Add initializer macros for struct fb_ops for framebuffers in DMA-able
memory areas. Also add a corresponding Kconfig token. As of now, this
is equivalent to system framebuffers and mostly useful for labeling
drivers correctly.
A later patch may add a generic DMA-specific mmap operation. Linux
offers a number of dma_mmap_*() helpers for different use cases.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230707083422.18691-2-tzimmermann@suse.de
Currently the CONFIG_FB option has to be enabled even if no legacy fbdev
drivers are needed (e.g: only to have support for framebuffer consoles).
The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB
and so it can only be enabled if that dependency is enabled as well.
That means fbdev drivers have to be explicitly disabled if users want to
enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer.
This patch introduces a non-visible CONFIG_FB_CORE symbol that could be
enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION,
allowing CONFIG_FB to be disabled (and automatically disabling all the
fbdev drivers).
Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulation
layer so these two objects can be compiled out when CONFIG_FB is disabled.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com
