Re: [PATCH v4 07/11] drm/meson: meson_dw_hdmi: add bridge and switch to drm_bridge_funcs

From: Neil Armstrong <narmstrong@baylibre.com>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: jernej.skrabec@siol.net, jonas@kwiboo.se,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com,
	linux-amlogic@lists.infradead.org
Subject: Re: [PATCH v4 07/11] drm/meson: meson_dw_hdmi: add bridge and switch to drm_bridge_funcs
Date: Fri, 7 Feb 2020 16:36:01 +0100	[thread overview]
Message-ID: <b4a29800-7d87-221b-24a5-a53d141800c3@baylibre.com> (raw)
In-Reply-To: <20200207155743.24ee9bf0@collabora.com>

On 07/02/2020 15:57, Boris Brezillon wrote:
> On Thu,  6 Feb 2020 20:18:30 +0100
> Neil Armstrong <narmstrong@baylibre.com> wrote:
> 
>> Switch the dw-hdmi driver to drm_bridge_funcs by implementing a new local
>> bridge, connecting it to the dw-hdmi bridge, then implement the
>> atomic_get_input_bus_fmts/atomic_get_output_bus_fmts.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>  drivers/gpu/drm/meson/meson_dw_hdmi.c | 105 +++++++++++++++++++++-----
>>  1 file changed, 85 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> index 3bb7ffe5fc39..4b3809626f7e 100644
>> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
>> @@ -16,6 +16,7 @@
>>  
>>  #include <drm/bridge/dw_hdmi.h>
>>  #include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_bridge.h>
>>  #include <drm/drm_device.h>
>>  #include <drm/drm_edid.h>
>>  #include <drm/drm_probe_helper.h>
>> @@ -135,6 +136,7 @@ struct meson_dw_hdmi_data {
>>  
>>  struct meson_dw_hdmi {
>>  	struct drm_encoder encoder;
>> +	struct drm_bridge bridge;
>>  	struct dw_hdmi_plat_data dw_plat_data;
>>  	struct meson_drm *priv;
>>  	struct device *dev;
>> @@ -151,6 +153,8 @@ struct meson_dw_hdmi {
>>  };
>>  #define encoder_to_meson_dw_hdmi(x) \
>>  	container_of(x, struct meson_dw_hdmi, encoder)
>> +#define bridge_to_meson_dw_hdmi(x) \
>> +	container_of(x, struct meson_dw_hdmi, bridge)
>>  
>>  static inline int dw_hdmi_is_compatible(struct meson_dw_hdmi *dw_hdmi,
>>  					const char *compat)
>> @@ -368,7 +372,7 @@ static inline void meson_dw_hdmi_phy_reset(struct meson_dw_hdmi *dw_hdmi)
>>  }
>>  
>>  static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
>> -			     struct drm_display_mode *mode)
>> +			     const struct drm_display_mode *mode)
>>  {
>>  	struct meson_drm *priv = dw_hdmi->priv;
>>  	int vic = drm_match_cea_mode(mode);
>> @@ -663,6 +667,10 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
>>  
>>  /* Encoder */
>>  
>> +static const u32 meson_dw_hdmi_out_bus_fmts[] = {
>> +	MEDIA_BUS_FMT_YUV8_1X24,
>> +};
>> +
>>  static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
>>  {
>>  	drm_encoder_cleanup(encoder);
>> @@ -672,16 +680,63 @@ static const struct drm_encoder_funcs meson_venc_hdmi_encoder_funcs = {
>>  	.destroy        = meson_venc_hdmi_encoder_destroy,
>>  };
>>  
>> -static int meson_venc_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
>> +static u32 *
>> +meson_venc_hdmi_encoder_get_out_bus_fmts(struct drm_bridge *bridge,
>> +					 struct drm_bridge_state *bridge_state,
>> +					 struct drm_crtc_state *crtc_state,
>> +					 struct drm_connector_state *conn_state,
>> +					 unsigned int *num_output_fmts)
>> +{
>> +	u32 *output_fmts;
>> +
>> +	*num_output_fmts = ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts);
>> +	output_fmts = kcalloc(*num_output_fmts, sizeof(*output_fmts),
>> +			      GFP_KERNEL);
>> +	if (!output_fmts)
>> +		return NULL;
>> +
>> +	memcpy(output_fmts, meson_dw_hdmi_out_bus_fmts, *num_output_fmts);
>> +
>> +	return output_fmts;
>> +}
>> +
>> +static u32 *
>> +meson_venc_hdmi_encoder_get_inp_bus_fmts(struct drm_bridge *bridge,
>> +					struct drm_bridge_state *bridge_state,
>> +					struct drm_crtc_state *crtc_state,
>> +					struct drm_connector_state *conn_state,
>> +					u32 output_fmt,
>> +					unsigned int *num_input_fmts)
>> +{
>> +	u32 *input_fmts = NULL;
>> +
>> +	if (output_fmt == meson_dw_hdmi_out_bus_fmts[0]) {
>> +		*num_input_fmts = 1;
>> +		input_fmts = kcalloc(*num_input_fmts,
>> +				     sizeof(*input_fmts),
>> +				     GFP_KERNEL);
>> +		if (!input_fmts)
>> +			return NULL;
>> +
>> +		input_fmts[0] = output_fmt;
>> +	} else {
>> +		*num_input_fmts = 0;
>> +	}
>> +
>> +	return input_fmts;
>> +}
>> +
>> +static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
>> +					struct drm_bridge_state *bridge_state,
>>  					struct drm_crtc_state *crtc_state,
>>  					struct drm_connector_state *conn_state)
>>  {
>>  	return 0;
>>  }
>>  
>> -static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
>> +static void meson_venc_hdmi_encoder_disable(struct drm_bridge *bridge)
>>  {
>> -	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>> +	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
>>  	struct meson_drm *priv = dw_hdmi->priv;
>>  
>>  	DRM_DEBUG_DRIVER("\n");
>> @@ -693,9 +748,9 @@ static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
>>  	writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
>>  }
>>  
>> -static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
>> +static void meson_venc_hdmi_encoder_enable(struct drm_bridge *bridge)
>>  {
>> -	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>> +	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
>>  	struct meson_drm *priv = dw_hdmi->priv;
>>  
>>  	DRM_DEBUG_DRIVER("%s\n", priv->venc.hdmi_use_enci ? "VENCI" : "VENCP");
>> @@ -706,11 +761,11 @@ static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
>>  		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
>>  }
>>  
>> -static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
>> -				   struct drm_display_mode *mode,
>> -				   struct drm_display_mode *adjusted_mode)
>> +static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
>> +				   const struct drm_display_mode *mode,
>> +				   const struct drm_display_mode *adjusted_mode)
>>  {
>> -	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>> +	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
>>  	struct meson_drm *priv = dw_hdmi->priv;
>>  	int vic = drm_match_cea_mode(mode);
>>  
>> @@ -726,12 +781,16 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
>>  	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
>>  }
>>  
>> -static const struct drm_encoder_helper_funcs
>> -				meson_venc_hdmi_encoder_helper_funcs = {
>> -	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
>> -	.disable	= meson_venc_hdmi_encoder_disable,
>> -	.enable		= meson_venc_hdmi_encoder_enable,
>> -	.mode_set	= meson_venc_hdmi_encoder_mode_set,
>> +static const struct drm_bridge_funcs meson_venc_hdmi_encoder_bridge_funcs = {
>> +	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
>> +	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
>> +	.atomic_get_output_bus_fmts = meson_venc_hdmi_encoder_get_out_bus_fmts,
> 
> Hm, can this bridge element be connected directly to the HDMI connector
> without the dw-hdmi bridge in the middle? If that's not the case, then
> you probably don't have to implement ->atomic_get_output_bus_fmts()
> (only used on the last bridge element).

