Thomas Zimmermann 8fc38062be fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE
Do not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latter
only controls backlight support within fbdev core code and data
structures.

Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let users
select it explicitly. Fixes warnings about recursive dependencies,
such as

error: recursive dependency detected!
	symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
	symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC
	symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE
	symbol FB_DEVICE depends on FB_CORE
	symbol FB_CORE is selected by DRM_GEM_DMA_HELPER
	symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341
	symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICE

BACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt to
it is the correct approach in any case. For most drivers, backlight
support is also configurable separately.

v3:
- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)
- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)
v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241216074450.8590-2-tzimmermann@suse.de
2024-12-17 18:06:10 +01:00
..
2021-05-10 11:19:39 +02:00

  FBTFT
=========

Linux Framebuffer drivers for small TFT LCD display modules.
The module 'fbtft' makes writing drivers for some of these displays very easy.

Development is done on a Raspberry Pi running the Raspbian "wheezy" distribution.

INSTALLATION
  Download kernel sources

  From Linux 3.15
    cd drivers/video/fbdev/fbtft
    git clone https://github.com/notro/fbtft.git

    Add to drivers/video/fbdev/Kconfig:   source "drivers/video/fbdev/fbtft/Kconfig"
    Add to drivers/video/fbdev/Makefile:  obj-y += fbtft/

  Before Linux 3.15
    cd drivers/video
    git clone https://github.com/notro/fbtft.git

    Add to drivers/video/Kconfig:   source "drivers/video/fbtft/Kconfig"
    Add to drivers/video/Makefile:  obj-y += fbtft/

  Enable driver(s) in menuconfig and build the kernel


See wiki for more information: https://github.com/notro/fbtft/wiki


Source: https://github.com/notro/fbtft/