Re: [v13,1/2] drm: add kms driver for loongson display controller

[Liu Peibao]

I test this on my 3A5000 + 7A1000 and 3A5000 + 7A2000 desktop,
and this works well, so:

Tested-by: Liu Peibao <liupeibao@xxxxxxxxxxx>

Br,
Peibao

On 5/15/23 11:57 PM, Sui Jingfeng wrote:
> Loongson display controller IP has been integrated in both Loongson north
> bridge chipset(ls7a1000/ls7a2000) and Loongson SoCs(ls2k1000/ls2k2000), it
> has been even included in Loongson self-made BMC products.
> 
> This display controller is a PCI device. It has two display pipes and each
> display pipe support a primary plane and a cursor plane. For the DC in the
> ls7a1000 and ls2k1000, each display pipe has a DVO output interface which
> provide RGB888 signals, vertical & horizontal synchronisations and pixel
> clock. Each CRTC is able to support 1920x1080@60Hz, the maximum resolution
> of each display pipe is 2048x2048 according to the hardware spec.
> 
> For the DC in LS7A2000, each display pipe is equipped with a built-in HDMI
> encoder which is compliant with the HDMI 1.4 specification, thus it support
> 3840x2160@30Hz. The first display pipe is also equipped with a transparent
> vga encoder which is parallel with the HDMI encoder. The DC in LS7A2000 is
> more complete compare with the one in old chips, besides above feature, it
> has two hardware cursors, two hardware vblank counter and two scanout
> position recorders unit. It also support tiled framebuffer format which
> can be scanout the tiled framebuffer rendered by the LoongGPU directly.
> 
> v1 -> v2:
>  1) Use hpd status reg when polling for ls7a2000
>  2) Fix all warnings emerged when compile with W=1
> 
> v2 -> v3:
>  1) Add COMPILE_TEST in Kconfig and make the driver off by default
>  2) Alphabetical sorting headers (Thomas)
>  3) Untangle register access functions as much as possible (Thomas)
>  4) Switch to TTM based memory manager and prefer cached mapping
>     for Loongson SoC (Thomas)
>  5) Add chip id detection method, now all models are distinguishable.
>  6) Revise builtin HDMI phy driver, nearly all main stream mode
>     below 4K@30Hz is tested, this driver supported these mode very
>     well including clone display mode and extend display mode.
> 
> v3 -> v4:
>  1) Quickly fix a small mistake.
> 
> v4 -> v5:
>  1) Drop potential support for Loongson 2K series SoC temporary,
>     this part should be resend with the DT binding patch in the future.
>  2) Add per display pipe debugfs support to the builtin HDMI encoder.
>  3) Rewrite atomic_update() for hardware cursors plane(Thomas)
>  4) Rewrite encoder and connector initialization part, untangle it
>     according to the chip(Thomas).
> 
> v5 -> v6:
>  1) Remove stray code which didn't get used, say lsdc_of_get_reserved_ram
>  2) Fix all typos I could found, make sentences and code more readable
>  3) Untangle lsdc_hdmi*_connector_detect() function according to the pipe
>  4) After a serious consideration, we rename this driver as loongson.
>     Because we also have drivers toward the LoongGPU IP in LS7A2000 and
>     LS2K2000. Besides, there are also drivers about the external encoder,
>     HDMI audio driver and vbios support etc. This patch only provide DC
>     driver part, my teammate Li Yi believe that loongson will be more
>     suitable for loongson graphics than lsdc in the long run.
> 
>     loongson.ko = LSDC + LoongGPU + encoders driver + vbios/DT ...
> 
> v6 -> v7:
>  1) Add prime support, self-sharing is works. sharing buffer with etnaviv
>     is also tested, and its works with limitation.
>  2) Implement buffer objects tracking with list_head.
>  3) S3(sleep to RAM) is tested on ls3a5000+ls7a2000 evb and it works.
>  4) Rewrite lsdc_bo_move, since ttm core stop allocating resources
>     during BO creation. Patch V1 ~ V6 of this series no longer works
>     on latest kernel. Thus, we send V7 to revival them.
> 
> v7 -> v8:
>  1) Zero a compile warnnings on 32-bit platform, compile with W=1
>  2) Revise lsdc_bo_gpu_offset() and minor cleanup
>  3) Pageflip tested on the virtual terminal with following commands
> 
>     modetest -M loongson -s 32:1920x1080 -v
>     modetest -M loongson -s 34:1920x1080 -v -F tiles
> 
>    It works like a charm, when running pageflip test with dual screnn
>    configuration, another two additional bo created by the modetest
>    emerged, VRAM usage up to 40+MB, well we have at least 64MB, still
>    enough.
> 
>    # cat bos
> 
>        bo[0000]: size:     8112kB VRAM
>        bo[0001]: size:       16kB VRAM
>        bo[0002]: size:       16kB VRAM
>        bo[0003]: size:    16208kB VRAM
>        bo[0004]: size:     8112kB VRAM
>        bo[0005]: size:     8112kB VRAM
> 
> v8 -> v9:
>  1) Select I2C and I2C_ALGOBIT in Kconfig and should depend on MMU.
>  2) Using pci_get_domain_bus_and_slot to get the GPU device.
>  3) Other minor improvements.
> 
>  Those patches are tested on ls3a5000 + ls7a1000 CRB, ls3a5000 + ls7a2000
