The drm_bridge structure contains an encoder pointer that is widely used
by bridge drivers. This pattern is largely documented as deprecated in
other KMS entities for atomic drivers.
However, one of the main use of that pointer is done in attach to just
call drm_bridge_attach on the next bridge to add it to the bridge list.
While this dereferences the bridge->encoder pointer, it's effectively
the same encoder the bridge was being attached to.
We can make it more explicit by adding the encoder the bridge is
attached to to the list of attach parameters. This also removes the need
to dereference bridge->encoder in most drivers.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313-bridge-connector-v6-1-511c54a604fb@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
ARCH=arm build fails with:
CC [M] drivers/gpu/drm/bridge/ti-tdp158.o
../drivers/gpu/drm/bridge/ti-tdp158.c: In function ‘tdp158_enable’:
../drivers/gpu/drm/bridge/ti-tdp158.c:31:9: error: implicit declaration of function ‘gpiod_set_value_cansleep’ [-Werror=implicit-function-declaration]
31 | gpiod_set_value_cansleep(tdp158->enable, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/bridge/ti-tdp158.c: In function ‘tdp158_probe’:
../drivers/gpu/drm/bridge/ti-tdp158.c:80:26: error: implicit declaration of function ‘devm_gpiod_get_optional’; did you mean ‘devm_regulator_get_optional’? [-Werror=implicit-function-declaration]
80 | tdp158->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
| ^~~~~~~~~~~~~~~~~~~~~~~
| devm_regulator_get_optional
../drivers/gpu/drm/bridge/ti-tdp158.c:80:65: error: ‘GPIOD_OUT_LOW’ undeclared (first use in this function)
80 | tdp158->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
| ^~~~~~~~~~~~~
../drivers/gpu/drm/bridge/ti-tdp158.c:80:65: note: each undeclared identifier is reported only once for each function it appears in
Add the proper gpio consumer #include to fix this, and juggle the
include order to be a bit more pleasant on the eye while at it.
Fixes: a15710027a ("drm/bridge: add support for TI TDP158")
Cc: Marc Gonzalez <mgonzalez@freebox.fr>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240904085206.3331553-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
TDP158 is an AC-coupled DVI / HDMI to TMDS level shifting Redriver.
It supports DVI 1.0, HDMI 1.4b and 2.0b.
It supports 4 TMDS channels, HPD, and a DDC interface.
It supports dual power supply rails (1.1V on VDD, 3.3V on VCC)
for power reduction. Several methods of power management are
implemented to reduce overall power consumption.
It supports fixed receiver EQ gain using I2C or pin strap to
compensate for different lengths input cable or board traces.
Features
- AC-coupled TMDS or DisplayPort dual-mode physical layer input
to HDMI 2.0b TMDS physical layer output supporting up to 6Gbps
data rate, compatible with HDMI 2.0b electrical parameters
- DisplayPort dual-mode standard version 1.1
- Programmable fixed receiver equalizer up to 15.5dB
- Global or independent high speed lane control, pre-emphasis
and transmit swing, and slew rate control
- I2C or pin strap programmable
- Configurable as a DisplayPort redriver through I2C
- Full lane swap on main lanes
- Low power consumption (200 mW at 6Gbps, 8 mW in shutdown)
https://www.ti.com/lit/ds/symlink/tdp158.pdf
On our board, I2C_EN is pulled high.
Thus, this code defines a module_i2c_driver.
The default settings work fine for our use-case.
So this basic driver doesn't need to tweak any I2C registers.
Signed-off-by: Marc Gonzalez <mgonzalez@freebox.fr>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240812-tdp158-v5-2-78684a84ec23@freebox.fr
