diff options
| -rw-r--r-- | drivers/thermal/imx_thermal.c | 140 |
1 files changed, 127 insertions, 13 deletions
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c index c9a55b0214e5..1d6c801c1eb9 100644 --- a/drivers/thermal/imx_thermal.c +++ b/drivers/thermal/imx_thermal.c @@ -12,6 +12,7 @@ #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> @@ -31,6 +32,8 @@ #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) @@ -66,33 +69,62 @@ struct imx_thermal_data { 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; - static unsigned long last_temp; unsigned int n_meas; + bool wait; 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); + 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. */ - usleep_range(20, 50); + if (wait) + 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 (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"); @@ -104,9 +136,24 @@ static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp) /* See imx_get_sensor_data() for formula derivation */ *temp = data->c2 + data->c1 * n_meas; - if (*temp != last_temp) { + /* 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); - last_temp = *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; @@ -126,13 +173,30 @@ 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; @@ -181,6 +245,8 @@ static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip, data->temp_passive = temp; + imx_set_alarm_temp(data, temp); + return 0; } @@ -299,11 +365,34 @@ static int imx_get_sensor_data(struct platform_device *pdev) 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); @@ -318,6 +407,18 @@ static int imx_thermal_probe(struct platform_device *pdev) } 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); @@ -356,6 +457,15 @@ static int imx_thermal_probe(struct platform_device *pdev) 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; @@ -364,6 +474,10 @@ static int imx_thermal_probe(struct platform_device *pdev) 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); |