1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c
new file mode 100644
index 000000000..f53f4ceb6
--- /dev/null
+++ b/drivers/thermal/thermal_hwmon.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  thermal_hwmon.c - Generic Thermal Management hwmon support.
+ *
+ *  Code based on Intel thermal_core.c. Copyrights of the original code:
+ *  Copyright (C) 2008 Intel Corp
+ *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
+ *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
+ *
+ *  Copyright (C) 2013 Texas Instruments
+ *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
+ */
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/hwmon.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+#include "thermal_hwmon.h"
+
+/* hwmon sys I/F */
+/* thermal zone devices with the same type share one hwmon device */
+struct thermal_hwmon_device {
+	char type[THERMAL_NAME_LENGTH];
+	struct device *device;
+	int count;
+	struct list_head tz_list;
+	struct list_head node;
+};
+
+struct thermal_hwmon_attr {
+	struct device_attribute attr;
+	char name[16];
+};
+
+/* one temperature input for each thermal zone */
+struct thermal_hwmon_temp {
+	struct list_head hwmon_node;
+	struct thermal_zone_device *tz;
+	struct thermal_hwmon_attr temp_input;	/* hwmon sys attr */
+	struct thermal_hwmon_attr temp_crit;	/* hwmon sys attr */
+};
+
+static LIST_HEAD(thermal_hwmon_list);
+
+static DEFINE_MUTEX(thermal_hwmon_list_lock);
+
+static ssize_t
+temp_input_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	int temperature;
+	int ret;
+	struct thermal_hwmon_attr *hwmon_attr
+			= container_of(attr, struct thermal_hwmon_attr, attr);
+	struct thermal_hwmon_temp *temp
+			= container_of(hwmon_attr, struct thermal_hwmon_temp,
+				       temp_input);
+	struct thermal_zone_device *tz = temp->tz;
+
+	ret = thermal_zone_get_temp(tz, &temperature);
+
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%d\n", temperature);
+}
+
+static ssize_t
+temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct thermal_hwmon_attr *hwmon_attr
+			= container_of(attr, struct thermal_hwmon_attr, attr);
+	struct thermal_hwmon_temp *temp
+			= container_of(hwmon_attr, struct thermal_hwmon_temp,
+				       temp_crit);
+	struct thermal_zone_device *tz = temp->tz;
+	int temperature;
+	int ret;
+
+	ret = tz->ops->get_crit_temp(tz, &temperature);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%d\n", temperature);
+}
+
+
+static struct thermal_hwmon_device *
+thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz)
+{
+	struct thermal_hwmon_device *hwmon;
+	char type[THERMAL_NAME_LENGTH];
+
+	mutex_lock(&thermal_hwmon_list_lock);
+	list_for_each_entry(hwmon, &thermal_hwmon_list, node) {
+		strcpy(type, tz->type);
+		strreplace(type, '-', '_');
+		if (!strcmp(hwmon->type, type)) {
+			mutex_unlock(&thermal_hwmon_list_lock);
+			return hwmon;
+		}
+	}
+	mutex_unlock(&thermal_hwmon_list_lock);
+
+	return NULL;
+}
+
+/* Find the temperature input matching a given thermal zone */
+static struct thermal_hwmon_temp *
+thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon,
+			  const struct thermal_zone_device *tz)
+{
+	struct thermal_hwmon_temp *temp;
+
+	mutex_lock(&thermal_hwmon_list_lock);
+	list_for_each_entry(temp, &hwmon->tz_list, hwmon_node)
+		if (temp->tz == tz) {
+			mutex_unlock(&thermal_hwmon_list_lock);
+			return temp;
+		}
+	mutex_unlock(&thermal_hwmon_list_lock);
+
+	return NULL;
+}
+
+static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz)
+{
+	int temp;
+	return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp);
+}
+
+int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+	struct thermal_hwmon_device *hwmon;
+	struct thermal_hwmon_temp *temp;
