phy: Add Tegra XUSB pad controller support

Add a new driver for the XUSB pad controller found on NVIDIA Tegra SoCs.
This hardware block used to be exposed as a pin controller, but it turns
out that this isn't a good fit. The new driver and DT binding much more
accurately describe the hardware and are more flexible in supporting new
SoC generations.

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 1021 insertions, 0 deletions

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
new file mode 100644
index 000000000000..ec83dfdbc206
--- /dev/null
+++ b/drivers/phy/tegra/xusb.c
@@ -0,0 +1,1021 @@
+/*
+ * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include <soc/tegra/fuse.h>
+
+#include "xusb.h"
+
+static struct phy *tegra_xusb_pad_of_xlate(struct device *dev,
+					   struct of_phandle_args *args)
+{
+	struct tegra_xusb_pad *pad = dev_get_drvdata(dev);
+	struct phy *phy = NULL;
+	unsigned int i;
+
+	if (args->args_count != 0)
+		return ERR_PTR(-EINVAL);
+
+	for (i = 0; i < pad->soc->num_lanes; i++) {
+		if (!pad->lanes[i])
+			continue;
+
+		if (pad->lanes[i]->dev.of_node == args->np) {
+			phy = pad->lanes[i];
+			break;
+		}
+	}
+
+	if (phy == NULL)
+		phy = ERR_PTR(-ENODEV);
+
+	return phy;
+}
+
+static const struct of_device_id tegra_xusb_padctl_of_match[] = {
+#if defined(CONFIG_ARCH_TEGRA_124_SOC) || defined(CONFIG_ARCH_TEGRA_132_SOC)
+	{
+		.compatible = "nvidia,tegra124-xusb-padctl",
+		.data = &tegra124_xusb_padctl_soc,
+	},
+#endif
+#if defined(CONFIG_ARCH_TEGRA_210_SOC)
+	{
+		.compatible = "nvidia,tegra210-xusb-padctl",
+		.data = &tegra210_xusb_padctl_soc,
+	},
+#endif
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tegra_xusb_padctl_of_match);
+
+static struct device_node *
+tegra_xusb_find_pad_node(struct tegra_xusb_padctl *padctl, const char *name)
+{
+	/*
+	 * of_find_node_by_name() drops a reference, so make sure to grab one.
+	 */
+	struct device_node *np = of_node_get(padctl->dev->of_node);
+
+	np = of_find_node_by_name(np, "pads");
+	if (np)
+		np = of_find_node_by_name(np, name);
+
+	return np;
+}
+
+static struct device_node *
+tegra_xusb_pad_find_phy_node(struct tegra_xusb_pad *pad, unsigned int index)
+{
+	/*
+	 * of_find_node_by_name() drops a reference, so make sure to grab one.
