thermal/int3400: export uuids

INT3400 currently supports only one policy, which can't be changed.
This change exports all available policies (uuids) to user space and
allow this to be changed.
It introduces an attribute group uuids in INT3400 platform driver.
There are two attributes exposed:
- available_uuids
- current_uuid

User space can set current_uuid via this interface to one of the
available uuids. The uuid change is communicated to firmware, only
when the current zone mode is changed to "enabled". So the ideal
sequence should be
- set INT3400 zone mode to "disabled"
- change current_uuid
- set INT3400 zone mode to "enabled"

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/int340x_thermal/int3400_thermal.c

@@ -43,6 +43,74 @@ struct int3400_thermal_priv {
 	struct trt *trts;
 	u8 uuid_bitmap;
 	int rel_misc_dev_res;
+	int current_uuid_index;
+};
+
+static ssize_t available_uuids_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct int3400_thermal_priv *priv = platform_get_drvdata(pdev);
+	int i;
+	int length = 0;
+
+	for (i = 0; i < INT3400_THERMAL_MAXIMUM_UUID; i++) {
+		if (priv->uuid_bitmap & (1 << i))
+			if (PAGE_SIZE - length > 0)
+				length += snprintf(&buf[length],
+						   PAGE_SIZE - length,
+						   "%s\n",
+						   int3400_thermal_uuids[i]);
+	}
+
+	return length;
+}
+
+static ssize_t current_uuid_show(struct device *dev,
+				 struct device_attribute *devattr, char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct int3400_thermal_priv *priv = platform_get_drvdata(pdev);
+
+	if (priv->uuid_bitmap & (1 << priv->current_uuid_index))
+		return sprintf(buf, "%s\n",
+			       int3400_thermal_uuids[priv->current_uuid_index]);
+	else
+		return sprintf(buf, "INVALID\n");
+}
+
+static ssize_t current_uuid_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct int3400_thermal_priv *priv = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < INT3400_THERMAL_MAXIMUM_UUID; ++i) {
+		if ((priv->uuid_bitmap & (1 << i)) &&
+		    !(strncmp(buf, int3400_thermal_uuids[i],
+			      sizeof(int3400_thermal_uuids[i]) - 1))) {
+			priv->current_uuid_index = i;
+			return count;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static DEVICE_ATTR(current_uuid, 0644, current_uuid_show, current_uuid_store);
+static DEVICE_ATTR_RO(available_uuids);
+static struct attribute *uuid_attrs[] = {
+	&dev_attr_available_uuids.attr,
+	&dev_attr_current_uuid.attr,
+	NULL
+};
+
+static struct attribute_group uuid_attribute_group = {
+	.attrs = uuid_attrs,
+	.name = "uuids"
 };
 
 static int int3400_thermal_get_uuids(struct int3400_thermal_priv *priv)
@@ -160,9 +228,9 @@ static int int3400_thermal_set_mode(struct thermal_zone_device *thermal,
 
 	if (enable != priv->mode) {
 		priv->mode = enable;
-		/* currently, only PASSIVE COOLING is supported */
 		result = int3400_thermal_run_osc(priv->adev->handle,
-					INT3400_THERMAL_PASSIVE_1, enable);
+						 priv->current_uuid_index,
+						 enable);
 	}
 	return result;
 }
@@ -223,7 +291,14 @@ static int int3400_thermal_probe(struct platform_device *pdev)
 	priv->rel_misc_dev_res = acpi_thermal_rel_misc_device_add(
 							priv->adev->handle);
 
+	result = sysfs_create_group(&pdev->dev.kobj, &uuid_attribute_group);
+	if (result)
+		goto free_zone;
+
 	return 0;
+
+free_zone:
+	thermal_zone_device_unregister(priv->thermal);
 free_trt:
 	kfree(priv->trts);
 free_art:
@@ -240,6 +315,7 @@ static int int3400_thermal_remove(struct platform_device *pdev)
 	if (!priv->rel_misc_dev_res)
 		acpi_thermal_rel_misc_device_remove(priv->adev->handle);
 
+	sysfs_remove_group(&pdev->dev.kobj, &uuid_attribute_group);
 	thermal_zone_device_unregister(priv->thermal);
 	kfree(priv->trts);
 	kfree(priv->arts);