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-rw-r--r--drivers/thermal/thermal_hwmon.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c
new file mode 100644
index 000000000..dd5d8ee37
--- /dev/null
+++ b/drivers/thermal/thermal_hwmon.c
@@ -0,0 +1,250 @@
+// 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/hwmon.h>
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/err.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);
+ strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH);
+ strreplace(hwmon->type, '-', '_');
+ hwmon->device = hwmon_device_register_with_info(&tz->device, hwmon->type,
+ hwmon, NULL, NULL);
+ 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:
+ if (new_hwmon_device)
+ 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);