[3/3,v3] thermal: db8500: Rewrite to be a pure OF sensor

diff --git a/drivers/thermal/db8500_thermal.c b/drivers/thermal/db8500_thermal.c
index d250bcf3c10c..459fd6ceb075 100644
--- a/drivers/thermal/db8500_thermal.c
+++ b/drivers/thermal/db8500_thermal.c
@@ -3,9 +3,9 @@ 
  * db8500_thermal.c - DB8500 Thermal Management Implementation
  *
  * Copyright (C) 2012 ST-Ericsson
- * Copyright (C) 2012 Linaro Ltd.
+ * Copyright (C) 2012-2019 Linaro Ltd.
  *
- * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
+ * Authors: Hongbo Zhang, Linus Walleij
  */
 
 #include <linux/cpu_cooling.h>
@@ -19,458 +19,231 @@ 
 
 #define PRCMU_DEFAULT_MEASURE_TIME	0xFFF
 #define PRCMU_DEFAULT_LOW_TEMP		0
-#define COOLING_DEV_MAX 8
 
-struct db8500_trip_point {
-	unsigned long temp;
-	enum thermal_trip_type type;
-	char cdev_name[COOLING_DEV_MAX][THERMAL_NAME_LENGTH];
-};
-
-struct db8500_thsens_platform_data {
-	struct db8500_trip_point trip_points[THERMAL_MAX_TRIPS];
-	int num_trips;
+/**
+ * db8500_thermal_points - the interpolation points that trigger
+ * interrupts
+ */
+static const unsigned long db8500_thermal_points[] = {
+	15000,
+	20000,
+	25000,
+	30000,
+	35000,
+	40000,
+	45000,
+	50000,
+	55000,
+	60000,
+	65000,
+	70000,
+	75000,
+	80000,
+	/*
+	 * This is where things start to get really bad for the
+	 * SoC and the thermal zones should be set up to trigger
+	 * critical temperature at 85000 mC so we don't get above
+	 * this point.
+	 */
+	85000,
+	90000,
+	95000,
+	100000,
 };
 
 struct db8500_thermal_zone {
-	struct thermal_zone_device *therm_dev;
-	struct mutex th_lock;
-	struct work_struct therm_work;
-	struct db8500_thsens_platform_data *trip_tab;
-	enum thermal_device_mode mode;
+	struct thermal_zone_device *tz;
+	struct work_struct work;
 	enum thermal_trend trend;
-	unsigned long cur_temp_pseudo;
+	unsigned long interpolated_temp;
 	unsigned int cur_index;
 };
 
-/* Local function to check if thermal zone matches cooling devices */
-static int db8500_thermal_match_cdev(struct thermal_cooling_device *cdev,
-		struct db8500_trip_point *trip_point)
-{
-	int i;
-
-	if (!strlen(cdev->type))
-		return -EINVAL;
-
-	for (i = 0; i < COOLING_DEV_MAX; i++) {
-		if (!strcmp(trip_point->cdev_name[i], cdev->type))
-			return 0;
-	}
-
-	return -ENODEV;
-}
-
-/* Callback to bind cooling device to thermal zone */
-static int db8500_cdev_bind(struct thermal_zone_device *thermal,
-		struct thermal_cooling_device *cdev)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	unsigned long max_state, upper, lower;
-	int i, ret = -EINVAL;
-
-	cdev->ops->get_max_state(cdev, &max_state);
-
-	for (i = 0; i < ptrips->num_trips; i++) {
-		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
-			continue;
-
-		upper = lower = i > max_state ? max_state : i;
-
-		ret = thermal_zone_bind_cooling_device(thermal, i, cdev,
-			upper, lower, THERMAL_WEIGHT_DEFAULT);
-
-		dev_info(&cdev->device, "%s bind to %d: %d-%s\n", cdev->type,
-			i, ret, ret ? "fail" : "succeed");
-	}
-
-	return ret;
-}
-
-/* Callback to unbind cooling device from thermal zone */
-static int db8500_cdev_unbind(struct thermal_zone_device *thermal,
-		struct thermal_cooling_device *cdev)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	int i, ret = -EINVAL;
-
-	for (i = 0; i < ptrips->num_trips; i++) {
-		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
-			continue;
-
-		ret = thermal_zone_unbind_cooling_device(thermal, i, cdev);
-
-		dev_info(&cdev->device, "%s unbind from %d: %s\n", cdev->type,
-			i, ret ? "fail" : "succeed");
-	}
-
-	return ret;
-}
-
 /* Callback to get current temperature */
-static int db8500_sys_get_temp(struct thermal_zone_device *thermal, int *temp)
+static int db8500_thermal_get_temp(void *data, int *temp)
 {
-	struct db8500_thermal_zone *pzone = thermal->devdata;
+	struct db8500_thermal_zone *th = data;
 
