flash read support */
 static inline bool spi_flash_read_supported(struct spi_device *spi)
 {
-	return spi->master->spi_flash_read &&
-	       (!spi->master->flash_read_supported ||
-	       spi->master->flash_read_supported(spi));
+	return spi->controller->spi_flash_read &&
+	       (!spi->controller->flash_read_supported ||
+	       spi->controller->flash_read_supported(spi));
 }
 
 int spi_flash_read(struct spi_device *spi,
@@ -1220,7 +1252,7 @@ int spi_flash_read(struct spi_device *spi,
  * @irq: Initializes spi_device.irq; depends on how the board is wired.
  * @max_speed_hz: Initializes spi_device.max_speed_hz; based on limits
  *	from the chip datasheet and board-specific signal quality issues.
- * @bus_num: Identifies which spi_master parents the spi_device; unused
+ * @bus_num: Identifies which spi_controller parents the spi_device; unused
  *	by spi_new_device(), and otherwise depends on board wiring.
  * @chip_select: Initializes spi_device.chip_select; depends on how
  *	the board is wired.
@@ -1261,7 +1293,7 @@ struct spi_board_info {
 
 
 	/* bus_num is board specific and matches the bus_num of some
-	 * spi_master that will probably be registered later.
+	 * spi_controller that will probably be registered later.
 	 *
 	 * chip_select reflects how this chip is wired to that master;
 	 * it's less than num_chipselect.
@@ -1295,7 +1327,7 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n)
 /* If you're hotplugging an adapter with devices (parport, usb, etc)
  * use spi_new_device() to describe each device.  You can also call
  * spi_unregister_device() to start making that device vanish, but
- * normally that would be handled by spi_unregister_master().
+ * normally that would be handled by spi_unregister_controller().
  *
  * You can also use spi_alloc_device() and spi_add_device() to use a two
  * stage registration sequence for each spi_device.  This gives the caller
@@ -1304,13 +1336,13 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n)
  * be defined using the board info.
  */
 extern struct spi_device *
-spi_alloc_device(struct spi_master *master);
+spi_alloc_device(struct spi_controller *ctlr);
 
 extern int
 spi_add_device(struct spi_device *spi);
 
 extern struct spi_device *
-spi_new_device(struct spi_master *, struct spi_board_info *);
+spi_new_device(struct spi_controller *, struct spi_board_info *);
 
 extern void spi_unregister_device(struct spi_device *spi);
 
@@ -1318,9 +1350,32 @@ extern const struct spi_device_id *
 spi_get_device_id(const struct spi_device *sdev);
 
 static inline bool
-spi_transfer_is_last(struct spi_master *master, struct spi_transfer *xfer)
+spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
 {
-	return list_is_last(&xfer->transfer_list, &master->cur_msg->transfers);
+	return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
 }
 
+
+/* Compatibility layer */
+#define spi_master			spi_controller
+
+#define SPI_MASTER_HALF_DUPLEX		SPI_CONTROLLER_HALF_DUPLEX
+#define SPI_MASTER_NO_RX		SPI_CONTROLLER_NO_RX
+#define SPI_MASTER_NO_TX		SPI_CONTROLLER_NO_TX
+#define SPI_MASTER_MUST_RX		SPI_CONTROLLER_MUST_RX
+#define SPI_MASTER_MUST_TX		SPI_CONTROLLER_MUST_TX
+
+#define spi_master_get_devdata(_ctlr)	spi_controller_get_devdata(_ctlr)
+#define spi_master_set_devdata(_ctlr, _data)	\
+	spi_controller_set_devdata(_ctlr, _data)
+#define spi_master_get(_ctlr)		spi_controller_get(_ctlr)
+#define spi_master_put(_ctlr)		spi_controller_put(_ctlr)
+#define spi_master_suspend(_ctlr)	spi_controller_suspend(_ctlr)
+#define spi_master_resume(_ctlr)	spi_controller_resume(_ctlr)
+
+#define spi_register_master(_ctlr)	spi_register_controller(_ctlr)
+#define devm_spi_register_master(_dev, _ctlr) \
+	devm_spi_register_controller(_dev, _ctlr)
+#define spi_unregister_master(_ctlr)	spi_unregister_controller(_ctlr)
+
 #endif /* __LINUX_SPI_H */
diff --git a/include/trace/events/spi.h b/include/trace/events/spi.h
index 7e02c983bbe26..f9f702b6ae2e9 100644
--- a/include/trace/events/spi.h
+++ b/include/trace/events/spi.h
@@ -7,37 +7,37 @@
 #include <linux/ktime.h>
 #include <linux/tracepoint.h>
 
-DECLARE_EVENT_CLASS(spi_master,
+DECLARE_EVENT_CLASS(spi_controller,
 
-	TP_PROTO(struct spi_master *master),
+	TP_PROTO(struct spi_controller *controller),
 
-	TP_ARGS(master),
+	TP_ARGS(controller),
 
 	TP_STRUCT__entry(
 		__field(        int,           bus_num             )
 	),
 
 	TP_fast_assign(
-		__entry->bus_num = master->bus_num;
+		__entry->bus_num = controller->bus_num;
 	),
 
 	TP_printk("spi%d", (int)__entry->bus_num)
 
 );
 
-DEFINE_EVENT(spi_master, spi_master_idle,
+DEFINE_EVENT(spi_controller, spi_controller_idle,
 
-	TP_PROTO(struct spi_master *master),
+	TP_PROTO(struct spi_controller *controller),
 
-	TP_ARGS(master)
+	TP_ARGS(controller)
 
 );
 
-DEFINE_EVENT(spi_master, spi_master_busy,
+DEFINE_EVENT(spi_controller, spi_controller_busy,
 
-	TP_PROTO(struct spi_master *master),
+	TP_PROTO(struct spi_controller *controller),
 
-	TP_ARGS(master)
+	TP_ARGS(controller)
 
 );
 
@@ -54,7 +54,7 @@ DECLARE_EVENT_CLASS(spi_message,
 	),
 
 	TP_fast_assign(
-		__entry->bus_num = msg->spi->master->bus_num;
+		__entry->bus_num = msg->spi->controller->bus_num;
 		__entry->chip_select = msg->spi->chip_select;
 		__entry->msg = msg;
 	),
@@ -95,7 +95,7 @@ TRACE_EVENT(spi_message_done,
 	),
 
 	TP_fast_assign(
-		__entry->bus_num = msg->spi->master->bus_num;
+		__entry->bus_num = msg->spi->controller->bus_num;
 		__entry->chip_select = msg->spi->chip_select;
 		__entry->msg = msg;
 		__entry->frame = msg->frame_length;
@@ -122,7 +122,7 @@ DECLARE_EVENT_CLASS(spi_transfer,
 	),
 
 	TP_fast_assign(
-		__entry->bus_num = msg->spi->master->bus_num;
+		__entry->bus_num = msg->spi->controller->bus_num;
 		__entry->chip_select = msg->spi->chip_select;
 		__entry->xfer = xfer;
 		__entry->len = xfer->len;