+	 */
+	struct device_node *np = of_node_get(pad->dev.of_node);
+
+	np = of_find_node_by_name(np, "lanes");
+	if (!np)
+		return NULL;
+
+	return of_find_node_by_name(np, pad->soc->lanes[index].name);
+}
+
+int tegra_xusb_lane_lookup_function(struct tegra_xusb_lane *lane,
+				    const char *function)
+{
+	unsigned int i;
+
+	for (i = 0; i < lane->soc->num_funcs; i++)
+		if (strcmp(function, lane->soc->funcs[i]) == 0)
+			return i;
+
+	return -EINVAL;
+}
+
+int tegra_xusb_lane_parse_dt(struct tegra_xusb_lane *lane,
+			     struct device_node *np)
+{
+	struct device *dev = &lane->pad->dev;
+	const char *function;
+	int err;
+
+	err = of_property_read_string(np, "nvidia,function", &function);
+	if (err < 0)
+		return err;
+
+	err = tegra_xusb_lane_lookup_function(lane, function);
+	if (err < 0) {
+		dev_err(dev, "invalid function \"%s\" for lane \"%s\"\n",
+			function, np->name);
+		return err;
+	}
+
+	lane->function = err;
+
+	return 0;
+}
+
+static void tegra_xusb_lane_destroy(struct phy *phy)
+{
+	if (phy) {
+		struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
+
+		lane->pad->ops->remove(lane);
+		phy_destroy(phy);
+	}
+}
+
+static void tegra_xusb_pad_release(struct device *dev)
+{
+	struct tegra_xusb_pad *pad = to_tegra_xusb_pad(dev);
+
+	pad->soc->ops->remove(pad);
+}
+
+static struct device_type tegra_xusb_pad_type = {
+	.release = tegra_xusb_pad_release,
+};
+
+int tegra_xusb_pad_init(struct tegra_xusb_pad *pad,
+			struct tegra_xusb_padctl *padctl,
+			struct device_node *np)
+{
+	int err;
+
+	device_initialize(&pad->dev);
+	INIT_LIST_HEAD(&pad->list);
+	pad->dev.parent = padctl->dev;
+	pad->dev.type = &tegra_xusb_pad_type;
+	pad->dev.of_node = np;
+	pad->padctl = padctl;
+
+	err = dev_set_name(&pad->dev, "%s", pad->soc->name);
+	if (err < 0)
+		goto unregister;
+
+	err = device_add(&pad->dev);
+	if (err < 0)
+		goto unregister;
+
+	return 0;
+
+unregister:
+	device_unregister(&pad->dev);
+	return err;
+}
+
+int tegra_xusb_pad_register(struct tegra_xusb_pad *pad,
+			    const struct phy_ops *ops)
+{
+	struct device_node *children;
+	struct phy *lane;
+	unsigned int i;
+	int err;
+
+	children = of_find_node_by_name(pad->dev.of_node, "lanes");
+	if (!children)
+		return -ENODEV;
+
+	pad->lanes = devm_kcalloc(&pad->dev, pad->soc->num_lanes, sizeof(lane),
+				  GFP_KERNEL);
+	if (!pad->lanes) {
+		of_node_put(children);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < pad->soc->num_lanes; i++) {
+		struct device_node *np = tegra_xusb_pad_find_phy_node(pad, i);
+		struct tegra_xusb_lane *lane;
+
+		/* skip disabled lanes */
+		if (!np || !of_device_is_available(np)) {
+			of_node_put(np);
+			continue;
+		}
+
+		pad->lanes[i] = phy_create(&pad->dev, np, ops);
+		if (IS_ERR(pad->lanes[i])) {
+			err = PTR_ERR(pad->lanes[i]);
+			of_node_put(np);
+			goto remove;
+		}
+
+		lane = pad->ops->probe(pad, np, i);
+		if (IS_ERR(lane)) {
+			phy_destroy(pad->lanes[i]);
+			err = PTR_ERR(lane);