 	/*
 	 * TODO: There is no PRCMU interface to get temperature data currently,
 	 * so a pseudo temperature is returned , it works for thermal framework
 	 * and this will be fixed when the PRCMU interface is available.
 	 */
-	*temp = pzone->cur_temp_pseudo;
+	*temp = th->interpolated_temp;
 
 	return 0;
 }
 
 /* Callback to get temperature changing trend */
-static int db8500_sys_get_trend(struct thermal_zone_device *thermal,
-		int trip, enum thermal_trend *trend)
+static int db8500_thermal_get_trend(void *data, int trip, enum thermal_trend *trend)
 {
-	struct db8500_thermal_zone *pzone = thermal->devdata;
+	struct db8500_thermal_zone *th = data;
 
-	*trend = pzone->trend;
+	*trend = th->trend;
 
 	return 0;
 }
 
-/* Callback to get thermal zone mode */
-static int db8500_sys_get_mode(struct thermal_zone_device *thermal,
-		enum thermal_device_mode *mode)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-
-	mutex_lock(&pzone->th_lock);
-	*mode = pzone->mode;
-	mutex_unlock(&pzone->th_lock);
-
-	return 0;
-}
-
-/* Callback to set thermal zone mode */
-static int db8500_sys_set_mode(struct thermal_zone_device *thermal,
-		enum thermal_device_mode mode)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-
-	mutex_lock(&pzone->th_lock);
-
-	pzone->mode = mode;
-	if (mode == THERMAL_DEVICE_ENABLED)
-		schedule_work(&pzone->therm_work);
-
-	mutex_unlock(&pzone->th_lock);
-
-	return 0;
-}
-
-/* Callback to get trip point type */
-static int db8500_sys_get_trip_type(struct thermal_zone_device *thermal,
-		int trip, enum thermal_trip_type *type)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-
-	if (trip >= ptrips->num_trips)
-		return -EINVAL;
-
-	*type = ptrips->trip_points[trip].type;
-
-	return 0;
-}
-
-/* Callback to get trip point temperature */
-static int db8500_sys_get_trip_temp(struct thermal_zone_device *thermal,
-		int trip, int *temp)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-
-	if (trip >= ptrips->num_trips)
-		return -EINVAL;
-
-	*temp = ptrips->trip_points[trip].temp;
-
-	return 0;
-}
-
-/* Callback to get critical trip point temperature */
-static int db8500_sys_get_crit_temp(struct thermal_zone_device *thermal,
-		int *temp)
-{
-	struct db8500_thermal_zone *pzone = thermal->devdata;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	int i;
-
-	for (i = ptrips->num_trips - 1; i > 0; i--) {
-		if (ptrips->trip_points[i].type == THERMAL_TRIP_CRITICAL) {
-			*temp = ptrips->trip_points[i].temp;
-			return 0;
-		}
-	}
-
-	return -EINVAL;
-}
-
-static struct thermal_zone_device_ops thdev_ops = {
-	.bind = db8500_cdev_bind,
-	.unbind = db8500_cdev_unbind,
-	.get_temp = db8500_sys_get_temp,
-	.get_trend = db8500_sys_get_trend,
-	.get_mode = db8500_sys_get_mode,
-	.set_mode = db8500_sys_set_mode,
-	.get_trip_type = db8500_sys_get_trip_type,
-	.get_trip_temp = db8500_sys_get_trip_temp,
-	.get_crit_temp = db8500_sys_get_crit_temp,
+static struct thermal_zone_of_device_ops thdev_ops = {
+	.get_temp = db8500_thermal_get_temp,
+	.get_trend = db8500_thermal_get_trend,
 };
 
-static void db8500_thermal_update_config(struct db8500_thermal_zone *pzone,
-		unsigned int idx, enum thermal_trend trend,
-		unsigned long next_low, unsigned long next_high)
+static void db8500_thermal_update_config(struct db8500_thermal_zone *th,
+					 unsigned int idx,
+					 enum thermal_trend trend,
+					 unsigned long next_low,
+					 unsigned long next_high)
 {
 	prcmu_stop_temp_sense();
 
