From c26ebe98a103479dae9284fe0a86a95af4a5cd46 Mon Sep 17 00:00:00 2001 From: Quentin Schulz Date: Thu, 8 Jun 2017 10:07:42 +0200 Subject: PCI: imx6: Add regulator support Some boards might require to control a regulator to power the PCIe port. Add support for an optional regulator defined in Device Tree linked in the PCIe controller under `vpcie-supply`. If present, the regulator will be disabled and then enabled as part of the PCIe host initialization process and will be disabled when shutting down. Signed-off-by: Quentin Schulz [bhelgaas: use dev_err() instead of pr_err() in imx6_pcie_assert_core_reset()] Signed-off-by: Bjorn Helgaas Acked-by: Rob Herring Acked-by: Richard Zhu --- drivers/pci/dwc/pci-imx6.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c index a98cba55c7f0..9717ef71e71b 100644 --- a/drivers/pci/dwc/pci-imx6.c +++ b/drivers/pci/dwc/pci-imx6.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -59,6 +60,7 @@ struct imx6_pcie { u32 tx_swing_full; u32 tx_swing_low; int link_gen; + struct regulator *vpcie; }; /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */ @@ -257,6 +259,8 @@ static int imx6q_pcie_abort_handler(unsigned long addr, static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie) { + struct device *dev = imx6_pcie->pci->dev; + switch (imx6_pcie->variant) { case IMX7D: reset_control_assert(imx6_pcie->pciephy_reset); @@ -283,6 +287,14 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie) IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16); break; } + + if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { + int ret = regulator_disable(imx6_pcie->vpcie); + + if (ret) + dev_err(dev, "failed to disable vpcie regulator: %d\n", + ret); + } } static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie) @@ -349,10 +361,19 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie) struct device *dev = pci->dev; int ret; + if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) { + ret = regulator_enable(imx6_pcie->vpcie); + if (ret) { + dev_err(dev, "failed to enable vpcie regulator: %d\n", + ret); + return; + } + } + ret = clk_prepare_enable(imx6_pcie->pcie_phy); if (ret) { dev_err(dev, "unable to enable pcie_phy clock\n"); - return; + goto err_pcie_phy; } ret = clk_prepare_enable(imx6_pcie->pcie_bus); @@ -412,6 +433,13 @@ err_pcie: clk_disable_unprepare(imx6_pcie->pcie_bus); err_pcie_bus: clk_disable_unprepare(imx6_pcie->pcie_phy); +err_pcie_phy: + if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) { + ret = regulator_disable(imx6_pcie->vpcie); + if (ret) + dev_err(dev, "failed to disable vpcie regulator: %d\n", + ret); + } } static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie) @@ -775,6 +803,13 @@ static int imx6_pcie_probe(struct platform_device *pdev) if (ret) imx6_pcie->link_gen = 1; + imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie"); + if (IS_ERR(imx6_pcie->vpcie)) { + if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER) + return -EPROBE_DEFER; + imx6_pcie->vpcie = NULL; + } + platform_set_drvdata(pdev, imx6_pcie); ret = imx6_add_pcie_port(imx6_pcie, pdev); -- cgit v1.2.3