On Thu, Jun 26, 2025 at 03:38:04PM +0800, Richard Zhu wrote:
> The PCI Express reference clock of i.MX9 PCIes might come from external
> clock source. Add the external reference clock mode support.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> ---
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> drivers/pci/controller/dwc/pci-imx6.c | 20 +++++++++++++-------
> 1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 5a38cfaf989b..9309959874c0 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -149,6 +149,7 @@ struct imx_pcie {
> struct gpio_desc *reset_gpiod;
> struct clk_bulk_data *clks;
> int num_clks;
> + bool enable_ext_refclk;
> struct regmap *iomuxc_gpr;
> u16 msi_ctrl;
> u32 controller_id;
> @@ -241,6 +242,8 @@ static unsigned int imx_pcie_grp_offset(const struct imx_pcie *imx_pcie)
>
> static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
> {
> + bool ext = imx_pcie->enable_ext_refclk;
> +
> /*
> * ERR051624: The Controller Without Vaux Cannot Exit L23 Ready
> * Through Beacon or PERST# De-assertion
> @@ -259,13 +262,12 @@ static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
> IMX95_PCIE_PHY_CR_PARA_SEL,
> IMX95_PCIE_PHY_CR_PARA_SEL);
>
> - regmap_update_bits(imx_pcie->iomuxc_gpr,
> - IMX95_PCIE_PHY_GEN_CTRL,
> - IMX95_PCIE_REF_USE_PAD, 0);
> - regmap_update_bits(imx_pcie->iomuxc_gpr,
> - IMX95_PCIE_SS_RW_REG_0,
> + regmap_update_bits(imx_pcie->iomuxc_gpr, IMX95_PCIE_PHY_GEN_CTRL,
> + ext ? IMX95_PCIE_REF_USE_PAD : 0,
> + IMX95_PCIE_REF_USE_PAD);
> + regmap_update_bits(imx_pcie->iomuxc_gpr, IMX95_PCIE_SS_RW_REG_0,
> IMX95_PCIE_REF_CLKEN,
> - IMX95_PCIE_REF_CLKEN);
> + ext ? 0 : IMX95_PCIE_REF_CLKEN);
>
> return 0;
> }
> @@ -1600,7 +1602,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
> struct imx_pcie *imx_pcie;
> struct device_node *np;
> struct device_node *node = dev->of_node;
> - int ret, domain;
> + int i, ret, domain;
> u16 val;
>
> imx_pcie = devm_kzalloc(dev, sizeof(*imx_pcie), GFP_KERNEL);
> @@ -1651,6 +1653,10 @@ static int imx_pcie_probe(struct platform_device *pdev)
> if (imx_pcie->num_clks < 0)
> return dev_err_probe(dev, imx_pcie->num_clks,
> "failed to get clocks\n");
> + imx_pcie->enable_ext_refclk = true;
> + for (i = 0; i < imx_pcie->num_clks; i++)
> + if (strncmp(imx_pcie->clks[i].id, "ref", 3) == 0)
> + imx_pcie->enable_ext_refclk = false;
>
> if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_PHYDRV)) {
> imx_pcie->phy = devm_phy_get(dev, "pcie-phy");
> --
> 2.37.1
>
