Re: [PATCH v7 02/16] PCI: imx6: Simplify phy handling by using by using IMX6_PCIE_FLAG_HAS_PHY

Manivannan Sadhasivam
2024-01-06T15:33:31Z

On Wed, Dec 27, 2023 at 01:27:13PM -0500, Frank Li wrote:
> Refactors the phy handling logic in the imx6 PCI driver by adding
> IMX6_PCIE_FLAG_HAS_PHY bitmask define for drvdata::flags.
>
> The drvdata::flags and a bitmask ensures a cleaner and more scalable
> switch-case structure for handling phy.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>
> Notes:
> Change from v4 to v5:
> - none, Keep IMX6_PCIE_FLAG_HAS_PHY to indicate dts mismatch when platform
> require phy suppport.
>
> Change from v1 to v3:
> - none
>
> drivers/pci/controller/dwc/pci-imx6.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 50d9faaa17f71..4d620249f3d52 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -60,6 +60,9 @@ enum imx6_pcie_variants {
> #define IMX6_PCIE_FLAG_IMX6_PHY BIT(0)
> #define IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE BIT(1)
> #define IMX6_PCIE_FLAG_SUPPORTS_SUSPEND BIT(2)
> +#define IMX6_PCIE_FLAG_HAS_PHY BIT(3)

Every PCIe setup requires PHY for its operation. Perhaps you are referring to
external PHY? If so, please rename this to IMX6_PCIE_FLAG_HAS_EXT_PHY.

> +
> +#define imx6_check_flag(pci, val) (pci->drvdata->flags & val)
>
> #define IMX6_PCIE_MAX_CLKS 6
>
> @@ -1277,6 +1280,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY)) {

IMO, we would not need these kind of checks in the driver if the DT binding is
properly validated using schema. But folks always want to validate "broken DT"
in the drivers :(

But I'm fine with this check for now since not everyone agree with above.

- Mani

> + imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
> + if (IS_ERR(imx6_pcie->phy))
> + return dev_err_probe(dev, PTR_ERR(imx6_pcie->phy),
> + "failed to get pcie phy\n");
> + }
> +
> switch (imx6_pcie->drvdata->variant) {
> case IMX7D:
> if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> @@ -1306,11 +1316,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> return dev_err_probe(dev, PTR_ERR(imx6_pcie->apps_reset),
> "failed to get pcie apps reset control\n");
>
> - imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
> - if (IS_ERR(imx6_pcie->phy))
> - return dev_err_probe(dev, PTR_ERR(imx6_pcie->phy),
> - "failed to get pcie phy\n");
> -
> break;
> default:
> break;
> @@ -1444,13 +1449,15 @@ static const struct imx6_pcie_drvdata drvdata[] = {
> },
> [IMX8MM] = {
> .variant = IMX8MM,
> - .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
> + .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
> + IMX6_PCIE_FLAG_HAS_PHY,
> .gpr = "fsl,imx8mm-iomuxc-gpr",
> .clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> },
> [IMX8MP] = {
> .variant = IMX8MP,
> - .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
> + .flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
> + IMX6_PCIE_FLAG_HAS_PHY,
> .gpr = "fsl,imx8mp-iomuxc-gpr",
> .clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> },
> @@ -1462,12 +1469,14 @@ static const struct imx6_pcie_drvdata drvdata[] = {
> },
> [IMX8MM_EP] = {
> .variant = IMX8MM_EP,
> + .flags = IMX6_PCIE_FLAG_HAS_PHY,
> .mode = DW_PCIE_EP_TYPE,
> .gpr = "fsl,imx8mm-iomuxc-gpr",
> .clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> },
> [IMX8MP_EP] = {
> .variant = IMX8MP_EP,
> + .flags = IMX6_PCIE_FLAG_HAS_PHY,
> .mode = DW_PCIE_EP_TYPE,
> .gpr = "fsl,imx8mp-iomuxc-gpr",
> .clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> --
> 2.34.1
>

--
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