Thermal: Make Thermal trip points writeable

Some of the thermal drivers using the Generic Thermal Framework
require (all/some) trip points to be writeable. This patch makes
the trip point temperatures writeable on a per-trip point basis,
and modifies the required function call in thermal.c. This patch
also updates the Documentation to reflect the new change.

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/thermal/sysfs-api.txt

@@ -32,7 +32,8 @@ temperature) and throttle appropriate devices.
 
 1.1 thermal zone device interface
 1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name,
-		int trips, void *devdata, struct thermal_zone_device_ops *ops)
+		int trips, int mask, void *devdata,
+		struct thermal_zone_device_ops *ops)
 
     This interface function adds a new thermal zone device (sensor) to
     /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
@@ -40,6 +41,7 @@ temperature) and throttle appropriate devices.
 
     name: the thermal zone name.
     trips: the total number of trip points this thermal zone supports.
+    mask: Bit string: If 'n'th bit is set, then trip point 'n' is writeable.
     devdata: device private data
     ops: thermal zone device call-backs.
 	.bind: bind the thermal zone device with a thermal cooling device.

drivers/acpi/thermal.c

@@ -845,7 +845,7 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 
 	if (tz->trips.passive.flags.valid)
 		tz->thermal_zone =
-			thermal_zone_device_register("acpitz", trips, tz,
+			thermal_zone_device_register("acpitz", trips, 0, tz,
 						     &acpi_thermal_zone_ops,
 						     tz->trips.passive.tc1,
 						     tz->trips.passive.tc2,
@@ -853,7 +853,7 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 						     tz->polling_frequency*100);
 	else
 		tz->thermal_zone =
-			thermal_zone_device_register("acpitz", trips, tz,
+			thermal_zone_device_register("acpitz", trips, 0, tz,
 						     &acpi_thermal_zone_ops,
 						     0, 0, 0,
 						     tz->polling_frequency*100);

drivers/platform/x86/acerhdf.c

@@ -660,7 +660,7 @@ static int acerhdf_register_thermal(void)
 	if (IS_ERR(cl_dev))
 		return -EINVAL;
 
-	thz_dev = thermal_zone_device_register("acerhdf", 1, NULL,
+	thz_dev = thermal_zone_device_register("acerhdf", 1, 0, NULL,
 					      &acerhdf_dev_ops, 0, 0, 0,
 					      (kernelmode) ? interval*1000 : 0);
 	if (IS_ERR(thz_dev))

drivers/platform/x86/intel_mid_thermal.c

@@ -499,7 +499,7 @@ static int mid_thermal_probe(struct platform_device *pdev)
 			goto err;
 		}
 		pinfo->tzd[i] = thermal_zone_device_register(name[i],
-				0, td_info, &tzd_ops, 0, 0, 0, 0);
+				0, 0, td_info, &tzd_ops, 0, 0, 0, 0);
 		if (IS_ERR(pinfo->tzd[i])) {
 			kfree(td_info);
 			ret = PTR_ERR(pinfo->tzd[i]);

drivers/thermal/spear_thermal.c

@@ -147,7 +147,7 @@ static int spear_thermal_probe(struct platform_device *pdev)
 	stdev->flags = pdata->thermal_flags;
 	writel_relaxed(stdev->flags, stdev->thermal_base);
 
-	spear_thermal = thermal_zone_device_register("spear_thermal", 0,
+	spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
 				stdev, &ops, 0, 0, 0, 0);
 	if (IS_ERR(spear_thermal)) {
 		dev_err(&pdev->dev, "thermal zone device is NULL\n");

drivers/thermal/thermal_sys.c

@@ -195,6 +195,28 @@ trip_point_type_show(struct device *dev, struct device_attribute *attr,
 	}
 }
 