+			goto remove;
+		}
+
+		list_add_tail(&lane->list, &pad->padctl->lanes);
+		phy_set_drvdata(pad->lanes[i], lane);
+	}
+
+	pad->provider = of_phy_provider_register_full(&pad->dev, children,
+						      tegra_xusb_pad_of_xlate);
+	if (IS_ERR(pad->provider)) {
+		err = PTR_ERR(pad->provider);
+		goto remove;
+	}
+
+	return 0;
+
+remove:
+	while (i--)
+		tegra_xusb_lane_destroy(pad->lanes[i]);
+
+	of_node_put(children);
+
+	return err;
+}
+
+void tegra_xusb_pad_unregister(struct tegra_xusb_pad *pad)
+{
+	unsigned int i = pad->soc->num_lanes;
+
+	of_phy_provider_unregister(pad->provider);
+
+	while (i--)
+		tegra_xusb_lane_destroy(pad->lanes[i]);
+
+	device_unregister(&pad->dev);
+}
+
+static struct tegra_xusb_pad *
+tegra_xusb_pad_create(struct tegra_xusb_padctl *padctl,
+		      const struct tegra_xusb_pad_soc *soc)
+{
+	struct tegra_xusb_pad *pad;
+	struct device_node *np;
+	int err;
+
+	np = tegra_xusb_find_pad_node(padctl, soc->name);
+	if (!np || !of_device_is_available(np))
+		return NULL;
+
+	pad = soc->ops->probe(padctl, soc, np);
+	if (IS_ERR(pad)) {
+		err = PTR_ERR(pad);
+		dev_err(padctl->dev, "failed to create pad %s: %d\n",
+			soc->name, err);
+		return ERR_PTR(err);
+	}
+
+	/* XXX move this into ->probe() to avoid string comparison */
+	if (strcmp(soc->name, "pcie") == 0)
+		padctl->pcie = pad;
+
+	if (strcmp(soc->name, "sata") == 0)
+		padctl->sata = pad;
+
+	if (strcmp(soc->name, "usb2") == 0)
+		padctl->usb2 = pad;
+
+	if (strcmp(soc->name, "ulpi") == 0)
+		padctl->ulpi = pad;
+
+	if (strcmp(soc->name, "hsic") == 0)
+		padctl->hsic = pad;
+
+	return pad;
+}
+
+static void __tegra_xusb_remove_pads(struct tegra_xusb_padctl *padctl)
+{
+	struct tegra_xusb_pad *pad, *tmp;
+
+	list_for_each_entry_safe_reverse(pad, tmp, &padctl->pads, list) {
+		list_del(&pad->list);
+		tegra_xusb_pad_unregister(pad);
+	}
+}
+
+static void tegra_xusb_remove_pads(struct tegra_xusb_padctl *padctl)
+{
+	mutex_lock(&padctl->lock);
+	__tegra_xusb_remove_pads(padctl);
+	mutex_unlock(&padctl->lock);
+}
+
+static void tegra_xusb_lane_program(struct tegra_xusb_lane *lane)
+{
+	struct tegra_xusb_padctl *padctl = lane->pad->padctl;
+	const struct tegra_xusb_lane_soc *soc = lane->soc;
+	u32 value;
+
+	/* choose function */
+	value = padctl_readl(padctl, soc->offset);
+	value &= ~(soc->mask << soc->shift);
+	value |= lane->function << soc->shift;
+	padctl_writel(padctl, value, soc->offset);
+}
+
+static void tegra_xusb_pad_program(struct tegra_xusb_pad *pad)
+{
+	unsigned int i;
+
+	for (i = 0; i < pad->soc->num_lanes; i++) {
+		struct tegra_xusb_lane *lane;
+
+		if (pad->lanes[i]) {
+			lane = phy_get_drvdata(pad->lanes[i]);
+			tegra_xusb_lane_program(lane);
+		}
+	}
+}
+
+static int tegra_xusb_setup_pads(struct tegra_xusb_padctl *padctl)
+{
+	struct tegra_xusb_pad *pad;
+	unsigned int i;
+
+	mutex_lock(&padctl->lock);
+
+	for (i = 0; i < padctl->soc->num_pads; i++) {
+		const struct tegra_xusb_pad_soc *soc = padctl->soc->pads[i];
