msm: mdss: Notify userspace of idle screen case

Expose two new sysfs nodes - idle_time and idle_notify - that
are used to notify userspace whenever the display is idle with
no screen updates. The idle_time node needs to be configured
with the duration in milliseconds to detect no screen updates.
The userspace app can poll on the idle_notify node to get
notifications of the idle state.

Change-Id: I7435a084ad2c928d952c5d106ff9ef92aaa385b9
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>

2 files changed, 79 insertions, 0 deletions

diff --git a/drivers/video/fbdev/msm/mdss_fb.c b/drivers/video/fbdev/msm/mdss_fb.c
index 4f6f204069aa..c68b1c25797e 100644
--- a/drivers/video/fbdev/msm/mdss_fb.c
+++ b/drivers/video/fbdev/msm/mdss_fb.c
@@ -327,14 +327,75 @@ static ssize_t mdss_mdp_show_blank_event(struct device *dev,
 	return ret;
 }
 
+static void __mdss_fb_idle_notify_work(struct work_struct *work)
+{
+	struct delayed_work *dw = to_delayed_work(work);
+	struct msm_fb_data_type *mfd = container_of(dw, struct msm_fb_data_type,
+		idle_notify_work);
+
+	/* Notify idle-ness here */
+	pr_debug("Idle timeout %dms expired!\n", mfd->idle_time);
+	sysfs_notify(&mfd->fbi->dev->kobj, NULL, "idle_notify");
+}
+
+static ssize_t mdss_fb_get_idle_time(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fbi = dev_get_drvdata(dev);
+	struct msm_fb_data_type *mfd = fbi->par;
+	int ret;
+
+	ret = scnprintf(buf, PAGE_SIZE, "%d", mfd->idle_time);
+
+	return ret;
+}
+
+static ssize_t mdss_fb_set_idle_time(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct fb_info *fbi = dev_get_drvdata(dev);
+	struct msm_fb_data_type *mfd = fbi->par;
+	int rc = 0;
+	int idle_time = 0;
+
+	rc = kstrtoint(buf, 10, &idle_time);
+	if (rc) {
+		pr_err("kstrtoint failed. rc=%d\n", rc);
+		return rc;
+	}
+
+	pr_debug("Idle time = %d\n", idle_time);
+	mfd->idle_time = idle_time;
+
+	return count;
+}
+
+static ssize_t mdss_fb_get_idle_notify(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct fb_info *fbi = dev_get_drvdata(dev);
+	struct msm_fb_data_type *mfd = fbi->par;
+	int ret;
+
+	ret = scnprintf(buf, PAGE_SIZE, "%s",
+		work_busy(&mfd->idle_notify_work.work) ? "no" : "yes");
+
+	return ret;
+}
+
 static DEVICE_ATTR(msm_fb_type, S_IRUGO, mdss_fb_get_type, NULL);
 static DEVICE_ATTR(msm_fb_split, S_IRUGO, mdss_fb_get_split, NULL);
 static DEVICE_ATTR(show_blank_event, S_IRUGO, mdss_mdp_show_blank_event, NULL);
+static DEVICE_ATTR(idle_time, S_IRUGO | S_IWUSR | S_IWGRP,
+	mdss_fb_get_idle_time, mdss_fb_set_idle_time);
+static DEVICE_ATTR(idle_notify, S_IRUGO, mdss_fb_get_idle_notify, NULL);
 
 static struct attribute *mdss_fb_attrs[] = {
 	&dev_attr_msm_fb_type.attr,
 	&dev_attr_msm_fb_split.attr,
 	&dev_attr_show_blank_event.attr,
+	&dev_attr_idle_time.attr,
+	&dev_attr_idle_notify.attr,
 	NULL,
 };
 
@@ -489,6 +550,8 @@ static int mdss_fb_probe(struct platform_device *pdev)
 		}
 	}
 
+	INIT_DELAYED_WORK(&mfd->idle_notify_work, __mdss_fb_idle_notify_work);
+
 	return rc;
 }
 
@@ -803,6 +866,11 @@ static int mdss_fb_blank_sub(int blank_mode, struct fb_info *info,
 			mfd->update.type = NOTIFY_TYPE_UPDATE;
 			mfd->update.is_suspend = 0;
 			mutex_unlock(&mfd->update.lock);
+
+			/* Start the work thread to signal idle time */
+			if (mfd->idle_time)
+				schedule_delayed_work(&mfd->idle_notify_work,
+					msecs_to_jiffies(mfd->idle_time));
 		}
 		break;
 
@@ -1555,10 +1623,18 @@ static int __mdss_fb_sync_buf_done_callback(struct notifier_block *p,
 		unsigned long event, void *data)
 {
 	struct msm_sync_pt_data *sync_pt_data;
+	struct msm_fb_data_type *mfd;
 
 	sync_pt_data = container_of(p, struct msm_sync_pt_data, notifier);
+	mfd = container_of(sync_pt_data, struct msm_fb_data_type,
+		mdp_sync_pt_data);
 
 	switch (event) {
+	case MDP_NOTIFY_FRAME_BEGIN:
+		if (mfd->idle_time)
+			mod_delayed_work(system_wq, &mfd->idle_notify_work,
+				msecs_to_jiffies(mfd->idle_time));
+		break;
 	case MDP_NOTIFY_FRAME_READY:
 		if (sync_pt_data->async_wait_fences)
 			mdss_fb_wait_for_fence(sync_pt_data);
diff --git a/drivers/video/fbdev/msm/mdss_fb.h b/drivers/video/fbdev/msm/mdss_fb.h
index 6718da87cd23..7811f7f9f347 100644
--- a/drivers/video/fbdev/msm/mdss_fb.h
+++ b/drivers/video/fbdev/msm/mdss_fb.h
@@ -172,6 +172,9 @@ struct msm_fb_data_type {
 	u32 dest;
 	struct fb_info *fbi;
 
+	int idle_time;
+	struct delayed_work idle_notify_work;
+
 	int op_enable;
 	u32 fb_imgType;
 	int panel_reconfig;