[PATCH V2] of: thermal: Allow multiple devices to share cooling map

[Viresh Kumar]

A cooling map entry may now contain a list of phandles and their
arguments representing multiple devices which share the trip point.

This patch updates the thermal OF core to parse them properly. The trip
point and contribution value is shared by multiple cooling devices now
and so a new structure is created, struct __thermal_cooling_bind_param,
which represents a cooling device and its min/max states and the
existing struct __thermal_bind_params now contains an array of this new
cooling device structure.

Tested on Hikey960.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
V2:
- Updated commit log to include new structures information
- Updated two error messages to give better error log

 drivers/thermal/of-thermal.c | 142 +++++++++++++++++++++++++----------
 1 file changed, 103 insertions(+), 39 deletions(-)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index 977a8307fbb1..16b890a4fb50 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -19,22 +19,33 @@
 /***   Private data structures to represent thermal device tree data ***/
 
 /**
- * struct __thermal_bind_param - a match between trip and cooling device
+ * struct __thermal_cooling_bind_param - a cooling device for a trip point
  * @cooling_device: a pointer to identify the referred cooling device
- * @trip_id: the trip point index
- * @usage: the percentage (from 0 to 100) of cooling contribution
  * @min: minimum cooling state used at this trip point
  * @max: maximum cooling state used at this trip point
  */
 
-struct __thermal_bind_params {
+struct __thermal_cooling_bind_param {
 	struct device_node *cooling_device;
-	unsigned int trip_id;
-	unsigned int usage;
 	unsigned long min;
 	unsigned long max;
 };
 
+/**
+ * struct __thermal_bind_param - a match between trip and cooling device
+ * @tcbp: a pointer to an array of cooling devices
+ * @count: number of elements in array
+ * @trip_id: the trip point index
+ * @usage: the percentage (from 0 to 100) of cooling contribution
+ */
+
+struct __thermal_bind_params {
+	struct __thermal_cooling_bind_param *tcbp;
+	unsigned int count;
+	unsigned int trip_id;
+	unsigned int usage;
+};
+
 /**
  * struct __thermal_zone - internal representation of a thermal zone
  * @mode: current thermal zone device mode (enabled/disabled)
@@ -192,25 +203,31 @@ static int of_thermal_bind(struct thermal_zone_device *thermal,
 			   struct thermal_cooling_device *cdev)
 {
 	struct __thermal_zone *data = thermal->devdata;
-	int i;
+	struct __thermal_bind_params *tbp;
+	struct __thermal_cooling_bind_param *tcbp;
+	int i, j;
 
 	if (!data || IS_ERR(data))
 		return -ENODEV;
 
 	/* find where to bind */
 	for (i = 0; i < data->num_tbps; i++) {
-		struct __thermal_bind_params *tbp = data->tbps + i;
+		tbp = data->tbps + i;
 
-		if (tbp->cooling_device == cdev->np) {
-			int ret;
+		for (j = 0; j < tbp->count; j++) {
+			tcbp = tbp->tcbp + j;
 
-			ret = thermal_zone_bind_cooling_device(thermal,
+			if (tcbp->cooling_device == cdev->np) {
+				int ret;
+
+				ret = thermal_zone_bind_cooling_device(thermal,
 						tbp->trip_id, cdev,
-						tbp->max,
-						tbp->min,
+						tcbp->max,
+						tcbp->min,
 						tbp->usage);
-			if (ret)
-				return ret;
+				if (ret)
+					return ret;
+			}
 		}
 	}
 
@@ -221,22 +238,28 @@ static int of_thermal_unbind(struct thermal_zone_device *thermal,
 			     struct thermal_cooling_device *cdev)
 {
 	struct __thermal_zone *data = thermal->devdata;
-	int i;
+	struct __thermal_bind_params *tbp;
+	struct __thermal_cooling_bind_param *tcbp;
+	int i, j;
 
 	if (!data || IS_ERR(data))
 		return -ENODEV;
 
 	/* find where to unbind */
 	for (i = 0; i < data->num_tbps; i++) {
-		struct __thermal_bind_params *tbp = data->tbps + i;
+		tbp = data->tbps + i;
+
+		for (j = 0; j < tbp->count; j++) {
+			tcbp = tbp->tcbp + j;
 
