[PATCH v2 0/1] drm/lsdc: add drm driver for loongson display controller

[PATCH v2 0/1] drm/lsdc: add drm driver for loongson display controller

[Sui Jingfeng]

v2: fixup warnings reported by kernel test robot

There is a display controller in loongson's LS2K1000 SoC and LS7A1000
bridge, and the DC in those chip is a PCI device. This display controller
have two display pipes but with only one hardware cursor.

This display controller is uncommon outside of china, it don't have rich
document either. This patch try to provided a minimal support for this
display controller which is for graphic environment bring up. Hope the
code can speak for itself.

For ls7a1000, there are 4 gpios who register is located at dc register
space which is used to emulation i2c. LS2K1000 and LS2K0500 SoC don't
have those hardware, they use general purpose gpio or hardware i2c to
serve this purpose.

LS2K1000 is a double core 1.0Ghz mips64r2 compatible SoC[1]. LS7A1000 is
a bridge chip made by Loongson corporation which act as north and/or south
bridge of loongson's desktop and server level processor. It is equivalent
to RS780E or something like that. More details can be read from its user
manual[2].

This bridge chip is typically use with LS3A3000, LS3A4000 and LS3A5000 cpu.
LS3A3000 is 4 core 1.45gHz mips64r2 compatible cpu.
LS3A4000 is 4 core 1.8gHz mips64r5 compatible cpu.
LS3A5000 is 4 core 2.5gHz loongarch cpu[3].

[1] https://wiki.debian.org/InstallingDebianOn/Lemote/Loongson2K1000
[2] https://loongson.github.io/LoongArch-Documentation/Loongson-7A1000-usermanual-EN.html
[3] https://loongson.github.io/LoongArch-Documentation/Loongson-3A5000-usermanual-EN.html

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: suijingfeng <suijingfeng@loongson.cn>
Signed-off-by: Sui Jingfeng <15330273260@189.cn>

suijingfeng (1):
  drm/lsdc: add drm driver for loongson display controller

 drivers/gpu/drm/Kconfig               |   2 +
 drivers/gpu/drm/Makefile              |   1 +
 drivers/gpu/drm/lsdc/Kconfig          |  38 ++
 drivers/gpu/drm/lsdc/Makefile         |  15 +
 drivers/gpu/drm/lsdc/lsdc_connector.c | 439 ++++++++++++++
 drivers/gpu/drm/lsdc/lsdc_connector.h |  60 ++
 drivers/gpu/drm/lsdc/lsdc_crtc.c      | 438 ++++++++++++++
 drivers/gpu/drm/lsdc/lsdc_drv.c       | 824 ++++++++++++++++++++++++++
 drivers/gpu/drm/lsdc/lsdc_drv.h       | 214 +++++++
 drivers/gpu/drm/lsdc/lsdc_encoder.c   |  79 +++
 drivers/gpu/drm/lsdc/lsdc_i2c.c       | 220 +++++++
 drivers/gpu/drm/lsdc/lsdc_i2c.h       |  61 ++
 drivers/gpu/drm/lsdc/lsdc_irq.c       |  77 +++
 drivers/gpu/drm/lsdc/lsdc_irq.h       |  37 ++
 drivers/gpu/drm/lsdc/lsdc_plane.c     | 694 ++++++++++++++++++++++
 drivers/gpu/drm/lsdc/lsdc_pll.c       | 605 +++++++++++++++++++
 drivers/gpu/drm/lsdc/lsdc_pll.h       | 109 ++++
 drivers/gpu/drm/lsdc/lsdc_regs.h      | 242 ++++++++
 18 files changed, 4155 insertions(+)
 create mode 100644 drivers/gpu/drm/lsdc/Kconfig
 create mode 100644 drivers/gpu/drm/lsdc/Makefile
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_connector.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_connector.h
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_crtc.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_drv.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_drv.h
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_encoder.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_i2c.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_i2c.h
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_irq.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_irq.h
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_plane.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_pll.c
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_pll.h
 create mode 100644 drivers/gpu/drm/lsdc/lsdc_regs.h

-- 
2.20.1

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

[Randy Dunlap]

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.

-- 
~Randy