thermal: add hwmon sysfs I/F

Add hwmon sys I/F for generic thermal driver.

Note: we have one hwmon class device for EACH TYPE of the thermal zone device.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 187 insertions, 0 deletions

diff --git a/drivers/thermal/thermal.c b/drivers/thermal/thermal.c
index cf56af4b7e02..6098787341f3 100644
--- a/drivers/thermal/thermal.c
+++ b/drivers/thermal/thermal.c
@@ -295,6 +295,164 @@ thermal_cooling_device_trip_point_show(struct device *dev,
 
 /* Device management */
 
+#if defined(CONFIG_HWMON) ||    \
+        (defined(CONFIG_HWMON_MODULE) && defined(CONFIG_THERMAL_MODULE))
+/* hwmon sys I/F */
+#include <linux/hwmon.h>
+static LIST_HEAD(thermal_hwmon_list);
+
+static ssize_t
+name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct thermal_hwmon_device *hwmon = dev->driver_data;
+        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)
+{
+        struct thermal_hwmon_attr *hwmon_attr
+                        = container_of(attr, struct thermal_hwmon_attr, attr);
+        struct thermal_zone_device *tz
+                        = container_of(hwmon_attr, struct thermal_zone_device,
+                                       temp_input);
+
+        return tz->ops->get_temp(tz, buf);
+}
+
+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_zone_device *tz
+                        = container_of(hwmon_attr, struct thermal_zone_device,
+                                       temp_crit);
+
+        return tz->ops->get_trip_temp(tz, 0, buf);
+}
+
+
+static int
+thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+        struct thermal_hwmon_device *hwmon;
+        int new_hwmon_device = 1;
+        int result;
+
+        mutex_lock(&thermal_list_lock);
+        list_for_each_entry(hwmon, &thermal_hwmon_list, node)
+                if (!strcmp(hwmon->type, tz->type)) {
+                        new_hwmon_device = 0;
+                        mutex_unlock(&thermal_list_lock);
+                        goto register_sys_interface;
+                }
+        mutex_unlock(&thermal_list_lock);
+
+        hwmon = kzalloc(sizeof(struct thermal_hwmon_device), 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;
+        }
+        hwmon->device->driver_data = hwmon;
+        result = device_create_file(hwmon->device, &dev_attr_name);
+        if (result)
+                goto unregister_hwmon_device;
+
+ register_sys_interface:
+        tz->hwmon = hwmon;
+        hwmon->count++;
+
+        snprintf(tz->temp_input.name, THERMAL_NAME_LENGTH,
+                 "temp%d_input", hwmon->count);
+        tz->temp_input.attr.attr.name = tz->temp_input.name;
+        tz->temp_input.attr.attr.mode = 0444;
+        tz->temp_input.attr.show = temp_input_show;
+        result = device_create_file(hwmon->device, &tz->temp_input.attr);
+        if (result)
+                goto unregister_hwmon_device;
+
+        if (tz->ops->get_crit_temp) {
+                unsigned long temperature;
+                if (!tz->ops->get_crit_temp(tz, &temperature)) {
+                        snprintf(tz->temp_crit.name, THERMAL_NAME_LENGTH,
+                                "temp%d_crit", hwmon->count);
+                        tz->temp_crit.attr.attr.name = tz->temp_crit.name;
+                        tz->temp_crit.attr.attr.mode = 0444;
+                        tz->temp_crit.attr.show = temp_crit_show;
+                        result = device_create_file(hwmon->device,
+                                                    &tz->temp_crit.attr);
+                        if (result)
+                                goto unregister_hwmon_device;
+                }
+        }
+
+        mutex_lock(&thermal_list_lock);
+        if (new_hwmon_device)
+                list_add_tail(&hwmon->node, &thermal_hwmon_list);
+        list_add_tail(&tz->hwmon_node, &hwmon->tz_list);
+        mutex_unlock(&thermal_list_lock);
+
+        return 0;
+
+ unregister_hwmon_device:
+        device_remove_file(hwmon->device, &tz->temp_crit.attr);
+        device_remove_file(hwmon->device, &tz->temp_input.attr);
+        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;
+}
+
+static void
+thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+        struct thermal_hwmon_device *hwmon = tz->hwmon;
+
+        tz->hwmon = NULL;
+        device_remove_file(hwmon->device, &tz->temp_input.attr);
+        device_remove_file(hwmon->device, &tz->temp_crit.attr);
+
+        mutex_lock(&thermal_list_lock);
+        list_del(&tz->hwmon_node);
+        if (!list_empty(&hwmon->tz_list)) {
+                mutex_unlock(&thermal_list_lock);
+                return;
+        }
+        list_del(&hwmon->node);
+        mutex_unlock(&thermal_list_lock);
+
+        device_remove_file(hwmon->device, &dev_attr_name);
+        hwmon_device_unregister(hwmon->device);
+        kfree(hwmon);
+}
+#else
+static int
+thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+        return 0;
+}
+
+static void
+thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
+{
+}
+#endif
+
+
 /**
  * thermal_zone_bind_cooling_device - bind a cooling device to a thermal zone
  * @tz:         thermal zone device
@@ -642,6 +800,10 @@ struct thermal_zone_device *thermal_zone_device_register(char *type,
                         goto unregister;
         }
 
+        result = thermal_add_hwmon_sysfs(tz);
+        if (result)
+                goto unregister;
+
         mutex_lock(&thermal_list_lock);
         list_add_tail(&tz->node, &thermal_tz_list);
         if (ops->bind)
@@ -700,6 +862,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
         for (count = 0; count < tz->trips; count++)
                 TRIP_POINT_ATTR_REMOVE(&tz->device, count);
 
+        thermal_remove_hwmon_sysfs(tz);
         release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
         idr_destroy(&tz->idr);
         mutex_destroy(&tz->lock);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 16e6a8bdeb3c..06d3e6eb9ca8 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -66,6 +66,23 @@ struct thermal_cooling_device {
                                 ((long)t-2732+5)/10 : ((long)t-2732-5)/10)
 #define CELSIUS_TO_KELVIN(t)    ((t)*10+2732)
 
+#if defined(CONFIG_HWMON) ||    \
+        (defined(CONFIG_HWMON_MODULE) && defined(CONFIG_THERMAL_MODULE))
+/* 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];
+};
+#endif
+
 struct thermal_zone_device {
         int id;
         char type[THERMAL_NAME_LENGTH];
@@ -77,6 +94,13 @@ struct thermal_zone_device {
         struct idr idr;
         struct mutex lock;      /* protect cooling devices list */
         struct list_head node;
+#if defined(CONFIG_HWMON) ||    \
+        (defined(CONFIG_HWMON_MODULE) && defined(CONFIG_THERMAL_MODULE))
+        struct list_head hwmon_node;
+        struct thermal_hwmon_device *hwmon;
+        struct thermal_hwmon_attr temp_input;   /* hwmon sys attr */
+        struct thermal_hwmon_attr temp_crit;    /* hwmon sys attr */
+#endif
 };
 
 struct thermal_zone_device *thermal_zone_device_register(char *, int, void *,