Some configurations of sysfb outputs require format conversion from
framebuffer to scanout buffer. It is a driver bug if the conversion
helper is missing, yet it might happen on odd scanout formats. The old
code, based on drm_fb_blit(), only detects this situation during the
commit's hardware update, which is too late to abort the update.
Lookup the correct blit helper as part of the check phase. Then store
it in the sysfb plane state. Allows for detection of a missing helper
before the commit has started. Also avoids drm_fb_blit()'s large switch
statement on each updated scanline. Only a single lookup has to be done.
The lookup is in drm_sysfb_get_blit_func(), which only tracks formats
supported by sysfb drivers.
The lookup happens in sysfb's begin_fb_access helper instead of its
atomic_check helper. This allows vesadrm, and possibly other drivers,
to implement their own atomic_check without interfering with blit
lookups. Vesadrm implements XRGB8888 on top of R8 formats with the
help of the atomic_check. Doing the blit lookup in begin_fb_access then
always uses the correct CRTC format on all drivers.
v2:
- vesadrm: use drm_sysfb_plane_helper_begin_fb_access()
- fix type in commit description (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250918154207.84714-3-tzimmermann@suse.de
Use the color format stored in struct drm_sysfb_crtc_state for
color-format conversion instead of the scanout-buffer format
announced by firmware. Currently, both values are identical.
This will allow drivers to modify the CRTC's input format to a
certain extend. Specifically, vesadrm will be able to display RGB
framebuffers when the scanout buffer is of C8 format. With color-
format conversion to RGB332 and correct setup of the C8 palette,
displaying XRGB8888-based buffers under C8 can be achieved.
v2:
- refer to RGB332 as CRTC input format
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250714151513.309475-5-tzimmermann@suse.de
Share efidrm's and vesadrm's validation of struct screen_info in
shared helpers. Update the drivers.
Most validation helpers test individual values against limits and
can be shared as they are. For color formats, a common helper looks
up the correct DRM format info from a driver-provided list of color
formats.
These screen_info helpers are only available if CONFIG_SCREEN_INFO
has been selected, as done by efidrm and vesadrm.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250410083834.10810-4-tzimmermann@suse.de
Split drm_sysfb_helper.c into two source files. There's now one
source file for the mode-setting pipeline and one source file for
module meta data. Prepares for adding additional source code to
sysfb helpers.
v2:
- fix typo in commit message (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250410083834.10810-2-tzimmermann@suse.de
Add EDID support to sysfb connector helpers. Read the EDID property
from the OF node in ofdrm. Without EDID, this does nothing.
Some systems with OF display, such as 32-bit PPC Macintoshs, provide
the system display's EDID data as node property in their DT. Exporting
this information allows compositors to implement correct DPI and
meaningful color management.
v3:
- avoid parser error by clearing EDID extension field
v2:
- return errno codes on errors (Jani)
- simplify EDID read logic (Jani)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-13-tzimmermann@suse.de
Merge the primary plane code of ofdrm and simpledrm. Replace the
plane implementation in each driver with the shared helpers. Set
up driver callbacks and format modifiers with initializer macros.
The plane code in ofdrm and simpledrm is very similar. Ofdrm has a
more sophisticated implementation of atomic_disable, which clears
individual scanlines. The code in simpledrm clears the whole buffer
at once. Take the ofdrm version.
Simpledrm supports get_scanout_buffer. Import it into the shared
helpers, which makes it available in ofdrm.
The supported formats are all native formats plus an optional enulated
XRGB8888 if that's not already a native format. Provide an initializer
macro that computes the size of the formats array.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-12-tzimmermann@suse.de
Merge the CRTC functions of ofdrm and simpledrm. Replace the code
in each driver with the shared helpers. Set up callbacks with
initializer macros.
Ofdrm supports a gamma LUT, while simpledrm does not. So far ofdrm's
LUT size has been hard-coded in the driver CRTC's atomic_check helper.
Now pass the size of the LUT to the sysfb device. Ofdrm's custom
atomic_flush is still required to apply changes to the LUT. Simpledrm
passes a LUT size of 0, which disables the gamma LUT.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-11-tzimmermann@suse.de
Move ofdrm's struct ofdrm_crtc_state plus functions to sysfb
helpers and rename everything to drm_sysfb_crtc_state.
The sysfb CRTC state is a regular CRTC state with information on
the primary plane's color format, as required for color management.
Helpers for sysfb planes will later set this up automatically.
In ofdrm and simpledrm, replace existing code with the new helpers.
Ofdrm continues to use the CRTC state for color management. This
has no effect on simpledrm.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-10-tzimmermann@suse.de
Merge the connector functions of ofdrm and simpledrm. Replace the
code in each driver with the shared helpers. Set up callbacks with
initializer macros.
No effective code changes. The sysfb connector only returns the
preconfigured display mode.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-9-tzimmermann@suse.de
Add struct drm_sysfb_device that stores the system display's hardware
settings. Further helpers for the mode-setting pipeline will use these
fields. Convert ofdrm and simpledrm by embedding the sysfb device in
their device structs.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-6-tzimmermann@suse.de
