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

From: Prasad Malisetty
Date: Tue Aug 24 2021 - 04:10:58 EST


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@xxxxxxxxxxxxxx>
---
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