msm: mdss: add sysfs node for AD backlight notification

This change adds a sysfs node for assertive display attenuation
backlight change notification. Any AD related backlight notification
will be posted to the ad_bl_event sysfs node, so userspace clients
can be notified if they poll on the same sysfs node.
It will simplify and optimize the previous notification ioctl
implementation.

Change-Id: I7a8f86563d5802a41dc200f5901a8d0bed1cf765
Signed-off-by: Ping Li <pingli@codeaurora.org>

4 files changed, 52 insertions, 9 deletions

diff --git a/drivers/video/fbdev/msm/mdss_fb.c b/drivers/video/fbdev/msm/mdss_fb.c
index 2d5f3af80c52..761cb9546ea4 100644
--- a/drivers/video/fbdev/msm/mdss_fb.c
+++ b/drivers/video/fbdev/msm/mdss_fb.c
@@ -122,7 +122,8 @@ void mdss_fb_no_update_notify_timer_cb(unsigned long data)
 	complete(&mfd->no_update.comp);
 }
 
-void mdss_fb_bl_update_notify(struct msm_fb_data_type *mfd)
+void mdss_fb_bl_update_notify(struct msm_fb_data_type *mfd,
+		uint32_t notification_type)
 {
 	struct mdss_overlay_private *mdp5_data = NULL;
 	if (!mfd) {
@@ -130,9 +131,13 @@ void mdss_fb_bl_update_notify(struct msm_fb_data_type *mfd)
 		return;
 	}
 	mutex_lock(&mfd->update.lock);
+	if (mfd->update.is_suspend) {
+		mutex_unlock(&mfd->update.lock);
+		return;
+	}
 	if (mfd->update.ref_count > 0) {
 		mutex_unlock(&mfd->update.lock);
-		mfd->update.value = NOTIFY_TYPE_BL_UPDATE;
+		mfd->update.value = notification_type;
 		complete(&mfd->update.comp);
 		mutex_lock(&mfd->update.lock);
 	}
@@ -141,15 +146,20 @@ void mdss_fb_bl_update_notify(struct msm_fb_data_type *mfd)
 	mutex_lock(&mfd->no_update.lock);
 	if (mfd->no_update.ref_count > 0) {
 		mutex_unlock(&mfd->no_update.lock);
-		mfd->no_update.value = NOTIFY_TYPE_BL_UPDATE;
+		mfd->no_update.value = notification_type;
 		complete(&mfd->no_update.comp);
 		mutex_lock(&mfd->no_update.lock);
 	}
 	mutex_unlock(&mfd->no_update.lock);
 	mdp5_data = mfd_to_mdp5_data(mfd);
 	if (mdp5_data) {
-		mdp5_data->bl_events++;
-		sysfs_notify_dirent(mdp5_data->bl_event_sd);
+		if (notification_type == NOTIFY_TYPE_BL_AD_ATTEN_UPDATE) {
+			mdp5_data->ad_bl_events++;
+			sysfs_notify_dirent(mdp5_data->ad_bl_event_sd);
+		} else if (notification_type == NOTIFY_TYPE_BL_UPDATE) {
+			mdp5_data->bl_events++;
+			sysfs_notify_dirent(mdp5_data->bl_event_sd);
+		}
 	}
 }
 
@@ -1221,6 +1231,7 @@ void mdss_fb_set_backlight(struct msm_fb_data_type *mfd, u32 bkl_lvl)
 {
 	struct mdss_panel_data *pdata;
 	u32 temp = bkl_lvl;
+	bool ad_bl_notify_needed = false;
 	bool bl_notify_needed = false;
 
 	if ((((mdss_fb_is_power_off(mfd) && mfd->dcm_state != DCM_ENTER)
@@ -1237,9 +1248,7 @@ void mdss_fb_set_backlight(struct msm_fb_data_type *mfd, u32 bkl_lvl)
 	if ((pdata) && (pdata->set_backlight)) {
 		if (mfd->mdp.ad_calc_bl)
 			(*mfd->mdp.ad_calc_bl)(mfd, temp, &temp,
-							&bl_notify_needed);
-		if (bl_notify_needed)
-			mdss_fb_bl_update_notify(mfd);
+							&ad_bl_notify_needed);
 		if (!IS_CALIB_MODE_BL(mfd))
 			mdss_fb_scale_bl(mfd, &temp);
 		/*
@@ -1253,11 +1262,19 @@ void mdss_fb_set_backlight(struct msm_fb_data_type *mfd, u32 bkl_lvl)
 		if (mfd->bl_level_scaled == temp) {
 			mfd->bl_level = bkl_lvl;
 		} else {
+			if (mfd->bl_level != bkl_lvl)
+				bl_notify_needed = true;
 			pr_debug("backlight sent to panel :%d\n", temp);
 			pdata->set_backlight(pdata, temp);
 			mfd->bl_level = bkl_lvl;
 			mfd->bl_level_scaled = temp;
 		}
+		if (ad_bl_notify_needed)
+			mdss_fb_bl_update_notify(mfd,
+				NOTIFY_TYPE_BL_AD_ATTEN_UPDATE);
+		else if (bl_notify_needed)
+			mdss_fb_bl_update_notify(mfd,
+				NOTIFY_TYPE_BL_UPDATE);
 	}
 }
 
