ARM: tegra: Implement XUSB pad controller

This controller was introduced on Tegra114 to handle XUSB pads. On
Tegra124 it is also used for PCIe and SATA pin muxing and PHY control.
Only the Tegra124 PCIe and SATA functionality is currently implemented,
with weak symbols on Tegra114.

Tegra20 and Tegra30 also provide weak symbols for these functions so
that drivers can use the same API irrespective of which SoC they're
being built for.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

5 files changed, 781 insertions, 0 deletions

diff --git a/arch/arm/cpu/tegra-common/Makefile b/arch/arm/cpu/tegra-common/Makefile
index c7603ee..a78869e 100644
--- a/arch/arm/cpu/tegra-common/Makefile
+++ b/arch/arm/cpu/tegra-common/Makefile
@@ -14,5 +14,6 @@ obj-y += clock.o
 obj-y += lowlevel_init.o
 obj-y += pinmux-common.o
 obj-y += powergate.o
+obj-y += xusb-padctl.o
 obj-$(CONFIG_DISPLAY_CPUINFO) += sys_info.o
 obj-$(CONFIG_TEGRA124) += vpr.o
diff --git a/arch/arm/cpu/tegra-common/xusb-padctl.c b/arch/arm/cpu/tegra-common/xusb-padctl.c
new file mode 100644
index 0000000..65f8d2e
--- /dev/null
+++ b/arch/arm/cpu/tegra-common/xusb-padctl.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <errno.h>
+
+#include <asm/arch-tegra/xusb-padctl.h>
+
+struct tegra_xusb_phy * __weak tegra_xusb_phy_get(unsigned int type)
+{
+	return NULL;
+}
+
+int __weak tegra_xusb_phy_prepare(struct tegra_xusb_phy *phy)
+{
+	return -ENOSYS;
+}
+
+int __weak tegra_xusb_phy_enable(struct tegra_xusb_phy *phy)
+{
+	return -ENOSYS;
+}
+
+int __weak tegra_xusb_phy_disable(struct tegra_xusb_phy *phy)
+{
+	return -ENOSYS;
+}
+
+int __weak tegra_xusb_phy_unprepare(struct tegra_xusb_phy *phy)
+{
+	return -ENOSYS;
+}
+
+void __weak tegra_xusb_padctl_init(const void *fdt)
+{
+}
diff --git a/arch/arm/cpu/tegra124-common/Makefile b/arch/arm/cpu/tegra124-common/Makefile
index ff77992..7b59fb1 100644
--- a/arch/arm/cpu/tegra124-common/Makefile
+++ b/arch/arm/cpu/tegra124-common/Makefile
@@ -8,3 +8,4 @@
 obj-y	+= clock.o
 obj-y	+= funcmux.o
 obj-y	+= pinmux.o
+obj-y	+= xusb-padctl.o
diff --git a/arch/arm/cpu/tegra124-common/xusb-padctl.c b/arch/arm/cpu/tegra124-common/xusb-padctl.c
new file mode 100644
index 0000000..43af883
--- /dev/null
+++ b/arch/arm/cpu/tegra124-common/xusb-padctl.c
@@ -0,0 +1,716 @@
+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#define pr_fmt(fmt) "tegra-xusb-padctl: " fmt
+
+#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <malloc.h>
+
+#include <asm/io.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/xusb-padctl.h>
+
+#include <dt-bindings/pinctrl/pinctrl-tegra-xusb.h>
+
+#define XUSB_PADCTL_ELPG_PROGRAM 0x01c
+#define XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_VCORE_DOWN (1 << 26)
+#define XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN_EARLY (1 << 25)
+#define XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN (1 << 24)
+
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL1 0x040
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL1_PLL0_LOCKDET (1 << 19)
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL1_REFCLK_SEL_MASK (0xf << 12)
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL1_PLL_RST (1 << 1)
+
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL2 0x044
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL2_REFCLKBUF_EN (1 << 6)
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL2_TXCLKREF_EN (1 << 5)
+#define XUSB_PADCTL_IOPHY_PLL_P0_CTL2_TXCLKREF_SEL (1 << 4)
+
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1 0x138