+		int err;
+
+		pad = tegra_xusb_pad_create(padctl, soc);
+		if (IS_ERR(pad)) {
+			err = PTR_ERR(pad);
+			dev_err(padctl->dev, "failed to create pad %s: %d\n",
+				soc->name, err);
+			__tegra_xusb_remove_pads(padctl);
+			mutex_unlock(&padctl->lock);
+			return err;
+		}
+
+		if (!pad)
+			continue;
+
+		list_add_tail(&pad->list, &padctl->pads);
+	}
+
+	list_for_each_entry(pad, &padctl->pads, list)
+		tegra_xusb_pad_program(pad);
+
+	mutex_unlock(&padctl->lock);
+	return 0;
+}
+
+static bool tegra_xusb_lane_check(struct tegra_xusb_lane *lane,
+				  const char *function)
+{
+	const char *func = lane->soc->funcs[lane->function];
+
+	return strcmp(function, func) == 0;
+}
+
+struct tegra_xusb_lane *tegra_xusb_find_lane(struct tegra_xusb_padctl *padctl,
+					     const char *type,
+					     unsigned int index)
+{
+	struct tegra_xusb_lane *lane, *hit = ERR_PTR(-ENODEV);
+	char *name;
+
+	name = kasprintf(GFP_KERNEL, "%s-%u", type, index);
+	if (!name)
+		return ERR_PTR(-ENOMEM);
+
+	list_for_each_entry(lane, &padctl->lanes, list) {
+		if (strcmp(lane->soc->name, name) == 0) {
+			hit = lane;
+			break;
+		}
+	}
+
+	kfree(name);
+	return hit;
+}
+
+struct tegra_xusb_lane *
+tegra_xusb_port_find_lane(struct tegra_xusb_port *port,
+			  const struct tegra_xusb_lane_map *map,
+			  const char *function)
+{
+	struct tegra_xusb_lane *lane, *match = ERR_PTR(-ENODEV);
+
+	for (map = map; map->type; map++) {
+		if (port->index != map->port)
+			continue;
+
+		lane = tegra_xusb_find_lane(port->padctl, map->type,
+					    map->index);
+		if (IS_ERR(lane))
+			continue;
+
+		if (!tegra_xusb_lane_check(lane, function))
+			continue;
+
+		if (!IS_ERR(match))
+			dev_err(&port->dev, "conflicting match: %s-%u / %s\n",
+				map->type, map->index, match->soc->name);
+		else
+			match = lane;
+	}
+
+	return match;
+}
+
+static struct device_node *
+tegra_xusb_find_port_node(struct tegra_xusb_padctl *padctl, const char *type,
+			  unsigned int index)
+{
+	/*
+	 * of_find_node_by_name() drops a reference, so make sure to grab one.
+	 */
+	struct device_node *np = of_node_get(padctl->dev->of_node);
+
+	np = of_find_node_by_name(np, "ports");
+	if (np) {
+		char *name;
+
+		name = kasprintf(GFP_KERNEL, "%s-%u", type, index);
+		np = of_find_node_by_name(np, name);
+		kfree(name);
+	}
+
+	return np;
+}
+
+struct tegra_xusb_port *
+tegra_xusb_find_port(struct tegra_xusb_padctl *padctl, const char *type,
+		     unsigned int index)
+{
+	struct tegra_xusb_port *port;
+	struct device_node *np;
+
+	np = tegra_xusb_find_port_node(padctl, type, index);
+	if (!np)
+		return NULL;
+
+	list_for_each_entry(port, &padctl->ports, list) {
+		if (np == port->dev.of_node) {
+			of_node_put(np);
+			return port;
+		}
+	}
+
+	of_node_put(np);
+
+	return NULL;
+}
+
+struct tegra_xusb_usb2_port *
+tegra_xusb_find_usb2_port(struct tegra_xusb_padctl *padctl, unsigned int index)
+{
+	struct tegra_xusb_port *port;
+
+	port = tegra_xusb_find_port(padctl, "usb2", index);
