video: tegra: dc: support for vblank sync

Add wait for vsync support for one-shot panels. The code supports extension
of this feature to other panels.

Bug 1033411.

Change-Id: Ie4d6cb45e5de81083458169ccdfa33230235ed72
Signed-off-by: Rakesh Iyer <riyer@nvidia.com>
Reviewed-on: http://git-master/r/128927
Reviewed-by: Mrutyunjay Sawant <msawant@nvidia.com>
Tested-by: Mrutyunjay Sawant <msawant@nvidia.com>

5 files changed, 129 insertions, 15 deletions

diff --git a/arch/arm/mach-tegra/include/mach/dc.h b/arch/arm/mach-tegra/include/mach/dc.h
index 3483fe91ce66..d7aaed0bdcdc 100644
--- a/arch/arm/mach-tegra/include/mach/dc.h
+++ b/arch/arm/mach-tegra/include/mach/dc.h
@@ -24,6 +24,7 @@
 
 #include <linux/pm.h>
 #include <linux/types.h>
+#include <linux/fb.h>
 #include <drm/drm_fixed.h>
 
 #define TEGRA_MAX_DC		2
@@ -368,6 +369,8 @@ struct tegra_dc_out {
 
 	u8			*out_sel_configs;
 	unsigned		n_out_sel_configs;
+	bool			user_needs_vblank;
+	struct completion	user_vblank_comp;
 
 	int	(*enable)(void);
 	int	(*postpoweron)(void);
@@ -525,6 +528,8 @@ bool tegra_dc_get_connected(struct tegra_dc *);
 bool tegra_dc_hpd(struct tegra_dc *dc);
 
 
+void tegra_dc_get_fbvblank(struct tegra_dc *dc, struct fb_vblank *vblank);
+int tegra_dc_wait_for_vsync(struct tegra_dc *dc);
 void tegra_dc_blank(struct tegra_dc *dc);
 
 void tegra_dc_enable(struct tegra_dc *dc);
diff --git a/drivers/video/tegra/dc/dc.c b/drivers/video/tegra/dc/dc.c
index a3011b873aae..80d052a61e12 100644
--- a/drivers/video/tegra/dc/dc.c
+++ b/drivers/video/tegra/dc/dc.c
@@ -873,6 +873,36 @@ static inline void enable_dc_irq(unsigned int irq)
 #endif
 }
 
+void tegra_dc_get_fbvblank(struct tegra_dc *dc, struct fb_vblank *vblank)
+{
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE)
+		vblank->flags = FB_VBLANK_HAVE_VSYNC;
+}
+
+int tegra_dc_wait_for_vsync(struct tegra_dc *dc)
+{
+	int ret = -ENOTTY;
+
+	if (!(dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE) || !dc->enabled)
+		return ret;
+
+	/*
+	 * Logic is as follows
+	 * a) Indicate we need a vblank.
+	 * b) Wait for completion to be signalled from isr.
+	 * c) Initialize completion for next iteration.
+	 */
+
+	tegra_dc_hold_dc_out(dc);
+	dc->out->user_needs_vblank = true;
+
+	ret = wait_for_completion_interruptible(&dc->out->user_vblank_comp);
+	init_completion(&dc->out->user_vblank_comp);
+	tegra_dc_release_dc_out(dc);
+
+	return ret;
+}
+
 static void tegra_dc_vblank(struct work_struct *work)
 {
 	struct tegra_dc *dc = container_of(work, struct tegra_dc, vblank_work);
@@ -1023,6 +1053,13 @@ static void tegra_dc_underflow_handler(struct tegra_dc *dc)
 #ifndef CONFIG_TEGRA_FPGA_PLATFORM
 static void tegra_dc_one_shot_irq(struct tegra_dc *dc, unsigned long status)
 {
+	/* pending user vblank, so wakeup */
+	if ((status & (V_BLANK_INT | MSF_INT)) &&
+	    (dc->out->user_needs_vblank)) {
+		dc->out->user_needs_vblank = false;
+		complete(&dc->out->user_vblank_comp);
+	}
+
 	if (status & V_BLANK_INT) {
 		/* Sync up windows. */
 		tegra_dc_trigger_windows(dc);
@@ -1232,6 +1269,7 @@ static u32 get_syncpt(struct tegra_dc *dc, int idx)
 static int tegra_dc_init(struct tegra_dc *dc)
 {
 	int i;
+	int int_enable;
 