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL1_LOCKDET (1 << 27)
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL1_MODE (1 << 24)
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_PWR_OVRD (1 << 3)
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_RST (1 << 1)
+#define XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_IDDQ (1 << 0)
+
+#define XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1 0x148
+#define XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ_OVRD (1 << 1)
+#define XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ (1 << 0)
+
+enum tegra124_function {
+	TEGRA124_FUNC_SNPS,
+	TEGRA124_FUNC_XUSB,
+	TEGRA124_FUNC_UART,
+	TEGRA124_FUNC_PCIE,
+	TEGRA124_FUNC_USB3,
+	TEGRA124_FUNC_SATA,
+	TEGRA124_FUNC_RSVD,
+};
+
+static const char *const tegra124_functions[] = {
+	"snps",
+	"xusb",
+	"uart",
+	"pcie",
+	"usb3",
+	"sata",
+	"rsvd",
+};
+
+static const unsigned int tegra124_otg_functions[] = {
+	TEGRA124_FUNC_SNPS,
+	TEGRA124_FUNC_XUSB,
+	TEGRA124_FUNC_UART,
+	TEGRA124_FUNC_RSVD,
+};
+
+static const unsigned int tegra124_usb_functions[] = {
+	TEGRA124_FUNC_SNPS,
+	TEGRA124_FUNC_XUSB,
+};
+
+static const unsigned int tegra124_pci_functions[] = {
+	TEGRA124_FUNC_PCIE,
+	TEGRA124_FUNC_USB3,
+	TEGRA124_FUNC_SATA,
+	TEGRA124_FUNC_RSVD,
+};
+
+struct tegra_xusb_padctl_lane {
+	const char *name;
+
+	unsigned int offset;
+	unsigned int shift;
+	unsigned int mask;
+	unsigned int iddq;
+
+	const unsigned int *funcs;
+	unsigned int num_funcs;
+};
+
+#define TEGRA124_LANE(_name, _offset, _shift, _mask, _iddq, _funcs)	\
+	{								\
+		.name = _name,						\
+		.offset = _offset,					\
+		.shift = _shift,					\
+		.mask = _mask,						\
+		.iddq = _iddq,						\
+		.num_funcs = ARRAY_SIZE(tegra124_##_funcs##_functions),	\
+		.funcs = tegra124_##_funcs##_functions,			\
+	}
+
+static const struct tegra_xusb_padctl_lane tegra124_lanes[] = {
+	TEGRA124_LANE("otg-0",  0x004,  0, 0x3, 0, otg),
+	TEGRA124_LANE("otg-1",  0x004,  2, 0x3, 0, otg),
+	TEGRA124_LANE("otg-2",  0x004,  4, 0x3, 0, otg),
+	TEGRA124_LANE("ulpi-0", 0x004, 12, 0x1, 0, usb),
+	TEGRA124_LANE("hsic-0", 0x004, 14, 0x1, 0, usb),
+	TEGRA124_LANE("hsic-1", 0x004, 15, 0x1, 0, usb),
+	TEGRA124_LANE("pcie-0", 0x134, 16, 0x3, 1, pci),
+	TEGRA124_LANE("pcie-1", 0x134, 18, 0x3, 2, pci),
+	TEGRA124_LANE("pcie-2", 0x134, 20, 0x3, 3, pci),
+	TEGRA124_LANE("pcie-3", 0x134, 22, 0x3, 4, pci),
+	TEGRA124_LANE("pcie-4", 0x134, 24, 0x3, 5, pci),
+	TEGRA124_LANE("sata-0", 0x134, 26, 0x3, 6, pci),
+};
+
+struct tegra_xusb_phy_ops {
+	int (*prepare)(struct tegra_xusb_phy *phy);
+	int (*enable)(struct tegra_xusb_phy *phy);
+	int (*disable)(struct tegra_xusb_phy *phy);
+	int (*unprepare)(struct tegra_xusb_phy *phy);
+};
+
+struct tegra_xusb_phy {
+	const struct tegra_xusb_phy_ops *ops;
+
+	struct tegra_xusb_padctl *padctl;
+};
+
+struct tegra_xusb_padctl_pin {
+	const struct tegra_xusb_padctl_lane *lane;
+
+	unsigned int func;
+	int iddq;
+};
+
+#define MAX_GROUPS 3
+#define MAX_PINS 6
+
+struct tegra_xusb_padctl_group {
+	const char *name;
+
+	const char *pins[MAX_PINS];
+	unsigned int num_pins;
+
+	const char *func;
+	int iddq;
+};
+
+struct tegra_xusb_padctl_config {
+	const char *name;
+
+	struct tegra_xusb_padctl_group groups[MAX_GROUPS];
+	unsigned int num_groups;
+};
+
+struct tegra_xusb_padctl {
+	struct fdt_resource regs;
+
+	unsigned int enable;
+
+	struct tegra_xusb_phy phys[2];
+
+	const struct tegra_xusb_padctl_lane *lanes;
+	unsigned int num_lanes;
+
+	const char *const *functions;
