Re: [PATCH v6 4/6] clk: qcom: gpucc-sc7280: Add cx collapse reset support

From: Philipp Zabel
Date: Thu Sep 01 2022 - 06:35:14 EST


On Wed, Aug 31, 2022 at 10:48:25AM +0530, Akhil P Oommen wrote:
> Allow a consumer driver to poll for cx gdsc collapse through Reset
> framework.
>
> Signed-off-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
>
> (no changes since v3)
>
> Changes in v3:
> - Convert 'struct qcom_reset_ops cx_gdsc_reset' to 'static const' (Krzysztof)
>
> Changes in v2:
> - Minor update to use the updated custom reset ops implementation
>
> drivers/clk/qcom/gpucc-sc7280.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/clk/qcom/gpucc-sc7280.c b/drivers/clk/qcom/gpucc-sc7280.c
> index 9a832f2..fece3f4 100644
> --- a/drivers/clk/qcom/gpucc-sc7280.c
> +++ b/drivers/clk/qcom/gpucc-sc7280.c
> @@ -433,12 +433,22 @@ static const struct regmap_config gpu_cc_sc7280_regmap_config = {
> .fast_io = true,
> };
>
> +static const struct qcom_reset_ops cx_gdsc_reset = {
> + .reset = gdsc_wait_for_collapse,

This should be accompanied by a comment explaining the not-quite-reset
nature of this workaround, i.e. what is the prerequisite for this to
actually work as expected?

> +};
> +
> +static const struct qcom_reset_map gpucc_sc7280_resets[] = {
> + [GPU_CX_COLLAPSE] = { .ops = &cx_gdsc_reset, .priv = &cx_gdsc },
> +};
> +
> static const struct qcom_cc_desc gpu_cc_sc7280_desc = {
> .config = &gpu_cc_sc7280_regmap_config,
> .clks = gpu_cc_sc7280_clocks,
> .num_clks = ARRAY_SIZE(gpu_cc_sc7280_clocks),
> .gdscs = gpu_cc_sc7180_gdscs,
> .num_gdscs = ARRAY_SIZE(gpu_cc_sc7180_gdscs),
> + .resets = gpucc_sc7280_resets,
> + .num_resets = ARRAY_SIZE(gpucc_sc7280_resets),

See my comment on patch 2. I think instead of adding a const struct
qcom_reset_ops * to gpucc_sc7280_resets, this should just add a const
struct reset_control * to gpu_cc_sc7280_desc.

regards
Philipp