diff options
Diffstat (limited to 'drivers/thermal/imx_thermal.c')
| -rw-r--r-- | drivers/thermal/imx_thermal.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c new file mode 100644 index 000000000000..1d6c801c1eb9 --- /dev/null +++ b/drivers/thermal/imx_thermal.c @@ -0,0 +1,541 @@ +/* + * 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/interrupt.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_ALARM_VALUE_SHIFT 20 +#define TEMPSENSE0_ALARM_VALUE_MASK (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT) +#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 + +#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() */ + unsigned long temp_passive; + unsigned long temp_critical; + unsigned long alarm_temp; + unsigned long last_temp; + bool irq_enabled; + int irq; +}; + +static void imx_set_alarm_temp(struct imx_thermal_data *data, + signed long alarm_temp) +{ + struct regmap *map = data->tempmon; + int alarm_value; + + data->alarm_temp = alarm_temp; + alarm_value = (alarm_temp - data->c2) / data->c1; + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK); + regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value << + TEMPSENSE0_ALARM_VALUE_SHIFT); +} + +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; + unsigned int n_meas; + bool wait; + u32 val; + + if (data->mode == THERMAL_DEVICE_ENABLED) { + /* Check if a measurement is currently in progress */ + regmap_read(map, TEMPSENSE0, &val); + wait = !(val & TEMPSENSE0_FINISHED); + } else { + /* + * 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); + + wait = true; + } + + /* + * According to the temp sensor designers, it may require up to ~17us + * to complete a measurement. + */ + if (wait) + usleep_range(20, 50); + + regmap_read(map, TEMPSENSE0, &val); + + if (data->mode != THERMAL_DEVICE_ENABLED) { + 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; + + /* Update alarm value to next higher trip point */ + if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive) + imx_set_alarm_temp(data, data->temp_critical); + if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) { + imx_set_alarm_temp(data, data->temp_passive); + dev_dbg(&tz->device, "thermal alarm off: T < %lu\n", + data->alarm_temp / 1000); + } + + if (*temp != data->last_temp) { + dev_dbg(&tz->device, "millicelsius: %ld\n", *temp); + data->last_temp = *temp; + } + + /* Reenable alarm IRQ if temperature below alarm temperature */ + if (!data->irq_enabled && *temp < data->alarm_temp) { + data->irq_enabled = true; + enable_irq(data->irq); + } + + 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; + struct regmap *map = data->tempmon; + + if (mode == THERMAL_DEVICE_ENABLED) { + tz->polling_delay = IMX_POLLING_DELAY; + tz->passive_delay = IMX_PASSIVE_DELAY; + + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); + + if (!data->irq_enabled) { + data->irq_enabled = true; + enable_irq(data->irq); + } + } else { + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); + + tz->polling_delay = 0; + tz->passive_delay = 0; + + if (data->irq_enabled) { + disable_irq(data->irq); + data->irq_enabled = false; + } + } + + 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) +{ + struct imx_thermal_data *data = tz->devdata; + + *temp = data->temp_critical; + return 0; +} + +static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip, + unsigned long *temp) +{ + struct imx_thermal_data *data = tz->devdata; + + *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive : + data->temp_critical; + return 0; +} + +static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip, + unsigned long temp) +{ + struct imx_thermal_data *data = tz->devdata; + + if (trip == IMX_TRIP_CRITICAL) + return -EPERM; + + if (temp > IMX_TEMP_PASSIVE) + return -EINVAL; + + data->temp_passive = temp; + + imx_set_alarm_temp(data, temp); + + 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, + .set_trip_temp = imx_set_trip_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; + + /* + * Set the default passive cooling trip point to 20 °C below the + * maximum die temperature. Can be changed from userspace. + */ + data->temp_passive = 1000 * (t2 - 20); + + /* + * The maximum die temperature is t2, let's give 5 °C cushion + * for noise and possible temperature rise between measurements. + */ + data->temp_critical = 1000 * (t2 - 5); + + return 0; +} + +static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev) +{ + struct imx_thermal_data *data = dev; + + disable_irq_nosync(irq); + data->irq_enabled = false; + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev) +{ + struct imx_thermal_data *data = dev; + + dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n", + data->alarm_temp / 1000); + + thermal_zone_device_update(data->tz); + + return IRQ_HANDLED; +} + +static int imx_thermal_probe(struct platform_device *pdev) +{ + struct imx_thermal_data *data; + struct cpumask clip_cpus; + struct regmap *map; + int measure_freq; + 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; + + data->irq = platform_get_irq(pdev, 0); + if (data->irq < 0) + return data->irq; + + ret = devm_request_threaded_irq(&pdev->dev, data->irq, + imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread, + 0, "imx_thermal", data); + if (ret < 0) { + dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret); + return ret; + } + + 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, + BIT(IMX_TRIP_PASSIVE), 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; + } + + /* Enable measurements at ~ 10 Hz */ + regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ); + measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */ + regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq); + imx_set_alarm_temp(data, data->temp_passive); + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); + + data->irq_enabled = true; + 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); + struct regmap *map = data->tempmon; + + /* Disable measurements */ + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); + + 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"); |