+	unsigned int num_functions;
+
+	struct tegra_xusb_padctl_config config;
+};
+
+static inline u32 padctl_readl(struct tegra_xusb_padctl *padctl,
+			       unsigned long offset)
+{
+	return readl(padctl->regs.start + offset);
+}
+
+static inline void padctl_writel(struct tegra_xusb_padctl *padctl,
+				 u32 value, unsigned long offset)
+{
+	writel(value, padctl->regs.start + offset);
+}
+
+static int tegra_xusb_padctl_enable(struct tegra_xusb_padctl *padctl)
+{
+	u32 value;
+
+	if (padctl->enable++ > 0)
+		return 0;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value &= ~XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	udelay(100);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value &= ~XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN_EARLY;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	udelay(100);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value &= ~XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_VCORE_DOWN;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	return 0;
+}
+
+static int tegra_xusb_padctl_disable(struct tegra_xusb_padctl *padctl)
+{
+	u32 value;
+
+	if (padctl->enable == 0) {
+		error("tegra-xusb-padctl: unbalanced enable/disable");
+		return 0;
+	}
+
+	if (--padctl->enable > 0)
+		return 0;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value |= XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_VCORE_DOWN;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	udelay(100);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value |= XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN_EARLY;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	udelay(100);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM);
+	value |= XUSB_PADCTL_ELPG_PROGRAM_AUX_MUX_LP0_CLAMP_EN;
+	padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM);
+
+	return 0;
+}
+
+static int phy_prepare(struct tegra_xusb_phy *phy)
+{
+	return tegra_xusb_padctl_enable(phy->padctl);
+}
+
+static int phy_unprepare(struct tegra_xusb_phy *phy)
+{
+	return tegra_xusb_padctl_disable(phy->padctl);
+}
+
+static int pcie_phy_enable(struct tegra_xusb_phy *phy)
+{
+	struct tegra_xusb_padctl *padctl = phy->padctl;
+	int err = -ETIMEDOUT;
+	unsigned long start;
+	u32 value;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_PLL_P0_CTL1_REFCLK_SEL_MASK;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_P0_CTL2);
+	value |= XUSB_PADCTL_IOPHY_PLL_P0_CTL2_REFCLKBUF_EN |
+		 XUSB_PADCTL_IOPHY_PLL_P0_CTL2_TXCLKREF_EN |
+		 XUSB_PADCTL_IOPHY_PLL_P0_CTL2_TXCLKREF_SEL;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_P0_CTL2);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+	value |= XUSB_PADCTL_IOPHY_PLL_P0_CTL1_PLL_RST;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+
+	start = get_timer(0);
+
+	while (get_timer(start) < 50) {
+		value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+		if (value & XUSB_PADCTL_IOPHY_PLL_P0_CTL1_PLL0_LOCKDET) {
+			err = 0;
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int pcie_phy_disable(struct tegra_xusb_phy *phy)
+{
+	struct tegra_xusb_padctl *padctl = phy->padctl;
+	u32 value;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_PLL_P0_CTL1_PLL_RST;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_P0_CTL1);
+
+	return 0;
+}
+
+static int sata_phy_enable(struct tegra_xusb_phy *phy)
+{
+	struct tegra_xusb_padctl *padctl = phy->padctl;
+	int err = -ETIMEDOUT;
+	unsigned long start;
+	u32 value;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ_OVRD;