+	if (port)
+		return to_usb2_port(port);
+
+	return NULL;
+}
+
+struct tegra_xusb_usb3_port *
+tegra_xusb_find_usb3_port(struct tegra_xusb_padctl *padctl, unsigned int index)
+{
+	struct tegra_xusb_port *port;
+
+	port = tegra_xusb_find_port(padctl, "usb3", index);
+	if (port)
+		return to_usb3_port(port);
+
+	return NULL;
+}
+
+static void tegra_xusb_port_release(struct device *dev)
+{
+}
+
+static struct device_type tegra_xusb_port_type = {
+	.release = tegra_xusb_port_release,
+};
+
+static int tegra_xusb_port_init(struct tegra_xusb_port *port,
+				struct tegra_xusb_padctl *padctl,
+				struct device_node *np,
+				const char *name,
+				unsigned int index)
+{
+	int err;
+
+	INIT_LIST_HEAD(&port->list);
+	port->padctl = padctl;
+	port->index = index;
+
+	device_initialize(&port->dev);
+	port->dev.type = &tegra_xusb_port_type;
+	port->dev.of_node = of_node_get(np);
+	port->dev.parent = padctl->dev;
+
+	err = dev_set_name(&port->dev, "%s-%u", name, index);
+	if (err < 0)
+		goto unregister;
+
+	err = device_add(&port->dev);
+	if (err < 0)
+		goto unregister;
+
+	return 0;
+
+unregister:
+	device_unregister(&port->dev);
+	return err;
+}
+
+static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
+{
+	device_unregister(&port->dev);
+}
+
+static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
+{
+	struct tegra_xusb_port *port = &usb2->base;
+	struct device_node *np = port->dev.of_node;
+
+	usb2->internal = of_property_read_bool(np, "nvidia,internal");
+
+	usb2->supply = devm_regulator_get(&port->dev, "vbus");
+	if (IS_ERR(usb2->supply))
+		return PTR_ERR(usb2->supply);
+
+	return 0;
+}
+
+static int tegra_xusb_add_usb2_port(struct tegra_xusb_padctl *padctl,
+				    unsigned int index)
+{
+	struct tegra_xusb_usb2_port *usb2;
+	struct device_node *np;
+	int err = 0;
+
+	/*
+	 * USB2 ports don't require additional properties, but if the port is
+	 * marked as disabled there is no reason to register it.
+	 */
+	np = tegra_xusb_find_port_node(padctl, "usb2", index);
+	if (!np || !of_device_is_available(np))
+		goto out;
+
+	usb2 = devm_kzalloc(padctl->dev, sizeof(*usb2), GFP_KERNEL);
+	if (!usb2) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = tegra_xusb_port_init(&usb2->base, padctl, np, "usb2", index);
+	if (err < 0)
+		goto out;
+
+	usb2->base.ops = padctl->soc->ports.usb2.ops;
+
+	usb2->base.lane = usb2->base.ops->map(&usb2->base);
+	if (IS_ERR(usb2->base.lane)) {
+		err = PTR_ERR(usb2->base.lane);
+		goto out;
+	}
+
+	err = tegra_xusb_usb2_port_parse_dt(usb2);
+	if (err < 0) {
+		tegra_xusb_port_unregister(&usb2->base);
+		goto out;
+	}
+
+	list_add_tail(&usb2->base.list, &padctl->ports);
+
+out:
+	of_node_put(np);
+	return err;
+}
+
+static int tegra_xusb_ulpi_port_parse_dt(struct tegra_xusb_ulpi_port *ulpi)
+{
+	struct tegra_xusb_port *port = &ulpi->base;
+	struct device_node *np = port->dev.of_node;
+
+	ulpi->internal = of_property_read_bool(np, "nvidia,internal");
+
+	return 0;
+}
