drm/panel: Add a driver for the TPO TPG110

The TPO (Toppoly) TPG110 is a pretty generic display driver
similar in vein to the Ilitek 93xx devices. It is not a panel
per se but a driver used with several low-cost noname panels.

This is used on the Nomadik NHK15 combined with a OSD
OSD057VA01CT display for WVGA 800x480.

The driver is pretty minimalistic right now but can be
extended to handle non-default polarities, gamma correction
etc.

The driver is based on the baked-in code in
drivers/video/fbdev/amba-clcd-nomadik.c which will be
decomissioned once this us upstream.

Cc: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190111175406.27646-1-linus.walleij@linaro.org

MAINTAINERS

@@ -4910,6 +4910,13 @@ DRM DRIVER FOR TDFX VIDEO CARDS
 S:	Orphan / Obsolete
 F:	drivers/gpu/drm/tdfx/
 
+DRM DRIVER FOR TPO TPG110 PANELS
+M:	Linus Walleij <linus.walleij@linaro.org>
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+S:	Maintained
+F:	drivers/gpu/drm/panel/panel-tpo-tpg110.c
+F:	Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt
+
 DRM DRIVER FOR USB DISPLAYLINK VIDEO ADAPTERS
 M:	Dave Airlie <airlied@redhat.com>
 R:	Sean Paul <sean@poorly.run>

drivers/gpu/drm/panel/Kconfig

@@ -204,6 +204,15 @@ config DRM_PANEL_SITRONIX_ST7789V
 	  Say Y here if you want to enable support for the Sitronix
 	  ST7789V controller for 240x320 LCD panels
 
+config DRM_PANEL_TPO_TPG110
+	tristate "TPO TPG 800x400 panel"
+	depends on OF && SPI && GPIOLIB
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for TPO TPG110
+	  400CH LTPS TFT LCD Single Chip Digital Driver for up to
+	  800x400 LCD panels.
+
 config DRM_PANEL_TRULY_NT35597_WQXGA
 	tristate "Truly WQXGA"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -21,4 +21,5 @@ obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
+obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
 obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o