Re: [PATCH v5 4/4] PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280

[Prasad Malisetty <pmaliset@codeaurora.org>]

On 2021-08-17 22:56, Prasad Malisetty wrote:
> On 2021-08-10 09:38, Prasad Malisetty wrote:
>> On the SC7280, By default the clock source for pcie_1_pipe is
>> TCXO for gdsc enable. But after the PHY is initialized, the clock
>> source must be switched to gcc_pcie_1_pipe_clk from TCXO.
>> 
>> Signed-off-by: Prasad Malisetty <pmaliset@codeaurora.org>
>> ---
>>  drivers/pci/controller/dwc/pcie-qcom.c | 18 ++++++++++++++++++
>>  1 file changed, 18 insertions(+)
>> 
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c
>> b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 8a7a300..39e3b21 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -166,6 +166,8 @@ 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;
>> +	struct clk *phy_pipe_clk;
>>  };
>> 
>>  union qcom_pcie_resources {
>> @@ -1167,6 +1169,16 @@ 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->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);
>> +	}
>> +
> 
> Hi All,
> 
> Greetings!
> 
> I would like to check is there any other better approach instead of
> compatible method here as well or is it fine to use compatible method.
> 
> Thanks
> -Prasad
> 
>>  	res->pipe_clk = devm_clk_get(dev, "pipe");
>>  	return PTR_ERR_OR_ZERO(res->pipe_clk);
>>  }
>> @@ -1255,6 +1267,12 @@ 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;
>> +	struct device_node *node = dev->of_node;
>> +
>> +	if (of_property_read_bool(node, "pipe-clk-source-switch"))
>> +		clk_set_parent(res->gcc_pcie_1_pipe_clk_src, res->phy_pipe_clk);
>> 
>>  	return clk_prepare_enable(res->pipe_clk);
>>  }

Hi,

Kindly provide your inputs and confirmation on latest queries, I will 
share new patch version.

Thanks
-Prasad