No, the HDMI bridge is mandatory here.

Ok, makes sense, I'll remove it then.

Neil

> 
>> +	.atomic_get_input_bus_fmts = meson_venc_hdmi_encoder_get_inp_bus_fmts,
>> +	.atomic_reset = drm_atomic_helper_bridge_reset,
>> +	.atomic_check = meson_venc_hdmi_encoder_atomic_check,
>> +	.enable	= meson_venc_hdmi_encoder_enable,
>> +	.disable = meson_venc_hdmi_encoder_disable,
>> +	.mode_set = meson_venc_hdmi_encoder_mode_set,
>>  };
>>  
>>  /* DW HDMI Regmap */
>> @@ -852,6 +911,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>>  	struct drm_device *drm = data;
>>  	struct meson_drm *priv = drm->dev_private;
>>  	struct dw_hdmi_plat_data *dw_plat_data;
>> +	struct drm_bridge *next_bridge;
>>  	struct drm_encoder *encoder;
>>  	struct resource *res;
>>  	int irq;
>> @@ -953,8 +1013,6 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>>  
>>  	/* Encoder */
>>  
>> -	drm_encoder_helper_add(encoder, &meson_venc_hdmi_encoder_helper_funcs);
>> -
>>  	ret = drm_encoder_init(drm, encoder, &meson_venc_hdmi_encoder_funcs,
>>  			       DRM_MODE_ENCODER_TMDS, "meson_hdmi");
>>  	if (ret) {
>> @@ -962,6 +1020,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>>  		return ret;
>>  	}
>>  
>> +	meson_dw_hdmi->bridge.funcs = &meson_venc_hdmi_encoder_bridge_funcs;
>> +	drm_bridge_attach(encoder, &meson_dw_hdmi->bridge, NULL);
>> +
>>  	encoder->possible_crtcs = BIT(0);
>>  
>>  	DRM_DEBUG_DRIVER("encoder initialized\n");
>> @@ -984,11 +1045,15 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>>  
>>  	platform_set_drvdata(pdev, meson_dw_hdmi);
>>  
>> -	meson_dw_hdmi->hdmi = dw_hdmi_bind(pdev, encoder,
>> -					   &meson_dw_hdmi->dw_plat_data);
>> +	meson_dw_hdmi->hdmi = dw_hdmi_probe(pdev,
>> +					    &meson_dw_hdmi->dw_plat_data);
>>  	if (IS_ERR(meson_dw_hdmi->hdmi))
>>  		return PTR_ERR(meson_dw_hdmi->hdmi);
>>  
>> +	next_bridge = of_drm_find_bridge(pdev->dev.of_node);
>> +	if (next_bridge)
>> +		drm_bridge_attach(encoder, next_bridge, &meson_dw_hdmi->bridge);
>> +
>>  	DRM_DEBUG_DRIVER("HDMI controller initialized\n");
>>  
>>  	return 0;
> 

_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic