drm: panel: Add novatek nt36672a panel driver

Novatek NT36672a is a generic DSI IC that drives command and video mode
panels. Add the driver for it.

Right now adding support for some Poco F1 phones that have an LCD panel
from Tianma connected with this IC, with a resolution of 1080x2246 that
operates in DSI video mode.

During testing, Benni Steini <bennisteinir@gmail.com> helped us fix
the reset sequence timing (from 10ms to 20ms), to get the bootanimation
to work on Android.

With current AOSP, we need to increase it to 200ms - this seems to be a
safe high value to avoid a white screen occasionally.
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benni Steini <bennisteinir@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200902064407.30712-3-sumit.semwal@linaro.org

MAINTAINERS

@@ -5542,6 +5542,13 @@ T:	git git://anongit.freedesktop.org/drm/drm-misc
 F:	Documentation/devicetree/bindings/display/panel/novatek,nt35510.yaml
 F:	drivers/gpu/drm/panel/panel-novatek-nt35510.c
 
+DRM DRIVER FOR NOVATEK NT36672A PANELS
+M:	Sumit Semwal <sumit.semwal@linaro.org>
+S:	Maintained
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+F:	Documentation/devicetree/bindings/display/panel/novatek,nt36672a.yaml
+F:	drivers/gpu/drm/panel/panel-novatek-nt36672a.c
+
 DRM DRIVER FOR NVIDIA GEFORCE/QUADRO GPUS
 M:	Ben Skeggs <bskeggs@redhat.com>
 L:	dri-devel@lists.freedesktop.org

drivers/gpu/drm/panel/Kconfig

@@ -208,6 +208,16 @@ config DRM_PANEL_NOVATEK_NT35510
 	  around the Novatek NT35510 display controller, such as some
 	  Hydis panels.
 
+config DRM_PANEL_NOVATEK_NT36672A
+	tristate "Novatek NT36672A DSI panel"
+	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 panels built
+	  around the Novatek NT36672A display controller, such as some
+	  Tianma panels used in a few Xiaomi Poco F1 mobile phones.
+
 config DRM_PANEL_NOVATEK_NT39016
 	tristate "Novatek NT39016 RGB/SPI panel"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.o
+obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
 obj-$(CONFIG_DRM_PANEL_MANTIX_MLAF057WE51) += panel-mantix-mlaf057we51.o
 obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o