Commit Graph

10 Commits

Author SHA1 Message Date
Boris Brezillon
5fa8e4a221 drm/panel: Make of_drm_find_panel() return an ERR_PTR() instead of NULL
Right now, the DRM panel logic returns NULL when a panel pointing to
the passed OF node is not present in the list of registered panels.

Most drivers interpret this NULL value as -EPROBE_DEFER, but we are
about to modify the semantic of of_drm_find_panel() and let the
framework return -ENODEV when the device node we're pointing to has
a status property that is not equal to "okay" or "ok".

Let's first patch the of_drm_find_panel() implementation to return
ERR_PTR(-EPROBE_DEFER) instead of NULL and patch all callers to replace
the '!panel' check by an 'IS_ERR(panel)' one.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180509130042.9435-2-boris.brezillon@bootlin.com
2018-07-10 17:59:05 +02:00
Jyri Sarha
0c08754b59 drm/panel: Add device_link from panel device to DRM device
Add device_link from panel device (supplier) to DRM device (consumer)
when drm_panel_attach() is called. This patch should protect the master
DRM driver if an attached panel driver unbinds while it is in use. The
device_link should make sure the DRM device is unbound before the panel
driver becomes unavailable.

The device_link is removed when drm_panel_detach() is called. The
drm_panel_detach() should be called by the consumer DRM driver, not the
panel driver, otherwise both drivers are racing to delete the same link.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b53584fd988d045c13de22d81825395b0ae0aad7.1524727888.git.jsarha@ti.com
2018-05-18 11:22:06 +02:00
Masahiro Yamada
e4e818cc2d drm: make drm_panel.h self-contained
-ENOSYS and -EINVAL are referenced in some static inline functions.
of_drm_find_pane() takes a pointer to struct device_node.

Make this header self-contained to not depend on specific include
order.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1493009447-31524-2-git-send-email-yamada.masahiro@socionext.com
2017-05-16 17:17:02 +02:00
Rob Herring
b61c8d5d9a drm: make of_drm_find_panel also depend on CONFIG_DRM_PANEL
For drm_of_find_panel_or_bridge() added in the next commit, an empty
version of of_drm_find_panel is needed for !CONFIG_DRM_PANEL.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
2017-04-06 17:00:27 -04:00
Laurent Pinchart
327bc44341 drm/panel: Constify device node argument to of_drm_find_panel()
The argument is never modified by the function, make it const.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2017-01-04 08:30:37 +01:00
Thierry Reding
83127f67e4 drm/panel: Flesh out kerneldoc
Write more complete kerneldoc comments for the DRM panel API and
integrate the helpers in the DRM DocBook reference.

Signed-off-by: Thierry Reding <treding@nvidia.com>drm/panel: Add helper for simple panel connector
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160506140137.GA4641@ulmo.ba.sec
2016-05-06 16:04:48 +02:00
Philipp Zabel
2938931f37 drm/panel: Add display timing support
Many panel data sheets, additionally to typical values, list allowed
ranges for timings such as hsync/vsync lengths, porches, and the pixel
clock rate. These can be stored in a struct display_timing, to be used
by an encoder mode_fixup callback to clamp user provided timing values
or to validate workarounds for clock source limitations.

This patch adds a new drm_panel_funcs callback that returns the panel's
available display_timing entries.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-04-02 19:04:12 +02:00
Ajay Kumar
7bf93c73ad drm/panel: Provide convenience wrapper for .get_modes()
Add a convenience wrapper for the struct drm_panel_funcs' .get_modes()
function so that not every driver needs to check that the panel driver
implements the function before calling it.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
[treding: extract from larger patch, commit message]
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-08-06 16:44:09 +02:00
Ajay Kumar
45527d435c drm/panel: add .prepare() and .unprepare() functions
Panels often require an initialization sequence that consists of three
steps: a) powering up the panel, b) starting transmission of video data
and c) enabling the panel (e.g. turn on backlight). This is usually
necessary to avoid visual glitches at the beginning of video data
transmission.

Similarly, the shutdown sequence is typically done in three steps as
well: a) disable the panel (e.g. turn off backlight), b) cease video
data transmission and c) power down the panel.

Currently drivers can only implement .enable() and .disable() functions,
which is not enough to implement the above sequences. This commit adds a
second pair of functions, .prepare() and .unprepare() to allow more
fine-grained control over when the above steps are performed.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
[treding: rewrite changelog, add kerneldoc]
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-08-06 16:44:09 +02:00
Thierry Reding
aead40ea0b drm: Add panel support
Add a very simple framework to register and lookup panels. Panel drivers
can initialize a DRM panel and register it with the framework, allowing
them to be retrieved and used by display drivers. Currently only support
for DPMS and obtaining panel modes is provided. However it should be
sufficient to enable a large number of panels. The framework should also
be easily extensible to support more sophisticated kinds of panels such
as DSI.

The framework hasn't been tied into the DRM core, even though it should
be easily possible to do so if that's what we want. In the current
implementation, display drivers can simple make use of it to retrieve a
panel, obtain its modes and control its DPMS mode.

Note that this is currently only tested on systems that boot from a
device tree. No glue code has been written yet for systems that use
platform data, but it should be easy to add.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2013-12-17 18:09:46 +01:00