+
+static int tegra_xusb_add_ulpi_port(struct tegra_xusb_padctl *padctl,
+				    unsigned int index)
+{
+	struct tegra_xusb_ulpi_port *ulpi;
+	struct device_node *np;
+	int err = 0;
+
+	np = tegra_xusb_find_port_node(padctl, "ulpi", index);
+	if (!np || !of_device_is_available(np))
+		goto out;
+
+	ulpi = devm_kzalloc(padctl->dev, sizeof(*ulpi), GFP_KERNEL);
+	if (!ulpi) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = tegra_xusb_port_init(&ulpi->base, padctl, np, "ulpi", index);
+	if (err < 0)
+		goto out;
+
+	ulpi->base.ops = padctl->soc->ports.ulpi.ops;
+
+	ulpi->base.lane = ulpi->base.ops->map(&ulpi->base);
+	if (IS_ERR(ulpi->base.lane)) {
+		err = PTR_ERR(ulpi->base.lane);
+		goto out;
+	}
+
+	err = tegra_xusb_ulpi_port_parse_dt(ulpi);
+	if (err < 0) {
+		tegra_xusb_port_unregister(&ulpi->base);
+		goto out;
+	}
+
+	list_add_tail(&ulpi->base.list, &padctl->ports);
+
+out:
+	of_node_put(np);
+	return err;
+}
+
+static int tegra_xusb_hsic_port_parse_dt(struct tegra_xusb_hsic_port *hsic)
+{
+	/* XXX */
+	return 0;
+}
+
+static int tegra_xusb_add_hsic_port(struct tegra_xusb_padctl *padctl,
+				    unsigned int index)
+{
+	struct tegra_xusb_hsic_port *hsic;
+	struct device_node *np;
+	int err = 0;
+
+	np = tegra_xusb_find_port_node(padctl, "hsic", index);
+	if (!np || !of_device_is_available(np))
+		goto out;
+
+	hsic = devm_kzalloc(padctl->dev, sizeof(*hsic), GFP_KERNEL);
+	if (!hsic) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = tegra_xusb_port_init(&hsic->base, padctl, np, "hsic", index);
+	if (err < 0)
+		goto out;
+
+	hsic->base.ops = padctl->soc->ports.hsic.ops;
+
+	hsic->base.lane = hsic->base.ops->map(&hsic->base);
+	if (IS_ERR(hsic->base.lane)) {
+		err = PTR_ERR(hsic->base.lane);
+		goto out;
+	}
+
+	err = tegra_xusb_hsic_port_parse_dt(hsic);
+	if (err < 0) {
+		tegra_xusb_port_unregister(&hsic->base);
+		goto out;
+	}
+
+	list_add_tail(&hsic->base.list, &padctl->ports);
+
+out:
+	of_node_put(np);
+	return err;
+}
+
+static int tegra_xusb_usb3_port_parse_dt(struct tegra_xusb_usb3_port *usb3)
+{
+	struct tegra_xusb_port *port = &usb3->base;
+	struct device_node *np = port->dev.of_node;
+	u32 value;
+	int err;
+
+	err = of_property_read_u32(np, "nvidia,usb2-companion", &value);
+	if (err < 0) {
+		dev_err(&port->dev, "failed to read port: %d\n", err);
+		return err;
+	}
+
+	usb3->port = value;
+
+	usb3->internal = of_property_read_bool(np, "nvidia,internal");
+
+	usb3->supply = devm_regulator_get(&port->dev, "vbus");
+	if (IS_ERR(usb3->supply))
+		return PTR_ERR(usb3->supply);
+
+	return 0;
+}
+
+static int tegra_xusb_add_usb3_port(struct tegra_xusb_padctl *padctl,
+				    unsigned int index)
+{
+	struct tegra_xusb_usb3_port *usb3;
+	struct device_node *np;
+	int err = 0;
+
+	/*
+	 * If there is no supplemental configuration in the device tree the
+	 * port is unusable. But it is valid to configure only a single port,
+	 * hence return 0 instead of an error to allow ports to be optional.