+	value &= ~XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_PWR_OVRD;
+	value &= ~XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_IDDQ;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value |= XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL1_MODE;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value |= XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_RST;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	start = get_timer(0);
+
+	while (get_timer(start) < 50) {
+		value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+		if (value & XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL1_LOCKDET) {
+			err = 0;
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int sata_phy_disable(struct tegra_xusb_phy *phy)
+{
+	struct tegra_xusb_padctl *padctl = phy->padctl;
+	u32 value;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_RST;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value &= ~XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL1_MODE;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+	value |= XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_PWR_OVRD;
+	value |= XUSB_PADCTL_IOPHY_PLL_S0_CTL1_PLL_IDDQ;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_PLL_S0_CTL1);
+
+	value = padctl_readl(padctl, XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1);
+	value |= ~XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ_OVRD;
+	value |= ~XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1_IDDQ;
+	padctl_writel(padctl, value, XUSB_PADCTL_IOPHY_MISC_PAD_S0_CTL1);
+
+	return 0;
+}
+
+static const struct tegra_xusb_phy_ops pcie_phy_ops = {
+	.prepare = phy_prepare,
+	.enable = pcie_phy_enable,
+	.disable = pcie_phy_disable,
+	.unprepare = phy_unprepare,
+};
+
+static const struct tegra_xusb_phy_ops sata_phy_ops = {
+	.prepare = phy_prepare,
+	.enable = sata_phy_enable,
+	.disable = sata_phy_disable,
+	.unprepare = phy_unprepare,
+};
+
+static struct tegra_xusb_padctl *padctl = &(struct tegra_xusb_padctl) {
+	.phys = {
+		[0] = {
+			.ops = &pcie_phy_ops,
+		},
+		[1] = {
+			.ops = &sata_phy_ops,
+		},
+	},
+};
+
+static const struct tegra_xusb_padctl_lane *
+tegra_xusb_padctl_find_lane(struct tegra_xusb_padctl *padctl, const char *name)
+{
+	unsigned int i;
+
+	for (i = 0; i < padctl->num_lanes; i++)
+		if (strcmp(name, padctl->lanes[i].name) == 0)
+			return &padctl->lanes[i];
+
+	return NULL;
+}
+
+static int
+tegra_xusb_padctl_group_parse_dt(struct tegra_xusb_padctl *padctl,
+				 struct tegra_xusb_padctl_group *group,
+				 const void *fdt, int node)
+{
+	unsigned int i;
+	int len, err;
+
+	group->name = fdt_get_name(fdt, node, &len);
+
+	len = fdt_count_strings(fdt, node, "nvidia,lanes");
+	if (len < 0) {
+		error("tegra-xusb-padctl: failed to parse \"nvidia,lanes\" property");
+		return -EINVAL;
+	}
+
+	group->num_pins = len;
+
+	for (i = 0; i < group->num_pins; i++) {
+		err = fdt_get_string_index(fdt, node, "nvidia,lanes", i,
+					   &group->pins[i]);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to read string from \"nvidia,lanes\" property");
+			return -EINVAL;
+		}
+	}
+
+	group->num_pins = len;
+
+	err = fdt_get_string(fdt, node, "nvidia,function", &group->func);
+	if (err < 0) {
+		error("tegra-xusb-padctl: failed to parse \"nvidia,func\" property");
+		return -EINVAL;
+	}
+
+	group->iddq = fdtdec_get_int(fdt, node, "nvidia,iddq", -1);
+
+	return 0;
+}
+
+static int tegra_xusb_padctl_find_function(struct tegra_xusb_padctl *padctl,
+					   const char *name)
+{
+	unsigned int i;
+
+	for (i = 0; i < padctl->num_functions; i++)
+		if (strcmp(name, padctl->functions[i]) == 0)
+			return i;
+
+	return -ENOENT;
+}
+
+static int
+tegra_xusb_padctl_lane_find_function(struct tegra_xusb_padctl *padctl,
+				     const struct tegra_xusb_padctl_lane *lane,
+				     const char *name)
+{
+	unsigned int i;
+	int func;
+
+	func = tegra_xusb_padctl_find_function(padctl, name);
+	if (func < 0)
+		return func;
+
+	for (i = 0; i < lane->num_funcs; i++)
+		if (lane->funcs[i] == func)
+			return i;
+
+	return -ENOENT;
+}
+
+static int
+tegra_xusb_padctl_group_apply(struct tegra_xusb_padctl *padctl,
+			      const struct tegra_xusb_padctl_group *group)
+{
+	unsigned int i;
+
+	for (i = 0; i < group->num_pins; i++) {
+		const struct tegra_xusb_padctl_lane *lane;
+		unsigned int func;
+		u32 value;
+
+		lane = tegra_xusb_padctl_find_lane(padctl, group->pins[i]);
+		if (!lane) {
+			error("tegra-xusb-padctl: no lane for pin %s",
+			      group->pins[i]);
+			continue;
+		}
+
+		func = tegra_xusb_padctl_lane_find_function(padctl, lane,
+							    group->func);
+		if (func < 0) {
+			error("tegra-xusb-padctl: function %s invalid for lane %s: %d",
+			      group->func, lane->name, func);
+			continue;
+		}
+
+		value = padctl_readl(padctl, lane->offset);
+
+		/* set pin function */
+		value &= ~(lane->mask << lane->shift);
+		value |= func << lane->shift;
+
+		/*
+		 * Set IDDQ if supported on the lane and specified in the
+		 * configuration.
+		 */
+		if (lane->iddq > 0 && group->iddq >= 0) {
+			if (group->iddq != 0)
+				value &= ~(1 << lane->iddq);
+			else
+				value |= 1 << lane->iddq;
+		}
+
+		padctl_writel(padctl, value, lane->offset);
+	}
+
+	return 0;
+}
+
+static int
+tegra_xusb_padctl_config_apply(struct tegra_xusb_padctl *padctl,
+			       struct tegra_xusb_padctl_config *config)
+{
+	unsigned int i;
+
+	for (i = 0; i < config->num_groups; i++) {
+		const struct tegra_xusb_padctl_group *group;
+		int err;
+
+		group = &config->groups[i];
+
+		err = tegra_xusb_padctl_group_apply(padctl, group);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to apply group %s: %d",
+			      group->name, err);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+static int
+tegra_xusb_padctl_config_parse_dt(struct tegra_xusb_padctl *padctl,
+				  struct tegra_xusb_padctl_config *config,
+				  const void *fdt, int node)
+{
+	int subnode;
+
+	config->name = fdt_get_name(fdt, node, NULL);
+
+	fdt_for_each_subnode(fdt, subnode, node) {
+		struct tegra_xusb_padctl_group *group;
+		int err;
+
+		group = &config->groups[config->num_groups];
+
+		err = tegra_xusb_padctl_group_parse_dt(padctl, group, fdt,
+						       subnode);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to parse group %s",
+			      group->name);
+			return err;
+		}
+
+		config->num_groups++;
+	}
+
+	return 0;
+}
+
+static int tegra_xusb_padctl_parse_dt(struct tegra_xusb_padctl *padctl,
+				      const void *fdt, int node)
+{
+	int subnode, err;
+
+	err = fdt_get_resource(fdt, node, "reg", 0, &padctl->regs);
+	if (err < 0) {
+		error("tegra-xusb-padctl: registers not found");
+		return err;
+	}
+
+	fdt_for_each_subnode(fdt, subnode, node) {
+		struct tegra_xusb_padctl_config *config = &padctl->config;
+
+		err = tegra_xusb_padctl_config_parse_dt(padctl, config, fdt,
+							subnode);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to parse entry %s: %d",
+			      config->name, err);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+static int process_nodes(const void *fdt, int nodes[], unsigned int count)
+{
