dm: usb: Add a uclass for USB controllers

Add a uclass that can represent a USB controller. For now we do not create
devices for things attached to the controller. This will be added later.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>

drivers/usb/Kconfig

@@ -35,6 +35,20 @@ config USB
 
 if USB
 
+config DM_USB
+	bool "Enable driver model for USB"
+	depends on USB && DM
+	help
+	  Enable driver model for USB. The USB interface is then implemented
+	  by the USB uclass. Multiple USB controllers of different types
+	  (XHCI, EHCI) can be attached and used. The 'usb' command works as
+	  normal. OCHI is not supported at present.
+
+	  Much of the code is shared but with this option enabled the USB
+	  uclass takes care of device enumeration. USB devices can be
+	  declared with the USB_DEVICE() macro and will be automatically
+	  probed when found on the bus.
+
 source "drivers/usb/host/Kconfig"
 
 config USB_STORAGE

drivers/usb/host/Makefile

@@ -5,6 +5,10 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+ifdef CONFIG_DM_USB
+obj-$(CONFIG_CMD_USB) += usb-uclass.o
+endif
+
 # ohci
 obj-$(CONFIG_USB_OHCI_NEW) += ohci-hcd.o
 obj-$(CONFIG_USB_ATMEL) += ohci-at91.o

drivers/usb/host/usb-uclass.c

@@ -0,0 +1,392 @@
+/*
+ * (C) Copyright 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <usb.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/root.h>
+#include <dm/uclass-internal.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+extern bool usb_started; /* flag for the started/stopped USB status */
+static bool asynch_allowed;
+
+int usb_disable_asynch(int disable)
+{
+	int old_value = asynch_allowed;
+
+	asynch_allowed = !disable;
+	return old_value;
+}
+
+int submit_int_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
+		   int length, int interval)
+{
+	struct udevice *bus = udev->controller_dev;
+	struct dm_usb_ops *ops = usb_get_ops(bus);
+
+	if (!ops->interrupt)
+		return -ENOSYS;
+
+	return ops->interrupt(bus, udev, pipe, buffer, length, interval);
+}
+
+int submit_control_msg(struct usb_device *udev, unsigned long pipe,
+		       void *buffer, int length, struct devrequest *setup)
+{
+	struct udevice *bus = udev->controller_dev;
+	struct dm_usb_ops *ops = usb_get_ops(bus);
+
+	if (!ops->control)
+		return -ENOSYS;
+
+	return ops->control(bus, udev, pipe, buffer, length, setup);
+}
+
+int submit_bulk_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
+		    int length)
+{
+	struct udevice *bus = udev->controller_dev;
+	struct dm_usb_ops *ops = usb_get_ops(bus);
+
+	if (!ops->bulk)
+		return -ENOSYS;
+
+	return ops->bulk(bus, udev, pipe, buffer, length);
+}
+
+int usb_alloc_device(struct usb_device *udev)
+{
+	struct udevice *bus = udev->controller_dev;
+	struct dm_usb_ops *ops = usb_get_ops(bus);
+
+	/* This is only requird by some controllers - current XHCI */
+	if (!ops->alloc_device)
+		return 0;
+
+	return ops->alloc_device(bus, udev);
+}
+
+int usb_stop(void)
+{
+	struct udevice *bus;
+	struct uclass *uc;
+	int err = 0, ret;
+
+	/* De-activate any devices that have been activated */
+	ret = uclass_get(UCLASS_USB, &uc);
+	if (ret)
+		return ret;
+	uclass_foreach_dev(bus, uc) {
+		ret = device_remove(bus);
+		if (ret && !err)
+			err = ret;
+	}
+
+	usb_stor_reset();
+	usb_hub_reset();
+	usb_started = 0;
+
+	return err;
+}
+
+static int usb_scan_bus(struct udevice *bus, bool recurse)
+{
+	struct usb_bus_priv *priv;
+	struct udevice *dev;
+	int ret;
+
+	priv = dev_get_uclass_priv(bus);
+
+	assert(recurse);	/* TODO: Support non-recusive */
+
+	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
+	if (ret)
+		return ret;
+
+	return priv->next_addr;
+}
+
+int usb_init(void)
+{
+	int controllers_initialized = 0;