+static ssize_t
+trip_point_temp_store(struct device *dev, struct device_attribute *attr,
+		     const char *buf, size_t count)
+{
+	struct thermal_zone_device *tz = to_thermal_zone(dev);
+	int trip, ret;
+	unsigned long temperature;
+
+	if (!tz->ops->set_trip_temp)
+		return -EPERM;
+
+	if (!sscanf(attr->attr.name, "trip_point_%d_temp", &trip))
+		return -EINVAL;
+
+	if (kstrtoul(buf, 10, &temperature))
+		return -EINVAL;
+
+	ret = tz->ops->set_trip_temp(tz, trip, temperature);
+
+	return ret ? ret : count;
+}
+
 static ssize_t
 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
 		     char *buf)
@@ -283,33 +305,6 @@ static DEVICE_ATTR(temp, 0444, temp_show, NULL);
 static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
 static DEVICE_ATTR(passive, S_IRUGO | S_IWUSR, passive_show, passive_store);
 
-static struct device_attribute trip_point_attrs[] = {
-	__ATTR(trip_point_0_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_0_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_1_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_1_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_2_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_2_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_3_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_3_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_4_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_4_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_5_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_5_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_6_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_6_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_7_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_7_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_8_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_8_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_9_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_9_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_10_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_10_temp, 0444, trip_point_temp_show, NULL),
-	__ATTR(trip_point_11_type, 0444, trip_point_type_show, NULL),
-	__ATTR(trip_point_11_temp, 0444, trip_point_temp_show, NULL),
-};
-
 /* sys I/F for cooling device */
 #define to_cooling_device(_dev)	\
 	container_of(_dev, struct thermal_cooling_device, device)
@@ -1088,10 +1083,82 @@ leave:
 }
 EXPORT_SYMBOL(thermal_zone_device_update);
 
+/**
+ * create_trip_attrs - create attributes for trip points
+ * @tz:		the thermal zone device
+ * @mask:	Writeable trip point bitmap.
+ */
+static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
+{
+	int indx;
+
+	tz->trip_type_attrs =
+		kzalloc(sizeof(struct thermal_attr) * tz->trips, GFP_KERNEL);
+	if (!tz->trip_type_attrs)
+		return -ENOMEM;
+
+	tz->trip_temp_attrs =
+		kzalloc(sizeof(struct thermal_attr) * tz->trips, GFP_KERNEL);
+	if (!tz->trip_temp_attrs) {
+		kfree(tz->trip_type_attrs);
+		return -ENOMEM;
+	}
+
+	for (indx = 0; indx < tz->trips; indx++) {
+
+		/* create trip type attribute */
+		snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
+			 "trip_point_%d_type", indx);
+
+		sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
+		tz->trip_type_attrs[indx].attr.attr.name =
+						tz->trip_type_attrs[indx].name;
+		tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
+		tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
+
+		device_create_file(&tz->device,
+				   &tz->trip_type_attrs[indx].attr);
+
+		/* create trip temp attribute */
+		snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
+			 "trip_point_%d_temp", indx);
+
+		sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
+		tz->trip_temp_attrs[indx].attr.attr.name =
+						tz->trip_temp_attrs[indx].name;
+		tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
+		tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
+		if (mask & (1 << indx)) {
+			tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
+			tz->trip_temp_attrs[indx].attr.store =
+							trip_point_temp_store;
+		}
+
+		device_create_file(&tz->device,
+				   &tz->trip_temp_attrs[indx].attr);
+	}
+	return 0;
+}
+
+static void remove_trip_attrs(struct thermal_zone_device *tz)
+{
+	int indx;
+
+	for (indx = 0; indx < tz->trips; indx++) {
+		device_remove_file(&tz->device,
+				   &tz->trip_type_attrs[indx].attr);
+		device_remove_file(&tz->device,
+				   &tz->trip_temp_attrs[indx].attr);
+	}
+	kfree(tz->trip_type_attrs);
+	kfree(tz->trip_temp_attrs);
+}
+
 /**
  * thermal_zone_device_register - register a new thermal zone device
  * @type:	the thermal zone device type
  * @trips:	the number of trip points the thermal zone support
+ * @mask:	a bit string indicating the writeablility of trip points
  * @devdata:	private device data
  * @ops:	standard thermal zone device callbacks
  * @tc1:	thermal coefficient 1 for passive calculations
@@ -1107,7 +1174,7 @@ EXPORT_SYMBOL(thermal_zone_device_update);
  * section 11.1.5.1 of the ACPI specification 3.0.
  */
 struct thermal_zone_device *thermal_zone_device_register(char *type,
-	int trips, void *devdata,
+	int trips, int mask, void *devdata,
 	const struct thermal_zone_device_ops *ops,
 	int tc1, int tc2, int passive_delay, int polling_delay)
 {
@@ -1121,7 +1188,7 @@ struct thermal_zone_device *thermal_zone_device_register(char *type,
 	if (strlen(type) >= THERMAL_NAME_LENGTH)
 		return ERR_PTR(-EINVAL);
 