@@ -1279,7 +1296,8 @@ void mdss_fb_update_backlight(struct msm_fb_data_type *mfd)
 				(*mfd->mdp.ad_calc_bl)(mfd, temp, &temp,
 								&bl_notify);
 			if (bl_notify)
-				mdss_fb_bl_update_notify(mfd);
+				mdss_fb_bl_update_notify(mfd,
+					NOTIFY_TYPE_BL_AD_ATTEN_UPDATE);
 			pdata->set_backlight(pdata, temp);
 			mfd->bl_level_scaled = mfd->unset_bl_level;
 			mfd->bl_updated = 1;
diff --git a/drivers/video/fbdev/msm/mdss_mdp.h b/drivers/video/fbdev/msm/mdss_mdp.h
index f711dc86b3ec..8a0ad0835c65 100644
--- a/drivers/video/fbdev/msm/mdss_mdp.h
+++ b/drivers/video/fbdev/msm/mdss_mdp.h
@@ -563,6 +563,7 @@ struct mdss_overlay_private {
 	struct kernfs_node *hist_event_sd;
 	struct kernfs_node *bl_event_sd;
 	struct kernfs_node *ad_event_sd;
+	struct kernfs_node *ad_bl_event_sd;
 	int borderfill_enable;
 	int overlay_play_enable;
 	int hw_refresh;
@@ -604,6 +605,7 @@ struct mdss_overlay_private {
 	u32 hist_events;
 	u32 bl_events;
 	u32 ad_events;
+	u32 ad_bl_events;
 };
 
 struct mdss_mdp_set_ot_params {
diff --git a/drivers/video/fbdev/msm/mdss_mdp_overlay.c b/drivers/video/fbdev/msm/mdss_mdp_overlay.c
index bdfbc9725743..8f05d9c37939 100644
--- a/drivers/video/fbdev/msm/mdss_mdp_overlay.c
+++ b/drivers/video/fbdev/msm/mdss_mdp_overlay.c
@@ -2713,6 +2713,18 @@ static ssize_t mdss_mdp_ad_show_event(struct device *dev,
 	return ret;
 }
 
+static ssize_t mdss_mdp_ad_bl_show_event(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fbi = dev_get_drvdata(dev);
+	struct msm_fb_data_type *mfd = (struct msm_fb_data_type *)fbi->par;
+	struct mdss_overlay_private *mdp5_data = mfd_to_mdp5_data(mfd);
+	int ret;
+
+	ret = scnprintf(buf, PAGE_SIZE, "%d\n", mdp5_data->ad_bl_events);
+	return ret;
+}
+
 static inline int mdss_mdp_ad_is_supported(struct msm_fb_data_type *mfd)
 {
 	struct mdss_mdp_ctl *ctl = mfd_to_ctl(mfd);
@@ -2930,6 +2942,7 @@ static DEVICE_ATTR(dyn_pu, S_IRUGO | S_IWUSR | S_IWGRP, mdss_mdp_dyn_pu_show,
 static DEVICE_ATTR(hist_event, S_IRUGO, mdss_mdp_hist_show_event, NULL);
 static DEVICE_ATTR(bl_event, S_IRUGO, mdss_mdp_bl_show_event, NULL);
 static DEVICE_ATTR(ad_event, S_IRUGO, mdss_mdp_ad_show_event, NULL);
+static DEVICE_ATTR(ad_bl_event, S_IRUGO, mdss_mdp_ad_bl_show_event, NULL);
 
 static struct attribute *mdp_overlay_sysfs_attrs[] = {
 	&dev_attr_vsync_event.attr,
@@ -2939,6 +2952,7 @@ static struct attribute *mdp_overlay_sysfs_attrs[] = {
 	&dev_attr_hist_event.attr,
 	&dev_attr_bl_event.attr,
 	&dev_attr_ad_event.attr,
+	&dev_attr_ad_bl_event.attr,
 	NULL,
 };
 
@@ -4928,6 +4942,14 @@ int mdss_mdp_overlay_init(struct msm_fb_data_type *mfd)
 		goto init_fail;
 	}
 
+	mdp5_data->ad_bl_event_sd = sysfs_get_dirent(dev->kobj.sd,
+							 "ad_bl_event");
+	if (!mdp5_data->ad_bl_event_sd) {
+		pr_err("ad_bl_event sysfs lookup failed\n");
+		rc = -ENODEV;
+		goto init_fail;
+	}
+
 	rc = sysfs_create_link_nowarn(&dev->kobj,
 			&mdp5_data->mdata->pdev->dev.kobj, "mdp");
 	if (rc)
diff --git a/include/uapi/linux/msm_mdp.h b/include/uapi/linux/msm_mdp.h
index c06954354b06..4fbaaac79b98 100644
--- a/include/uapi/linux/msm_mdp.h
+++ b/include/uapi/linux/msm_mdp.h
@@ -125,6 +125,7 @@ enum {
 	NOTIFY_TYPE_SUSPEND,
 	NOTIFY_TYPE_UPDATE,
 	NOTIFY_TYPE_BL_UPDATE,
+	NOTIFY_TYPE_BL_AD_ATTEN_UPDATE,
 };
 
 enum {