>  evb, and lemote a1901 board(ls3a4000 + ls7a1000). On loongson mips CPU,
>  the write combine support should be enabled, to get a decent performance
>  for writing framebuffer data to the VRAM.
> 
> v9 -> v10:
>  1) Revise lsdc_drm_freeze() to implement S3 completely and correctly.
>     I suddenly realized that pinned buffer can not move and VRAM lost
>     power when sleep to RAM. Thus, the data in the buffer who is pinned
>     in VRAM will get lost when resume. Yet it's not big problem because
>     we are software rendering solution which relay on the CPU update the
>     front framebuffer. We can see the garbage data when resume from S3,
>     but the screen will show correct image as I move the cursor. This is
>     due to the cpu repaint. v10 of this patch make S3 perfect by unpin
>     all of BOs in VRAM, evict them all to system RAM.
> 
> v10 -> v11:
>  1) On double screen case, the single giant framebuffer is referenced by
>     two GEM object, hence, it will be pinned by prepare_fb() at lease two
>     times. This cause its pin count > 1. V10 of this patch only unpin VRAM
>     BOs once when suspend, which is not correct on double screen case. V11
>     of this patch unpin BOs until its pin count reach to zero when suspend.
>     Then, we make the S3 support complete finally. With v11, I can't see
>     any garbage data after resume. Tested on both ls7a1000 and ls7a2000
>     platform, with single screen and double screen configuration.
>  2) Fix vblank wait timeout when disable CRTC.
>  3) Test against IGT, at least fbdev test and kms_flip test passed.
>  4) Rewrite pixel PLL update function, magic numbers eliminated (Emil)
>  5) Drop a few common hardware features description in lsdc_desc (Emil)
>  6) Drop lsdc_mode_config_mode_valid(), instead add restrictions in dumb
>     create function. (Emil)
>  7) Untangle the ls7a1000 case and ls7a2000 case completely (Thomas)
> 
> v11 -> v12:
>  none
> 
> v12 -> v13:
>  1) Add benchmark to figure out the bandwidth of the hardware platform.
>     Usage:
>     # cd /sys/kernel/debug/dri/0/
>     # cat benchmark
> 
>  2) VRAM is filled with garbage data if uninitialized, add a buffer
>     clearing procedure, clear it on the BO creation time.
>  3) Update copyrights and adjust coding style (Huacai)
> 
> Signed-off-by: Li Yi <liyi@xxxxxxxxxxx>
> Signed-off-by: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
> Cc: "Christian König" <christian.koenig@xxxxxxx>
> ---
>  drivers/gpu/drm/Kconfig                     |    2 +
>  drivers/gpu/drm/Makefile                    |    1 +
>  drivers/gpu/drm/loongson/Kconfig            |   17 +
>  drivers/gpu/drm/loongson/Makefile           |   21 +
>  drivers/gpu/drm/loongson/ls7a1000_outputs.c |  161 +++
>  drivers/gpu/drm/loongson/ls7a2000_outputs.c |  531 +++++++++
>  drivers/gpu/drm/loongson/lsdc_benchmark.c   |  132 +++
>  drivers/gpu/drm/loongson/lsdc_benchmark.h   |   13 +
>  drivers/gpu/drm/loongson/lsdc_crtc.c        | 1068 +++++++++++++++++++
>  drivers/gpu/drm/loongson/lsdc_debugfs.c     |   91 ++
>  drivers/gpu/drm/loongson/lsdc_device.c      |  104 ++
>  drivers/gpu/drm/loongson/lsdc_drv.c         |  484 +++++++++
>  drivers/gpu/drm/loongson/lsdc_drv.h         |  452 ++++++++
>  drivers/gpu/drm/loongson/lsdc_gem.c         |  324 ++++++
>  drivers/gpu/drm/loongson/lsdc_gem.h         |   37 +
>  drivers/gpu/drm/loongson/lsdc_gfxpll.c      |  199 ++++
>  drivers/gpu/drm/loongson/lsdc_gfxpll.h      |   52 +
>  drivers/gpu/drm/loongson/lsdc_i2c.c         |  179 ++++
>  drivers/gpu/drm/loongson/lsdc_i2c.h         |   29 +
>  drivers/gpu/drm/loongson/lsdc_irq.c         |   81 ++
>  drivers/gpu/drm/loongson/lsdc_irq.h         |   16 +
>  drivers/gpu/drm/loongson/lsdc_output.h      |   21 +
>  drivers/gpu/drm/loongson/lsdc_pixpll.c      |  481 +++++++++
>  drivers/gpu/drm/loongson/lsdc_pixpll.h      |   86 ++
>  drivers/gpu/drm/loongson/lsdc_plane.c       |  639 +++++++++++
>  drivers/gpu/drm/loongson/lsdc_probe.c       |   56 +
>  drivers/gpu/drm/loongson/lsdc_probe.h       |   12 +
>  drivers/gpu/drm/loongson/lsdc_regs.h        |  400 +++++++
>  drivers/gpu/drm/loongson/lsdc_ttm.c         |  610 +++++++++++
>  drivers/gpu/drm/loongson/lsdc_ttm.h         |   99 ++
>  30 files changed, 6398 insertions(+)
>  create mode 100644 drivers/gpu/drm/loongson/Kconfig
>  create mode 100644 drivers/gpu/drm/loongson/Makefile
>  create mode 100644 drivers/gpu/drm/loongson/ls7a1000_outputs.c
>  create mode 100644 drivers/gpu/drm/loongson/ls7a2000_outputs.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_crtc.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_debugfs.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_device.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_output.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_plane.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_regs.h
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.c
>  create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.h