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Commit 0a901f21 authored by Vidya Sagar's avatar Vidya Sagar Committed by Bjorn Helgaas
Browse files

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: default avatarVidya Sagar <vidyas@nvidia.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: default avatarAndrew Murray <andrew.murray@arm.com>
Acked-by: default avatarThierry Reding <treding@nvidia.com>
parent f4ff4faf

drivers/pci/controller/dwc/pcie-tegra194.c

+83 −0
Original line number Diff line number Diff line
@@ -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 @@ static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie, 
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);