-	if (trips > THERMAL_MAX_TRIPS || trips < 0)
+	if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips)
 		return ERR_PTR(-EINVAL);
 
 	if (!ops || !ops->get_temp)
@@ -1175,15 +1242,11 @@ struct thermal_zone_device *thermal_zone_device_register(char *type,
 			goto unregister;
 	}
 
+	result = create_trip_attrs(tz, mask);
+	if (result)
+		goto unregister;
+
 	for (count = 0; count < trips; count++) {
-		result = device_create_file(&tz->device,
-					    &trip_point_attrs[count * 2]);
-		if (result)
-			break;
-		result = device_create_file(&tz->device,
-					    &trip_point_attrs[count * 2 + 1]);
-		if (result)
-			goto unregister;
 		tz->ops->get_trip_type(tz, count, &trip_type);
 		if (trip_type == THERMAL_TRIP_PASSIVE)
 			passive = 1;
@@ -1232,7 +1295,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 {
 	struct thermal_cooling_device *cdev;
 	struct thermal_zone_device *pos = NULL;
-	int count;
 
 	if (!tz)
 		return;
@@ -1259,13 +1321,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 	device_remove_file(&tz->device, &dev_attr_temp);
 	if (tz->ops->get_mode)
 		device_remove_file(&tz->device, &dev_attr_mode);
+	remove_trip_attrs(tz);
 
-	for (count = 0; count < tz->trips; count++) {
-		device_remove_file(&tz->device,
-				   &trip_point_attrs[count * 2]);
-		device_remove_file(&tz->device,
-				   &trip_point_attrs[count * 2 + 1]);
-	}
 	thermal_remove_hwmon_sysfs(tz);
 	release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 	idr_destroy(&tz->idr);

include/linux/thermal.h

@@ -58,6 +58,8 @@ struct thermal_zone_device_ops {
 		enum thermal_trip_type *);
 	int (*get_trip_temp) (struct thermal_zone_device *, int,
 			      unsigned long *);
+	int (*set_trip_temp) (struct thermal_zone_device *, int,
+			      unsigned long);
 	int (*get_crit_temp) (struct thermal_zone_device *, unsigned long *);
 	int (*notify) (struct thermal_zone_device *, int,
 		       enum thermal_trip_type);
@@ -85,10 +87,17 @@ struct thermal_cooling_device {
 				((long)t-2732+5)/10 : ((long)t-2732-5)/10)
 #define CELSIUS_TO_KELVIN(t)	((t)*10+2732)
 
+struct thermal_attr {
+	struct device_attribute attr;
+	char name[THERMAL_NAME_LENGTH];
+};
+
 struct thermal_zone_device {
 	int id;
 	char type[THERMAL_NAME_LENGTH];
 	struct device device;
+	struct thermal_attr *trip_temp_attrs;
+	struct thermal_attr *trip_type_attrs;
 	void *devdata;
 	int trips;
 	int tc1;
@@ -137,9 +146,9 @@ enum {
 };
 #define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)
 
-struct thermal_zone_device *thermal_zone_device_register(char *, int, void *,
-		const struct thermal_zone_device_ops *, int tc1, int tc2,
-		int passive_freq, int polling_freq);
+struct thermal_zone_device *thermal_zone_device_register(char *, int, int,
+		void *, const struct thermal_zone_device_ops *, int tc1,
+		int tc2, int passive_freq, int polling_freq);
 void thermal_zone_device_unregister(struct thermal_zone_device *);
 
 int thermal_zone_bind_cooling_device(struct thermal_zone_device *, int,