+	int new_hwmon_device = 1;
+	int result;
+
+	hwmon = thermal_hwmon_lookup_by_type(tz);
+	if (hwmon) {
+		new_hwmon_device = 0;
+		goto register_sys_interface;
+	}
+
+	hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&hwmon->tz_list);
+	strscpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH);
+	strreplace(hwmon->type, '-', '_');
+	hwmon->device = hwmon_device_register_for_thermal(&tz->device,
+							  hwmon->type, hwmon);
+	if (IS_ERR(hwmon->device)) {
+		result = PTR_ERR(hwmon->device);
+		goto free_mem;
+	}
+
+ register_sys_interface:
+	temp = kzalloc(sizeof(*temp), GFP_KERNEL);
+	if (!temp) {
+		result = -ENOMEM;
+		goto unregister_name;
+	}
+
+	temp->tz = tz;
+	hwmon->count++;
+
+	snprintf(temp->temp_input.name, sizeof(temp->temp_input.name),
+		 "temp%d_input", hwmon->count);
+	temp->temp_input.attr.attr.name = temp->temp_input.name;
+	temp->temp_input.attr.attr.mode = 0444;
+	temp->temp_input.attr.show = temp_input_show;
+	sysfs_attr_init(&temp->temp_input.attr.attr);
+	result = device_create_file(hwmon->device, &temp->temp_input.attr);
+	if (result)
+		goto free_temp_mem;
+
+	if (thermal_zone_crit_temp_valid(tz)) {
+		snprintf(temp->temp_crit.name,
+				sizeof(temp->temp_crit.name),
+				"temp%d_crit", hwmon->count);
+		temp->temp_crit.attr.attr.name = temp->temp_crit.name;
+		temp->temp_crit.attr.attr.mode = 0444;
+		temp->temp_crit.attr.show = temp_crit_show;
+		sysfs_attr_init(&temp->temp_crit.attr.attr);
+		result = device_create_file(hwmon->device,
+					    &temp->temp_crit.attr);
+		if (result)
+			goto unregister_input;
+	}
+
+	mutex_lock(&thermal_hwmon_list_lock);
+	if (new_hwmon_device)
+		list_add_tail(&hwmon->node, &thermal_hwmon_list);
+	list_add_tail(&temp->hwmon_node, &hwmon->tz_list);
+	mutex_unlock(&thermal_hwmon_list_lock);
+
+	return 0;
+
+ unregister_input:
+	device_remove_file(hwmon->device, &temp->temp_input.attr);
+ free_temp_mem:
+	kfree(temp);
+ unregister_name:
+	if (new_hwmon_device)
+		hwmon_device_unregister(hwmon->device);
+ free_mem:
+	kfree(hwmon);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs);
+
+void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+	struct thermal_hwmon_device *hwmon;
+	struct thermal_hwmon_temp *temp;
+
+	hwmon = thermal_hwmon_lookup_by_type(tz);
+	if (unlikely(!hwmon)) {
+		/* Should never happen... */
+		dev_dbg(&tz->device, "hwmon device lookup failed!\n");
+		return;
+	}
+
+	temp = thermal_hwmon_lookup_temp(hwmon, tz);
+	if (unlikely(!temp)) {
+		/* Should never happen... */
+		dev_dbg(&tz->device, "temperature input lookup failed!\n");
+		return;
+	}
+
+	device_remove_file(hwmon->device, &temp->temp_input.attr);
+	if (thermal_zone_crit_temp_valid(tz))
+		device_remove_file(hwmon->device, &temp->temp_crit.attr);
+
+	mutex_lock(&thermal_hwmon_list_lock);
+	list_del(&temp->hwmon_node);
+	kfree(temp);
+	if (!list_empty(&hwmon->tz_list)) {
+		mutex_unlock(&thermal_hwmon_list_lock);
+		return;
+	}
+	list_del(&hwmon->node);
+	mutex_unlock(&thermal_hwmon_list_lock);
+
+	hwmon_device_unregister(hwmon->device);
+	kfree(hwmon);
+}
+EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs);
+
+static void devm_thermal_hwmon_release(struct device *dev, void *res)
+{
+	thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res);
+}
+
+int devm_thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+	struct thermal_zone_device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_thermal_hwmon_release, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = thermal_add_hwmon_sysfs(tz);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = tz;
+	devres_add(&tz->device, ptr);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs);
+
+MODULE_IMPORT_NS(HWMON_THERMAL);