From 0a901f2130802fdcabcd6f1cfabf4f62fa0d3cde Mon Sep 17 00:00:00 2001 From: Vidya Sagar Date: Thu, 5 Sep 2019 16:15:51 +0530 Subject: PCI: tegra: Add support to enable slot regulators Add support to get regulator information of 3.3V and 12V supplies of a PCIe slot from the respective controller's device-tree node and enable those supplies. This is required in platforms like p2972-0000 where the supplies to x16 slot owned by C5 controller need to be enabled before attempting to enumerate the devices. Signed-off-by: Vidya Sagar Signed-off-by: Lorenzo Pieralisi Reviewed-by: Andrew Murray Acked-by: Thierry Reding --- drivers/pci/controller/dwc/pcie-tegra194.c | 83 ++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) (limited to 'drivers/pci') diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 0b870287f6b6..f89f5acee72d 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -278,6 +278,8 @@ struct tegra_pcie_dw { u32 aspm_l0s_enter_lat; struct regulator *pex_ctl_supply; + struct regulator *slot_ctl_3v3; + struct regulator *slot_ctl_12v; unsigned int phy_count; struct phy **phys; @@ -1055,6 +1057,73 @@ static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie) } } +static int tegra_pcie_get_slot_regulators(struct tegra_pcie_dw *pcie) +{ + pcie->slot_ctl_3v3 = devm_regulator_get_optional(pcie->dev, "vpcie3v3"); + if (IS_ERR(pcie->slot_ctl_3v3)) { + if (PTR_ERR(pcie->slot_ctl_3v3) != -ENODEV) + return PTR_ERR(pcie->slot_ctl_3v3); + + pcie->slot_ctl_3v3 = NULL; + } + + pcie->slot_ctl_12v = devm_regulator_get_optional(pcie->dev, "vpcie12v"); + if (IS_ERR(pcie->slot_ctl_12v)) { + if (PTR_ERR(pcie->slot_ctl_12v) != -ENODEV) + return PTR_ERR(pcie->slot_ctl_12v); + + pcie->slot_ctl_12v = NULL; + } + + return 0; +} + +static int tegra_pcie_enable_slot_regulators(struct tegra_pcie_dw *pcie) +{ + int ret; + + if (pcie->slot_ctl_3v3) { + ret = regulator_enable(pcie->slot_ctl_3v3); + if (ret < 0) { + dev_err(pcie->dev, + "Failed to enable 3.3V slot supply: %d\n", ret); + return ret; + } + } + + if (pcie->slot_ctl_12v) { + ret = regulator_enable(pcie->slot_ctl_12v); + if (ret < 0) { + dev_err(pcie->dev, + "Failed to enable 12V slot supply: %d\n", ret); + goto fail_12v_enable; + } + } + + /* + * According to PCI Express Card Electromechanical Specification + * Revision 1.1, Table-2.4, T_PVPERL (Power stable to PERST# inactive) + * should be a minimum of 100ms. + */ + if (pcie->slot_ctl_3v3 || pcie->slot_ctl_12v) + msleep(100); + + return 0; + +fail_12v_enable: + if (pcie->slot_ctl_3v3) + regulator_disable(pcie->slot_ctl_3v3); + return ret; +} + +static void tegra_pcie_disable_slot_regulators(struct tegra_pcie_dw *pcie) +{ + if (pcie->slot_ctl_12v) + regulator_disable(pcie->slot_ctl_12v); + if (pcie->slot_ctl_3v3) + regulator_disable(pcie->slot_ctl_3v3); +} + static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie, bool en_hw_hot_rst) { @@ -1068,6 +1137,10 @@ static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie, return ret; } + ret = tegra_pcie_enable_slot_regulators(pcie); + if (ret < 0) + goto fail_slot_reg_en; + ret = regulator_enable(pcie->pex_ctl_supply); if (ret < 0) { dev_err(pcie->dev, "Failed to enable regulator: %d\n", ret); @@ -1150,6 +1223,8 @@ fail_core_apb_rst: fail_core_clk: regulator_disable(pcie->pex_ctl_supply); fail_reg_en: + tegra_pcie_disable_slot_regulators(pcie); +fail_slot_reg_en: tegra_pcie_bpmp_set_ctrl_state(pcie, false); return ret; @@ -1182,6 +1257,8 @@ static int __deinit_controller(struct tegra_pcie_dw *pcie) return ret; } + tegra_pcie_disable_slot_regulators(pcie); + ret = tegra_pcie_bpmp_set_ctrl_state(pcie, false); if (ret) { dev_err(pcie->dev, "Failed to disable controller %d: %d\n", @@ -1381,6 +1458,12 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev) return ret; } + ret = tegra_pcie_get_slot_regulators(pcie); + if (ret < 0) { + dev_err(dev, "Failed to get slot regulators: %d\n", ret); + return ret; + } + pcie->pex_ctl_supply = devm_regulator_get(dev, "vddio-pex-ctl"); if (IS_ERR(pcie->pex_ctl_supply)) { ret = PTR_ERR(pcie->pex_ctl_supply); -- cgit v1.2.3