drm: panel: Add Himax HX8394 panel controller driver

The driver is for panels based on the Himax HX8394 controller, such as the
HannStar HSD060BHW4 720x1440 TFT LCD panel that uses a MIPI-DSI interface.
Signed-off-by: Kamil Trzciński <ayufan@ayufan.eu>
Co-developed-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Co-developed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Tom Fitzhenry <tom@tom-fitzhenry.me.uk>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102230733.3506624-3-javierm@redhat.com

drivers/gpu/drm/panel/Kconfig

@@ -154,6 +154,18 @@ config DRM_PANEL_FEIYANG_FY07024DI26A30D
 	  Say Y if you want to enable support for panels based on the
 	  Feiyang FY07024DI26A30-D MIPI-DSI interface.
 
+config DRM_PANEL_HIMAX_HX8394
+	tristate "HIMAX HX8394 MIPI-DSI LCD panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Himax HX8394 controller, such as the HannStar HSD060BHW4
+	  720x1440 TFT LCD panel that uses a MIPI-DSI interface.
+
+	  If M is selected the module will be called panel-himax-hx8394.
+
 config DRM_PANEL_ILITEK_IL9322
 	tristate "Ilitek ILI9322 320x240 QVGA panels"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_PANEL_EBBG_FT8719) += panel-ebbg-ft8719.o
 obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
 obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
 obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
+obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o