linux.git/drivers/video/fbdev/core/Makefile, branch v6.6.131

fbdev: Provide I/O-memory helpers as module

2024-06-12T09:11:56+00:00

[ Upstream commit 6b180f66c0dd6266eeb2f74b59ee79a9f14fe430 ]

Provide helpers for accessing I/O memory in a helper module. The fbdev
core uses these helpers, so select the module unconditionally for fbdev.
Drivers will later be able to select the module individually and the
helpers will become optional.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20230927074722.6197-2-tzimmermann@suse.de
Stable-dep-of: 01c0cce88c54 ("drm/omapdrm: Fix console with deferred ops")
Signed-off-by: Sasha Levin

fbdev: Split frame buffer support in FB and FB_CORE symbols

2023-07-22T10:25:04+00:00

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 
Reviewed-by: Arnd Bergmann 
Tested-by: Arnd Bergmann 
Acked-by: Helge Deller 
Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com

fbdev: Make support for userspace interfaces configurable

2023-06-27T07:58:51+00:00

Add Kconfig option CONFIG_FB_DEVICE and make the virtual fbdev
device optional. If the new option has not been selected, fbdev
does not create files in devfs, sysfs or procfs.

Most modern Linux systems run a DRM-based graphics stack that uses
the kernel's framebuffer console, but has otherwise deprecated fbdev
support. Yet fbdev userspace interfaces are still present.

The option makes it possible to use the fbdev subsystem as console
implementation without support for userspace. This closes potential
entry points to manipulate kernel or I/O memory via framebuffers. It
also prevents the execution of driver code via ioctl or sysfs, both
of which might allow malicious software to exploit bugs in the fbdev
code.

A small number of fbdev drivers require struct fbinfo.dev to be
initialized, usually for the support of sysfs interface. Make these
drivers depend on FB_DEVICE. They can later be fixed if necessary.

v3:
	* effect -> affect in Kconfig help (Daniel)
v2:
	* set FB_DEVICE default to y (Geert)
	* comment on {get,put}_device() (Sam)
	* Kconfig fixes (Sam)
	* add TODO item about FB_DEVICE dependencies (Sam)

Signed-off-by: Thomas Zimmermann 
Acked-by: Greg Kroah-Hartman 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-39-tzimmermann@suse.de

fbdev/core: Move file-I/O code into separate file

2023-06-27T07:58:51+00:00

Move fbdev's file-I/O code into a separate file and contain it in
init and cleanup helpers. No functional changes.

v3:
	* add missing file fb_chrdev.c
v2:
	* rename source file (Sam)
	* include  (Javier, kernel test robot)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-37-tzimmermann@suse.de

fbdev/core: Move procfs code to separate file

2023-06-27T07:58:51+00:00

Move fbdev's procfs code into a separate file and contain it in
init and cleanup helpers. For the cleanup, replace remove_proc_entry()
with proc_remove(). It is equivalent in functionality, but looks
more like an inverse of proc_create_seq().

v2:
	* document proc_remove() usage (Sam)
	* revert unrelated removal of for_each_registered_fb()

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-36-tzimmermann@suse.de

fbdev/core: Move framebuffer and backlight helpers into separate files

2023-06-27T07:58:51+00:00

Move framebuffer and backlight helpers into separate files. Leave
fbsysfs.c to sysfs-related code. No functional changes.

The framebuffer helpers are not in fbmem.c because they are under
GPL-2.0-or-later copyright, while fbmem.c is GPL-2.0.

v2:
	* include  (Sam)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-34-tzimmermann@suse.de

fbdev: Move I/O read and write code into helper functions

2023-05-08T13:28:34+00:00

Move the existing I/O read and write code for I/O memory into
the new helpers fb_cfb_read() and fb_cfb_write(). Make them the
default fp_ops. No functional changes.

In the near term, the new functions will be useful to the DRM
subsystem, which currently provides it's own implementation. It
can then use the shared code. In the longer term, it might make
sense to revise the I/O helper's default status and make them
opt-in by the driver. Systems that don't use them would not
contain the code any longer.

v2:
	* add detailed commit message (Javier)
	* rename fb_cfb_() to fb_io_() (Geert)
	* add fixes that got lost while moving the code (Geert)

Signed-off-by: Thomas Zimmermann 
Tested-by: Sui Jingfeng 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Helge Deller 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230428122452.4856-19-tzimmermann@suse.de

fbdev: Handle video= parameter in video/cmdline.c

2023-02-20T13:56:48+00:00

Handle the command-line parameter video= in video/cmdline.c. Implement
the fbdev helper fb_get_options() on top. Will allows to handle the
kernel parameter in DRM without fbdev dependencies.

Note that __video_get_options() has the meaning of its return value
inverted compared to fb_get_options(). The new helper returns true if
the adapter has been enabled, and false otherwise.

There is the ofonly parameter, which disables output for non-OF-based
framebuffers. It is only for offb and looks like a workaround. The actual
purpose it not clear to me. Use 'video=off' or 'nomodeset' instead.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20230209135509.7786-9-tzimmermann@suse.de

fbdev: remove object duplication in Makefile

2020-01-15T16:31:52+00:00

The objects in $(fb-objs) $(fb-y) $(fb-m) are linked to fb.ko .

This line adds $(fb-y) to fb-objs, so the objects from $(fb-y) are
listed twice as the dependency of the module.

It works because Kbuild trims the duplicated objects from linking,
but there is no good reason to have this line.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Bartlomiej Zolnierkiewicz 
Link: https://patchwork.freedesktop.org/patch/msgid/20200106081352.27730-1-masahiroy@kernel.org

fbcon: Remove dmi quirk table

2017-12-04T22:03:22+00:00

This is now all handled in the drivers and communicated through
fb_info.fbcon_rotate_hint.

Acked-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Hans de Goede 
Link: https://patchwork.freedesktop.org/patch/msgid/20171125193553.23986-8-hdegoede@redhat.com