+	struct udevice *bus;
+	struct uclass *uc;
+	int count = 0;
+	int ret;
+
+	asynch_allowed = 1;
+	usb_hub_reset();
+
+	ret = uclass_get(UCLASS_USB, &uc);
+	if (ret)
+		return ret;
+
+	uclass_foreach_dev(bus, uc) {
+		/* init low_level USB */
+		count++;
+		printf("USB");
+		printf("%d:   ", bus->seq);
+		ret = device_probe(bus);
+		if (ret == -ENODEV) {	/* No such device. */
+			puts("Port not available.\n");
+			controllers_initialized++;
+			continue;
+		}
+
+		if (ret) {		/* Other error. */
+			printf("probe failed, error %d\n", ret);
+			continue;
+		}
+		/*
+		 * lowlevel init is OK, now scan the bus for devices
+		 * i.e. search HUBs and configure them
+		 */
+		controllers_initialized++;
+		printf("scanning bus %d for devices... ", bus->seq);
+		debug("\n");
+		ret = usb_scan_bus(bus, true);
+		if (ret < 0)
+			printf("failed, error %d\n", ret);
+		else if (!ret)
+			printf("No USB Device found\n");
+		else
+			printf("%d USB Device(s) found\n", ret);
+		usb_started = true;
+	}
+
+	debug("scan end\n");
+	/* if we were not able to find at least one working bus, bail out */
+	if (!count)
+		printf("No controllers found\n");
+	else if (controllers_initialized == 0)
+		printf("USB error: all controllers failed lowlevel init\n");
+
+	return usb_started ? 0 : -1;
+}
+
+int usb_reset_root_port(void)
+{
+	return -ENOSYS;
+}
+
+static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
+{
+	struct usb_device *udev;
+	struct udevice *dev;
+
+	if (!device_active(parent))
+		return NULL;
+	udev = dev_get_parentdata(parent);
+	if (udev->devnum == devnum)
+		return udev;
+
+	for (device_find_first_child(parent, &dev);
+	     dev;
+	     device_find_next_child(&dev)) {
+		udev = find_child_devnum(dev, devnum);
+		if (udev)
+			return udev;
+	}
+
+	return NULL;
+}
+
+struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
+{
+	struct udevice *hub;
+	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
+
+	device_find_first_child(bus, &hub);
+	if (device_get_uclass_id(hub) == UCLASS_USB_HUB)
+		return find_child_devnum(hub, devnum);
+
+	return NULL;
+}
+
+int usb_post_bind(struct udevice *dev)
+{
+	/* Scan the bus for devices */
+	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
+}
+
+int usb_port_reset(struct usb_device *parent, int portnr)
+{
+	unsigned short portstatus;
+	int ret;
+
+	debug("%s: start\n", __func__);
+
+	if (parent) {
+		/* reset the port for the second time */
+		assert(portnr > 0);
+		debug("%s: reset %d\n", __func__, portnr - 1);
+		ret = legacy_hub_port_reset(parent, portnr - 1, &portstatus);
+		if (ret < 0) {
+			printf("\n     Couldn't reset port %i\n", portnr);
+			return ret;
+		}
+	} else {
+		debug("%s: reset root\n", __func__);
+		usb_reset_root_port();
+	}
+
+	return 0;
+}
+
+int usb_legacy_port_reset(struct usb_device *parent, int portnr)
+{
+	return usb_port_reset(parent, portnr);
+}
+
+int usb_scan_device(struct udevice *parent, int port,
+		    enum usb_device_speed speed, struct udevice **devp)
+{
+	struct udevice *dev;
+	bool created = false;
+	struct usb_dev_platdata *plat;
+	struct usb_bus_priv *priv;
+	struct usb_device *parent_udev;
+	int ret;
+	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
+	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
+
+	*devp = NULL;
+	memset(udev, '\0', sizeof(*udev));
+	ret = usb_get_bus(parent, &udev->controller_dev);
+	if (ret)
+		return ret;
+	priv = dev_get_uclass_priv(udev->controller_dev);
+
+	/*
+	 * Somewhat nasty, this. We create a local device and use the normal
+	 * USB stack to read its descriptor. Then we know what type of device
+	 * to create for real.
+	 *
+	 * udev->dev is set to the parent, since we don't have a real device
