Commit d2ce69ca authored by Richard Zhu's avatar Richard Zhu Committed by Bjorn Helgaas
Browse files

PCI: imx6: Enable PHY internal regulator when supplied >3V 

The i.MX8MQ PCIe PHY needs 1.8V in default but can be supplied by either a
1.8V or a 3.3V regulator.

The "vph-supply" DT property tells us which external regulator supplies the
PHY. If that regulator supplies anything over 3V, enable the PHY's internal
3.3V-to-1.8V regulator.

Link: https://lore.kernel.org/r/1622771269-13844-3-git-send-email-hongxing.zhu@nxp.com


Signed-off-by: default avatarRichard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarLucas Stach <l.stach@pengutronix.de>
parent c9d511dc

drivers/pci/controller/dwc/pci-imx6.c

+20 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#define IMX8MQ_GPR_PCIE_REF_USE_PAD		BIT(9)

#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN	BIT(10)

#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE	BIT(11)

#define IMX8MQ_GPR_PCIE_VREG_BYPASS		BIT(12)

#define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE	GENMASK(11, 8)

#define IMX8MQ_PCIE2_BASE_ADDR			0x33c00000
@@ -80,6 +81,7 @@ struct imx6_pcie { 
	u32			tx_swing_full;

	u32			tx_swing_low;

	struct regulator	*vpcie;

	struct regulator	*vph;

	void __iomem		*phy_base;



	/* power domain for pcie */
@@ -621,6 +623,17 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie) 
				   imx6_pcie_grp_offset(imx6_pcie),

				   IMX8MQ_GPR_PCIE_REF_USE_PAD,

				   IMX8MQ_GPR_PCIE_REF_USE_PAD);

		/*

		 * Regarding the datasheet, the PCIE_VPH is suggested

		 * to be 1.8V. If the PCIE_VPH is supplied by 3.3V, the

		 * VREG_BYPASS should be cleared to zero.

		 */

		if (imx6_pcie->vph &&

		    regulator_get_voltage(imx6_pcie->vph) > 3000000)

			regmap_update_bits(imx6_pcie->iomuxc_gpr,

					   imx6_pcie_grp_offset(imx6_pcie),

					   IMX8MQ_GPR_PCIE_VREG_BYPASS,

					   0);

		break;

	case IMX7D:

		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
@@ -1128,6 +1141,13 @@ static int imx6_pcie_probe(struct platform_device *pdev) 
		imx6_pcie->vpcie = NULL;

	}



	imx6_pcie->vph = devm_regulator_get_optional(&pdev->dev, "vph");

	if (IS_ERR(imx6_pcie->vph)) {

		if (PTR_ERR(imx6_pcie->vph) != -ENODEV)

			return PTR_ERR(imx6_pcie->vph);

		imx6_pcie->vph = NULL;

	}



	platform_set_drvdata(pdev, imx6_pcie);



	ret = imx6_pcie_attach_pd(dev);