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

From: Rob Herring
Date: Tue Dec 08 2015 - 10:10:08 EST

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".

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
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/