Re: [PATCH v2 1/1] drm/lsdc: add drm driver for loongson display controller

Hi--

On 1/29/22 22:04, Sui Jingfeng wrote:

diff --git a/drivers/gpu/drm/lsdc/Kconfig b/drivers/gpu/drm/lsdc/Kconfig new file mode 100644 index 000000000000..f470892ddf60 --- /dev/null +++ b/drivers/gpu/drm/lsdc/Kconfig @@ -0,0 +1,38 @@ +config DRM_LSDC

• tristate "DRM Support for loongson's display controller"
• depends on DRM && PCI
• depends on MACH_LOONGSON64 || LOONGARCH || MIPS || COMPILE_TEST
• select OF
• select CMA if HAVE_DMA_CONTIGUOUS
• select DMA_CMA if HAVE_DMA_CONTIGUOUS
• select DRM_KMS_HELPER
• select DRM_KMS_FB_HELPER
• select DRM_GEM_CMA_HELPER
• select VIDEOMODE_HELPERS
• select BACKLIGHT_PWM if CPU_LOONGSON2K
• select I2C_GPIO if CPU_LOONGSON2K
• select I2C_LS2X if CPU_LOONGSON2K
• default m
• help

•  This is a KMS driver for the display controller in the LS7A1000
  

•  bridge chip and LS2K1000 SoC. The display controller have two
  

has two

•  display pipes and it is a PCI device.
  

•  When using this driver on LS2K1000/LS2K0500 SoC, its framebuffer
  

•  is located at system memory.
  

•  If "M" is selected, the module will be called lsdc.
  

•  If in doubt, say "Y".
  

+config DRM_LSDC_VRAM_DRIVER

• bool "vram helper based device driver support"
• depends on DRM_LSDC
• select DRM_VRAM_HELPER
• default y
• help

•  When using this driver on LS7A1000 + LS3A3000/LS3A4000/LS3A5000
  

•  platform, the LS7A1000 bridge chip have dedicated video RAM.
  

has

•  Pass lsdc.use_vram_helper = 1 to the kernel cmd line will enable
  

Using "lsdc.use_vram_helper=1" in the kernel command line will enable

(No spaces allowed in the kernel command line.)

•  this driver mode and then the framebuffer will located at the
  

•  VRAM at the price of losing PRIME support.