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>
In some cases observed during ESD tests, the TI SN65DSI83 cannot recover
from errors by itself. A full restart of the bridge is needed in those
cases to have the bridge output LVDS signals again.
Also, during tests, cases were observed where reading the status of the
bridge was not even possible. Indeed, in those cases, the bridge stops
to acknowledge I2C transactions. Only a full reset of the bridge (power
off/on) brings back the bridge to a functional state.
The TI SN65DSI83 has some error detection capabilities. Introduce an
error recovery mechanism based on this detection.
The errors detected are signaled through an interrupt. On system where
this interrupt is not available, the driver uses a polling monitoring
fallback to check for errors. When an error is present or when reading
the bridge status leads to an I2C failure, the recovery process is
launched.
Restarting the bridge needs to redo the initialization sequence. This
initialization sequence has to be done with the DSI data lanes driven in
LP11 state. In order to do that, the recovery process resets the whole
output path (i.e the path from the encoder to the connector) where the
bridge is located.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250210132620.42263-5-herve.codina@bootlin.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Add a optional properties to change LVDS output voltage. This should not
be static as this depends mainly on the connected display voltage
requirement. We have three properties:
- "ti,lvds-termination-ohms", which sets near end termination,
- "ti,lvds-vod-swing-data-microvolt" and
- "ti,lvds-vod-swing-clock-microvolt" which both set LVDS differential
output voltage for data and clock lanes. They are defined as an array
with min and max values. The appropriate bitfield will be set if
selected constraints can be met.
If "ti,lvds-termination-ohms" is not defined the default of 200 Ohm near
end termination will be used. Selecting only one:
"ti,lvds-vod-swing-data-microvolt" or
"ti,lvds-vod-swing-clock-microvolt" can be done, but the output voltage
constraint for only data/clock lanes will be met. Setting both is
recommended.
Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20241216085410.1968634-3-andrej.picej@norik.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241216085410.1968634-3-andrej.picej@norik.com
This reverts commit 8a91b29f1f.
The regulator_disable() added by the original commit solves one kind of
regulator imbalance but adds another one as it allows the regulator to be
disabled one more time than it is enabled in the following scenario:
1. Start video pipeline -> sn65dsi83_atomic_pre_enable -> regulator_enable
2. PLL lock fails -> regulator_disable
3. Stop video pipeline -> sn65dsi83_atomic_disable -> regulator_disable
The reason is clear from the code flow, which looks like this (after
removing unrelated code):
static void sn65dsi83_atomic_pre_enable()
{
regulator_enable(ctx->vcc);
if (PLL failed locking) {
regulator_disable(ctx->vcc); <---- added by patch being reverted
return;
}
}
static void sn65dsi83_atomic_disable()
{
regulator_disable(ctx->vcc);
}
The use case for introducing the additional regulator_disable() was
removing the module for debugging (see link below for the discussion). If
the module is removed after a .atomic_pre_enable, i.e. with an active
pipeline from the DRM point of view, .atomic_disable is not called and thus
the regulator would not be disabled.
According to the discussion however there is no actual use case for
removing the module with an active pipeline, except for
debugging/development.
On the other hand, the occurrence of a PLL lock failure is possible due to
any physical reason (e.g. a temporary hardware failure for electrical
reasons) so handling it gracefully should be supported. As there is no way
for .atomic[_pre]_enable to report an error to the core, the only clean way
to support it is calling regulator_disabled() only in .atomic_disable,
unconditionally, as it was before.
Link: https://lore.kernel.org/all/15244220.uLZWGnKmhe@steina-w/
Fixes: 8a91b29f1f ("drm/bridge: ti-sn65dsi83: Fix enable error path")
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240426122259.46808-1-luca.ceresoli@bootlin.com
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714174545.4056287-1-robh@kernel.org
The datasheet describes the following initialization flow including
minimum delay times between each step:
1. DSI data lanes need to be in LP-11 and the clock lane in HS mode
2. toggle EN signal
3. initialize registers
4. enable PLL
5. soft reset
6. enable DSI stream
7. check error status register
To meet this requirement we need to make sure the host bridge's
pre_enable() is called first by using the pre_enable_prev_first
flag.
Furthermore we need to split enable() into pre_enable() which covers
steps 2-5 from above and enable() which covers step 7 and is called
after the host bridge's enable().
