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>
Convert most mutex_(un)lock calls to use (scoped_)guard instead. This
generally reduces line count and prevents bugs like forgetting to unlock
the mutex. I've left traditional calls in a few places where scoped
helpers would be more verbose. This mostly happens where
debugfs_file_put needs to be called regardless. I looked into defining a
CLASS for debugfs_file, but it seems like more effort than it's worth
since debugfs_file_get can fail.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250207162528.1651426-3-sean.anderson@linux.dev
Add basic DisplayPort audio support.
Support non-live audio playback from two PCMs (DMA channels), and the
volume control in the audio mixer.
As older dtb files may not have the audio DMA channels defined, the
driver will just mark the audio support as disabled if the audio DMA is
missing, and will continue with only display support.
Note: Reset doesn't seem to work (ZYNQMP_DISP_AUD_SOFT_RESET). If we do
a reset, audio playback won't start again even if, afaics, we do set up
all the necessary registers. So, at the moment, resetting the audio
block in dp_dai_hw_free() is commented out.
Tested-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241023-xilinx-dp-audio-v4-3-5128881457be@ideasonboard.com
Add a debugfs interface for exercising the various test modes supported
by the DisplayPort controller. This allows performing compliance
testing, or performing signal integrity measurements on a failing link.
At the moment, we do not support sink-driven link quality testing,
although such support would be fairly easy to add.
Additionally, add some debugfs files for ignoring AUX errors and HPD
events, as this can allow testing with equipment that cannot emulate a
DPRX.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
[Tomi: fixed a few minor formatting issues]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240809193600.3360015-9-sean.anderson@linux.dev
Add some locking to prevent the IRQ/workers/bridge API calls from stepping
on each other's toes. This lock protects:
- Non-atomic registers configuring the link. That is, everything but the
IRQ registers (since these are accessed in an atomic fashion), and the DP
AUX registers (since these don't affect the link). We also access AUX
while holding this lock, so it would be very tricky to support.
- Link configuration. This is effectively everything in zynqmp_dp which
isn't read-only after probe time. So from next_bridge onward.
This lock is designed to protect configuration changes so we don't have to
do anything tricky. Configuration should never be in the hot path, so I'm
not worried about performance.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240809193600.3360015-3-sean.anderson@linux.dev
Filter out status register against the interrupts' mask.
Some events are being reported via DP status register, even if
corresponding interrupts have been disabled. One instance of such event
leads to generation of VBLANK when the driver is in DRM bridge mode,
which in turn results in NULL pointer dereferencing. We should avoid
processing such events in an interrupt handler context.
This problem is less noticeable when the driver operates in DMA mode, as
in this case we have DRM CRTC object instantiated and DRM framework
simply discards unwanted VBLANKs in drm_handle_vblank().
Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240124025402.373620-5-anatoliy.klymenko@amd.com
ZynqMP DPSUB supports 2 input modes: DMA based and live video.
In the first mode, the driver implements CRTC and DP encoder DRM bridge
to model the complete display pipeline. In this case, DRM bridge is
being directly instantiated within the driver, not using any bridge
discovery mechanisms.
In the live video input mode video signal is generated by FPGA fabric
and passed into DPSUB over the connected bus. In this mode driver
exposes the DP encoder as a DRM bridge, expecting external CRTC to
discover it via drm_of_find_panel_or_bridge() or a similar call. This
discovery relies on drm_bridge.of_node being properly set.
Assign device OF node to the bridge prior to registering it. This will
make said bridge discoverable by an external CRTC driver.
Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240124025402.373620-2-anatoliy.klymenko@amd.com
Fixes the following W=1 kernel build warning(s):
drivers/gpu/drm/xlnx/zynqmp_dp.c:793: warning: expecting prototype for zynqmp_dp_link_train(). Prototype was for zynqmp_dp_train() instead
Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The mode_valid field in drm_bridge_helper_funcs is expected to be of
type
enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge,
struct drm_display_mode *mode);
The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition. A new
warning in clang will catch this at compile time:
drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
.mode_valid = zynqmp_dp_bridge_mode_valid,
^~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
The return type of zynqmp_dp_bridge_mode_valid should be changed from
int to enum drm_mode_status.
