On Mon, Jun 23, 2025 at 1:44 PM Michal Wilczynski
<m.wilczyn...@samsung.com> wrote:
>
> Introduce the pwrseq-thead-gpu driver, a power sequencer provider for
> the Imagination BXM-4-64 GPU on the T-HEAD TH1520 SoC. This driver
> controls an auxiliary device instantiated by the AON power domain.
>
> The TH1520 GPU requires a specific sequence to correctly initialize and
> power down its resources:
> - Enable GPU clocks (core and sys).
> - De-assert the GPU clock generator reset (clkgen_reset).
> - Introduce a short hardware-required delay.
> - De-assert the GPU core reset. The power-down sequence performs these
> steps in reverse.
>
> Implement this sequence via the pwrseq_power_on and pwrseq_power_off
> callbacks.
>
> Crucially, the driver's match function is called when a consumer (the
> Imagination GPU driver) requests the "gpu-power" target. During this
> match, the sequencer uses clk_bulk_get() and
> reset_control_get_exclusive() on the consumer's device to obtain handles
> to the GPU's "core" and "sys" clocks, and the GPU core reset. These,
> along with clkgen_reset obtained from parent aon node, allow it to
> perform the complete sequence.
>
> Reviewed-by: Ulf Hansson <ulf.hans...@linaro.org>
> Signed-off-by: Michal Wilczynski <m.wilczyn...@samsung.com>
> ---
[snip]
> +
> + /* Additionally verify consumer device has AON as power-domain */
> + if (pwr_spec.np != ctx->aon_node || pwr_spec.args[0] !=
> TH1520_GPU_PD) {
> + of_node_put(pwr_spec.np);
> + return 0;
> + }
> +
> + of_node_put(pwr_spec.np);
> +
> + /* If a consumer is already bound, only allow a re-match from it */
> + if (ctx->consumer_node)
> + return ctx->consumer_node == dev->of_node;
> +
That should be `!!(ctx->consumer_node == dev->of_node)` or preferably
`ctx->consumer_node == dev->of_node ? 1 : 0`. I can amend it when
applying if you have no objections. The rest looks good to me and I'd
like to pick it up into pwrseq/for-next in the next two days.
Bart
[snip]