 	tegra_dc_writel(dc, 0x00000100, DC_CMD_GENERAL_INCR_SYNCPT_CNTRL);
 	if (dc->ndev->id == 0) {
@@ -1267,8 +1305,12 @@ static int tegra_dc_init(struct tegra_dc *dc)
 	tegra_dc_writel(dc, 0x00000000, DC_DISP_DISP_MISC_CONTROL);
 #endif
 	/* enable interrupts for vblank, frame_end and underflows */
-	tegra_dc_writel(dc, (FRAME_END_INT | V_BLANK_INT | ALL_UF_INT),
-		DC_CMD_INT_ENABLE);
+	int_enable = (FRAME_END_INT | V_BLANK_INT | ALL_UF_INT);
+	/* for panels with one-shot mode enable tearing effect interrupt */
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE)
+		int_enable |= MSF_INT;
+
+	tegra_dc_writel(dc, int_enable, DC_CMD_INT_ENABLE);
 	tegra_dc_writel(dc, ALL_UF_INT, DC_CMD_INT_MASK);
 
 	tegra_dc_writel(dc, 0x00000000, DC_DISP_BORDER_COLOR);
diff --git a/drivers/video/tegra/dc/dc_sysfs.c b/drivers/video/tegra/dc/dc_sysfs.c
index bf27e963f233..09a8e2dbb5b1 100644
--- a/drivers/video/tegra/dc/dc_sysfs.c
+++ b/drivers/video/tegra/dc/dc_sysfs.c
@@ -313,6 +313,14 @@ static ssize_t nvdps_store(struct device *dev,
 
 static DEVICE_ATTR(nvdps, S_IRUGO|S_IWUSR, nvdps_show, nvdps_store);
 
+static ssize_t smart_panel_show(struct device *device,
+	struct device_attribute *attr, char  *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "1\n");
+}
+
+static DEVICE_ATTR(smart_panel, S_IRUGO, smart_panel_show, NULL);
+
 void __devexit tegra_dc_remove_sysfs(struct device *dev)
 {
 	struct nvhost_device *ndev = to_nvhost_device(dev);
@@ -332,6 +340,9 @@ void __devexit tegra_dc_remove_sysfs(struct device *dev)
 
 	if (sd_settings)
 		nvsd_remove_sysfs(dev);
+
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE)
+		device_remove_file(dev, &dev_attr_smart_panel);
 }
 
 void tegra_dc_create_sysfs(struct device *dev)
@@ -355,6 +366,9 @@ void tegra_dc_create_sysfs(struct device *dev)
 	if (sd_settings)
 		error |= nvsd_create_sysfs(dev);
 
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE)
+		error |= device_create_file(dev, &dev_attr_smart_panel);
+
 	if (error)
 		dev_err(&ndev->dev, "Failed to create sysfs attributes!\n");
 }
diff --git a/drivers/video/tegra/dc/dsi.c b/drivers/video/tegra/dc/dsi.c
index 4a9e507bcdb9..d3b1d40d535b 100644
--- a/drivers/video/tegra/dc/dsi.c
+++ b/drivers/video/tegra/dc/dsi.c
@@ -79,6 +79,8 @@
 #define DSI_LP_OP_WRITE			0x1
 #define DSI_LP_OP_READ			0x2
 
+#define DSI_HOST_IDLE_PERIOD		1000
+
 static bool enable_read_debug;
 module_param(enable_read_debug, bool, 0644);
 MODULE_PARM_DESC(enable_read_debug,
@@ -129,6 +131,11 @@ struct tegra_dc_dsi_data {
 	bool ulpm;
 	bool enabled;
 	bool host_suspended;
+	struct mutex host_resume_lock;
+	struct delayed_work idle_work;
+	unsigned long idle_delay;
+	spinlock_t host_ref_lock;
+	u8 host_ref;
 
 	u8 driven_mode;
 	u8 controller_index;
@@ -296,6 +303,7 @@ const u32 init_reg[] = {
 
 static int tegra_dsi_host_suspend(struct tegra_dc *dc);
 static int tegra_dsi_host_resume(struct tegra_dc *dc);
+static void tegra_dc_dsi_idle_work(struct work_struct *work);
 
 inline unsigned long tegra_dsi_readl(struct tegra_dc_dsi_data *dsi, u32 reg)
 {
@@ -654,6 +662,13 @@ static void tegra_dsi_init_sw(struct tegra_dc *dc,
 		dsi->info.video_clock_mode = TEGRA_DSI_VIDEO_CLOCK_CONTINUOUS;
 	}
 
+	dsi->host_ref = 0;
+	dsi->host_suspended = false;
+	spin_lock_init(&dsi->host_ref_lock);
+	mutex_init(&dsi->host_resume_lock);
+	init_completion(&dc->out->user_vblank_comp);
+	INIT_DELAYED_WORK(&dsi->idle_work, tegra_dc_dsi_idle_work);
+	dsi->idle_delay = msecs_to_jiffies(DSI_HOST_IDLE_PERIOD);
 }
 
 #define SELECT_T_PHY(platform_t_phy_ns, default_phy, clk_ns, hw_inc) ( \
@@ -1373,6 +1388,10 @@ static void tegra_dsi_soft_reset(struct tegra_dc_dsi_data *dsi)
 static void tegra_dsi_stop_dc_stream(struct tegra_dc *dc,
 					struct tegra_dc_dsi_data *dsi)
 {
+	/* Mask the MSF interrupt. */
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_MODE)
+		tegra_dc_mask_interrupt(dc, MSF_INT);
+
 	tegra_dc_writel(dc, DISP_CTRL_MODE_STOP, DC_CMD_DISPLAY_COMMAND);
 	tegra_dc_writel(dc, 0, DC_DISP_DISP_WIN_OPTIONS);
 	tegra_dc_writel(dc, GENERAL_UPDATE, DC_CMD_STATE_CONTROL);
@@ -1453,6 +1472,9 @@ static void tegra_dsi_start_dc_stream(struct tegra_dc *dc,
 		tegra_dc_writel(dc, GENERAL_UPDATE, DC_CMD_STATE_CONTROL);
 		tegra_dc_writel(dc, GENERAL_ACT_REQ | NC_HOST_TRIG,
 						DC_CMD_STATE_CONTROL);
+
+		/* Unmask the MSF interrupt. */
+		tegra_dc_unmask_interrupt(dc, MSF_INT);
 	} else {
 		/* set continuous mode */
 		tegra_dc_writel(dc, DISP_CTRL_MODE_C_DISPLAY,
@@ -2114,13 +2136,10 @@ static void tegra_dc_dsi_hold_host(struct tegra_dc *dc)
 	struct tegra_dc_dsi_data *dsi = tegra_dc_get_outdata(dc);
 
 	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_LP_MODE) {
-		/*
-		 * The reference count should never be more than 1.
-		 */
-		BUG_ON(tegra_is_clk_enabled(dc->clk) > 1);
-
-		if (dsi->host_suspended)
-			tegra_dsi_host_resume(dc);
+		spin_lock(&dsi->host_ref_lock);
+		dsi->host_ref++;
+		spin_unlock(&dsi->host_ref_lock);
+		tegra_dsi_host_resume(dc);
 
 		/*
 		 * Take an extra refrence to count for the clk_disable in
@@ -2132,14 +2151,27 @@ static void tegra_dc_dsi_hold_host(struct tegra_dc *dc)
 
 static void tegra_dc_dsi_release_host(struct tegra_dc *dc)
 {
-	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_LP_MODE)
+	struct tegra_dc_dsi_data *dsi = tegra_dc_get_outdata(dc);
+	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_LP_MODE) {
 		clk_disable(dc->clk);
+		spin_lock(&dsi->host_ref_lock);
+		dsi->host_ref--;
+
+		if (!dsi->host_ref &&
+		    (dsi->status.dc_stream == DSI_DC_STREAM_ENABLE))
+			schedule_delayed_work(&dsi->idle_work, dsi->idle_delay);
+
+		spin_unlock(&dsi->host_ref_lock);
+	}
 }
 
-static void tegra_dc_dsi_idle(struct tegra_dc *dc)
+static void tegra_dc_dsi_idle_work(struct work_struct *work)
 {
-	if (dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_LP_MODE)
-		tegra_dsi_host_suspend(dc);
+	struct tegra_dc_dsi_data *dsi = container_of(
+		to_delayed_work(work), struct tegra_dc_dsi_data, idle_work);
+
+	if (dsi->dc->out->flags & TEGRA_DC_OUT_ONE_SHOT_LP_MODE)
+		tegra_dsi_host_suspend(dsi->dc);
 }
 
 int tegra_dsi_write_data(struct tegra_dc *dc,
@@ -3297,6 +3329,8 @@ static int tegra_dsi_host_suspend(struct tegra_dc *dc)
 	if (dsi->host_suspended)
 		return 0;
 
+	BUG_ON(!tegra_is_clk_enabled(dc->clk));
+	tegra_dc_io_start(dc);
 	dsi->host_suspended = true;
 
 	tegra_dsi_stop_dc_stream(dc, dsi);
@@ -3308,6 +3342,7 @@ static int tegra_dsi_host_suspend(struct tegra_dc *dc)
 
 	tegra_dc_clk_disable(dc);
 
+	tegra_dc_io_end(dc);
 	return err;
 }
 
@@ -3317,8 +3352,12 @@ static int tegra_dsi_host_resume(struct tegra_dc *dc)
 	int err = 0;
 	struct tegra_dc_dsi_data *dsi = tegra_dc_get_outdata(dc);
 
-	if (!dsi->host_suspended)
+	mutex_lock(&dsi->host_resume_lock);
+	cancel_delayed_work_sync(&dsi->idle_work);
+	if (!dsi->host_suspended) {
+		mutex_unlock(&dsi->host_resume_lock);
 		return 0;
+	}
 
 	tegra_dc_clk_enable(dc);
 	switch (dsi->info.suspend_aggr) {
@@ -3366,8 +3405,10 @@ static int tegra_dsi_host_resume(struct tegra_dc *dc)
 	}
 
 	tegra_dsi_start_dc_stream(dc, dsi);
+
 	dsi->enabled = true;
 	dsi->host_suspended = false;
+	mutex_unlock(&dsi->host_resume_lock);
 fail:
 	return err;
 }
@@ -3462,7 +3503,6 @@ struct tegra_dc_out_ops tegra_dc_dsi_ops = {
 	.disable = tegra_dc_dsi_disable,
 	.hold = tegra_dc_dsi_hold_host,
 	.release = tegra_dc_dsi_release_host,
-	.idle = tegra_dc_dsi_idle,
 #ifdef CONFIG_PM
 	.suspend = tegra_dc_dsi_suspend,
 	.resume = tegra_dc_dsi_resume,
diff --git a/drivers/video/tegra/fb.c b/drivers/video/tegra/fb.c
index a9964946f2cc..69b30884e4df 100644
--- a/drivers/video/tegra/fb.c
+++ b/drivers/video/tegra/fb.c
@@ -325,8 +325,10 @@ static void tegra_fb_imageblit(struct fb_info *info,
 
 static int tegra_fb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
 {
+	struct tegra_fb_info *tegra_fb = (struct tegra_fb_info *)info->par;
 	struct tegra_fb_modedb modedb;
 	struct fb_modelist *modelist;
+	struct fb_vblank vblank = {};
 	int i;
 
 	switch (cmd) {
@@ -369,6 +371,17 @@ static int tegra_fb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long
 			return -EFAULT;
 		break;
 
+	case FBIOGET_VBLANK:
+		tegra_dc_get_fbvblank(tegra_fb->win->dc, &vblank);
+
+		if (copy_to_user(
+			(void __user *)arg, &vblank, sizeof(vblank)))
+			return -EFAULT;
+		break;
+
+	case FBIO_WAITFORVSYNC:
+		return tegra_dc_wait_for_vsync(tegra_fb->win->dc);
+
 	default:
 		return -ENOTTY;
 	}