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

[Prasad Malisetty <pmaliset@codeaurora.org>]

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@codeaurora.org>
>> ---
>>  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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