fbdev: rework backlight dependencies

Rather than having CONFIG_FB_BACKLIGHT select CONFIG_BACKLIGHT_CLASS_DEVICE,
make any driver that needs it have a dependency on the class device
being available, to prevent circular dependencies.

This is the same way that the backlight is already treated for the DRM
subsystem.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index 64012cd..356afb6 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -170,6 +170,7 @@
 config HT16K33
 	tristate "Holtek Ht16K33 LED controller with keyscan"
 	depends on FB && I2C && INPUT
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_SYS_FOPS
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA
diff --git a/drivers/macintosh/Kconfig b/drivers/macintosh/Kconfig
index 5cdc361..cb0fbdf 100644
--- a/drivers/macintosh/Kconfig
+++ b/drivers/macintosh/Kconfig
@@ -113,6 +113,7 @@
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on PPC_PMAC && ADB_PMU && FB = y && (BROKEN || !PPC64)
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	help
 	  Say Y here to enable Macintosh specific extensions of the generic
diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig
index dad1ddc..c4f2f01 100644
--- a/drivers/staging/fbtft/Kconfig
+++ b/drivers/staging/fbtft/Kconfig
@@ -3,6 +3,7 @@
 	tristate "Support for small TFT LCD display modules"
 	depends on FB && SPI
 	depends on GPIOLIB || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA
 	select FB_SYS_IMAGEBLIT
diff --git a/drivers/staging/olpc_dcon/Kconfig b/drivers/staging/olpc_dcon/Kconfig
index d1a0dea..a9f3653 100644
--- a/drivers/staging/olpc_dcon/Kconfig
+++ b/drivers/staging/olpc_dcon/Kconfig
@@ -4,7 +4,7 @@
 	depends on OLPC && FB
 	depends on I2C
 	depends on GPIO_CS5535 && ACPI
-	select BACKLIGHT_CLASS_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	help
 	  In order to support very low power operation, the XO laptop uses a
 	  secondary Display CONtroller, or DCON.  This secondary controller
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index c187a93..3ad4994 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -186,7 +186,7 @@
 config FB_BACKLIGHT
 	tristate
 	depends on FB
-	select BACKLIGHT_CLASS_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 
 config FB_MODE_HELPERS
 	bool "Enable Video Mode Handling Helpers"
@@ -275,12 +275,12 @@
 	tristate "ARM PrimeCell PL110 support"
 	depends on ARM || ARM64 || COMPILE_TEST
 	depends on FB && ARM_AMBA && HAS_IOMEM
+	depends on BACKLIGHT_CLASS_DEVICE || !OF
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
 	select FB_MODE_HELPERS if OF
 	select VIDEOMODE_HELPERS if OF
-	select BACKLIGHT_CLASS_DEVICE if OF
 	help
 	  This framebuffer device driver is for the ARM PrimeCell PL110
 	  Colour LCD controller.  ARM PrimeCells provide the building
@@ -863,6 +863,7 @@
 	tristate "AT91 LCD Controller support"
 	depends on FB && OF && HAVE_CLK && HAS_IOMEM
 	depends on HAVE_FB_ATMEL || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
@@ -916,6 +917,7 @@
 config FB_NVIDIA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_NVIDIA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_NVIDIA
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -963,6 +965,7 @@
 config FB_RIVA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RIVA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RIVA
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1234,6 +1237,7 @@
 config FB_RADEON_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RADEON
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RADEON
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1265,6 +1269,7 @@
 config FB_ATY128_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_ATY128
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY128
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1314,6 +1319,7 @@
 
 config FB_ATY_BACKLIGHT
 	bool "Support for backlight control"
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY
 	depends on FB_ATY
 	default y
 	help
@@ -1838,6 +1844,7 @@
 	tristate "SuperH Mobile LCDC framebuffer support"
 	depends on FB && HAVE_CLK && HAS_IOMEM
 	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA
 	select FB_SYS_IMAGEBLIT
@@ -2166,7 +2173,7 @@
 config FB_MX3
 	tristate "MX3 Framebuffer support"
 	depends on FB && MX3_IPU
-	select BACKLIGHT_CLASS_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -2222,6 +2229,7 @@
 	tristate "Solomon SSD1307 framebuffer support"
 	depends on FB && I2C
 	depends on GPIOLIB || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_SYS_FOPS
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA