thermal driverlr/mmp3-thermal-v1

3 files changed, 267 insertions, 0 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 7edc8dc6bbabe..c3369da68e5a9 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -401,6 +401,12 @@ config DA9062_THERMAL
 	  zone.
 	  Compatible with the DA9062 and DA9061 PMICs.
 
+config MMP3_THERMAL
+	tristate "MMP3 Thermal interface support"
+	depends on THERMAL
+	help
+	  Adds thermal management for Marvell MMP3.
+
 config MTK_THERMAL
 	tristate "Temperature sensor driver for mediatek SoCs"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index b64dd50a66292..c902216a86537 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -55,6 +55,7 @@ obj-y				+= st/
 obj-$(CONFIG_QCOM_TSENS)	+= qcom/
 obj-y				+= tegra/
 obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
+obj-$(CONFIG_MMP3_THERMAL)	+= mmp3_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
 obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
 obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
diff --git a/drivers/thermal/mmp3_thermal.c b/drivers/thermal/mmp3_thermal.c
new file mode 100644
index 0000000000000..aba4e15b8d07b
--- /dev/null
+++ b/drivers/thermal/mmp3_thermal.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2012 Marvell Semiconductor, Inc.
+ * Copyright 2012 One Laptop per Child
+ * Copyright 2020 Lubomir Rintel <lkundrak@v3.sk>
+ */
+
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/thermal.h>
+#include <linux/platform_device.h>
+
+struct mmp3_thermal {
+	struct device *dev;
+	struct thermal_zone_device *tz;
+	u32 __iomem *regs;
+	struct clk_bulk_data *clks;
+	int nr_clks;
+};
+
+#define TEMP_RESERVED		BIT(31) // undoc'd, appears in original marvell code
+#define TEMP_START		BIT(30)
+#define TEMP_STATUS		BIT(29)
+#define TEMP_OVER_INT		BIT(28)
+#define TEMP_LOWRANGE		BIT(27)
+#define TEMP_EN_WDOG		BIT(26)
+#define TEMP_TEMP_INT		BIT(25)
+#define TEMP_EN_OVER_INT	BIT(24)
+#define TEMP_EN_TEMP_INT	BIT(23)
+#define TEMP_AUTO_READ		BIT(21) // undoc'd, useful for watchdog but causes interrupt storm
+#define TEMP_WDOG_THSHLD	0x0f00
+#define TEMP_WDOG_SHIFT		8
+#define TEMP_INT_TSHLD_MASK	0x00f0
+#define TEMP_TEMP_VALUE_MASK	0x000f
+
+enum {
+        HIRANGE = 0,
+        LORANGE = 1,
+};
+
+static unsigned int gray_to_temp[2][16] = {{
+        780,  805,  855,  830,  955,  930,  880,  905,
+          0, 1130, 1080, 1105,  980, 1005, 1055, 1030
+}, {
+        260,  285,  335,  310,  435,  410,  360,  385,
+          0,  610,  560,  585,  460,  485,  535,  510,
+}};
+
+static DEFINE_MUTEX(mmp3_thermal_sensor_mutex);
+
+static unsigned long read_temperature_sensor(struct mmp3_thermal *priv, int range, int index)
+{
+	int i, j, gray;
+	unsigned long temp;
+	u32 val;
+
+	mutex_lock(&mmp3_thermal_sensor_mutex);
+
+	val = readl(priv->regs + index);
+
+	if (val & TEMP_EN_WDOG) {
+		if ((range == HIRANGE) == ((val & TEMP_LOWRANGE) == 0))
+			return 0;
+	}
+
+	if (range == HIRANGE) {
+		val &= ~TEMP_LOWRANGE;
+	} else {
+		val |= TEMP_LOWRANGE;
+	}
+
+	val &= ~TEMP_START;
+	writel(val, priv->regs + index);
+	usleep_range(300, 1000);
+
+	for (i = 0; i < 10; i++) {
+		writel(val | TEMP_START, priv->regs + index);
+		for (j = 0; j < 10; j++) {
+			usleep_range(300, 1000);
+			if (readl(priv->regs + index) & TEMP_STATUS)
+				goto done;
+		}
+		usleep_range(300, 1000);
+		writel(val, priv->regs + index);
+	}
+    done:
+
+	if (i == 10) {
+		printk(KERN_ERR "mmp3_thermal: timeout reading sensor %d, range %d\n",
+			index, range);
+		writel(val, priv->regs + index);
+		temp = 0;  // filtering may fix this
+	} else {
+		gray = readl(priv->regs + index) & TEMP_TEMP_VALUE_MASK;
+		temp = gray_to_temp[range][gray];
+	}
+
+	mutex_unlock(&mmp3_thermal_sensor_mutex);
+
+	return temp;	// return value is tenths, C
+}
+
+static unsigned long read_filtered_temp(struct mmp3_thermal *priv, int range, int sensor)
+{
+	int i;
+	unsigned long tvals[3];
+
+	for (i = 0; i < 3; i++)