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Fixes: ceb515ba29 ("drm/bridge: ti-sn65dsi83: Add TI SN65DSI83 and SN65DSI84 driver")
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> #TQMa8MxML/MBa8Mx
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230503163313.2640898-3-frieder@fris.de
Commit 24417d5b0c ("drm/bridge: ti-sn65dsi83: Implement .detach
callback") moved the unregistration of the bridge DSI device and bridge
itself to the detach callback.
While this is correct for the DSI device detach and unregistration, the
bridge is added in the driver probe, and should thus be removed as part
of its remove callback.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Fixes: 24417d5b0c ("drm/bridge: ti-sn65dsi83: Implement .detach callback")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025151536.1048186-14-maxime@cerno.tech
Current code always sets reset line low in .pre_enable callback and
holds it low for 10ms. This is sub-optimal and increases the time
between enablement of the DSI83 and valid LVDS clock.
Rework the reset handling such that the reset line is held low for 10ms
both in probe() of the driver and .disable callback, which guarantees
that the reset line was always held low for more than 10ms and therefore
the reset line timing requirement is satisfied. Furthermore, move the
reset handling into .enable callback so the entire DSI83 initialization
is now in one place.
This reduces DSI83 enablement delay by up to 10ms.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211016210402.171595-1-marex@denx.de
The driver currently iterates over all connectors to get the bus format,
used to configure the LVDS output format. This causes several issues:
- If other connectors than the LVDS output are present, the format used
by the driver may end up belonging to an entirely different output.
- The code can crash if some connectors are not connected, as bus_format
may then be NULL.
- There's no guarantee that the bus format on the connector at the
output of the pipeline matches the output of the sn65dsi83, as there
may be other bridges in the pipeline.
Solve this by retrieving the format from the bridge state instead, which
provides the format corresponding to the output of the bridge.
The struct sn65dsi83 lvds_format_24bpp and lvds_format_jeida fields are
moved to local variables in sn65dsi83_atomic_enable() as they're now
used in that function only.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210621125518.13715-5-laurent.pinchart@ideasonboard.com
Fix the following sparse warnings generated by "make C=1":
drivers/gpu/drm/bridge/ti-sn65dsi83.c:429:13: warning: incorrect type in assignment (different base types)
drivers/gpu/drm/bridge/ti-sn65dsi83.c:429:13: expected unsigned short [assigned] [usertype] val
drivers/gpu/drm/bridge/ti-sn65dsi83.c:429:13: got restricted __le16 [usertype]
drivers/gpu/drm/bridge/ti-sn65dsi83.c:432:13: warning: incorrect type in assignment (different base types)
drivers/gpu/drm/bridge/ti-sn65dsi83.c:432:13: expected unsigned short [addressable] [assigned] [usertype] val
drivers/gpu/drm/bridge/ti-sn65dsi83.c:432:13: got restricted __le16 [usertype]
drivers/gpu/drm/bridge/ti-sn65dsi83.c:436:13: warning: incorrect type in assignment (different base types)
drivers/gpu/drm/bridge/ti-sn65dsi83.c:436:13: expected unsigned short [addressable] [assigned] [usertype] val
drivers/gpu/drm/bridge/ti-sn65dsi83.c:436:13: got restricted __le16 [usertype]
drivers/gpu/drm/bridge/ti-sn65dsi83.c:438:13: warning: incorrect type in assignment (different base types)
drivers/gpu/drm/bridge/ti-sn65dsi83.c:438:13: expected unsigned short [addressable] [assigned] [usertype] val
drivers/gpu/drm/bridge/ti-sn65dsi83.c:438:13: got restricted __le16 [usertype]
drivers/gpu/drm/bridge/ti-sn65dsi83.c:441:13: warning: incorrect type in assignment (different base types)
drivers/gpu/drm/bridge/ti-sn65dsi83.c:441:13: expected unsigned short [addressable] [assigned] [usertype] val
drivers/gpu/drm/bridge/ti-sn65dsi83.c:441:13: got restricted __le16 [usertype]
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Adam Ford <aford173@gmail.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Frieder Schrempf <frieder.schrempf@kontron.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Marek Vasut <marex@denx.de>
Cc: Philippe Schenker <philippe.schenker@toradex.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Valentin Raevsky <valentin@compulab.co.il>
To: dri-devel@lists.freedesktop.org
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608142211.82333-1-marex@denx.de