-	pzone->cur_index = idx;
-	pzone->cur_temp_pseudo = (next_low + next_high)/2;
-	pzone->trend = trend;
+	th->cur_index = idx;
+	th->interpolated_temp = (next_low + next_high)/2;
+	th->trend = trend;
 
+	/*
+	 * The PRCMU accept absolute temperatures in celsius so divide
+	 * down the millicelsius with 1000
+	 */
 	prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
 	prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
 }
 
 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
 {
-	struct db8500_thermal_zone *pzone = irq_data;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	unsigned int idx = pzone->cur_index;
+	struct db8500_thermal_zone *th = irq_data;
+	unsigned int idx = th->cur_index;
 	unsigned long next_low, next_high;
 
-	if (unlikely(idx == 0))
+	if (idx == 0)
 		/* Meaningless for thermal management, ignoring it */
 		return IRQ_HANDLED;
 
 	if (idx == 1) {
-		next_high = ptrips->trip_points[0].temp;
+		next_high = db8500_thermal_points[0];
 		next_low = PRCMU_DEFAULT_LOW_TEMP;
 	} else {
-		next_high = ptrips->trip_points[idx-1].temp;
-		next_low = ptrips->trip_points[idx-2].temp;
+		next_high = db8500_thermal_points[idx - 1];
+		next_low = db8500_thermal_points[idx - 2];
 	}
 	idx -= 1;
 
-	db8500_thermal_update_config(pzone, idx, THERMAL_TREND_DROPPING,
-		next_low, next_high);
-
-	dev_dbg(&pzone->therm_dev->device,
+	db8500_thermal_update_config(th, idx, THERMAL_TREND_DROPPING,
+				     next_low, next_high);
+	dev_dbg(&th->tz->device,
 		"PRCMU set max %ld, min %ld\n", next_high, next_low);
 
-	schedule_work(&pzone->therm_work);
+	schedule_work(&th->work);
 
 	return IRQ_HANDLED;
 }
 
 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
 {
-	struct db8500_thermal_zone *pzone = irq_data;
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	unsigned int idx = pzone->cur_index;
+	struct db8500_thermal_zone *th = irq_data;
+	unsigned int idx = th->cur_index;
 	unsigned long next_low, next_high;
+	int num_points = ARRAY_SIZE(db8500_thermal_points);
 
-	if (idx < ptrips->num_trips - 1) {
-		next_high = ptrips->trip_points[idx+1].temp;
-		next_low = ptrips->trip_points[idx].temp;
+	if (idx < num_points - 1) {
+		next_high = db8500_thermal_points[idx+1];
+		next_low = db8500_thermal_points[idx];
 		idx += 1;
 
-		db8500_thermal_update_config(pzone, idx, THERMAL_TREND_RAISING,
-			next_low, next_high);
+		db8500_thermal_update_config(th, idx, THERMAL_TREND_RAISING,
+					     next_low, next_high);
 
-		dev_dbg(&pzone->therm_dev->device,
-		"PRCMU set max %ld, min %ld\n", next_high, next_low);
-	} else if (idx == ptrips->num_trips - 1)
-		pzone->cur_temp_pseudo = ptrips->trip_points[idx].temp + 1;
+		dev_info(&th->tz->device,
+			 "PRCMU set max %ld, min %ld\n", next_high, next_low);
+	} else if (idx == num_points - 1)
+		/* So we roof out 1 degree over the max point */
+		th->interpolated_temp = db8500_thermal_points[idx] + 1;
 
-	schedule_work(&pzone->therm_work);
+	schedule_work(&th->work);
 
 	return IRQ_HANDLED;
 }
 
+/**
+ * db8500_thermal_work - work to update the thermal zone
+ * @work: the work to perform
+ *
+ * This work is scheduled at each IRQ from the PRCMU when passing a measure
+ * point upward or downward, as well as after system resume.
+ */
 static void db8500_thermal_work(struct work_struct *work)
 {
-	enum thermal_device_mode cur_mode;
-	struct db8500_thermal_zone *pzone;
-
-	pzone = container_of(work, struct db8500_thermal_zone, therm_work);
+	struct db8500_thermal_zone *th;
 
-	mutex_lock(&pzone->th_lock);
-	cur_mode = pzone->mode;
-	mutex_unlock(&pzone->th_lock);
+	th = container_of(work, struct db8500_thermal_zone, work);
 