+	 * yet. The USB stack should not access udev.dev anyway, except perhaps
+	 * to find the controller, and the controller will either be @parent,
+	 * or some parent of @parent.
+	 *
+	 * Another option might be to create the device as a generic USB
+	 * device, then morph it into the correct one when we know what it
+	 * should be. This means that a generic USB device would morph into
+	 * a network controller, or a USB flash stick, for example. However,
+	 * we don't support such morphing and it isn't clear that it would
+	 * be easy to do.
+	 *
+	 * Yet another option is to split out the USB stack parts of udev
+	 * into something like a 'struct urb' (as Linux does) which can exist
+	 * independently of any device. This feels cleaner, but calls for quite
+	 * a big change to the USB stack.
+	 *
+	 * For now, the approach is to set up an empty udev, read its
+	 * descriptor and assign it an address, then bind a real device and
+	 * stash the resulting information into the device's parent
+	 * platform data. Then when we probe it, usb_child_pre_probe() is called
+	 * and it will pull the information out of the stash.
+	 */
+	udev->dev = parent;
+	udev->speed = speed;
+	udev->devnum = priv->next_addr + 1;
+	udev->portnr = port;
+	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
+	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
+		dev_get_parentdata(parent) : NULL;
+	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev, port);
+	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
+	if (ret)
+		return ret;
+	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
+	debug("** usb_find_child returns %d\n", ret);
+
+	/* TODO: Find a suitable driver and create the device */
+	return -ENOENT;
+}
+
+int usb_child_post_bind(struct udevice *dev)
+{
+	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
+	const void *blob = gd->fdt_blob;
+	int val;
+
+	if (dev->of_offset == -1)
+		return 0;
+
+	/* We only support matching a few things */
+	val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
+	if (val != -1) {
+		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
+		plat->id.bDeviceClass = val;
+	}
+	val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
+	if (val != -1) {
+		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
+		plat->id.bInterfaceClass = val;
+	}
+
+	return 0;
+}
+
+int usb_get_bus(struct udevice *dev, struct udevice **busp)
+{
+	struct udevice *bus;
+
+	*busp = NULL;
+	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
+		bus = bus->parent;
+	if (!bus) {
+		/* By design this cannot happen */
+		assert(bus);
+		debug("USB HUB '%s' does not have a controller\n", dev->name);
+		return -EXDEV;
+	}
+	*busp = bus;
+
+	return 0;
+}
+
+int usb_child_pre_probe(struct udevice *dev)
+{
+	struct udevice *bus;
+	struct usb_device *udev = dev_get_parentdata(dev);
+	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
+	int ret;
+
+	ret = usb_get_bus(dev, &bus);
+	if (ret)
+		return ret;
+	udev->controller_dev = bus;
+	udev->dev = dev;
+	udev->devnum = plat->devnum;
+	udev->slot_id = plat->slot_id;
+	udev->portnr = plat->portnr;
+	udev->speed = plat->speed;
+	debug("** device '%s': getting slot_id=%d\n", dev->name, plat->slot_id);
+
+	ret = usb_select_config(udev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+UCLASS_DRIVER(usb) = {
+	.id		= UCLASS_USB,
+	.name		= "usb",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+	.post_bind	= usb_post_bind,
+	.per_child_auto_alloc_size = sizeof(struct usb_device),
+	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
+	.child_post_bind = usb_child_post_bind,
+	.child_pre_probe = usb_child_pre_probe,
+	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
+};