+		tvals[i] = read_temperature_sensor(priv, range, sensor);
+
+	// sort the values 
+	if (tvals[0] > tvals[1]) swap(tvals[0], tvals[1]);
+	if (tvals[1] > tvals[2]) swap(tvals[1], tvals[2]);
+	if (tvals[0] > tvals[1]) swap(tvals[0], tvals[1]);
+
+	// return the middle value 
+	return tvals[1];
+}
+
+static int mmp3_thermal_get_temp(void *data, int *temp)
+{
+	struct mmp3_thermal *priv = data;
+	unsigned long t, t0, t1, t2;
+
+	t0 = read_filtered_temp(priv, HIRANGE, 0);
+	t1 = read_filtered_temp(priv, HIRANGE, 1);
+	t2 = read_filtered_temp(priv, HIRANGE, 2);
+        t = max(t0,t1);
+        t = max(t,t2);
+
+	if (t < 800) {
+		t0 = read_filtered_temp(priv, LORANGE, 0);
+		t1 = read_filtered_temp(priv, LORANGE, 1);
+		t2 = read_filtered_temp(priv, LORANGE, 2);
+		t = max(t0,t1);
+		t = max(t,t2);
+
+		// the sensors can't report values between 60 and 80
+		if (t > 600)
+			t = 700;
+	}
+
+	*temp = t * 100; // return value is in millidegrees C
+
+	return 0;
+}
+
+static void mmp3_thermal_set_watchdog(struct mmp3_thermal *priv, unsigned int temp)
+{
+	int range = HIRANGE;
+        int grey = 8;
+	int t = 0;
+        int r, i;
+	u32 val;
+
+        for (r = HIRANGE; r <= LORANGE; r++) {
+                for (i = 0; i < 16; i++) {
+                        if (gray_to_temp[r][i] > temp)
+                                continue;
+                        if (t > gray_to_temp[r][i])
+                                continue;
+                        range = r;
+                        grey = i;
+                        t = gray_to_temp[range][grey];
+                }
+        }
+
+	dev_info(priv->dev, "Enabling thermal watchdog at %d.%dC\n", t / 10, t % 10);
+
+	val = readl(priv->regs + 1);
+	val &= ~TEMP_LOWRANGE;
+	val |= grey << TEMP_WDOG_SHIFT;
+	val |= TEMP_AUTO_READ;
+	val |= TEMP_EN_WDOG;
+	writel(val, priv->regs + 1);
+}
+
+static const struct thermal_zone_of_device_ops mmp3_thermal_ops = {
+	.get_temp = mmp3_thermal_get_temp,
+};
+
+static int mmp3_thermal_probe(struct platform_device *pdev)
+{
+	struct mmp3_thermal *priv;
+	int index;
+	int temp;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	priv->regs = devm_of_iomap(priv->dev, dev_of_node(priv->dev), 0, NULL);
+	if (IS_ERR(priv->regs)) {
+		dev_warn(priv->dev, "Unable to get I/O range\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	priv->nr_clks = devm_clk_bulk_get_all(priv->dev, &priv->clks);
+	if (priv->nr_clks < 0) {
+		dev_warn(priv->dev, "Unable to get clocks\n");
+		return priv->nr_clks;
+	}
+
+	ret = clk_bulk_prepare_enable(priv->nr_clks, priv->clks);
+	if (ret) {
+		dev_warn(priv->dev, "Unable to enable clocks\n");
+		return ret;
+	}
+
+	for (index = 0; index < 3; index++)
+		writel(0, priv->regs + index);
+
+	priv->tz = devm_thermal_zone_of_sensor_register(priv->dev, 0, priv, &mmp3_thermal_ops);
+	if (IS_ERR(priv->tz)) {
+		dev_warn(priv->dev, "Unable to register a thermal zone\n");
+		return PTR_ERR(priv->tz);
+	}
+
+	if (priv->tz->ops->get_crit_temp(priv->tz, &temp))
+		mmp3_thermal_set_watchdog(priv, temp);
+
+	dev_info(priv->dev, "MMP3 Thermal Sensor\n");
+	return 0;
+}
+
+static int mmp3_thermal_remove(struct platform_device *pdev)
+{
+	struct mmp3_thermal *priv = platform_get_drvdata(pdev);
+
+	clk_bulk_disable_unprepare(priv->nr_clks, priv->clks);
+
+	return 0;
+}
+
+static const struct of_device_id mmp3_thermal_of_match[] = {
+	{ .compatible = "marvell,mmp3-thermal", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mmp3_thermal_of_match);
+
+static struct platform_driver mmp3_thermal_driver = {
+	.probe		= mmp3_thermal_probe,
+	.remove		= mmp3_thermal_remove,
+	.driver = {
+		.name = "mmp3-thermal",
+		.of_match_table = mmp3_thermal_of_match,
+	},
+};
+module_platform_driver(mmp3_thermal_driver);
+
+MODULE_AUTHOR("Marvell Semiconductor");
+MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
+MODULE_DESCRIPTION("MMP3 Thermal Sensor Driver");
+MODULE_LICENSE("GPL");