Re: [PATCH v7 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280

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On 2021-09-15 08:14, Bjorn Andersson wrote:
On Tue 14 Sep 11:19 PDT 2021, 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.

Signed-off-by: Prasad Malisetty <pmaliset@xxxxxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom.c | 90 +++++++++++++++++++++++++++++-----
 1 file changed, 79 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 8a7a300..380c962 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 *gcc_pcie_1_pipe_clk_src;

Afaict you have both 2 PCIe controllers on sc7280, so I think it seems
more reasonable to shorted this to "pipe_clk_src".

Agree. I will make it generic and update in next patch version.

+	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;
+	bool pcie_1_pipe_clk_src_switch;

Perhaps something little bit more generic, like pipe_clk_need_muxing?

Sure, I will change it and update in next patch version.

+};
+
 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;
+	bool pcie_1_pipe_clk_src_switch;
 };

 #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->pcie_1_pipe_clk_src_switch) {

This looks much better, now it will easily scale to other platforms that
have inherited this need.

Thanks Bjorn.


+		res->gcc_pcie_1_pipe_clk_src = devm_clk_get(dev, "pipe_mux");
+		if (IS_ERR(res->gcc_pcie_1_pipe_clk_src))
+			return PTR_ERR(res->gcc_pcie_1_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 gcc_pcie_1_pipe_clk_src */
+	if (pcie->pcie_1_pipe_clk_src_switch)
+		clk_set_parent(res->gcc_pcie_1_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 gcc_pcie_1_pipe_clk_src */
+	if (pcie->pcie_1_pipe_clk_src_switch)
+		clk_set_parent(res->gcc_pcie_1_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,
+	.pcie_1_pipe_clk_src_switch = 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 = NULL;

First use of this variable is an assignment, so I don't see a need for
zero initialize it.

Regards,
Bjorn

Sure, I will incorporate the changes in next patch version.

 	int ret;

 	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
@@ -1488,7 +1553,9 @@ 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;
+ pcie->pcie_1_pipe_clk_src_switch = pcie_cfg->pcie_1_pipe_clk_src_switch;

 	pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
 	if (IS_ERR(pcie->reset)) {
@@ -1545,16 +1612,17 @@ 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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a Linux Foundation Collaborative Project




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