Re: [PATCH v2 3/4] PCIe: qcom: Add support to control pipe clk mux
From: Bjorn Andersson <hidden>
Date: 2021-06-06 02:15:44
Also in:
linux-arm-msm, linux-usb, lkml
On Sat 05 Jun 09:40 CDT 2021, Prasad Malisetty wrote:
In PCIe driver pipe-clk mux needs to switch between pipe_clk and XO for GDSC enable. This is done by setting pipe_clk mux as parent of pipe_clk after phy init.
But you're not switching between pipe_clk and XO, you're only making sure that the pipe_clk is parented by the PHY's pipe clock. Also, can you please elaborate on how this relates to the GDSC?
quoted hunk ↗ jump to hunk
Signed-off-by: Prasad Malisetty <redacted> --- drivers/pci/controller/dwc/pcie-qcom.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 8a7a300..5cbbea4 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_mux; + struct clk *pipe_ext_src; + struct clk *ref_clk_src; }; union qcom_pcie_resources {@@ -1167,6 +1170,20 @@ 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->pipe_clk_mux = devm_clk_get(dev, "pipe_src"); + if (IS_ERR(res->pipe_clk_mux)) + return PTR_ERR(res->pipe_clk_mux); + + res->pipe_ext_src = devm_clk_get(dev, "pipe_ext"); + if (IS_ERR(res->pipe_ext_src)) + return PTR_ERR(res->pipe_ext_src); + + 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); }@@ -1255,6 +1272,11 @@ 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; + + if (of_device_is_compatible(dev->of_node, "qcom,pcie-sc7280"))
If this is something only found on 7280, you need to document (in the commit message at least) why this does not apply to other platforms with this controller. Thanks, Bjorn
+ clk_set_parent(res->pipe_clk_mux, res->pipe_ext_src); return clk_prepare_enable(res->pipe_clk); } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project