+	 */
+	np = tegra_xusb_find_port_node(padctl, "usb3", index);
+	if (!np || !of_device_is_available(np))
+		goto out;
+
+	usb3 = devm_kzalloc(padctl->dev, sizeof(*usb3), GFP_KERNEL);
+	if (!usb3) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = tegra_xusb_port_init(&usb3->base, padctl, np, "usb3", index);
+	if (err < 0)
+		goto out;
+
+	usb3->base.ops = padctl->soc->ports.usb3.ops;
+
+	usb3->base.lane = usb3->base.ops->map(&usb3->base);
+	if (IS_ERR(usb3->base.lane)) {
+		err = PTR_ERR(usb3->base.lane);
+		goto out;
+	}
+
+	err = tegra_xusb_usb3_port_parse_dt(usb3);
+	if (err < 0) {
+		tegra_xusb_port_unregister(&usb3->base);
+		goto out;
+	}
+
+	list_add_tail(&usb3->base.list, &padctl->ports);
+
+out:
+	of_node_put(np);
+	return err;
+}
+
+static void __tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
+{
+	struct tegra_xusb_port *port, *tmp;
+
+	list_for_each_entry_safe_reverse(port, tmp, &padctl->ports, list) {
+		list_del(&port->list);
+		tegra_xusb_port_unregister(port);
+	}
+}
+
+static int tegra_xusb_setup_ports(struct tegra_xusb_padctl *padctl)
+{
+	struct tegra_xusb_port *port;
+	unsigned int i;
+	int err = 0;
+
+	mutex_lock(&padctl->lock);
+
+	for (i = 0; i < padctl->soc->ports.usb2.count; i++) {
+		err = tegra_xusb_add_usb2_port(padctl, i);
+		if (err < 0)
+			goto remove_ports;
+	}
+
+	for (i = 0; i < padctl->soc->ports.ulpi.count; i++) {
+		err = tegra_xusb_add_ulpi_port(padctl, i);
+		if (err < 0)
+			goto remove_ports;
+	}
+
+	for (i = 0; i < padctl->soc->ports.hsic.count; i++) {
+		err = tegra_xusb_add_hsic_port(padctl, i);
+		if (err < 0)
+			goto remove_ports;
+	}
+
+	for (i = 0; i < padctl->soc->ports.usb3.count; i++) {
+		err = tegra_xusb_add_usb3_port(padctl, i);
+		if (err < 0)
+			goto remove_ports;
+	}
+
+	list_for_each_entry(port, &padctl->ports, list) {
+		err = port->ops->enable(port);
+		if (err < 0)
+			dev_err(padctl->dev, "failed to enable port %s: %d\n",
+				dev_name(&port->dev), err);
+	}
+
+	goto unlock;
+
+remove_ports:
+	__tegra_xusb_remove_ports(padctl);
+unlock:
+	mutex_unlock(&padctl->lock);
+	return err;
+}
+
+static void tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
+{
+	mutex_lock(&padctl->lock);
+	__tegra_xusb_remove_ports(padctl);
+	mutex_unlock(&padctl->lock);
+}
+
+static int tegra_xusb_padctl_probe(struct platform_device *pdev)
+{
+	struct device_node *np = of_node_get(pdev->dev.of_node);
+	const struct tegra_xusb_padctl_soc *soc;
+	struct tegra_xusb_padctl *padctl;
+	const struct of_device_id *match;
+	struct resource *res;
+	int err;
+
+	/* for backwards compatibility with old device trees */
+	np = of_find_node_by_name(np, "pads");
+	if (!np) {
+		dev_warn(&pdev->dev, "deprecated DT, using legacy driver\n");
+		return tegra_xusb_padctl_legacy_probe(pdev);
+	}
+
+	of_node_put(np);
+
+	match = of_match_node(tegra_xusb_padctl_of_match, pdev->dev.of_node);
+	soc = match->data;
+
+	padctl = soc->ops->probe(&pdev->dev, soc);
+	if (IS_ERR(padctl))
+		return PTR_ERR(padctl);
+
+	platform_set_drvdata(pdev, padctl);
+	INIT_LIST_HEAD(&padctl->ports);
+	INIT_LIST_HEAD(&padctl->lanes);
+	INIT_LIST_HEAD(&padctl->pads);
+	mutex_init(&padctl->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	padctl->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(padctl->regs)) {
+		err = PTR_ERR(padctl->regs);
+		goto remove;
+	}
+
+	padctl->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(padctl->rst)) {