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[nathan: Rebase on drm-misc-next and fix conflicts
Add note about new clang warning]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Add partial live video support, with a single video input that bypasses
blending. Skip registration of the DRM device in that case, but register
the DRM bridge instead. The DRM device will be created by the driver for
the display controller in the PL.
Full live video mode with concurrent usage of the video and gfx inputs,
and blending in the DPSUB video pipeline, is currently unsupported.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The better convey its purpose, rename the zynqmp_dpsub_handle_vblank()
function that belongs to the DRM layer to
zynqmp_dpsub_drm_handle_vblank().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The zynqmp_disp and zynqmp_dp structures are allocated with
drmm_kzalloc(). While this simplifies management of memory, it requires
a DRM device, which will not be available at probe time when the DP
bridge will be used standalone, with a DRM device in the PL. To prepare
for this, switch to manual allocation for zynqmp_disp and zynqmp_dp. The
cleanup still uses the DRM managed infrastructure, but one level up, at
the top level. This will be addressed separately.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
There's no need to delay bridge initialization, move it to
zynqmp_dp_probe() and drop the zynqmp_dp_drm_init() function.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To prepare for operating as a standalone DP bridge with the DRM device
implemented in the PL, move registration of the AUX bus to bridge attach
time, as that's the earliest point when a DRM device is available.
The DRM device pointer stored in zynqmp_dp isn't used anymore, drop it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Decouple the CRTC handling from the display controller programming by
moving the corresponding code from zynqmp_disp.c to zynqmp_kms.c. This
prepares for using the DPSUB with a live video input, without creating a
DRM CRTC in the DPSUB driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The audio clock is an external resource from the DPSUB point of view,
not a resource internal to the display controller. Move it to the
zynqmp_dpsub structure, to allow accessing it from outside the disp
code.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Now that the driver uses the connector bridge helper, HPD can be
reported directly for the connector through the drm_bridge_hpd_notify()
function.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Replace the manual connector implementation and registration in the DP
encoder with the DRM connector bridge helper. This removes boilerplate
code and simplifies the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The next component in the display chain, after the DP encoder, is most
likely a DP connector. The display connector driver registers a bridge
for it. That bridge doesn't need to be controlled, but is needed in
order to use the DRM connector bridge helper. Retrieve it at init time,
and attach to it in the DP bridge attach handler.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
As part of the transitition of the DP encoder to a DRM bridge, turn the
DRM encoder into a dummy encoder and move it out of the DP code, to the
DPSUB core. DP encoder operations are handled by the DP bridge, which is
now attached to the encoder.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Connector creation requires the DRM encoder, and it thus typically
performed in the bridge attach operation. Move it there, to prepare for
registration of the DRM bridge. For now the zynqmp_dp_bridge_attach() is
called manually at initialization time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To prepare for the removal of the connector from the DP encoder, pass
the display info pointer to the zynqmp_dp_set_format() function instead
of accessing the connector internally. The display info is NULL when the
function is called at initialization time, as we have no display info at
that point. This doesn't change the existing behaviour, given that the
zynqmp_dp_set_format() was already handling this as a special case (the
display info isn't initialized at init time and is all zeroes).
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The DP encoder is currently modelled as a DRM encoder and DRM connector.
This doesn't support system configurations where the DP encoder is
driven by the FPGA programmable logic, using the live video input to the
DP subsystem. To enable such use cases, we need to model the encoder as
a DRM bridge.
As a first step, create a DRM bridge in the DP encoder driver. Move and
delegate the implementation of the DRM encoder and connector operations
to the bridge to prepare for the transition. The bridge will be
registered with the DRM core as a separate change.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The zynqmp_dp_encoder_mode_set_transfer_unit() function takes a mode
pointer argument that it doesn't need to modify. Make it const.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To prepare for the transition to the DRM bridge API, switch the encoder
operations to the atomic versions of .enable() and .disable(). This
doesn't cause any functional change by itself.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
