Re: [PATCH v9 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280
From: Bjorn Helgaas
Date: Tue Sep 28 2021 - 12:21:53 EST
[+cc linux-pci; please cc drivers/pci changes there]
On Tue, Sep 28, 2021 at 07:25:50PM +0530, Prasad Malisetty wrote:
> On the SC7280, the clock source for gcc_pcie_1_pipe_clk_src
> must be the TCXO while gdsc is enabled. After PHY init successful
> clock source should switch to pipe clock for gcc_pcie_1_pipe_clk_src.
This looks good. Ideally the commit log would say what the patch
*does*. I know it's in the subject, but it's nice to have it both
places so the body is complete in itself.
Again in an ideal world, I would split this into two patches:
1) Do the boilerplate conversions to struct qcom_pcie_cfg and
updates of qcom_pcie_match[]. This patch would have no functional
change.
2) Add the code to deal with pcie_1_pipe_clk_src, which should be a
much smaller patch.
This makes it easier to see the important part of dealing with
pcie_1_pipe_clk_src and makes any future bisect much more specific.
> Signed-off-by: Prasad Malisetty <pmaliset@xxxxxxxxxxxxxx>
> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 94 ++++++++++++++++++++++++++++++----
> 1 file changed, 83 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 8a7a300..7896a86 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_src;
> + struct clk *phy_pipe_clk;
> + struct clk *ref_clk_src;
> };
>
> union qcom_pcie_resources {
> @@ -189,6 +192,11 @@ struct qcom_pcie_ops {
> int (*config_sid)(struct qcom_pcie *pcie);
> };
>
> +struct qcom_pcie_cfg {
> + const struct qcom_pcie_ops *ops;
> + unsigned int pipe_clk_need_muxing:1;
> +};
> +
> struct qcom_pcie {
> struct dw_pcie *pci;
> void __iomem *parf; /* DT parf */
> @@ -197,6 +205,7 @@ struct qcom_pcie {
> struct phy *phy;
> struct gpio_desc *reset;
> const struct qcom_pcie_ops *ops;
> + unsigned int pipe_clk_need_muxing:1;
> };
>
> #define to_qcom_pcie(x) dev_get_drvdata((x)->dev)
> @@ -1167,6 +1176,20 @@ static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
> if (ret < 0)
> return ret;
>
> + if (pcie->pipe_clk_need_muxing) {
> + res->pipe_clk_src = devm_clk_get(dev, "pipe_mux");
> + if (IS_ERR(res->pipe_clk_src))
> + return PTR_ERR(res->pipe_clk_src);
> +
> + res->phy_pipe_clk = devm_clk_get(dev, "phy_pipe");
> + if (IS_ERR(res->phy_pipe_clk))
> + return PTR_ERR(res->phy_pipe_clk);
> +
> + 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);
> }
> @@ -1185,6 +1208,10 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
> return ret;
> }
>
> + /* Set TCXO as clock source for pcie_pipe_clk_src */
> + if (pcie->pipe_clk_need_muxing)
> + clk_set_parent(res->pipe_clk_src, res->ref_clk_src);
> +
> ret = clk_bulk_prepare_enable(res->num_clks, res->clks);
> if (ret < 0)
> goto err_disable_regulators;
> @@ -1256,6 +1283,10 @@ 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;
>
> + /* Set pipe clock as clock source for pcie_pipe_clk_src */
> + if (pcie->pipe_clk_need_muxing)
> + clk_set_parent(res->pipe_clk_src, res->phy_pipe_clk);
> +
> return clk_prepare_enable(res->pipe_clk);
> }
>
> @@ -1456,6 +1487,39 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
