dm: video: Add a video uclass

U-Boot has separate code for LCDs and 'video' devices. Both now use a
very similar API thanks to earlier work by Nikita Kiryanov. With the driver-
model conversion we should unify these into a single uclass.

Unfortunately there are different features supported by each. This
implementation provides for a common set of features which should serve
most purposes. The intent is to support:

- bitmap devices with 8, 16 and 32 bits per pixel
- text console wih white on black or vice versa
- rotated text console
- bitmap display (BMP format)

More can be added as additional boards are ported over to use driver model
for video.

The name 'video' is chosen for the uclass since it is more generic than LCD.
Another option would be 'display' but that would introduce a third concept
to U-Boot which seems like the wrong approach.

The existing LCD and video init functions are not needed now, so this uclass
makes no attempt to implement them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index caf1efc..946d958 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -4,6 +4,46 @@
 
 menu "Graphics support"
 
+config DM_VIDEO
+	bool "Enable driver model support for LCD/video"
+	depends on DM
+	help
+	  This enables driver model for LCD and video devices. These support
+	  a bitmap display of various sizes and depths which can be drawn on
+	  to display a command-line console or splash screen. Enabling this
+	  option compiles in the video uclass and routes all LCD/video access
+	  through this.
+
+config VIDEO_BPP8
+	bool "Support 8-bit-per-pixel displays"
+	depends on DM_VIDEO
+	default y if DM_VIDEO
+	help
+	  Support drawing text and bitmaps onto a 8-bit-per-pixel display.
+	  Enabling this will include code to support this display. Without
+	  this option, such displays will not be supported and console output
+	  will be empty.
+
+config VIDEO_BPP16
+	bool "Support 16-bit-per-pixel displays"
+	depends on DM_VIDEO
+	default y if DM_VIDEO
+	help
+	  Support drawing text and bitmaps onto a 16-bit-per-pixel display.
+	  Enabling this will include code to support this display. Without
+	  this option, such displays will not be supported and console output
+	  will be empty.
+
+config VIDEO_BPP32
+	bool "Support 32-bit-per-pixel displays"
+	depends on DM_VIDEO
+	default y if DM_VIDEO
+	help
+	  Support drawing text and bitmaps onto a 32-bit-per-pixel display.
+	  Enabling this will include code to support this display. Without
+	  this option, such displays will not be supported and console output
+	  will be empty.
+
 config VIDEO_VESA
 	bool "Enable VESA video driver support"
 	default n