Re: [PATCH 1/8] drm/display: hdmi: Add common TMDS character rate constants

[Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>]

On Tue, May 19, 2026 at 04:46:57PM +0200, Javier Martinez Canillas wrote:
> Several DRM drivers already define their own constants for minimum and
> maximum TMDS character rates.
> 
> By defining common rate constants in a shared header, drivers can just use
> them instead of having driver local define macros or use magic numbers.
> 
> The values defined in the <drm/display/drm_hdmi_helper.h> header correspond
> to maximum TMDS character rates defined by each HDMI specification version:
> 
>   - DRM_HDMI_TMDS_CHAR_RATE_MIN:    25 MHz (minimum for all versions)
>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_0: 165 MHz (HDMI 1.0 maximum)
>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_3: 340 MHz (HDMI 1.3 maximum)
>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_2_0: 600 MHz (HDMI 2.0 maximum)

These values are also used by the HDMI PHY drivers. Would it make sense
to define them in <linux/hdmi.h> instead?

> 
> Suggested-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
> 
>  include/drm/display/drm_hdmi_helper.h | 6 ++++++
>  1 file changed, 6 insertions(+)

-- 
With best wishes
Dmitry