-	if (cur_mode == THERMAL_DEVICE_DISABLED)
-		return;
-
-	thermal_zone_device_update(pzone->therm_dev, THERMAL_EVENT_UNSPECIFIED);
-	dev_dbg(&pzone->therm_dev->device, "thermal work finished.\n");
-}
-
-static struct db8500_thsens_platform_data*
-		db8500_thermal_parse_dt(struct device *dev)
-{
-	struct db8500_thsens_platform_data *ptrips;
-	struct device_node *np = dev->of_node;
-	char prop_name[32];
-	const char *tmp_str;
-	u32 tmp_data;
-	int i, j;
-
-	ptrips = devm_kzalloc(dev, sizeof(*ptrips), GFP_KERNEL);
-	if (!ptrips)
-		return NULL;
-
-	if (of_property_read_u32(np, "num-trips", &tmp_data))
-		goto err_parse_dt;
-
-	if (tmp_data > THERMAL_MAX_TRIPS)
-		goto err_parse_dt;
-
-	ptrips->num_trips = tmp_data;
-
-	for (i = 0; i < ptrips->num_trips; i++) {
-		sprintf(prop_name, "trip%d-temp", i);
-		if (of_property_read_u32(np, prop_name, &tmp_data))
-			goto err_parse_dt;
-
-		ptrips->trip_points[i].temp = tmp_data;
-
-		sprintf(prop_name, "trip%d-type", i);
-		if (of_property_read_string(np, prop_name, &tmp_str))
-			goto err_parse_dt;
-
-		if (!strcmp(tmp_str, "active"))
-			ptrips->trip_points[i].type = THERMAL_TRIP_ACTIVE;
-		else if (!strcmp(tmp_str, "passive"))
-			ptrips->trip_points[i].type = THERMAL_TRIP_PASSIVE;
-		else if (!strcmp(tmp_str, "hot"))
-			ptrips->trip_points[i].type = THERMAL_TRIP_HOT;
-		else if (!strcmp(tmp_str, "critical"))
-			ptrips->trip_points[i].type = THERMAL_TRIP_CRITICAL;
-		else
-			goto err_parse_dt;
-
-		sprintf(prop_name, "trip%d-cdev-num", i);
-		if (of_property_read_u32(np, prop_name, &tmp_data))
-			goto err_parse_dt;
-
-		if (tmp_data > COOLING_DEV_MAX)
-			goto err_parse_dt;
-
-		for (j = 0; j < tmp_data; j++) {
-			sprintf(prop_name, "trip%d-cdev-name%d", i, j);
-			if (of_property_read_string(np, prop_name, &tmp_str))
-				goto err_parse_dt;
-
-			if (strlen(tmp_str) >= THERMAL_NAME_LENGTH)
-				goto err_parse_dt;
-
-			strcpy(ptrips->trip_points[i].cdev_name[j], tmp_str);
-		}
-	}
-	return ptrips;
-
-err_parse_dt:
-	dev_err(dev, "Parsing device tree data error.\n");
-	return NULL;
+	thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
+	dev_dbg(&th->tz->device, "thermal work updated thermal zone\n");
 }
 
 static int db8500_thermal_probe(struct platform_device *pdev)
 {
-	struct db8500_thermal_zone *pzone = NULL;
-	struct db8500_thsens_platform_data *ptrips = NULL;
+	struct db8500_thermal_zone *th = NULL;
 	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
 	int low_irq, high_irq, ret = 0;
-	unsigned long dft_low, dft_high;
-
-	if (!np)
-		return -EINVAL;
-
-	ptrips = db8500_thermal_parse_dt(dev);
-	if (!ptrips)
-		return -EINVAL;
 
-	pzone = devm_kzalloc(dev, sizeof(*pzone), GFP_KERNEL);
-	if (!pzone)
+	th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL);
+	if (!th)
 		return -ENOMEM;
 