drivers/usb/musb-new/musb_uboot.c

@@ -180,7 +180,7 @@ void *poll_int_queue(struct usb_device *dev, struct int_queue *queue)
 	return NULL; /* URB still pending */
 }
 
-void usb_reset_root_port(void)
+int usb_reset_root_port(void)
 {
 	void *mbase = host->mregs;
 	u8 power;
@@ -208,6 +208,8 @@ void usb_reset_root_port(void)
 			(musb_readb(mbase, MUSB_DEVCTL) & MUSB_DEVCTL_FSDEV) ?
 			USB_SPEED_FULL : USB_SPEED_LOW;
 	mdelay((host_speed == USB_SPEED_LOW) ? 200 : 50);
+
+	return 0;
 }
 
 int usb_lowlevel_init(int index, enum usb_init_type init, void **controller)

include/dm/uclass-id.h

@@ -40,6 +40,7 @@ enum uclass_id {
 	UCLASS_PCH,		/* x86 platform controller hub */
 	UCLASS_ETH,		/* Ethernet device */
 	UCLASS_LPC,		/* x86 'low pin count' interface */
+	UCLASS_USB,		/* USB bus */
 
 	UCLASS_COUNT,
 	UCLASS_INVALID = -1,

include/usb.h

@@ -2,6 +2,9 @@
  * (C) Copyright 2001
  * Denis Peter, MPL AG Switzerland
  *
+ * Adapted for U-Boot driver model
+ * (C) Copyright 2015 Google, Inc
+ *
  * SPDX-License-Identifier:	GPL-2.0+
  * Note: Part of this code has been derived from linux
  *
@@ -9,6 +12,7 @@
 #ifndef _USB_H_
 #define _USB_H_
 
+#include <fdtdec.h>
 #include <usb_defs.h>
 #include <linux/usb/ch9.h>
 #include <asm/cache.h>
@@ -85,6 +89,19 @@ enum {
 	PACKET_SIZE_64  = 3,
 };
 
+/**
+ * struct usb_device - information about a USB device
+ *
+ * With driver model both UCLASS_USB (the USB controllers) and UCLASS_USB_HUB
+ * (the hubs) have this as parent data. Hubs are children of controllers or
+ * other hubs and there is always a single root hub for each controller.
+ * Therefore struct usb_device can always be accessed with
+ * dev_get_parentdata(dev), where dev is a USB device.
+ *
+ * Pointers exist for obtaining both the device (could be any uclass) and
+ * controller (UCLASS_USB) from this structure. The controller does not have
+ * a struct usb_device since it is not a device.
+ */
 struct usb_device {
 	int	devnum;			/* Device number on USB bus */
 	int	speed;			/* full/low/high */
@@ -123,13 +140,19 @@ struct usb_device {
 	unsigned long int_pending;	/* 1 bit per ep, used by int_queue */
 	int act_len;			/* transfered bytes */
 	int maxchild;			/* Number of ports if hub */
-	int portnr;
+	int portnr;			/* Port number, 1=first */
+#ifndef CONFIG_DM_USB
+	/* parent hub, or NULL if this is the root hub */
 	struct usb_device *parent;
 	struct usb_device *children[USB_MAXCHILDREN];
-
 	void *controller;		/* hardware controller private data */
+#endif
 	/* slot_id - for xHCI enabled devices */
 	unsigned int slot_id;
+#ifdef CONFIG_DM_USB
+	struct udevice *dev;		/* Pointer to associated device */
+	struct udevice *controller_dev;	/* Pointer to associated controller */
+#endif
 };
 
 struct int_queue;
@@ -160,8 +183,9 @@ enum usb_init_type {
 
 int usb_lowlevel_init(int index, enum usb_init_type init, void **controller);
 int usb_lowlevel_stop(int index);
-#ifdef CONFIG_MUSB_HOST
+
-void usb_reset_root_port(void);
+#if defined(CONFIG_MUSB_HOST) || defined(CONFIG_DM_USB)
+int usb_reset_root_port(void);
 #else
 #define usb_reset_root_port()
 #endif
@@ -245,7 +269,6 @@ int usb_stop(void); /* stop the USB Controller */
 int usb_set_protocol(struct usb_device *dev, int ifnum, int protocol);
 int usb_set_idle(struct usb_device *dev, int ifnum, int duration,
 			int report_id);
-struct usb_device *usb_get_dev_index(int index);
 int usb_control_msg(struct usb_device *dev, unsigned int pipe,
 			unsigned char request, unsigned char requesttype,
 			unsigned short value, unsigned short index,
@@ -423,6 +446,258 @@ struct usb_hub_device {
 	struct usb_hub_descriptor desc;
 };
 