-		if (tbp->cooling_device == cdev->np) {
-			int ret;
+			if (tcbp->cooling_device == cdev->np) {
+				int ret;
 
-			ret = thermal_zone_unbind_cooling_device(thermal,
-						tbp->trip_id, cdev);
-			if (ret)
-				return ret;
+				ret = thermal_zone_unbind_cooling_device(thermal,
+							tbp->trip_id, cdev);
+				if (ret)
+					return ret;
+			}
 		}
 	}
 
@@ -652,8 +675,9 @@ static int thermal_of_populate_bind_params(struct device_node *np,
 					   int ntrips)
 {
 	struct of_phandle_args cooling_spec;
+	struct __thermal_cooling_bind_param *__tcbp;
 	struct device_node *trip;
-	int ret, i;
+	int ret, i, count;
 	u32 prop;
 
 	/* Default weight. Usage is optional */
@@ -680,20 +704,44 @@ static int thermal_of_populate_bind_params(struct device_node *np,
 		goto end;
 	}
 
-	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
-					 0, &cooling_spec);
-	if (ret < 0) {
-		pr_err("missing cooling_device property\n");
+	count = of_count_phandle_with_args(np, "cooling-device",
+					   "#cooling-cells");
+	if (!count) {
+		pr_err("Add a cooling_device property with at least one device\n");
 		goto end;
 	}
-	__tbp->cooling_device = cooling_spec.np;
-	if (cooling_spec.args_count >= 2) { /* at least min and max */
-		__tbp->min = cooling_spec.args[0];
-		__tbp->max = cooling_spec.args[1];
-	} else {
-		pr_err("wrong reference to cooling device, missing limits\n");
+
+	__tcbp = kcalloc(count, sizeof(*__tcbp), GFP_KERNEL);
+	if (!__tcbp)
+		goto end;
+
+	for (i = 0; i < count; i++) {
+		ret = of_parse_phandle_with_args(np, "cooling-device",
+				"#cooling-cells", i, &cooling_spec);
+		if (ret < 0) {
+			pr_err("Invalid cooling-device entry\n");
+			goto free_tcbp;
+		}
+
+		__tcbp[i].cooling_device = cooling_spec.np;
+
+		if (cooling_spec.args_count >= 2) { /* at least min and max */
+			__tcbp[i].min = cooling_spec.args[0];
+			__tcbp[i].max = cooling_spec.args[1];
+		} else {
+			pr_err("wrong reference to cooling device, missing limits\n");
+		}
 	}
 
+	__tbp->tcbp= __tcbp;
+	__tbp->count = count;
+
+	goto end;
+
+free_tcbp:
+	for (i = i - 1; i >= 0; i--)
+		of_node_put(__tcbp[i].cooling_device);
+	kfree(__tcbp);
 end:
 	of_node_put(trip);
 
@@ -900,8 +948,16 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 	return tz;
 
 free_tbps:
-	for (i = i - 1; i >= 0; i--)
-		of_node_put(tz->tbps[i].cooling_device);
+	for (i = i - 1; i >= 0; i--) {
+		struct __thermal_bind_params *tbp = tz->tbps + i;
+		int j;
+
+		for (j = 0; j < tbp->count; j++)
+			of_node_put(tbp->tcbp[j].cooling_device);
+
+		kfree(tbp->tcbp);
+	}
+
 	kfree(tz->tbps);
 free_trips:
 	for (i = 0; i < tz->ntrips; i++)
@@ -917,10 +973,18 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
 
 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 {
-	int i;
+	struct __thermal_bind_params *tbp;
+	int i, j;
+
+	for (i = 0; i < tz->num_tbps; i++) {
+		tbp = tz->tbps + i;
+
+		for (j = 0; j < tbp->count; j++)
+			of_node_put(tbp->tcbp[j].cooling_device);
+
+		kfree(tbp->tcbp);
+	}
 
-	for (i = 0; i < tz->num_tbps; i++)
-		of_node_put(tz->tbps[i].cooling_device);
 	kfree(tz->tbps);
 	for (i = 0; i < tz->ntrips; i++)
 		of_node_put(tz->trips[i].np);
-- 
2.18.0.rc1.242.g61856ae69a2c