-	mutex_init(&pzone->th_lock);
-	mutex_lock(&pzone->th_lock);
-
-	pzone->mode = THERMAL_DEVICE_DISABLED;
-	pzone->trip_tab = ptrips;
-
-	INIT_WORK(&pzone->therm_work, db8500_thermal_work);
+	INIT_WORK(&th->work, db8500_thermal_work);
 
 	low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
 	if (low_irq < 0) {
-		dev_err(dev, "Get IRQ_HOTMON_LOW failed.\n");
-		ret = low_irq;
-		goto out_unlock;
+		dev_err(dev, "Get IRQ_HOTMON_LOW failed\n");
+		return low_irq;
 	}
 
 	ret = devm_request_threaded_irq(dev, low_irq, NULL,
 		prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
-		"dbx500_temp_low", pzone);
+		"dbx500_temp_low", th);
 	if (ret < 0) {
-		dev_err(dev, "Failed to allocate temp low irq.\n");
-		goto out_unlock;
+		dev_err(dev, "failed to allocate temp low irq\n");
+		return ret;
 	}
 
 	high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
 	if (high_irq < 0) {
-		dev_err(dev, "Get IRQ_HOTMON_HIGH failed.\n");
-		ret = high_irq;
-		goto out_unlock;
+		dev_err(dev, "Get IRQ_HOTMON_HIGH failed\n");
+		return high_irq;
 	}
 
 	ret = devm_request_threaded_irq(dev, high_irq, NULL,
 		prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
-		"dbx500_temp_high", pzone);
+		"dbx500_temp_high", th);
 	if (ret < 0) {
-		dev_err(dev, "Failed to allocate temp high irq.\n");
-		goto out_unlock;
+		dev_err(dev, "failed to allocate temp high irq\n");
+		return ret;
 	}
 
-	pzone->therm_dev = thermal_zone_device_register("db8500_thermal_zone",
-		ptrips->num_trips, 0, pzone, &thdev_ops, NULL, 0, 0);
-
-	if (IS_ERR(pzone->therm_dev)) {
-		dev_err(dev, "Register thermal zone device failed.\n");
-		ret = PTR_ERR(pzone->therm_dev);
-		goto out_unlock;
+	/* register of thermal sensor and get info from DT */
+	th->tz = devm_thermal_zone_of_sensor_register(dev, 0, th, &thdev_ops);
+	if (IS_ERR(th->tz)) {
+		dev_err(dev, "register thermal zone sensor failed\n");
+		return PTR_ERR(th->tz);
 	}
-	dev_info(dev, "Thermal zone device registered.\n");
-
-	dft_low = PRCMU_DEFAULT_LOW_TEMP;
-	dft_high = ptrips->trip_points[0].temp;
-
-	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
-		dft_low, dft_high);
+	dev_info(dev, "thermal zone sensor registered\n");
 
-	platform_set_drvdata(pdev, pzone);
-	pzone->mode = THERMAL_DEVICE_ENABLED;
+	/* Start measuring at the lowest point */
+	db8500_thermal_update_config(th, 0, THERMAL_TREND_STABLE,
+				     PRCMU_DEFAULT_LOW_TEMP,
+				     db8500_thermal_points[0]);
 
-out_unlock:
-	mutex_unlock(&pzone->th_lock);
+	platform_set_drvdata(pdev, th);
 
-	return ret;
+	return 0;
 }
 
 static int db8500_thermal_remove(struct platform_device *pdev)
 {
-	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
+	struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
 
-	thermal_zone_device_unregister(pzone->therm_dev);
-	cancel_work_sync(&pzone->therm_work);
-	mutex_destroy(&pzone->th_lock);
+	cancel_work_sync(&th->work);
 
 	return 0;
 }
@@ -478,9 +251,9 @@  static int db8500_thermal_remove(struct platform_device *pdev)
 static int db8500_thermal_suspend(struct platform_device *pdev,
 		pm_message_t state)
 {
-	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
+	struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
 
-	flush_work(&pzone->therm_work);
+	flush_work(&th->work);
 	prcmu_stop_temp_sense();
 
 	return 0;
@@ -488,15 +261,12 @@  static int db8500_thermal_suspend(struct platform_device *pdev,
 
 static int db8500_thermal_resume(struct platform_device *pdev)
 {
-	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
-	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
-	unsigned long dft_low, dft_high;
-
-	dft_low = PRCMU_DEFAULT_LOW_TEMP;
-	dft_high = ptrips->trip_points[0].temp;
+	struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
 
-	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
-		dft_low, dft_high);
+	/* Resume and start measuring at the lowest point */
+	db8500_thermal_update_config(th, 0, THERMAL_TREND_STABLE,
+				     PRCMU_DEFAULT_LOW_TEMP,
+				     db8500_thermal_points[0]);
 
 	return 0;
 }