+		err = PTR_ERR(padctl->rst);
+		goto remove;
+	}
+
+	err = reset_control_deassert(padctl->rst);
+	if (err < 0)
+		goto remove;
+
+	err = tegra_xusb_setup_pads(padctl);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to setup pads: %d\n", err);
+		goto reset;
+	}
+
+	err = tegra_xusb_setup_ports(padctl);
+	if (err) {
+		dev_err(&pdev->dev, "failed to setup XUSB ports: %d\n", err);
+		goto remove_pads;
+	}
+
+	return 0;
+
+remove_pads:
+	tegra_xusb_remove_pads(padctl);
+reset:
+	reset_control_assert(padctl->rst);
+remove:
+	soc->ops->remove(padctl);
+	return err;
+}
+
+static int tegra_xusb_padctl_remove(struct platform_device *pdev)
+{
+	struct tegra_xusb_padctl *padctl = platform_get_drvdata(pdev);
+	int err;
+
+	tegra_xusb_remove_ports(padctl);
+	tegra_xusb_remove_pads(padctl);
+
+	err = reset_control_assert(padctl->rst);
+	if (err < 0)
+		dev_err(&pdev->dev, "failed to assert reset: %d\n", err);
+
+	padctl->soc->ops->remove(padctl);
+
+	return err;
+}
+
+static struct platform_driver tegra_xusb_padctl_driver = {
+	.driver = {
+		.name = "tegra-xusb-padctl",
+		.of_match_table = tegra_xusb_padctl_of_match,
+	},
+	.probe = tegra_xusb_padctl_probe,
+	.remove = tegra_xusb_padctl_remove,
+};
+module_platform_driver(tegra_xusb_padctl_driver);
+
+struct tegra_xusb_padctl *tegra_xusb_padctl_get(struct device *dev)
+{
+	struct tegra_xusb_padctl *padctl;
+	struct platform_device *pdev;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "nvidia,xusb-padctl", 0);
+	if (!np)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * This is slightly ugly. A better implementation would be to keep a
+	 * registry of pad controllers, but since there will almost certainly
+	 * only ever be one per SoC that would be a little overkill.
+	 */
+	pdev = of_find_device_by_node(np);
+	if (!pdev) {
+		of_node_put(np);
+		return ERR_PTR(-ENODEV);
+	}
+
+	of_node_put(np);
+
+	padctl = platform_get_drvdata(pdev);
+	if (!padctl) {
+		put_device(&pdev->dev);
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	return padctl;
+}
+EXPORT_SYMBOL_GPL(tegra_xusb_padctl_get);
+
+void tegra_xusb_padctl_put(struct tegra_xusb_padctl *padctl)
+{
+	if (padctl)
+		put_device(padctl->dev);
+}
+EXPORT_SYMBOL_GPL(tegra_xusb_padctl_put);
+
+int tegra_xusb_padctl_usb3_save_context(struct tegra_xusb_padctl *padctl,
+					unsigned int port)
+{
+	if (padctl->soc->ops->usb3_save_context)
+		return padctl->soc->ops->usb3_save_context(padctl, port);
+
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(tegra_xusb_padctl_usb3_save_context);
+
+int tegra_xusb_padctl_hsic_set_idle(struct tegra_xusb_padctl *padctl,
+				    unsigned int port, bool idle)
+{
+	if (padctl->soc->ops->hsic_set_idle)
+		return padctl->soc->ops->hsic_set_idle(padctl, port, idle);
+
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(tegra_xusb_padctl_hsic_set_idle);
+
+int tegra_xusb_padctl_usb3_set_lfps_detect(struct tegra_xusb_padctl *padctl,
+					   unsigned int port, bool enable)
+{
+	if (padctl->soc->ops->usb3_set_lfps_detect)
+		return padctl->soc->ops->usb3_set_lfps_detect(padctl, port,
+							      enable);
+
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(tegra_xusb_padctl_usb3_set_lfps_detect);
+
+MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
+MODULE_DESCRIPTION("Tegra XUSB Pad Controller driver");
+MODULE_LICENSE("GPL v2");