[PATCH v2 0/8] hdmi: Add common TMDS character rate constants

[PATCH v2 0/8] hdmi: Add common TMDS character rate constants

[Javier Martinez Canillas]

Several DRM drivers define their own local macros or use magic numbers for
the standard HDMI TMDS character rate limits. Maxime Ripard suggested that
instead these common rate constants could be included to a shared header.

This series introduces these constants to the <linux/hdmi.h> header and
replaces the local defined constants or magic numbers in drivers.

I split the changes as one patch per driver, so that these can be reviewed
individually and merged at their own pace.

This is a version 2 that addresses issues pointed out by Maxime Ripard and
Dmitry Baryshkov.

Changes in v2:
- Change naming convention to HDMI_$SPEC_TMDS_CHAR_RATE_MAX_HZ (Maxime).
- Define the constants in <linux/hdmi.h> (Dmitry).

Javier Martinez Canillas (8):
  video/hdmi: Add common TMDS character rate constants
  drm/bridge: dw-hdmi: Use the common TMDS char rate constant
  drm/bridge: dw-hdmi-qp: Use the common TMDS char rate constant
  drm/bridge: inno-hdmi: Use the common TMDS char rate constant
  drm/sti: hdmi: Use the common TMDS char rate constants
  drm/sun4i: hdmi: Use the common TMDS char rate constant
  drm/msm/hdmi: Use the common TMDS char rate constants in 8996 PHY
  drm/msm/hdmi: Use the common TMDS char rate constants in 8998 PHY

 drivers/gpu/drm/bridge/inno-hdmi.c           |  4 +---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c |  6 ++----
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c    | 10 ++++------
 drivers/gpu/drm/msm/hdmi/hdmi_phy_8996.c     |  6 ++----
 drivers/gpu/drm/msm/hdmi/hdmi_phy_8998.c     |  6 ++----
 drivers/gpu/drm/sti/sti_hdmi_tx3g4c28phy.c   |  6 ++++--
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c       |  4 ++--
 include/linux/hdmi.h                         |  6 ++++++
 8 files changed, 23 insertions(+), 25 deletions(-)

-- 
2.54.0

base-commit: 88658ff0e4e7f46dbf8179af1280f2cb295fb0cb
branch: add-common-tmds-rates-v2

[PATCH v2 6/8] drm/sun4i: hdmi: Use the common TMDS char rate constant

[Javier Martinez Canillas]

Replace the 165000000 magic number with the shared constant defined
in the <linux/hdmi.h> header.

The old comment referenced "HDMI <= 1.2" but 165 MHz is actually
the maximum TMDS character rate defined by the HDMI 1.0 spec.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Chen-Yu Tsai <wens@kernel.org>
---

(no changes since v1)

 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index 07e2afcb4f95..74c7c3720ba8 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -189,8 +189,8 @@ sun4i_hdmi_connector_clock_valid(const struct drm_connector *connector,
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		return MODE_BAD;
 
-	/* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */
-	if (clock > 165000000)
+	/* HDMI 1.0 max TMDS character rate */
+	if (clock > HDMI_1_0_TMDS_CHAR_RATE_MAX_HZ)
 		return MODE_CLOCK_HIGH;
 
 	rounded_rate = clk_round_rate(hdmi->tmds_clk, clock);
-- 
2.54.0

Re: [PATCH v2 0/8] hdmi: Add common TMDS character rate constants

[Maxime Ripard]

On Wed, 20 May 2026 16:43:36 +0200, Javier Martinez Canillas wrote:
> Several DRM drivers define their own local macros or use magic numbers for
> the standard HDMI TMDS character rate limits. Maxime Ripard suggested that
> instead these common rate constants could be included to a shared header.
> 
> This series introduces these constants to the <linux/hdmi.h> header and
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime