[PATCH 4/7] drm/exynos/hdmi: add bridge support

[Inki Dae]

2017년 01월 20일 15:52에 Andrzej Hajda 이(가) 쓴 글:
> In some platforms there is attached another device to the end of HDMI.
> The patch adds support for it.

Andrzej, can you clarify what bridge device can be attached and actually is now attached to the end of HDMI?
And I wonder if we have the device tree file which defines the bridge device in mainline. Seems we have no the device tree file.

If nothing, then this patch should be merged with real use case.

Thanks.

> 
> Signed-off-by: Andrzej Hajda <a.hajda at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_hdmi.c | 56 +++++++++++++++++++++++++++++-------
>  1 file changed, 46 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
> index a73b192..41fb894 100644
> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
> @@ -35,6 +35,7 @@
>  #include <linux/io.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_graph.h>
>  #include <linux/hdmi.h>
>  #include <linux/component.h>
>  #include <linux/mfd/syscon.h>
> @@ -133,6 +134,7 @@ struct hdmi_context {
>  	struct regulator_bulk_data	regul_bulk[ARRAY_SIZE(supply)];
>  	struct regulator		*reg_hdmi_en;
>  	struct exynos_drm_clk		phy_clk;
> +	struct drm_bridge		*bridge;
>  };
>  
>  static inline struct hdmi_context *encoder_to_hdmi(struct drm_encoder *e)
> @@ -922,7 +924,15 @@ static int hdmi_create_connector(struct drm_encoder *encoder)
>  	drm_connector_register(connector);
>  	drm_mode_connector_attach_encoder(connector, encoder);
>  
> -	return 0;
> +	if (hdata->bridge) {
> +		encoder->bridge = hdata->bridge;
> +		hdata->bridge->encoder = encoder;
> +		ret = drm_bridge_attach(encoder->dev, hdata->bridge);
> +		if (ret)
> +			DRM_ERROR("Failed to attach bridge\n");
> +	}
> +
> +	return ret;
>  }
>  
>  static bool hdmi_mode_fixup(struct drm_encoder *encoder,
> @@ -1591,6 +1601,31 @@ static void hdmiphy_clk_enable(struct exynos_drm_clk *clk, bool enable)
>  		hdmiphy_disable(hdata);
>  }
>  
> +static int hdmi_bridge_init(struct hdmi_context *hdata)
> +{
> +	struct device *dev = hdata->dev;
> +	struct device_node *ep, *np;
> +
> +	ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
> +	if (!ep)
> +		return 0;
> +
> +	np = of_graph_get_remote_port_parent(ep);
> +	of_node_put(ep);
> +	if (!np) {
> +		DRM_ERROR("failed to get remote port parent");
> +		return -EINVAL;
> +	}
> +
> +	hdata->bridge = of_drm_find_bridge(np);
> +	of_node_put(np);
> +
> +	if (!hdata->bridge)
> +		return -EPROBE_DEFER;
> +
> +	return 0;
> +}
> +
>  static int hdmi_resources_init(struct hdmi_context *hdata)
>  {
>  	struct device *dev = hdata->dev;
> @@ -1630,17 +1665,18 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
>  
>  	hdata->reg_hdmi_en = devm_regulator_get_optional(dev, "hdmi-en");
>  
> -	if (PTR_ERR(hdata->reg_hdmi_en) == -ENODEV)
> -		return 0;
> +	if (PTR_ERR(hdata->reg_hdmi_en) != -ENODEV) {
> +		if (IS_ERR(hdata->reg_hdmi_en))
> +			return PTR_ERR(hdata->reg_hdmi_en);
>  
> -	if (IS_ERR(hdata->reg_hdmi_en))
> -		return PTR_ERR(hdata->reg_hdmi_en);
> -
> -	ret = regulator_enable(hdata->reg_hdmi_en);
> -	if (ret)
> -		DRM_ERROR("failed to enable hdmi-en regulator\n");
> +		ret = regulator_enable(hdata->reg_hdmi_en);
> +		if (ret) {
> +			DRM_ERROR("failed to enable hdmi-en regulator\n");
> +			return ret;
> +		}
> +	}
>  
> -	return ret;
> +	return hdmi_bridge_init(hdata);
>  }
>  
>  static struct of_device_id hdmi_match_types[] = {
>