diff options
Diffstat (limited to 'drivers/thermal/imx_thermal.c')
| -rw-r--r-- | drivers/thermal/imx_thermal.c | 111 |
1 files changed, 72 insertions, 39 deletions
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c index 1d6c801c1eb..2c516f2eebe 100644 --- a/drivers/thermal/imx_thermal.c +++ b/drivers/thermal/imx_thermal.c @@ -7,6 +7,7 @@ * */ +#include <linux/clk.h> #include <linux/cpu_cooling.h> #include <linux/cpufreq.h> #include <linux/delay.h> @@ -61,18 +62,23 @@ enum imx_thermal_trip { #define IMX_POLLING_DELAY 2000 /* millisecond */ #define IMX_PASSIVE_DELAY 1000 +#define FACTOR0 10000000 +#define FACTOR1 15976 +#define FACTOR2 4297157 + 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() */ + u32 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; + struct clk *thermal_clk; }; static void imx_set_alarm_temp(struct imx_thermal_data *data, @@ -82,7 +88,7 @@ static void imx_set_alarm_temp(struct imx_thermal_data *data, int alarm_value; data->alarm_temp = alarm_temp; - alarm_value = (alarm_temp - data->c2) / data->c1; + alarm_value = (data->c2 - alarm_temp) / data->c1; regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK); regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value << TEMPSENSE0_ALARM_VALUE_SHIFT); @@ -134,7 +140,7 @@ static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp) 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; + *temp = data->c2 - n_meas * data->c1; /* Update alarm value to next higher trip point */ if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive) @@ -284,7 +290,7 @@ static int imx_unbind(struct thermal_zone_device *tz, return 0; } -static const struct thermal_zone_device_ops imx_tz_ops = { +static struct thermal_zone_device_ops imx_tz_ops = { .bind = imx_bind, .unbind = imx_unbind, .get_temp = imx_get_temp, @@ -300,9 +306,10 @@ 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 t1, n1; int ret; u32 val; + u64 temp64; map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon-data"); @@ -326,41 +333,45 @@ static int imx_get_sensor_data(struct platform_device *pdev) /* * Sensor data layout: * [31:20] - sensor value @ 25C - * [19:8] - sensor value of hot - * [7:0] - hot temperature value + * Use universal formula now and only need sensor value @ 25C + * slope = 0.4297157 - (0.0015976 * 25C fuse) */ 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) + * Derived from linear interpolation: + * slope = 0.4297157 - (0.0015976 * 25C fuse) + * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0 + * (Nmeas - n1) / (Tmeas - t1) = slope * 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) + * Tmeas = (Nmeas - n1) / slope + t1 + * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1 + * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1 + * Let constant c1 = (-1000 / slope) + * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1 + * Let constant c2 = n1 *c1 + 1000 * t1 + * milli_Tmeas = c2 - Nmeas * c1 */ - data->c1 = 1000 * (t1 - t2) / (n1 - n2); - data->c2 = 1000 * t2 - data->c1 * n2; + temp64 = FACTOR0; + temp64 *= 1000; + do_div(temp64, FACTOR1 * n1 - FACTOR2); + data->c1 = temp64; + data->c2 = n1 * data->c1 + 1000 * t1; /* - * Set the default passive cooling trip point to 20 °C below the - * maximum die temperature. Can be changed from userspace. + * Set the default passive cooling trip point, + * can be changed from userspace. */ - data->temp_passive = 1000 * (t2 - 20); + data->temp_passive = IMX_TEMP_PASSIVE; /* - * The maximum die temperature is t2, let's give 5 °C cushion - * for noise and possible temperature rise between measurements. + * The maximum die temperature set to 20 C higher than + * IMX_TEMP_PASSIVE. */ - data->temp_critical = 1000 * (t2 - 5); + data->temp_critical = 1000 * 20 + data->temp_passive; return 0; } @@ -457,6 +468,22 @@ static int imx_thermal_probe(struct platform_device *pdev) return ret; } + data->thermal_clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(data->thermal_clk)) { + dev_warn(&pdev->dev, "failed to get thermal clk!\n"); + } else { + /* + * Thermal sensor needs clk on to get correct value, normally + * we should enable its clk before taking measurement and disable + * clk after measurement is done, but if alarm function is enabled, + * hardware will auto measure the temperature periodically, so we + * need to keep the clk always on for alarm function. + */ + ret = clk_prepare_enable(data->thermal_clk); + if (ret) + dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret); + } + /* Enable measurements at ~ 10 Hz */ regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ); measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */ @@ -478,6 +505,8 @@ static int imx_thermal_remove(struct platform_device *pdev) /* Disable measurements */ regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); + if (!IS_ERR(data->thermal_clk)) + clk_disable_unprepare(data->thermal_clk); thermal_zone_device_unregister(data->tz); cpufreq_cooling_unregister(data->cdev); @@ -490,27 +519,30 @@ 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; - } + /* + * Need to disable thermal sensor, otherwise, when thermal core + * try to get temperature before thermal sensor resume, a wrong + * temperature will be read as the thermal sensor is powered + * down. + */ + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP); + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN); + data->mode = THERMAL_DEVICE_DISABLED; return 0; } static int imx_thermal_resume(struct device *dev) { - /* Nothing to do for now */ + struct imx_thermal_data *data = dev_get_drvdata(dev); + struct regmap *map = data->tempmon; + + /* Enabled thermal sensor after resume */ + regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN); + regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP); + data->mode = THERMAL_DEVICE_ENABLED; + return 0; } #endif @@ -522,6 +554,7 @@ static const struct of_device_id of_imx_thermal_match[] = { { .compatible = "fsl,imx6q-tempmon", }, { /* end */ } }; +MODULE_DEVICE_TABLE(of, of_imx_thermal_match); static struct platform_driver imx_thermal = { .driver = { |