1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
new file mode 100644
index 000000000000..d16c33c7f3f0
--- /dev/null
+++ b/drivers/thermal/imx_thermal.c
@@ -0,0 +1,397 @@
+/*
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/cpu_cooling.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+#include <linux/types.h>
+
+#define REG_SET		0x4
+#define REG_CLR		0x8
+#define REG_TOG		0xc
+
+#define MISC0				0x0150
+#define MISC0_REFTOP_SELBIASOFF		(1 << 3)
+
+#define TEMPSENSE0			0x0180
+#define TEMPSENSE0_TEMP_CNT_SHIFT	8
+#define TEMPSENSE0_TEMP_CNT_MASK	(0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
+#define TEMPSENSE0_FINISHED		(1 << 2)
+#define TEMPSENSE0_MEASURE_TEMP		(1 << 1)
+#define TEMPSENSE0_POWER_DOWN		(1 << 0)
+
+#define TEMPSENSE1			0x0190
+#define TEMPSENSE1_MEASURE_FREQ		0xffff
+
+#define OCOTP_ANA1			0x04e0
+
+/* The driver supports 1 passive trip point and 1 critical trip point */
+enum imx_thermal_trip {
+	IMX_TRIP_PASSIVE,
+	IMX_TRIP_CRITICAL,
+	IMX_TRIP_NUM,
+};
+
+/*
+ * It defines the temperature in millicelsius for passive trip point
+ * that will trigger cooling action when crossed.
+ */
+#define IMX_TEMP_PASSIVE		85000
+
+/*
+ * The maximum die temperature on imx parts is 105C, let's give some cushion
+ * for noise and possible temperature rise between measurements.
+ */
+#define IMX_TEMP_CRITICAL		100000
+
+#define IMX_POLLING_DELAY		2000 /* millisecond */
+#define IMX_PASSIVE_DELAY		1000
+
+struct imx_thermal_data {
+	struct thermal_zone_device *tz;
+	struct thermal_cooling_device *cdev;
+	enum thermal_device_mode mode;
+	struct regmap *tempmon;
+	int c1, c2; /* See formula in imx_get_sensor_data() */
+};
+
+static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
+{
+	struct imx_thermal_data *data = tz->devdata;
+	struct regmap *map = data->tempmon;
+	static unsigned long last_temp;
+	unsigned int n_meas;
+	u32 val;
+
+	/*
+	 * Every time we measure the temperature, we will power on the
+	 * temperature sensor, enable measurements, take a reading,
+	 * disable measurements, power off the temperature sensor.
+	 */
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
+	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
+
+	/*
+	 * According to the temp sensor designers, it may require up to ~17us
+	 * to complete a measurement.
+	 */
+	usleep_range(20, 50);
+
+	regmap_read(map, TEMPSENSE0, &val);
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
+	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
+
+	if ((val & TEMPSENSE0_FINISHED) == 0) {
+		dev_dbg(&tz->device, "temp measurement never finished\n");
+		return -EAGAIN;
+	}
+
+	n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
+
+	/* See imx_get_sensor_data() for formula derivation */
+	*temp = data->c2 + data->c1 * n_meas;
+
+	if (*temp != last_temp) {
+		dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
+		last_temp = *temp;
+	}
+
+	return 0;
+}
+
+static int imx_get_mode(struct thermal_zone_device *tz,
+			enum thermal_device_mode *mode)
+{
+	struct imx_thermal_data *data = tz->devdata;
+
+	*mode = data->mode;
+
+	return 0;
+}
+
+static int imx_set_mode(struct thermal_zone_device *tz,
+			enum thermal_device_mode mode)
+{
+	struct imx_thermal_data *data = tz->devdata;
+
+	if (mode == THERMAL_DEVICE_ENABLED) {
+		tz->polling_delay = IMX_POLLING_DELAY;
+		tz->passive_delay = IMX_PASSIVE_DELAY;
+	} else {
+		tz->polling_delay = 0;
+		tz->passive_delay = 0;
+	}
+
+	data->mode = mode;
+	thermal_zone_device_update(tz);
+
+	return 0;
+}
+
+static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
+			     enum thermal_trip_type *type)
+{
+	*type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
+					     THERMAL_TRIP_CRITICAL;
+	return 0;
+}
+
+static int imx_get_crit_temp(struct thermal_zone_device *tz,
+			     unsigned long *temp)
+{
+	*temp = IMX_TEMP_CRITICAL;
+	return 0;
+}
+
+static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
+			     unsigned long *temp)
+{
+	*temp = (trip == IMX_TRIP_PASSIVE) ? IMX_TEMP_PASSIVE :
+					     IMX_TEMP_CRITICAL;
+	return 0;
+}
+
+static int imx_bind(struct thermal_zone_device *tz,
+		    struct thermal_cooling_device *cdev)
+{
+	int ret;
+
+	ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
+					       THERMAL_NO_LIMIT,
+					       THERMAL_NO_LIMIT);
+	if (ret) {
+		dev_err(&tz->device,
+			"binding zone %s with cdev %s failed:%d\n",
+			tz->type, cdev->type, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int imx_unbind(struct thermal_zone_device *tz,
+		      struct thermal_cooling_device *cdev)
+{
+	int ret;
+
+	ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
+	if (ret) {
+		dev_err(&tz->device,
+			"unbinding zone %s with cdev %s failed:%d\n",
+			tz->type, cdev->type, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct thermal_zone_device_ops imx_tz_ops = {
+	.bind = imx_bind,
+	.unbind = imx_unbind,
+	.get_temp = imx_get_temp,
+	.get_mode = imx_get_mode,
+	.set_mode = imx_set_mode,
+	.get_trip_type = imx_get_trip_type,
+	.get_trip_temp = imx_get_trip_temp,
+	.get_crit_temp = imx_get_crit_temp,
+};
+
+static int imx_get_sensor_data(struct platform_device *pdev)
+{
+	struct imx_thermal_data *data = platform_get_drvdata(pdev);
+	struct regmap *map;
+	int t1, t2, n1, n2;
+	int ret;
+	u32 val;
+
+	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+					      "fsl,tempmon-data");
+	if (IS_ERR(map)) {
+		ret = PTR_ERR(map);
+		dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_read(map, OCOTP_ANA1, &val);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
+		return ret;
+	}
+
+	if (val == 0 || val == ~0) {
+		dev_err(&pdev->dev, "invalid sensor calibration data\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Sensor data layout:
+	 *   [31:20] - sensor value @ 25C
+	 *    [19:8] - sensor value of hot
+	 *     [7:0] - hot temperature value
+	 */
+	n1 = val >> 20;
+	n2 = (val & 0xfff00) >> 8;
+	t2 = val & 0xff;
+	t1 = 25; /* t1 always 25C */
+
+	/*
+	 * Derived from linear interpolation,
+	 * Tmeas = T2 + (Nmeas - N2) * (T1 - T2) / (N1 - N2)
+	 * We want to reduce this down to the minimum computation necessary
+	 * for each temperature read.  Also, we want Tmeas in millicelsius
+	 * and we don't want to lose precision from integer division. So...
+	 * milli_Tmeas = 1000 * T2 + 1000 * (Nmeas - N2) * (T1 - T2) / (N1 - N2)
+	 * Let constant c1 = 1000 * (T1 - T2) / (N1 - N2)
+	 * milli_Tmeas = (1000 * T2) + c1 * (Nmeas - N2)
+	 * milli_Tmeas = (1000 * T2) + (c1 * Nmeas) - (c1 * N2)
+	 * Let constant c2 = (1000 * T2) - (c1 * N2)
+	 * milli_Tmeas = c2 + (c1 * Nmeas)
+	 */
+	data->c1 = 1000 * (t1 - t2) / (n1 - n2);
+	data->c2 = 1000 * t2 - data->c1 * n2;
+
+	return 0;
+}
+
+static int imx_thermal_probe(struct platform_device *pdev)
+{
+	struct imx_thermal_data *data;
+	struct cpumask clip_cpus;
+	struct regmap *map;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
+	if (IS_ERR(map)) {
+		ret = PTR_ERR(map);
+		dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
+		return ret;
+	}
+	data->tempmon = map;
+
+	platform_set_drvdata(pdev, data);
+
+	ret = imx_get_sensor_data(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get sensor data\n");
+		return ret;
+	}
+
+	/* Make sure sensor is in known good state for measurements */
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
+	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
+	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
+	regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
+	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
+
+	cpumask_set_cpu(0, &clip_cpus);
+	data->cdev = cpufreq_cooling_register(&clip_cpus);
+	if (IS_ERR(data->cdev)) {
+		ret = PTR_ERR(data->cdev);
+		dev_err(&pdev->dev,
+			"failed to register cpufreq cooling device: %d\n", ret);
+		return ret;
+	}
+
+	data->tz = thermal_zone_device_register("imx_thermal_zone",
+						IMX_TRIP_NUM, 0, data,
+						&imx_tz_ops, NULL,
+						IMX_PASSIVE_DELAY,
+						IMX_POLLING_DELAY);
+	if (IS_ERR(data->tz)) {
+		ret = PTR_ERR(data->tz);
+		dev_err(&pdev->dev,
+			"failed to register thermal zone device %d\n", ret);
+		cpufreq_cooling_unregister(data->cdev);
+		return ret;
+	}
+
+	data->mode = THERMAL_DEVICE_ENABLED;
+
+	return 0;
+}
+
+static int imx_thermal_remove(struct platform_device *pdev)
+{
+	struct imx_thermal_data *data = platform_get_drvdata(pdev);
+
+	thermal_zone_device_unregister(data->tz);
+	cpufreq_cooling_unregister(data->cdev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int imx_thermal_suspend(struct device *dev)
+{
+	struct imx_thermal_data *data = dev_get_drvdata(dev);
+	struct regmap *map = data->tempmon;
+	u32 val;
+
+	regmap_read(map, TEMPSENSE0, &val);
+	if ((val & TEMPSENSE0_POWER_DOWN) == 0) {
+		/*
+		 * If a measurement is taking place, wait for a long enough
+		 * time for it to finish, and then check again.  If it still
+		 * does not finish, something must go wrong.
+		 */
+		udelay(50);
+		regmap_read(map, TEMPSENSE0, &val);
+		if ((val & TEMPSENSE0_POWER_DOWN) == 0)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int imx_thermal_resume(struct device *dev)
+{
+	/* Nothing to do for now */
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
+			 imx_thermal_suspend, imx_thermal_resume);
+
+static const struct of_device_id of_imx_thermal_match[] = {
+	{ .compatible = "fsl,imx6q-tempmon", },
+	{ /* end */ }
+};
+
+static struct platform_driver imx_thermal = {
+	.driver = {
+		.name	= "imx_thermal",
+		.owner  = THIS_MODULE,
+		.pm	= &imx_thermal_pm_ops,
+		.of_match_table = of_imx_thermal_match,
+	},
+	.probe		= imx_thermal_probe,
+	.remove		= imx_thermal_remove,
+};
+module_platform_driver(imx_thermal);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:imx-thermal");