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path: root/drivers/thermal/thermal_hwmon.c
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-rw-r--r--drivers/thermal/thermal_hwmon.c269
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c
new file mode 100644
index 00000000000..fdb07199d9c
--- /dev/null
+++ b/drivers/thermal/thermal_hwmon.c
@@ -0,0 +1,269 @@
+/*
+ * 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>
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#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
+name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_hwmon_device *hwmon = dev_get_drvdata(dev);
+ return sprintf(buf, "%s\n", hwmon->type);
+}
+static DEVICE_ATTR(name, 0444, name_show, NULL);
+
+static ssize_t
+temp_input_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ long 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, "%ld\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;
+ long temperature;
+ int ret;
+
+ ret = tz->ops->get_trip_temp(tz, 0, &temperature);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%ld\n", temperature);
+}
+
+
+static struct thermal_hwmon_device *
+thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz)
+{
+ struct thermal_hwmon_device *hwmon;
+
+ mutex_lock(&thermal_hwmon_list_lock);
+ list_for_each_entry(hwmon, &thermal_hwmon_list, node)
+ if (!strcmp(hwmon->type, tz->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;
+}
+
+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);
+ hwmon->device = hwmon_device_register(NULL);
+ if (IS_ERR(hwmon->device)) {
+ result = PTR_ERR(hwmon->device);
+ goto free_mem;
+ }
+ dev_set_drvdata(hwmon->device, hwmon);
+ result = device_create_file(hwmon->device, &dev_attr_name);
+ if (result)
+ 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 (tz->ops->get_crit_temp) {
+ unsigned long temperature;
+ if (!tz->ops->get_crit_temp(tz, &temperature)) {
+ 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) {
+ device_remove_file(hwmon->device, &dev_attr_name);
+ hwmon_device_unregister(hwmon->device);
+ }
+ free_mem:
+ if (new_hwmon_device)
+ kfree(hwmon);
+
+ return result;
+}
+
+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 (tz->ops->get_crit_temp)
+ 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);
+
+ device_remove_file(hwmon->device, &dev_attr_name);
+ hwmon_device_unregister(hwmon->device);
+ kfree(hwmon);
+}