Subject: Re: [PATCH] drm: bridge: dw-hdmi: add HDMI vendor specific infoframe
 config
To: Nickey Yang <nickey.yang@rock-chips.com>, architt@codeaurora.org,
        airlied@linux.ie
Cc: laurent.pinchart+renesas@ideasonboard.com,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        dianders@chromium.org, linux-rockchip@lists.infradead.org,
        joabreu@synopsys.com, rmk+kernel@arm.linux.org.uk,
        andy.yan@rock-chips.com, vladimir_zapolskiy@mentor.com,
        zhengyang@rock-chips.com
From: Andrzej Hajda <a.hajda@samsung.com>
Message-id: <9cf73d37-78bb-dab8-9c48-5a951fb41c75@samsung.com>
Date: Tue, 21 Mar 2017 08:47:19 +0100
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On 20.03.2017 07:10, Nickey Yang wrote:
> Vendor specific infoframe is mandatory for 4K2K resolution.
> Without this, the HDMI protocol compliance fails.
>
> Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
> ---
>  drivers/gpu/drm/bridge/dw-hdmi.c | 50 ++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/bridge/dw-hdmi.h |  4 ++++
>  2 files changed, 54 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
> index 9a9ec27..79e2e48 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.c
> @@ -1195,6 +1195,55 @@ static void hdmi_config_AVI(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
>  	hdmi_writeb(hdmi, (frame.right_bar >> 8) & 0xff, HDMI_FC_AVISRB1);
>  }
>  
> +static void hdmi_config_vendor_specific_infoframe(struct dw_hdmi *hdmi,
> +						 struct drm_display_mode *mode)
> +{
> +	struct hdmi_vendor_infoframe frame;
> +	u8 buffer[10];
> +	ssize_t err;
> +
> +	err = drm_hdmi_vendor_infoframe_from_display_mode(&frame, mode);
> +	if (err) {
> +		dev_err(hdmi->dev,
> +			"Failed to get vendor infoframe from mode: %zd\n", err);
> +		return;
> +	}
> +
> +	err = hdmi_vendor_infoframe_pack(&frame, buffer, sizeof(buffer));
> +	if (!err) {
> +		dev_err(hdmi->dev, "Failed to pack vendor infoframe: %zd\n",
> +			err);
> +		return;
> +	}

AFAIK function returns number of packed bytes or -EINVAL so the check is
incorrect, and -EINVAL means that there is no need to generate vendor
infoframe, so definitely not dev_err.

> +	hdmi_modb(hdmi, 0 << HDMI_FC_DATAUTO0_VSD_OFFSET,
> +		  HDMI_FC_DATAUTO0_VSD_MASK, HDMI_FC_DATAUTO0);

I see no gain in constructs (0 << HDMI_FC_DATAUTO0_VSD_OFFSET),
additionally mask and offset are redundant (mask == 1 << offset), but it
seems you follow existing practice, so I do not oppose :)

Regards
Andrzej

> +
> +	/* Set the length of HDMI vendor specific InfoFrame payload */
> +	hdmi_writeb(hdmi, buffer[2], HDMI_FC_VSDSIZE);
> +
> +	/* Set 24bit IEEE Registration Identifier */
> +	hdmi_writeb(hdmi, buffer[4], HDMI_FC_VSDIEEEID0);
> +	hdmi_writeb(hdmi, buffer[5], HDMI_FC_VSDIEEEID1);
> +	hdmi_writeb(hdmi, buffer[6], HDMI_FC_VSDIEEEID2);
> +
> +	/* Set HDMI_Video_Format and HDMI_VIC/3D_Structure */
> +	hdmi_writeb(hdmi, buffer[7], HDMI_FC_VSDPAYLOAD0);
> +	hdmi_writeb(hdmi, buffer[8], HDMI_FC_VSDPAYLOAD1);
> +
> +	if (frame.s3d_struct >= HDMI_3D_STRUCTURE_SIDE_BY_SIDE_HALF)
> +		hdmi_writeb(hdmi, buffer[9], HDMI_FC_VSDPAYLOAD2);
> +
> +	/* Packet frame interpolation */
> +	hdmi_writeb(hdmi, 1, HDMI_FC_DATAUTO1);
> +
> +	/* Auto packets per frame and line spacing */
> +	hdmi_writeb(hdmi, 0x11, HDMI_FC_DATAUTO2);
> +
> +	/* Configures the Frame Composer On RDRB mode */
> +	hdmi_modb(hdmi, 1 << HDMI_FC_DATAUTO0_VSD_OFFSET,
> +		  HDMI_FC_DATAUTO0_VSD_MASK, HDMI_FC_DATAUTO0);
> +}
> +
>  static void hdmi_av_composer(struct dw_hdmi *hdmi,
>  			     const struct drm_display_mode *mode)
>  {
> @@ -1446,6 +1495,7 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
>  
>  		/* HDMI Initialization Step F - Configure AVI InfoFrame */
>  		hdmi_config_AVI(hdmi, mode);
> +		hdmi_config_vendor_specific_infoframe(hdmi, mode);
>  	} else {
>  		dev_dbg(hdmi->dev, "%s DVI mode\n", __func__);
>  	}
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.h b/drivers/gpu/drm/bridge/dw-hdmi.h
> index 325b0b8..c59f87e 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.h
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.h
> @@ -854,6 +854,10 @@ enum {
>  	HDMI_FC_DBGFORCE_FORCEAUDIO = 0x10,
>  	HDMI_FC_DBGFORCE_FORCEVIDEO = 0x1,
>  
> +/* FC_DATAUTO0 field values */
> +	HDMI_FC_DATAUTO0_VSD_MASK = 0x08,
> +	HDMI_FC_DATAUTO0_VSD_OFFSET = 3,
> +
>  /* PHY_CONF0 field values */
>  	HDMI_PHY_CONF0_PDZ_MASK = 0x80,
>  	HDMI_PHY_CONF0_PDZ_OFFSET = 7,