--- /dev/null
+/*
+ * 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");
projects / karo-tx-linux.git / commitdiff