drm/sysfb: corebootdrm: Add DRM driver for coreboot framebuffers

Add corebootdrm, a DRM driver for coreboot framebuffers. The driver
supports a pre-initialized framebuffer with various packed RGB fo

drm/sysfb: corebootdrm: Add DRM driver for coreboot framebuffers

Add corebootdrm, a DRM driver for coreboot framebuffers. The driver
supports a pre-initialized framebuffer with various packed RGB formats.
The driver code is fairly small and uses the same logic as the other
sysfb drivers. Most of the implementation comes from existing sysfb
helpers.

Until now, coreboot relied on simpledrm or simplefb for boot-up graphics
output. Initialize the platform device for corebootdrm in the same place
in framebuffer_probe(). With a later commit, the simple-framebuffer should
be removed.

v4:
- sort include statements (Tzung-Bi)
v3:
- comment on _HAS_LFB semantics (Tzung-Bi)
- fix typo in commit description (Tzung-Bi)
- comment on simple-framebuffer being obsolete for coreboot
v2:
- reimplement as platform driver
- limit resources and mappings to known framebuffer memory; no
page alignment
- create corebootdrm device from coreboot framebuffer code

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Julius Werner <jwerner@chromium.org>
Acked-by: Tzung-Bi Shih <tzungbi@kernel.org> # coreboot
Link: https://patch.msgid.link/20260217155836.96267-12-tzimmermann@suse.de

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drm/sysfb: efidrm: Support module builds

Make CONFIG_DRM_EFIDRM a tristate to enable module builds.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <jav

drm/sysfb: efidrm: Support module builds

Make CONFIG_DRM_EFIDRM a tristate to enable module builds.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250408091837.407401-3-tzimmermann@suse.de

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drm/sysfb: Add vesadrm for VESA displays

Add support for screen_info setups with VIDEO_TYPE_VLFB. Provide the
minimum functionality of reading modes, updating and clearing the display.

There is exi

drm/sysfb: Add vesadrm for VESA displays

Add support for screen_info setups with VIDEO_TYPE_VLFB. Provide the
minimum functionality of reading modes, updating and clearing the display.

There is existing support for these displays provided by simpledrm with
CONFIG_SYSFB_SIMPLEFB=y. Using vesadrm over simpledrm will allow for the
use of additional functionality provided by VESA, such as EDID information,
gamma correction and palette modes. This enhances the user experience and
adds support for more display configuratons.

v4:
- depend on CONFIG_X86
v3:
- depend on !SYSFB_SIMPLEFB (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-17-tzimmermann@suse.de

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drm/sysfb: Add efidrm for EFI displays

Add support for screen_info setups with VIDEO_TYPE_EFI. Provide the
minimum functionality of reading modes, updating and clearing the display.

There is existi

drm/sysfb: Add efidrm for EFI displays

Add support for screen_info setups with VIDEO_TYPE_EFI. Provide the
minimum functionality of reading modes, updating and clearing the display.

There is existing support for these displays provided by simpledrm with
CONFIG_SYSFB_SIMPLEFB=y. Using efidrm over simpledrm will allows for the
mapping of video memory with correct caching. Simpledrm always assumes WC
caching, while fully cached memory is possible with efidrm. Efidrm will
also allow for the use of additional functionality provided by EFI, such
as EDID information.

In addition to efidrm, add struct pixel_format plus initializer macros.
The type and macros describe pixel formats in a generic way on order to
find the DRM format from the screen_info settings. Similar existing code
in SIMPLEFB_FORMATS and fbdev is not really what is needed in efidrm,
but SIMPLEFB_FORMATS can later be converted to struct pixel_format.

v4:
- depend on CONFIG_EFI
- disallow module for now as efi_mem_desc_lookup() is not exported
v3:
- depend on !SYSFB_SIMPLEFB (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-15-tzimmermann@suse.de

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drm/sysfb: Add struct drm_sysfb_device

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 of

drm/sysfb: Add struct drm_sysfb_device

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

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drm: Move sysfb drivers into separate subdirectory

The ofdrm and simpledrm drivers are special as they operate on
externally provided framebuffers. Move them into their own sub-
directory. Will let

drm: Move sysfb drivers into separate subdirectory

The ofdrm and simpledrm drivers are special as they operate on
externally provided framebuffers. Move them into their own sub-
directory. Will let them share common code.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-5-tzimmermann@suse.de

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