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Date: Sun, 7 Jan 2024 11:21:06 +0530
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Frank Li <Frank.Li@nxp.com>
Cc: krzysztof.kozlowski@linaro.org, bhelgaas@google.com,
	conor+dt@kernel.org, devicetree@vger.kernel.org, festevam@gmail.com,
	helgaas@kernel.org, hongxing.zhu@nxp.com, imx@lists.linux.dev,
	kernel@pengutronix.de, krzysztof.kozlowski+dt@linaro.org,
	kw@linux.com, l.stach@pengutronix.de,
	linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	lpieralisi@kernel.org, robh@kernel.org, s.hauer@pengutronix.de,
	shawnguo@kernel.org
Subject: Re: [PATCH v7 12/16] PCI: imx6: Add iMX95 PCIe support
Message-ID: <20240107055106.GL3416@thinkpad>
References: <20231227182727.1747435-1-Frank.Li@nxp.com>
 <20231227182727.1747435-13-Frank.Li@nxp.com>
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In-Reply-To: <20231227182727.1747435-13-Frank.Li@nxp.com>

On Wed, Dec 27, 2023 at 01:27:23PM -0500, Frank Li wrote:

Mention 'RC' in subject.

> Add iMX95 PCIe basic root complex function support.
> 

Add iMX95 PCIe Root Complex support.

> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> 
> Notes:
>     Change from v1 to v3
>     - none
> 
>  drivers/pci/controller/dwc/pci-imx6.c | 90 +++++++++++++++++++++++++--
>  1 file changed, 85 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index d66a2db53bdb7..9e60ab6f1885a 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -42,6 +42,25 @@
>  #define IMX8MQ_GPR_PCIE_VREG_BYPASS		BIT(12)
>  #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE	GENMASK(11, 8)
>  
> +#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)
> +
> +#define IMX95_PE0_GEN_CTRL_1			0x1050
> +#define IMX95_PCIE_DEVICE_TYPE			GENMASK(3, 0)
> +
> +#define IMX95_PE0_GEN_CTRL_3			0x1058
> +#define IMX95_PCIE_LTSSM_EN			BIT(0)
> +
> +#define IMX95_PE0_PM_STS			0x1064
> +#define IMX95_PCIE_PM_LINKST_IN_L2		BIT(14)
> +
>  #define to_imx6_pcie(x)	dev_get_drvdata((x)->dev)
>  
>  enum imx6_pcie_variants {
> @@ -52,6 +71,7 @@ enum imx6_pcie_variants {
>  	IMX8MQ,
>  	IMX8MM,
>  	IMX8MP,
> +	IMX95,
>  	IMX8MQ_EP,
>  	IMX8MM_EP,
>  	IMX8MP_EP,
> @@ -63,6 +83,7 @@ enum imx6_pcie_variants {
>  #define IMX6_PCIE_FLAG_HAS_PHY			BIT(3)
>  #define IMX6_PCIE_FLAG_HAS_APP_RESET		BIT(4)
>  #define IMX6_PCIE_FLAG_HAS_PHY_RESET		BIT(5)
> +#define IMX6_PCIE_FLAG_HAS_SERDES		BIT(6)
>  
>  #define imx6_check_flag(pci, val)     (pci->drvdata->flags & val)
>  
> @@ -179,6 +200,24 @@ static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)
>  	return imx6_pcie->controller_id == 1 ? IOMUXC_GPR16 : IOMUXC_GPR14;
>  }
>  
> +static int imx95_pcie_init_phy(struct imx6_pcie *imx6_pcie)
> +{
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr,
> +			IMX95_PCIE_SS_RW_REG_0,
> +			IMX95_PCIE_PHY_CR_PARA_SEL,
> +			IMX95_PCIE_PHY_CR_PARA_SEL);
> +
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr,
> +			   IMX95_PCIE_PHY_GEN_CTRL,
> +			   IMX95_PCIE_REF_USE_PAD, 0);
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr,
> +			   IMX95_PCIE_SS_RW_REG_0,
> +			   IMX95_PCIE_REF_CLKEN,
> +			   IMX95_PCIE_REF_CLKEN);
> +
> +	return 0;
> +}
> +
>  static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
>  {
>  	const struct imx6_pcie_drvdata *drvdata = imx6_pcie->drvdata;
> @@ -579,6 +618,7 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
>  				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
>  		break;
>  	case IMX7D:
> +	case IMX95:
>  		break;
>  	case IMX8MM:
>  	case IMX8MM_EP:
> @@ -696,10 +736,19 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
>  {
>  	struct dw_pcie *pci = imx6_pcie->pci;
>  	struct device *dev = pci->dev;
> +	u32 val;
>  
>  	reset_control_deassert(imx6_pcie->pciephy_reset);
>  
>  	switch (imx6_pcie->drvdata->variant) {
> +	case IMX95:
> +		/* Polling the MPLL_STATE */
> +		if (regmap_read_poll_timeout(imx6_pcie->iomuxc_gpr,
> +					IMX95_PCIE_PHY_MPLLA_CTRL, val,
> +					val & IMX95_PCIE_PHY_MPLL_STATE,
> +					10, 10000))
> +			dev_err(dev, "PCIe PLL lock timeout\n");

You should return err here because, if core deassert is not performed then the
core itself cannot be used.

> +		break;
>  	case IMX7D:
>  		/* Workaround for ERR010728, failure of PCI-e PLL VCO to
>  		 * oscillate, especially when cold.  This turns off "Duty-cycle
> @@ -1281,12 +1330,32 @@ static int imx6_pcie_probe(struct platform_device *pdev)
>  		return PTR_ERR(imx6_pcie->turnoff_reset);
>  	}
>  
> +	if (imx6_pcie->drvdata->gpr) {
>  	/* Grab GPR config register range */
> -	imx6_pcie->iomuxc_gpr =
> -		 syscon_regmap_lookup_by_compatible(imx6_pcie->drvdata->gpr);
> -	if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
> -		dev_err(dev, "unable to find iomuxc registers\n");
> -		return PTR_ERR(imx6_pcie->iomuxc_gpr);
> +		imx6_pcie->iomuxc_gpr =
> +			 syscon_regmap_lookup_by_compatible(imx6_pcie->drvdata->gpr);
> +		if (IS_ERR(imx6_pcie->iomuxc_gpr))
> +			return dev_err_probe(dev, PTR_ERR(imx6_pcie->iomuxc_gpr),
> +					     "unable to find iomuxc registers\n");
> +	}
> +
> +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_SERDES)) {
> +		void __iomem *off = devm_platform_ioremap_resource_byname(pdev, "app");
> +
> +		if (IS_ERR(off))
> +			return dev_err_probe(dev, PTR_ERR(off),
> +					     "unable to find serdes registers\n");
> +
> +		static struct regmap_config regmap_config = {

const

- Mani

-- 
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