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 000000000000..fdb07199d9c2
--- /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);
+}