Re: [PATCH v10 14/17] drm: bridge: analogix/dp: try force hpd after plug in lookup failed

Yakir Yang <ykk@xxxxxxxxxxxxxx> · Wed, 9 Dec 2015 09:21:02 +0800

Hi Rob,

Thanks for your respond.

On 12/08/2015 11:09 PM, Rob Herring wrote:
On Mon, Dec 07, 2015 at 02:40:42PM +0800, Yakir Yang wrote:
Some edp screen do not have hpd signal, so we can't just return
failed when hpd plug in detect failed.

This is an hardware property, so we need add a devicetree property
"analogix,need-force-hpd" to indicate this sutiation.
I can see this being common. Just make it "force-hpd".

Okay, I would send the v10.1 out.

- Yakir

Rob

Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx>
Tested-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
---
Changes in v10: None
Changes in v9: None
Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
- Add "analogix,need-force-hpd" to indicate whether driver need foce
   hpd when hpd detect failed.

Changes in v2: None

  .../bindings/display/bridge/analogix_dp.txt        |  4 ++-
  .../bindings/display/exynos/exynos_dp.txt          |  1 +
  .../display/rockchip/analogix_dp-rockchip.txt      |  1 +
  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 36 +++++++++++++++++++---
  drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  2 ++
  drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  |  9 ++++++
  6 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
index 7659a7a..74f0e80 100644
--- a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
+++ b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
@@ -22,6 +22,9 @@ Required properties for dp-controller:
  		from general PHY binding: Should be "dp".
  
  Optional properties for dp-controller:
+	-analogix,need-force-hpd:
+		Indicate driver need force hpd when hpd detect failed, this
+		is used for some eDP screen which don't have hpd signal.
  	-hpd-gpios:
  		Hotplug detect GPIO.
  		Indicates which GPIO should be used for hotplug detection
@@ -31,7 +34,6 @@ Optional properties for dp-controller:
  		* Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
  		* Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
  
-
  [1]: Documentation/devicetree/bindings/media/video-interfaces.txt
  -------------------------------------------------------------------------------
  
diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
index 9905081..8800164 100644
--- a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
+++ b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
@@ -41,6 +41,7 @@ For the below properties, please refer to Analogix DP binding document:
  	-phys (required)
  	-phy-names (required)
  	-hpd-gpios (optional)
+	-analogix,need-force-hpd (optional)
  	-video interfaces (optional)
  
  Deprecated properties for DisplayPort:
diff --git a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
index dae86c4..1f1e594 100644
--- a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
+++ b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
@@ -32,6 +32,7 @@ For the below properties, please refer to Analogix DP binding document:
  - phys (required)
  - phy-names (required)
  - hpd-gpios (optional)
+- analogix,need-force-hpd (optional)
  -------------------------------------------------------------------------------
  
  Example:
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a11504b..94968e4 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -59,15 +59,38 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
  {
  	int timeout_loop = 0;
  
-	while (analogix_dp_get_plug_in_status(dp) != 0) {
+	while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
+		if (analogix_dp_get_plug_in_status(dp) == 0)
+			return 0;
+
  		timeout_loop++;
-		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
-			dev_err(dp->dev, "failed to get hpd plug status\n");
-			return -ETIMEDOUT;
-		}
  		usleep_range(10, 11);
  	}
  
+	/*
+	 * Some edp screen do not have hpd signal, so we can't just
+	 * return failed when hpd plug in detect failed, DT property
+	 * "need-force-hpd" would indicate whether driver need this.
+	 */
+	if (!dp->need_force_hpd)
+		return -ETIMEDOUT;
+
+	/*
+	 * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
+	 * will not work, so we need to give a force hpd action to
+	 * set HPD_STATUS manually.
+	 */
+	dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
+
+	analogix_dp_force_hpd(dp);
+
+	if (analogix_dp_get_plug_in_status(dp) != 0) {
+		dev_err(dp->dev, "failed to get hpd plug in status\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
+
  	return 0;
  }
  
@@ -1246,6 +1269,9 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
  	if (IS_ERR(dp->reg_base))
  		return PTR_ERR(dp->reg_base);
  
+	dp->need_force_hpd =
+		of_property_read_bool(dev->of_node, "analogix,need-force-hpd");
+
  	dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
  	if (!gpio_is_valid(dp->hpd_gpio))
  		dp->hpd_gpio = of_get_named_gpio(dev->of_node,
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
index e6f8243..d3c7e0a 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
@@ -160,6 +160,7 @@ struct analogix_dp_device {
  	struct phy		*phy;
  	int			dpms_mode;
  	int			hpd_gpio;
+	bool                    need_force_hpd;
  
  	struct analogix_dp_plat_data *plat_data;
  };
@@ -180,6 +181,7 @@ void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
  				       bool enable);
  void analogix_dp_init_analog_func(struct analogix_dp_device *dp);
  void analogix_dp_init_hpd(struct analogix_dp_device *dp);
+void analogix_dp_force_hpd(struct analogix_dp_device *dp);
  enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp);
  void analogix_dp_clear_hotplug_interrupts(struct analogix_dp_device *dp);
  void analogix_dp_reset_aux(struct analogix_dp_device *dp);
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 21a3287..c7e2959 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -365,6 +365,15 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp)
  	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
  }
  
+void analogix_dp_force_hpd(struct analogix_dp_device *dp)
+{
+	u32 reg;
+
+	reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+	reg = (F_HPD | HPD_CTRL);
+	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+}
+
  enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp)
  {
  	u32 reg;
--
1.9.1






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