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);