On Wed, 4 Jun 2025 at 18:48, Matt Coster <matt.cos...@imgtec.com> wrote:
>
> On 03/06/2025 13:27, Ulf Hansson wrote:
> > On Fri, 30 May 2025 at 00:24, Michal Wilczynski
> > <m.wilczyn...@samsung.com> wrote:
> >>
> >> Add a device tree node for the IMG BXM-4-64 GPU present in the T-HEAD
> >> TH1520 SoC used by the Lichee Pi 4A board. This node enables support for
> >> the GPU using the drm/imagination driver.
> >>
> >> By adding this node, the kernel can recognize and initialize the GPU,
> >> providing graphics acceleration capabilities on the Lichee Pi 4A and
> >> other boards based on the TH1520 SoC.
> >>
> >> Add fixed clock gpu_mem_clk, as the MEM clock on the T-HEAD SoC can't be
> >> controlled programatically.
> >>
> >> Signed-off-by: Michal Wilczynski <m.wilczyn...@samsung.com>
> >> ---
> >> arch/riscv/boot/dts/thead/th1520.dtsi | 22 ++++++++++++++++++++++
> >> 1 file changed, 22 insertions(+)
> >>
> >> diff --git a/arch/riscv/boot/dts/thead/th1520.dtsi
> >> b/arch/riscv/boot/dts/thead/th1520.dtsi
> >> index
> >> 6170eec79e919b606a2046ac8f52db07e47ef441..ee937bbdb7c08439a70306f035b1cc82ddb4bae2
> >> 100644
> >> --- a/arch/riscv/boot/dts/thead/th1520.dtsi
> >> +++ b/arch/riscv/boot/dts/thead/th1520.dtsi
> >> @@ -225,6 +225,13 @@ aonsys_clk: clock-73728000 {
> >> #clock-cells = <0>;
> >> };
> >>
> >> + gpu_mem_clk: mem-clk {
> >> + compatible = "fixed-clock";
> >> + clock-frequency = <0>;
> >> + clock-output-names = "gpu_mem_clk";
> >> + #clock-cells = <0>;
> >> + };
> >> +
> >> stmmac_axi_config: stmmac-axi-config {
> >> snps,wr_osr_lmt = <15>;
> >> snps,rd_osr_lmt = <15>;
> >> @@ -504,6 +511,21 @@ clk: clock-controller@ffef010000 {
> >> #clock-cells = <1>;
> >> };
> >>
> >> + gpu: gpu@ffef400000 {
> >> + compatible = "thead,th1520-gpu",
> >> "img,img-bxm-4-64",
> >> + "img,img-rogue";
> >> + reg = <0xff 0xef400000 0x0 0x100000>;
> >> + interrupt-parent = <&plic>;
> >> + interrupts = <102 IRQ_TYPE_LEVEL_HIGH>;
> >> + clocks = <&clk_vo CLK_GPU_CORE>,
> >> + <&gpu_mem_clk>,
> >> + <&clk_vo CLK_GPU_CFG_ACLK>;
> >> + clock-names = "core", "mem", "sys";
> >> + power-domains = <&aon TH1520_GPU_PD>;
> >> + power-domain-names = "a";
> >
> > If the power-domain-names are really needed, please pick a
> > useful/descriptive name.
>
> This isn't the first time our unfortunate power domain names have come
> up [1][2]. Sadly, we're stuck with them for Rogue.
Wow, that's really crazy.
BTW, are there any reasons why you can't rely on attaching them by
index instead, via dev_pm_domain_attach_by_id() for example? Thus
entirely drop the names in the DT docs?
It sounds like the names don't really have a meaning, or do they?
>
> Matt
>
> [1]:
> https://lore.kernel.org/r/ff4e96e4-ebc2-4c50-9715-82ba3d7b8...@imgtec.com/
> [2]:
> https://lore.kernel.org/r/cc6a19b3-ba35-465c-9fa6-a764df7c0...@imgtec.com/
>
> >
[...]
Kind regards
Uffe
