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authorDavid Brownell <david-b@pacbell.net>2006-06-18 16:39:33 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-06-18 16:39:33 +0100
commit9df5db80a781c1a1c67388c82f64f835093c3cc3 (patch)
tree65f80286fefe7a85a1d2cdb74a9befdcf9084564
parentebc67da65fda03cbe5b4019d91229287fddd5c6e (diff)
downloadlinux-9df5db80a781c1a1c67388c82f64f835093c3cc3.tar.gz
[ARM] 3534/1: add spi support to lubbock platform
Patch from David Brownell This adds the platform device for SSP/SPI controller, and declares the ads7846 device hooked up to it. Not all Lubbock boards appear to populate the connector needed to use this instead of the ucb1400 chip, but it can always be used as a temperature sensor. In short, this is probably most useful as an example of how to provide the configuration data used by the pxa2xx_spi driver. (Last tested against a slightly earlier version of that driver.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mach-pxa/lubbock.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/lubbock.c b/arch/arm/mach-pxa/lubbock.c
index 3e26d7ce5bb28..1ab26c6914f25 100644
--- a/arch/arm/mach-pxa/lubbock.c
+++ b/arch/arm/mach-pxa/lubbock.c
@@ -22,6 +22,10 @@
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
+#include <asm/arch/pxa2xx_spi.h>
+
#include <asm/setup.h>
#include <asm/memory.h>
#include <asm/mach-types.h>
@@ -196,6 +200,78 @@ static struct resource smc91x_resources[] = {
},
};
+/* ADS7846 is connected through SSP ... and if your board has J5 populated,
+ * you can select it to replace the ucb1400 by switching the touchscreen cable
+ * (to J5) and poking board registers (as done below). Else it's only useful
+ * for the temperature sensors.
+ */
+static struct resource pxa_ssp_resources[] = {
+ [0] = {
+ .start = __PREG(SSCR0_P(1)),
+ .end = __PREG(SSCR0_P(1)) + 0x14,
+ .flags = IORESOURCE_MEM,
+ },
+ [1] = {
+ .start = IRQ_SSP,
+ .end = IRQ_SSP,
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+static struct pxa2xx_spi_master pxa_ssp_master_info = {
+ .ssp_type = PXA25x_SSP,
+ .clock_enable = CKEN3_SSP,
+ .num_chipselect = 0,
+};
+
+static struct platform_device pxa_ssp = {
+ .name = "pxa2xx-spi",
+ .id = 1,
+ .resource = pxa_ssp_resources,
+ .num_resources = ARRAY_SIZE(pxa_ssp_resources),
+ .dev = {
+ .platform_data = &pxa_ssp_master_info,
+ },
+};
+
+static int lubbock_ads7846_pendown_state(void)
+{
+ /* TS_BUSY is bit 8 in LUB_MISC_RD, but pendown is irq-only */
+ return 0;
+}
+
+static struct ads7846_platform_data ads_info = {
+ .model = 7846,
+ .vref_delay_usecs = 100, /* internal, no cap */
+ .get_pendown_state = lubbock_ads7846_pendown_state,
+ // .x_plate_ohms = 500, /* GUESS! */
+ // .y_plate_ohms = 500, /* GUESS! */
+};
+
+static void ads7846_cs(u32 command)
+{
+ static const unsigned TS_nCS = 1 << 11;
+ lubbock_set_misc_wr(TS_nCS, (command == PXA2XX_CS_ASSERT) ? 0 : TS_nCS);
+}
+
+static struct pxa2xx_spi_chip ads_hw = {
+ .tx_threshold = 1,
+ .rx_threshold = 2,
+ .cs_control = ads7846_cs,
+};
+
+static struct spi_board_info spi_board_info[] __initdata = { {
+ .modalias = "ads7846",
+ .platform_data = &ads_info,
+ .controller_data = &ads_hw,
+ .irq = LUBBOCK_BB_IRQ,
+ .max_speed_hz = 120000 /* max sample rate at 3V */
+ * 26 /* command + data + overhead */,
+ .bus_num = 1,
+ .chip_select = 0,
+},
+};
+
static struct platform_device smc91x_device = {
.name = "smc91x",
.id = -1,
@@ -272,6 +348,7 @@ static struct platform_device *devices[] __initdata = {
&smc91x_device,
&lubbock_flash_device[0],
&lubbock_flash_device[1],
+ &pxa_ssp,
};
static struct pxafb_mach_info sharp_lm8v31 __initdata = {
@@ -400,6 +477,8 @@ static void __init lubbock_init(void)
lubbock_flash_data[flashboot^1].name = "application-flash";
lubbock_flash_data[flashboot].name = "boot-rom";
(void) platform_add_devices(devices, ARRAY_SIZE(devices));
+
+ spi_register_board_info(spi_board_info, ARRAY_SIZE(spi_board_info));
}
static struct map_desc lubbock_io_desc[] __initdata = {
@@ -416,6 +495,11 @@ static void __init lubbock_map_io(void)
pxa_map_io();
iotable_init(lubbock_io_desc, ARRAY_SIZE(lubbock_io_desc));
+ /* SSP data pins */
+ pxa_gpio_mode(GPIO23_SCLK_MD);
+ pxa_gpio_mode(GPIO25_STXD_MD);
+ pxa_gpio_mode(GPIO26_SRXD_MD);
+
/* This enables the BTUART */
pxa_gpio_mode(GPIO42_BTRXD_MD);
pxa_gpio_mode(GPIO43_BTTXD_MD);