Thermal: Add a thermal notifier for user space

This patch registers a governor which will let the
user land manage the platform thermals. Whenever a
trip happens, this governor just notifies the user
space using kobj_uevent().

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/Kconfig

@@ -67,3 +67,9 @@ config STEP_WISE
 	depends on THERMAL
 	help
 	  Enable this to manage platform thermals using a simple linear
+
+config USER_SPACE
+	bool "User_space thermal governor"
+	depends on THERMAL
+	help
+	  Enable this to let the user space manage the platform thermals.

drivers/thermal/Makefile

@@ -9,3 +9,4 @@ obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
 obj-$(CONFIG_EXYNOS_THERMAL)		+= exynos_thermal.o
 obj-$(CONFIG_FAIR_SHARE)		+= fair_share.o
 obj-$(CONFIG_STEP_WISE)			+= step_wise.o
+obj-$(CONFIG_USER_SPACE)		+= user_space.o

drivers/thermal/user_space.c

@@ -0,0 +1,68 @@
+/*
+ *  user_space.c - A simple user space Thermal events notifier
+ *
+ *  Copyright (C) 2012 Intel Corp
+ *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/thermal.h>
+
+#include "thermal_core.h"
+
+/**
+ * notify_user_space - Notifies user space about thermal events
+ * @tz - thermal_zone_device
+ *
+ * This function notifies the user space through UEvents.
+ */
+int notify_user_space(struct thermal_zone_device *tz, int trip)
+{
+	mutex_lock(&tz->lock);
+	kobject_uevent(&tz->device.kobj, KOBJ_CHANGE);
+	mutex_unlock(&tz->lock);
+	return 0;
+}
+
+struct thermal_governor thermal_gov_user_space = {
+	.name		= "user_space",
+	.throttle	= notify_user_space,
+	.owner		= THIS_MODULE,
+};
+
+static int __init thermal_gov_user_space_init(void)
+{
+	return thermal_register_governor(&thermal_gov_user_space);
+}
+
+static void __exit thermal_gov_user_space_exit(void)
+{
+	thermal_unregister_governor(&thermal_gov_user_space);
+}
+
+/* This should load after thermal framework */
+fs_initcall(thermal_gov_user_space_init);
+module_exit(thermal_gov_user_space_exit);
+
+MODULE_AUTHOR("Durgadoss R");
+MODULE_DESCRIPTION("A user space Thermal notifier");
+MODULE_LICENSE("GPL");