Re: [PATCH v2 5/6] PCI: imx6: Add PLL clock lock check for i.MX95 PCIe

[Frank Li <Frank.li@nxp.com>]

On Wed, Mar 26, 2025 at 03:59:14PM +0800, Richard Zhu wrote:
> Add PLL clock lock check for i.MX95 PCIe.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/pci/controller/dwc/pci-imx6.c | 28 +++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 42683d6be9f2..1c8834fbcfd5 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -45,6 +45,9 @@
>  #define IMX95_PCIE_PHY_GEN_CTRL			0x0
>  #define IMX95_PCIE_REF_USE_PAD			BIT(17)
>
> +#define IMX95_PCIE_PHY_MPLLA_CTRL		0x10
> +#define IMX95_PCIE_PHY_MPLL_STATE		BIT(30)
> +
>  #define IMX95_PCIE_SS_RW_REG_0			0xf0
>  #define IMX95_PCIE_REF_CLKEN			BIT(23)
>  #define IMX95_PCIE_PHY_CR_PARA_SEL		BIT(9)
> @@ -478,6 +481,23 @@ static void imx7d_pcie_wait_for_phy_pll_lock(struct imx_pcie *imx_pcie)
>  		dev_err(dev, "PCIe PLL lock timeout\n");
>  }
>
> +static int imx95_pcie_wait_for_phy_pll_lock(struct imx_pcie *imx_pcie)
> +{
> +	u32 val;
> +	struct device *dev = imx_pcie->pci->dev;
> +
> +	if (regmap_read_poll_timeout(imx_pcie->iomuxc_gpr,
> +				     IMX95_PCIE_PHY_MPLLA_CTRL, val,
> +				     val & IMX95_PCIE_PHY_MPLL_STATE,
> +				     PHY_PLL_LOCK_WAIT_USLEEP_MAX,
> +				     PHY_PLL_LOCK_WAIT_TIMEOUT)) {
> +		dev_err(dev, "PCIe PLL lock timeout\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
>  static int imx_setup_phy_mpll(struct imx_pcie *imx_pcie)
>  {
>  	unsigned long phy_rate = 0;
> @@ -821,6 +841,8 @@ static int imx95_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
>  		regmap_clear_bits(imx_pcie->iomuxc_gpr, IMX95_PCIE_RST_CTRL,
>  				  IMX95_PCIE_COLD_RST);
>  		udelay(10);
> +	} else {
> +		return imx95_pcie_wait_for_phy_pll_lock(imx_pcie);
>  	}
>
>  	return 0;
> @@ -840,11 +862,13 @@ static void imx_pcie_assert_core_reset(struct imx_pcie *imx_pcie)
>
>  static int imx_pcie_deassert_core_reset(struct imx_pcie *imx_pcie)
>  {
> +	int ret = 0;
> +
>  	reset_control_deassert(imx_pcie->pciephy_reset);
>  	reset_control_deassert(imx_pcie->apps_reset);
>
>  	if (imx_pcie->drvdata->core_reset)
> -		imx_pcie->drvdata->core_reset(imx_pcie, false);
> +		ret = imx_pcie->drvdata->core_reset(imx_pcie, false);
>
>  	/* Some boards don't have PCIe reset GPIO. */
>  	if (imx_pcie->reset_gpiod) {
> @@ -854,7 +878,7 @@ static int imx_pcie_deassert_core_reset(struct imx_pcie *imx_pcie)
>  		msleep(100);
>  	}
>
> -	return 0;
> +	return ret;
>  }
>
>  static int imx_pcie_wait_for_speed_change(struct imx_pcie *imx_pcie)
> --
> 2.37.1
>