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 <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: Thomas Zimmermann

arch/powerpc/configs/pmac32_defconfig

@@ -208,6 +208,7 @@ CONFIG_FB_ATY=y
 CONFIG_FB_ATY_CT=y
 CONFIG_FB_ATY_GX=y
 CONFIG_FB_3DFX=y
+CONFIG_BACKLIGHT_CLASS_DEVICE=y
 # CONFIG_VGA_CONSOLE is not set
 CONFIG_FRAMEBUFFER_CONSOLE=y
 CONFIG_LOGO=y

arch/powerpc/configs/ppc6xx_defconfig

@@ -716,6 +716,7 @@ CONFIG_FB_TRIDENT=m
 CONFIG_FB_SM501=m
 CONFIG_FB_IBM_GXT4500=y
 CONFIG_LCD_PLATFORM=m
+CONFIG_BACKLIGHT_CLASS_DEVICE=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
 CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y
 CONFIG_LOGO=y

drivers/auxdisplay/Kconfig

@@ -489,7 +489,7 @@ config IMG_ASCII_LCD
 
 config HT16K33
 	tristate "Holtek Ht16K33 LED controller with keyscan"
-	depends on FB && I2C && INPUT
+	depends on FB && I2C && INPUT && BACKLIGHT_CLASS_DEVICE
 	select FB_SYSMEM_HELPERS
 	select INPUT_MATRIXKMAP
 	select FB_BACKLIGHT

drivers/macintosh/Kconfig

@@ -120,6 +120,7 @@ config PMAC_MEDIABAY
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on PPC_PMAC && ADB_PMU && FB = y && (BROKEN || !PPC64)
+	depends on BACKLIGHT_CLASS_DEVICE=y
 	select FB_BACKLIGHT
 	help
 	  Say Y here to enable Macintosh specific extensions of the generic

drivers/staging/fbtft/Kconfig

@@ -3,6 +3,7 @@ menuconfig FB_TFT
 	tristate "Support for small TFT LCD display modules"
 	depends on FB && SPI
 	depends on FB_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on GPIOLIB || COMPILE_TEST
 	select FB_BACKLIGHT
 	select FB_SYSMEM_HELPERS_DEFERRED

drivers/video/fbdev/Kconfig

@@ -649,6 +649,7 @@ config FB_S1D13XXX
 config FB_ATMEL
 	tristate "AT91 LCD Controller support"
 	depends on FB && OF && HAVE_CLK && HAS_IOMEM
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on HAVE_FB_ATMEL || COMPILE_TEST
 	select FB_BACKLIGHT
 	select FB_IOMEM_HELPERS
@@ -660,7 +661,6 @@ config FB_ATMEL
 config FB_NVIDIA
 	tristate "nVidia Framebuffer Support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_NVIDIA_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -700,14 +700,15 @@ config FB_NVIDIA_DEBUG
 config FB_NVIDIA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_NVIDIA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_NVIDIA
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
 
 config FB_RIVA
 	tristate "nVidia Riva support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_RIVA_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -747,6 +748,8 @@ config FB_RIVA_DEBUG
 config FB_RIVA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RIVA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RIVA
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -934,7 +937,6 @@ config FB_MATROX_MAVEN
 config FB_RADEON
 	tristate "ATI Radeon display support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_RADEON_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -960,6 +962,8 @@ config FB_RADEON_I2C
 config FB_RADEON_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RADEON
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RADEON
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -975,7 +979,6 @@ config FB_RADEON_DEBUG
 config FB_ATY128
 	tristate "ATI Rage128 display support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_ATY128_BACKLIGHT
 	select FB_IOMEM_HELPERS
 	select FB_MACMODES if PPC_PMAC
 	help
@@ -989,6 +992,8 @@ config FB_ATY128
 config FB_ATY128_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_ATY128
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY128
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -999,7 +1004,6 @@ config FB_ATY
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
-	select FB_BACKLIGHT if FB_ATY_BACKLIGHT
 	select FB_IOMEM_FOPS
 	select FB_MACMODES if PPC
 	select FB_ATY_CT if SPARC64 && PCI
@@ -1040,6 +1044,8 @@ config FB_ATY_GX
 config FB_ATY_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_ATY
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1528,6 +1534,7 @@ config FB_SH_MOBILE_LCDC
 	depends on FB && HAVE_CLK && HAS_IOMEM
 	depends on SUPERH || COMPILE_TEST
 	depends on FB_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	select FB_DEFERRED_IO
 	select FB_DMAMEM_HELPERS
@@ -1793,6 +1800,7 @@ config FB_SSD1307
 	tristate "Solomon SSD1307 framebuffer support"
 	depends on FB && I2C
 	depends on GPIOLIB || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	select FB_SYSMEM_HELPERS_DEFERRED
 	help

drivers/video/fbdev/core/Kconfig

@@ -183,9 +183,8 @@ config FB_SYSMEM_HELPERS_DEFERRED
 	select FB_SYSMEM_HELPERS
 
 config FB_BACKLIGHT
-	tristate
+	bool
 	depends on FB
-	select BACKLIGHT_CLASS_DEVICE
 
 config FB_MODE_HELPERS
 	bool "Enable Video Mode Handling Helpers"