hwmon/lis3dh: add screen on/off notifier callback

Add screen on/off notifier callback so that accelerometer
sensor can be enabled/disabled upon screen on/off operations
as it behaves on Android.

Signed-off-by: Yong Wang <yong.y.wang@intel.com>

diff --git a/drivers/hwmon/lis3dh_acc.c b/drivers/hwmon/lis3dh_acc.c
index 4d976dc..87bd633 100644 (file)
--- a/drivers/hwmon/lis3dh_acc.c
+++ b/drivers/hwmon/lis3dh_acc.c
@@ -60,6 +60,7 @@
 #include <linux/slab.h>
 #include <linux/input/lis3dh.h>
 #include <linux/earlysuspend.h>
+#include <drm/drm_mode.h>
 
 #define        DEBUG   0
 #define DEBUG_DATA_LOG 0
@@ -225,6 +226,8 @@ struct lis3dh_acc_data {
        int need_resume;
 #ifdef CONFIG_HAS_EARLYSUSPEND
        struct early_suspend es;
+#else
+       struct notifier_block screen_notifier;
 #endif
 
        u8 sensitivity;
@@ -1125,6 +1128,43 @@ static void lis3dh_last_resume(struct device *dev)
        mutex_unlock(&acc->lock);
 }
 
+#ifndef CONFIG_HAS_EARLYSUSPEND
+extern int screen_register_receiver(struct notifier_block *nb);
+extern int screen_unregister_receiver(struct notifier_block *nb);
+
+static bool lis3dh_enabled;
+
+static int lis3dh_screen_notifier_callback(struct notifier_block *self,
+                                   unsigned long event_type, void *nt_data)
+{
+       struct lis3dh_acc_data *acc = container_of(self,
+                               struct lis3dh_acc_data, screen_notifier);
+       struct device *dev = &acc->client->dev;
+
+       if(dev == NULL)
+               return 0;
+
+       switch (event_type) {
+       case DRM_MODE_DPMS_ON:
+               if (lis3dh_enabled == false) {
+                       lis3dh_last_resume(dev);
+                       lis3dh_enabled = true;
+               }
+               break;
+       case DRM_MODE_DPMS_OFF:
+               if (lis3dh_enabled == true) {
+                       lis3dh_first_suspend(dev);
+                       lis3dh_enabled = false;
+               }
+               break;
+       default:
+               break;
+       }
+
+       return 0;
+}
+#endif
+
 static int lis3dh_acc_probe(struct i2c_client *client,
                            const struct i2c_device_id *id)
 {
@@ -1226,6 +1266,10 @@ static int lis3dh_acc_probe(struct i2c_client *client,
        acc->es.suspend = lis3dh_early_suspend;
        acc->es.resume = lis3dh_late_resume;
        register_early_suspend(&acc->es);
+#else
+       lis3dh_enabled = true;
+       acc->screen_notifier.notifier_call = lis3dh_screen_notifier_callback;
+       screen_register_receiver(&acc->screen_notifier);
 #endif
 
        mutex_unlock(&acc->lock);
@@ -1265,6 +1309,8 @@ static int __devexit lis3dh_acc_remove(struct i2c_client *client)
        sysfs_remove_group(&client->dev.kobj, &lis3dh_attr_group);
 #ifdef CONFIG_HAS_EARLYSUSPEND
        unregister_early_suspend(&acc->es);
+#else
+       screen_unregister_receiver(&acc->screen_notifier);
 #endif
 
        if (acc->pdata->exit)
@@ -1278,17 +1324,11 @@ static int __devexit lis3dh_acc_remove(struct i2c_client *client)
 #ifdef CONFIG_PM_SLEEP
 static int lis3dh_acc_resume(struct device *dev)
 {
-#ifndef CONFIG_HAS_EARLYSUSPEND
-       lis3dh_last_resume(dev);
-#endif
        return 0;
 }
 
 static int lis3dh_acc_suspend(struct device *dev)
 {
-#ifndef CONFIG_HAS_EARLYSUSPEND
-       lis3dh_first_suspend(dev);
-#endif
        return 0;
 }
 #endif /* CONFIG_PM_SLEEP */