+#ifdef CONFIG_DM_USB
+/**
+ * struct usb_platdata - Platform data about a USB controller
+ *
+ * Given a USB controller (UCLASS_USB) dev this is dev_get_platdata(dev)
+ */
+struct usb_platdata {
+	enum usb_init_type init_type;
+};
+
+/**
+ * struct usb_dev_platdata - Platform data about a USB device
+ *
+ * Given a USB device dev this structure is dev_get_parent_platdata(dev).
+ * This is used by sandbox to provide emulation data also.
+ *
+ * @id:		ID used to match this device
+ * @speed:	Stores the speed associated with a USB device
+ * @devnum:	Device address on the USB bus
+ * @slot_id:	USB3 slot ID, which is separate from the device address
+ * @portnr:	Port number of this device on its parent hub, numbered from 1
+ *		(0 mean this device is the root hub)
+ * @strings:	List of descriptor strings (for sandbox emulation purposes)
+ * @desc_list:	List of descriptors (for sandbox emulation purposes)
+ */
+struct usb_dev_platdata {
+	struct usb_device_id id;
+	enum usb_device_speed speed;
+	int devnum;
+	int slot_id;
+	int portnr;	/* Hub port number, 1..n */
+#ifdef CONFIG_SANDBOX
+	struct usb_string *strings;
+	/* NULL-terminated list of descriptor pointers */
+	struct usb_generic_descriptor **desc_list;
+#endif
+	int configno;
+};
+
+/**
+ * struct usb_bus_priv - information about the USB controller
+ *
+ * Given a USB controller (UCLASS_USB) 'dev', this is
+ * dev_get_uclass_priv(dev).
+ *
+ * @next_addr:	Next device address to allocate minus 1. Incremented by 1
+ *		each time a new device address is set, so this holds the
+ *		number of devices on the bus
+ * @desc_before_addr:	true if we can read a device descriptor before it
+ *		has been assigned an address. For XHCI this is not possible
+ *		so this will be false.
+ */
+struct usb_bus_priv {
+	int next_addr;
+	bool desc_before_addr;
+};
+
+/**
+ * struct dm_usb_ops - USB controller operations
+ *
+ * This defines the operations supoorted on a USB controller. Common
+ * arguments are:
+ *
+ * @bus:	USB bus (i.e. controller), which is in UCLASS_USB.
+ * @udev:	USB device parent data. Controllers are not expected to need
+ *		this, since the device address on the bus is encoded in @pipe.
+ *		It is used for sandbox, and can be handy for debugging and
+ *		logging.
+ * @pipe:	An assortment of bitfields which provide address and packet
+ *		type information. See create_pipe() above for encoding
+ *		details
+ * @buffer:	A buffer to use for sending/receiving. This should be
+ *		DMA-aligned.
+ * @length:	Buffer length in bytes
+ */
+struct dm_usb_ops {
+	/**
+	 * control() - Send a control message
+	 *
+	 * Most parameters are as above.
+	 *
+	 * @setup: Additional setup information required by the message
+	 */
+	int (*control)(struct udevice *bus, struct usb_device *udev,
+		       unsigned long pipe, void *buffer, int length,
+		       struct devrequest *setup);
+	/**
+	 * bulk() - Send a bulk message
+	 *
+	 * Parameters are as above.
+	 */
+	int (*bulk)(struct udevice *bus, struct usb_device *udev,
+		    unsigned long pipe, void *buffer, int length);
+	/**
+	 * interrupt() - Send an interrupt message
+	 *
+	 * Most parameters are as above.
+	 *
+	 * @interval: Interrupt interval
+	 */
+	int (*interrupt)(struct udevice *bus, struct usb_device *udev,
+			 unsigned long pipe, void *buffer, int length,
+			 int interval);
+	/**
+	 * alloc_device() - Allocate a new device context (XHCI)
+	 *
+	 * Before sending packets to a new device on an XHCI bus, a device
+	 * context must be created. If this method is not NULL it will be
+	 * called before the device is enumerated (even before its descriptor
+	 * is read). This should be NULL for EHCI, which does not need this.
+	 */
+	int (*alloc_device)(struct udevice *bus, struct usb_device *udev);
+};
+
+#define usb_get_ops(dev)	((struct dm_usb_ops *)(dev)->driver->ops)
+#define usb_get_emul_ops(dev)	((struct dm_usb_ops *)(dev)->driver->ops)
+
+#ifdef CONFIG_MUSB_HOST
+int usb_reset_root_port(void);
+#endif
+
+/**
+ * usb_get_dev_index() - look up a device index number
+ *
+ * Look up devices using their index number (starting at 0). This works since
+ * in U-Boot device addresses are allocated starting at 1 with no gaps.