> .config_sid = qcom_pcie_config_sid_sm8250,
> };
>
> +static const struct qcom_pcie_cfg apq8084_cfg = {
> + .ops = &ops_1_0_0,
> +};
> +
> +static const struct qcom_pcie_cfg ipq8064_cfg = {
> + .ops = &ops_2_1_0,
> +};
> +
> +static const struct qcom_pcie_cfg msm8996_cfg = {
> + .ops = &ops_2_3_2,
> +};
> +
> +static const struct qcom_pcie_cfg ipq8074_cfg = {
> + .ops = &ops_2_3_3,
> +};
> +
> +static const struct qcom_pcie_cfg ipq4019_cfg = {
> + .ops = &ops_2_4_0,
> +};
> +
> +static const struct qcom_pcie_cfg sdm845_cfg = {
> + .ops = &ops_2_7_0,
> +};
> +
> +static const struct qcom_pcie_cfg sm8250_cfg = {
> + .ops = &ops_1_9_0,
> +};
> +
> +static const struct qcom_pcie_cfg sc7280_cfg = {
> + .ops = &ops_1_9_0,
> + .pipe_clk_need_muxing = true,
> +};
> +
> static const struct dw_pcie_ops dw_pcie_ops = {
> .link_up = qcom_pcie_link_up,
> .start_link = qcom_pcie_start_link,
> @@ -1467,6 +1531,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
> struct pcie_port *pp;
> struct dw_pcie *pci;
> struct qcom_pcie *pcie;
> + const struct qcom_pcie_cfg *pcie_cfg;
> int ret;
>
> pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> @@ -1488,7 +1553,13 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>
> pcie->pci = pci;
>
> - pcie->ops = of_device_get_match_data(dev);
> + pcie_cfg = of_device_get_match_data(dev);
> + pcie->ops = pcie_cfg->ops;
> + if (!pcie->ops) {
> + dev_err(dev, "Invalid platform data\n");
> + return -EINVAL;
> + }
> + pcie->pipe_clk_need_muxing = pcie_cfg->pipe_clk_need_muxing;
>
> pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
> if (IS_ERR(pcie->reset)) {
> @@ -1545,16 +1616,17 @@ static int qcom_pcie_probe(struct platform_device *pdev)
> }
>
> static const struct of_device_id qcom_pcie_match[] = {
> - { .compatible = "qcom,pcie-apq8084", .data = &ops_1_0_0 },
> - { .compatible = "qcom,pcie-ipq8064", .data = &ops_2_1_0 },
> - { .compatible = "qcom,pcie-ipq8064-v2", .data = &ops_2_1_0 },
> - { .compatible = "qcom,pcie-apq8064", .data = &ops_2_1_0 },
> - { .compatible = "qcom,pcie-msm8996", .data = &ops_2_3_2 },
> - { .compatible = "qcom,pcie-ipq8074", .data = &ops_2_3_3 },
> - { .compatible = "qcom,pcie-ipq4019", .data = &ops_2_4_0 },
> - { .compatible = "qcom,pcie-qcs404", .data = &ops_2_4_0 },
> - { .compatible = "qcom,pcie-sdm845", .data = &ops_2_7_0 },
> - { .compatible = "qcom,pcie-sm8250", .data = &ops_1_9_0 },
> + { .compatible = "qcom,pcie-apq8084", .data = &apq8084_cfg },
> + { .compatible = "qcom,pcie-ipq8064", .data = &ipq8064_cfg },
> + { .compatible = "qcom,pcie-ipq8064-v2", .data = &ipq8064_cfg },
> + { .compatible = "qcom,pcie-apq8064", .data = &ipq8064_cfg },
> + { .compatible = "qcom,pcie-msm8996", .data = &msm8996_cfg },
> + { .compatible = "qcom,pcie-ipq8074", .data = &ipq8074_cfg },
> + { .compatible = "qcom,pcie-ipq4019", .data = &ipq4019_cfg },
> + { .compatible = "qcom,pcie-qcs404", .data = &ipq4019_cfg },
> + { .compatible = "qcom,pcie-sdm845", .data = &sdm845_cfg },
> + { .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg },
> + { .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
> { }
> };
>
> --
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