On Sat 05 Jun 09:40 CDT 2021, Prasad Malisetty wrote:
> In PCIe driver pipe-clk mux needs to switch between pipe_clk
> and XO for GDSC enable. This is done by setting pipe_clk mux
> as parent of pipe_clk after phy init.
But you're not switching between pipe_clk and XO, you're only making
sure that the pipe_clk is parented by the PHY's pipe clock.
Also, can you please elaborate on how this relates to the GDSC?
>
> Signed-off-by: Prasad Malisetty <pmaliset@xxxxxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 8a7a300..5cbbea4 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -166,6 +166,9 @@ struct qcom_pcie_resources_2_7_0 {
> struct regulator_bulk_data supplies[2];
> struct reset_control *pci_reset;
> struct clk *pipe_clk;
> + struct clk *pipe_clk_mux;
> + struct clk *pipe_ext_src;
> + struct clk *ref_clk_src;
> };
>
> union qcom_pcie_resources {
> @@ -1167,6 +1170,20 @@ static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
> if (ret < 0)
> return ret;
>
> + if (of_device_is_compatible(dev->of_node, "qcom,pcie-sc7280")) {
> + res->pipe_clk_mux = devm_clk_get(dev, "pipe_src");
> + if (IS_ERR(res->pipe_clk_mux))
> + return PTR_ERR(res->pipe_clk_mux);
> +
> + res->pipe_ext_src = devm_clk_get(dev, "pipe_ext");
> + if (IS_ERR(res->pipe_ext_src))
> + return PTR_ERR(res->pipe_ext_src);
> +
> + res->ref_clk_src = devm_clk_get(dev, "ref");
> + if (IS_ERR(res->ref_clk_src))
> + return PTR_ERR(res->ref_clk_src);
> + }
> +
> res->pipe_clk = devm_clk_get(dev, "pipe");
> return PTR_ERR_OR_ZERO(res->pipe_clk);
> }
> @@ -1255,6 +1272,11 @@ static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
> static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
> {
> struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> + struct dw_pcie *pci = pcie->pci;
> + struct device *dev = pci->dev;
> +
> + if (of_device_is_compatible(dev->of_node, "qcom,pcie-sc7280"))
If this is something only found on 7280, you need to document (in the
commit message at least) why this does not apply to other platforms with
this controller.
Thanks,
Bjorn
> + clk_set_parent(res->pipe_clk_mux, res->pipe_ext_src);
>
> return clk_prepare_enable(res->pipe_clk);
> }
> --
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> a Linux Foundation Collaborative Project
>