+ *
+ * TODO(sjg@chromium.org): Remove this function when usb_ether.c is modified
+ * to work better with driver model.
+ *
+ * @bus:	USB bus to check
+ * @index:	Index number of device to find (0=first). This is just the
+ *		device address less 1.
+ */
+struct usb_device *usb_get_dev_index(struct udevice *bus, int index);
+
+/**
+ * usb_legacy_port_reset() - Legacy function to reset a hub port
+ *
+ * @hub:	Hub device
+ * @portnr:	Port number (1=first)
+ */
+int usb_legacy_port_reset(struct usb_device *hub, int portnr);
+
+/**
+ * usb_setup_device() - set up a device ready for use
+ *
+ * @dev:	USB device pointer. This need not be a real device - it is
+ *		common for it to just be a local variable with its ->dev
+ *		member (i.e. @dev->dev) set to the parent device
+ * @do_read:	true to read the device descriptor before an address is set
+ *		(should be false for XHCI buses, true otherwise)
+ * @parent:	Parent device (either UCLASS_USB or UCLASS_USB_HUB)
+ * @portnr:	Port number on hub (1=first) or 0 for none
+ * @return 0 if OK, -ve on error */
+int usb_setup_device(struct usb_device *dev, bool do_read,
+		     struct usb_device *parent, int portnr);
+
+/**
+ * usb_hub_scan() - Scan a hub and find its devices
+ *
+ * @hub:	Hub device to scan
+ */
+int usb_hub_scan(struct udevice *hub);
+
+/**
+ * usb_scan_device() - Scan a device on a bus
+ *
+ * Scan a device on a bus. It has already been detected and is ready to
+ * be enumerated. This may be either the root hub (@parent is a bus) or a
+ * normal device (@parent is a hub)
+ *
+ * @parent:	Parent device
+ * @port:	Hub port number (numbered from 1)
+ * @speed:	USB speed to use for this device
+ * @devp:	Returns pointer to device if all is well
+ * @return 0 if OK, -ve on error
+ */
+int usb_scan_device(struct udevice *parent, int port,
+		    enum usb_device_speed speed, struct udevice **devp);
+
+/**
+ * usb_get_bus() - Find the bus for a device
+ *
+ * Search up through parents to find the bus this device is connected to. This
+ * will be a device with uclass UCLASS_USB.
+ *
+ * @dev:	Device to check
+ * @busp:	Returns bus, or NULL if not found
+ * @return 0 if OK, -EXDEV is somehow this bus does not have a controller (this
+ *	indicates a critical error in the USB stack
+ */
+int usb_get_bus(struct udevice *dev, struct udevice **busp);
+
+/**
+ * usb_select_config() - Set up a device ready for use
+ *
+ * This function assumes that the device already has an address and a driver
+ * bound, and is ready to be set up.
+ *
+ * This re-reads the device and configuration descriptors and sets the
+ * configuration
+ *
+ * @dev:	Device to set up
+ */
+int usb_select_config(struct usb_device *dev);
+
+/**
+ * usb_child_pre_probe() - Pre-probe function for USB devices
+ *
+ * This is called on all children of hubs and USB controllers (i.e. UCLASS_USB
+ * and UCLASS_USB_HUB) when a new device is about to be probed. It sets up the
+ * device from the saved platform data and calls usb_select_config() to
+ * finish set up.
+ *
+ * Once this is done, the device's normal driver can take over, knowing the
+ * device is accessible on the USB bus.
+ *
+ * This function is for use only by the internal USB stack.
+ *
+ * @dev:	Device to set up
+ */
+int usb_child_pre_probe(struct udevice *dev);
+
+struct ehci_ctrl;
+
+/**
+ * usb_setup_ehci_gadget() - Set up a USB device as a gadget
+ *
+ * TODO(sjg@chromium.org): Tidy this up when USB gadgets can use driver model
+ *
+ * This provides a way to tell a controller to start up as a USB device
+ * instead of as a host. It is untested.
+ */
+int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp);
+
+/**
+ * usb_stor_reset() - Prepare to scan USB storage devices
+ *
+ * Empty the list of USB storage devices in preparation for scanning them.
+ * This must be called before a USB scan.
+ */
+void usb_stor_reset(void);
+
+#else /* !CONFIG_DM_USB */
+
+struct usb_device *usb_get_dev_index(int index);
+
+#endif
+
+bool usb_device_has_child_on_port(struct usb_device *parent, int port);
+
 int usb_hub_probe(struct usb_device *dev, int ifnum);
 void usb_hub_reset(void);
 int hub_port_reset(struct usb_device *dev, int port,