From d2ce69ca2516906f08b0b239df9c4e9493a4c193 Mon Sep 17 00:00:00 2001 From: Richard Zhu Date: Fri, 4 Jun 2021 09:47:49 +0800 Subject: 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: Richard Zhu Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Lucas Stach --- drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers') diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index dc48dd7cd7c5..80fc98acf097 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -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); -- cgit v1.2.3