[PATCH 02/19] video: sunxi: Add mode_valid callback to sunxi_dw_hdmi

[Andre Przywara]

On Tue, 23 Feb 2021 21:46:14 +0100
Jernej Skrabec <jernej.skrabec at siol.net> wrote:

> Currently driver accepts all resolution which won't work on 4k screens.
> Add validation callback which limits acceptable resolutions to 297 MHz.

Makes sense. Newer SoCs seem to support more, but apparently not
without further code to enable higher clock rates.

> Signed-off-by: Jernej Skrabec <jernej.skrabec at siol.net>

Reviewed-by: Andre Przywara <andre.przywara at arm.com>

Cheers,
Andre

> ---
>  drivers/video/sunxi/sunxi_dw_hdmi.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/video/sunxi/sunxi_dw_hdmi.c b/drivers/video/sunxi/sunxi_dw_hdmi.c
> index 0b8cefc311ef..e3811a2ec15f 100644
> --- a/drivers/video/sunxi/sunxi_dw_hdmi.c
> +++ b/drivers/video/sunxi/sunxi_dw_hdmi.c
> @@ -305,6 +305,12 @@ static int sunxi_dw_hdmi_read_edid(struct udevice *dev, u8 *buf, int buf_size)
>  	return dw_hdmi_read_edid(&priv->hdmi, buf, buf_size);
>  }
>  
> +static bool sunxi_dw_hdmi_mode_valid(struct udevice *dev,
> +				     const struct display_timing *timing)
> +{
> +	return timing->pixelclock.typ <= 297000000;
> +}
> +
>  static int sunxi_dw_hdmi_enable(struct udevice *dev, int panel_bpp,
>  				const struct display_timing *edid)
>  {
> @@ -388,6 +394,7 @@ static int sunxi_dw_hdmi_probe(struct udevice *dev)
>  static const struct dm_display_ops sunxi_dw_hdmi_ops = {
>  	.read_edid = sunxi_dw_hdmi_read_edid,
>  	.enable = sunxi_dw_hdmi_enable,
> +	.mode_valid = sunxi_dw_hdmi_mode_valid,
>  };
>  
>  U_BOOT_DRIVER(sunxi_dw_hdmi) = {