[PATCH 1/3] drm/dsi: Support device shutdown

[PATCH 1/3] drm/dsi: Support device shutdown

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Hook up the MIPI DSI bus's .shutdown() function to allow drivers to
implement code that should be run when a device is shut down.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_mipi_dsi.c | 10 ++++++++++
 include/drm/drm_mipi_dsi.h     |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 09821f46d768..e633df2f68d8 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -282,6 +282,14 @@ static int mipi_dsi_drv_remove(struct device *dev)
 	return drv->remove(dsi);
 }
 
+static void mipi_dsi_drv_shutdown(struct device *dev)
+{
+	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
+
+	drv->shutdown(dsi);
+}
+
 /**
  * mipi_dsi_driver_register - register a driver for DSI devices
  * @drv: DSI driver structure
@@ -293,6 +301,8 @@ int mipi_dsi_driver_register(struct mipi_dsi_driver *drv)
 		drv->driver.probe = mipi_dsi_drv_probe;
 	if (drv->remove)
 		drv->driver.remove = mipi_dsi_drv_remove;
+	if (drv->shutdown)
+		drv->driver.shutdown = mipi_dsi_drv_shutdown;
 
 	return driver_register(&drv->driver);
 }
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 7209df15a3cd..944f33f8ba38 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -135,11 +135,13 @@ ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, unsigned int channel,
  * @driver: device driver model driver
  * @probe: callback for device binding
  * @remove: callback for device unbinding
+ * @shutdown: called at shutdown time to quiesce the device
  */
 struct mipi_dsi_driver {
 	struct device_driver driver;
 	int(*probe)(struct mipi_dsi_device *dsi);
 	int(*remove)(struct mipi_dsi_device *dsi);
+	void (*shutdown)(struct mipi_dsi_device *dsi);
 };
 
 #define to_mipi_dsi_driver(d) container_of(d, struct mipi_dsi_driver, driver)
-- 
1.9.2

[PATCH 2/3] drm/panel: simple - Disable panel on shutdown

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

When a device is shut down, disable the panel to make sure the display
backlight doesn't stay lit.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 309f29e9234a..a790f4c337cf 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -262,6 +262,13 @@ static int panel_simple_remove(struct device *dev)
 	return 0;
 }
 
+static void panel_simple_shutdown(struct device *dev)
+{
+	struct panel_simple *panel = dev_get_drvdata(dev);
+
+	panel_simple_disable(&panel->base);
+}
+
 static const struct drm_display_mode auo_b101aw03_mode = {
 	.clock = 51450,
 	.hdisplay = 1024,
@@ -412,6 +419,11 @@ static int panel_simple_platform_remove(struct platform_device *pdev)
 	return panel_simple_remove(&pdev->dev);
 }
 
+static void panel_simple_platform_shutdown(struct platform_device *pdev)
+{
+	panel_simple_shutdown(&pdev->dev);
+}
+
 static struct platform_driver panel_simple_platform_driver = {
 	.driver = {
 		.name = "panel-simple",
@@ -420,6 +432,7 @@ static struct platform_driver panel_simple_platform_driver = {
 	},
 	.probe = panel_simple_platform_probe,
 	.remove = panel_simple_platform_remove,
+	.shutdown = panel_simple_platform_shutdown,
 };
 
 struct panel_desc_dsi {
@@ -561,6 +574,11 @@ static int panel_simple_dsi_remove(struct mipi_dsi_device *dsi)
 	return panel_simple_remove(&dsi->dev);
 }
 
+static void panel_simple_dsi_shutdown(struct mipi_dsi_device *dsi)
+{
+	panel_simple_shutdown(&dsi->dev);
+}
+
 static struct mipi_dsi_driver panel_simple_dsi_driver = {
 	.driver = {
 		.name = "panel-simple-dsi",
@@ -569,6 +587,7 @@ static struct mipi_dsi_driver panel_simple_dsi_driver = {
 	},
 	.probe = panel_simple_dsi_probe,
 	.remove = panel_simple_dsi_remove,
+	.shutdown = panel_simple_dsi_shutdown,
 };
 
 static int __init panel_simple_init(void)
-- 
1.9.2

[PATCH 3/3] pwm-backlight: Disable backlight on shutdown

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

When a device is shut down, make sure to disable the backlight. If it
stays lit, it gives the impression that the device hasn't turned off.
Furthermore keeping the backlight on may consume power, which is not
what users expect when they shut down a device.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/video/backlight/pwm_bl.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 994f424eb289..b85479b14971 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -368,6 +368,14 @@ static int pwm_backlight_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void pwm_backlight_shutdown(struct platform_device *pdev)
+{
+	struct backlight_device *bl = platform_get_drvdata(pdev);
+	struct pwm_bl_data *pb = bl_get_data(bl);
+
+	pwm_backlight_power_off(pb);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int pwm_backlight_suspend(struct device *dev)
 {
@@ -413,6 +421,7 @@ static struct platform_driver pwm_backlight_driver = {
 	},
 	.probe		= pwm_backlight_probe,
 	.remove		= pwm_backlight_remove,
+	.shutdown	= pwm_backlight_shutdown,
 };
 
 module_platform_driver(pwm_backlight_driver);
-- 
1.9.2

Re: [PATCH 1/3] drm/dsi: Support device shutdown

[Stephen Warren]

On 04/29/2014 09:28 AM, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Hook up the MIPI DSI bus's .shutdown() function to allow drivers to
> implement code that should be run when a device is shut down.

The series,
Tested-by: Stephen Warren <swarren@nvidia.com>

(On an NVIDIA Tegra Dalmore board. Now, the backlight actually turns off
when the system is shut down. Note that the backlight power on this
system is directly sourced from the AC adapter for some strange reason,
rather than passing through the main system PMIC, and hence backlight
power isn't shut off even when the rest of the system really is powered off)