+	unsigned int i;
+
+	for (i = 0; i < count; i++) {
+		enum fdt_compat_id id;
+		int err;
+
+		if (!fdtdec_get_is_enabled(fdt, nodes[i]))
+			continue;
+
+		id = fdtdec_lookup(fdt, nodes[i]);
+		switch (id) {
+		case COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL:
+			break;
+
+		default:
+			error("tegra-xusb-padctl: unsupported compatible: %s",
+			      fdtdec_get_compatible(id));
+			continue;
+		}
+
+		padctl->num_lanes = ARRAY_SIZE(tegra124_lanes);
+		padctl->lanes = tegra124_lanes;
+
+		padctl->num_functions = ARRAY_SIZE(tegra124_functions);
+		padctl->functions = tegra124_functions;
+
+		err = tegra_xusb_padctl_parse_dt(padctl, fdt, nodes[i]);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to parse DT: %d",
+			      err);
+			continue;
+		}
+
+		/* deassert XUSB padctl reset */
+		reset_set_enable(PERIPH_ID_XUSB_PADCTL, 0);
+
+		err = tegra_xusb_padctl_config_apply(padctl, &padctl->config);
+		if (err < 0) {
+			error("tegra-xusb-padctl: failed to apply pinmux: %d",
+			      err);
+			continue;
+		}
+
+		/* only a single instance is supported */
+		break;
+	}
+
+	return 0;
+}
+
+struct tegra_xusb_phy *tegra_xusb_phy_get(unsigned int type)
+{
+	struct tegra_xusb_phy *phy = NULL;
+
+	switch (type) {
+	case TEGRA_XUSB_PADCTL_PCIE:
+		phy = &padctl->phys[0];
+		phy->padctl = padctl;
+		break;
+
+	case TEGRA_XUSB_PADCTL_SATA:
+		phy = &padctl->phys[1];
+		phy->padctl = padctl;
+		break;
+	}
+
+	return phy;
+}
+
+int tegra_xusb_phy_prepare(struct tegra_xusb_phy *phy)
+{
+	if (phy && phy->ops && phy->ops->prepare)
+		return phy->ops->prepare(phy);
+
+	return phy ? -ENOSYS : -EINVAL;
+}
+
+int tegra_xusb_phy_enable(struct tegra_xusb_phy *phy)
+{
+	if (phy && phy->ops && phy->ops->enable)
+		return phy->ops->enable(phy);
+
+	return phy ? -ENOSYS : -EINVAL;
+}
+
+int tegra_xusb_phy_disable(struct tegra_xusb_phy *phy)
+{
+	if (phy && phy->ops && phy->ops->disable)
+		return phy->ops->disable(phy);
+
+	return phy ? -ENOSYS : -EINVAL;
+}
+
+int tegra_xusb_phy_unprepare(struct tegra_xusb_phy *phy)
+{
+	if (phy && phy->ops && phy->ops->unprepare)
+		return phy->ops->unprepare(phy);
+
+	return phy ? -ENOSYS : -EINVAL;
+}
+
+void tegra_xusb_padctl_init(const void *fdt)
+{
+	int count, nodes[1];
+
+	count = fdtdec_find_aliases_for_id(fdt, "padctl",
+					   COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
+					   nodes, ARRAY_SIZE(nodes));
+	if (process_nodes(fdt, nodes, count))
+		return;
+}
diff --git a/arch/arm/include/asm/arch-tegra/xusb-padctl.h b/arch/arm/include/asm/arch-tegra/xusb-padctl.h
new file mode 100644
index 0000000..b4b4c8b
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra/xusb-padctl.h
@@ -0,0 +1,24 @@
+#ifndef _TEGRA_XUSB_PADCTL_H_
+#define _TEGRA_XUSB_PADCTL_H_
+
+struct tegra_xusb_phy;
+
+/**
+ * tegra_xusb_phy_get() - obtain a reference to a specified padctl PHY
+ * @type: the type of PHY to obtain
+ *
+ * The type of PHY varies between SoC generations. Typically there are XUSB,
+ * PCIe and SATA PHYs, though not all generations support all of them. The
+ * value of type can usually be directly parsed from a device tree.
+ *
+ * Return: a pointer to the PHY or NULL if no such PHY exists
+ */
+struct tegra_xusb_phy *tegra_xusb_phy_get(unsigned int type);
+
+void tegra_xusb_padctl_init(const void *fdt);
+int tegra_xusb_phy_prepare(struct tegra_xusb_phy *phy);
+int tegra_xusb_phy_enable(struct tegra_xusb_phy *phy);
+int tegra_xusb_phy_disable(struct tegra_xusb_phy *phy);
+int tegra_xusb_phy_unprepare(struct tegra_xusb_phy *phy);
+
+#endif