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authorRichard Zhu <hongxing.zhu@nxp.com>2021-06-04 09:47:49 +0800
committerBjorn Helgaas <bhelgaas@google.com>2021-06-24 14:50:34 -0500
commitd2ce69ca2516906f08b0b239df9c4e9493a4c193 (patch)
tree6aad2dbe8bf0cc5688f30bc4f836780af57a7e8a /drivers/pci
parentc9d511dc84610498f370bbfff16e1c194b93c8d8 (diff)
downloadlinux-d2ce69ca2516906f08b0b239df9c4e9493a4c193.tar.bz2
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 <hongxing.zhu@nxp.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/controller/dwc/pci-imx6.c20
1 files changed, 20 insertions, 0 deletions
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);