| /* |
| * 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"); |