[PATCH v3 0/7] Add dts for mt8183 GPU (and misc panfrost patches)

Nicolas Boichat drinkcat at chromium.org
Mon Jan 13 23:15:55 PST 2020


Follow-up on the v2: https://patchwork.kernel.org/cover/11322801/ .

The main purpose of this series is to upstream the dts change and the binding
document, but I wanted to see how far I could probe the GPU, to check that the
binding is indeed correct. The rest of the patches are RFC/work-in-progress, but
I think some of them could already be picked up.

So this is tested on MT8183 with a chromeos-4.19 kernel, and a ton of
backports to get the latest panfrost driver (I should probably try on
linux-next at some point but this was the path of least resistance).

I tested it as a module as it's more challenging (originally probing would
work built-in, on boot, but not as a module, as I didn't have the power
domain changes, and all power domains are on by default during boot).

Probing logs looks like this, currently. They look sane.
[  501.319728] panfrost 13040000.gpu: clock rate = 511999970
[  501.320041] panfrost 13040000.gpu: Linked as a consumer to regulator.14
[  501.320102] panfrost 13040000.gpu: Linked as a consumer to regulator.31
[  501.320651] panfrost 13040000.gpu: Linked as a consumer to genpd:0:13040000.gpu
[  501.320954] panfrost 13040000.gpu: Linked as a consumer to genpd:1:13040000.gpu
[  501.321062] panfrost 13040000.gpu: Linked as a consumer to genpd:2:13040000.gpu
[  501.321734] panfrost 13040000.gpu: mali-g72 id 0x6221 major 0x0 minor 0x3 status 0x0
[  501.321741] panfrost 13040000.gpu: features: 00000000,13de77ff, issues: 00000000,00000400
[  501.321747] panfrost 13040000.gpu: Features: L2:0x07120206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
[  501.321752] panfrost 13040000.gpu: shader_present=0x7 l2_present=0x1
[  501.324951] [drm] Initialized panfrost 1.1.0 20180908 for 13040000.gpu on minor 2

Some more changes are still required to get devfreq working, and of course
I do not have a userspace driver to test this with.



v3 (see individual patches, too):
 - Match a specific mediatek,mt8183-mali instead of the generic bifrost,
   as this instance requires 2 special cases:
    - 2 regulators
    - 3 power domains

 - Use sram instead of mali_sram as SRAM supply name.
 - Rename mali@ to gpu at .
 - Add dt-bindings changes
 - Stacking patches after the device tree change that allow basic
   probing (still incomplete and broken).

Nicolas Boichat (7):
  dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183
  arm64: dts: mt8183: Add node for the Mali GPU
  drm/panfrost: Improve error reporting in panfrost_gpu_power_on
  drm/panfrost: Add support for multiple regulators
  drm/panfrost: Add support for multiple power domains
  RFC: drm/panfrost: Add mt8183-mali compatible string
  RFC: drm/panfrost: devfreq: Add support for 2 regulators

 .../bindings/gpu/arm,mali-bifrost.yaml        |  18 +++
 arch/arm64/boot/dts/mediatek/mt8183-evb.dts   |   7 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      | 104 +++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_devfreq.c   |  17 +++
 drivers/gpu/drm/panfrost/panfrost_device.c    | 120 +++++++++++++++---
 drivers/gpu/drm/panfrost/panfrost_device.h    |  25 +++-
 drivers/gpu/drm/panfrost/panfrost_drv.c       |  38 ++++--
 drivers/gpu/drm/panfrost/panfrost_gpu.c       |  11 +-
 8 files changed, 310 insertions(+), 30 deletions(-)


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