drm/panel: Add Sitronix ST7701 panel driver

ST7701 designed for small and medium sizes of TFT LCD display, is
capable of supporting up to 480RGBX864 in resolution. It provides
several system interfaces like MIPI/RGB/SPI.

Currently added support for Techstar TS8550B which is ST7701 based
480x854, 2-lane MIPI DSI LCD panel.

Driver now registering mipi_dsi device, but indeed it can extendable
for RGB if any requirement trigger in future.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190124215131.17452-2-jagan@amarulasolutions.com

MAINTAINERS

@@ -4894,6 +4894,12 @@ S:	Orphan / Obsolete
 F:	drivers/gpu/drm/sis/
 F:	include/uapi/drm/sis_drm.h
 
+DRM DRIVER FOR SITRONIX ST7701 PANELS
+M:	Jagan Teki <jagan@amarulasolutions.com>
+S:	Maintained
+F:	drivers/gpu/drm/panel/panel-sitronix-st7701.c
+F:	Documentation/devicetree/bindings/display/panel/sitronix,st7701.txt
+
 DRM DRIVER FOR SITRONIX ST7586 PANELS
 M:	David Lechner <david@lechnology.com>
 S:	Maintained

drivers/gpu/drm/panel/Kconfig

@@ -196,6 +196,16 @@ config DRM_PANEL_SHARP_LS043T1LE01
 	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
 	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
 
+config DRM_PANEL_SITRONIX_ST7701
+	tristate "Sitronix ST7701 panel driver"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for the Sitronix
+	  ST7701 controller for 480X864 LCD panels with MIPI/RGB/SPI
+	  system interfaces.
+
 config DRM_PANEL_SITRONIX_ST7789V
 	tristate "Sitronix ST7789V panel"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
 obj-$(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-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
 obj-$(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