path: root/include/linux/usb.h

#ifndef __LINUX_USB_H
#define __LINUX_USB_H

#include <linux/mod_devicetable.h>
#include <linux/usb_ch9.h>

#define USB_MAJOR			180
#define USB_DEVICE_MAJOR		189


#ifdef __KERNEL__

#include <linux/config.h>
#include <linux/errno.h>        /* for -ENODEV */
#include <linux/delay.h>	/* for mdelay() */
#include <linux/interrupt.h>	/* for in_interrupt() */
#include <linux/list.h>		/* for struct list_head */
#include <linux/kref.h>		/* for struct kref */
#include <linux/device.h>	/* for struct device */
#include <linux/fs.h>		/* for struct file_operations */
#include <linux/completion.h>	/* for struct completion */
#include <linux/sched.h>	/* for current && schedule_timeout */

struct usb_device;
struct usb_driver;

/*-------------------------------------------------------------------------*/

/*
 * Host-side wrappers for standard USB descriptors ... these are parsed
 * from the data provided by devices.  Parsing turns them from a flat
 * sequence of descriptors into a hierarchy:
 *
 *  - devices have one (usually) or more configs;
 *  - configs have one (often) or more interfaces;
 *  - interfaces have one (usually) or more settings;
 *  - each interface setting has zero or (usually) more endpoints.
 *
 * And there might be other descriptors mixed in with those.
 *
 * Devices may also have class-specific or vendor-specific descriptors.
 */

/**
 * struct usb_host_endpoint - host-side endpoint descriptor and queue
 * @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
 * @urb_list: urbs queued to this endpoint; maintained by usbcore
 * @hcpriv: for use by HCD; typically holds hardware dma queue head (QH)
 *	with one or more transfer descriptors (TDs) per urb
 * @extra: descriptors following this endpoint in the configuration
 * @extralen: how many bytes of "extra" are valid
 *
 * USB requests are always queued to a given endpoint, identified by a
 * descriptor within an active interface in a given USB configuration.
 */
struct usb_host_endpoint {
	struct usb_endpoint_descriptor	desc;
	struct list_head		urb_list;
	void				*hcpriv;
	char 				*attr_name;
	struct attribute_group		*attr_group;
	struct attribute 		**attrs;
	int				num_attrs;

	unsigned char *extra;   /* Extra descriptors */
	int extralen;
};

/* host-side wrapper for one interface setting's parsed descriptors */
struct usb_host_interface {
	struct usb_interface_descriptor	desc;

	/* array of desc.bNumEndpoint endpoints associated with this
	 * interface setting.  these will be in no particular order.
	 */
	struct usb_host_endpoint *endpoint;

	char *string;		/* iInterface string, if present */
	unsigned char *extra;   /* Extra descriptors */
	int extralen;
};

enum usb_interface_condition {
	USB_INTERFACE_UNBOUND = 0,
	USB_INTERFACE_BINDING,
	USB_INTERFACE_BOUND,
	USB_INTERFACE_UNBINDING,
};

/**
 * struct usb_interface - what usb device drivers talk to
 * @altsetting: array of interface structures, one for each alternate
 * 	setting that may be selected.  Each one includes a set of
 * 	endpoint configurations.  They will be in no particular order.
 * @num_altsetting: number of altsettings defined.
 * @cur_altsetting: the current altsetting.
 * @driver: the USB driver that is bound to this interface.
 * @minor: the minor number assigned to this interface, if this
 *	interface is bound to a driver that uses the USB major number.
 *	If this interface does not use the USB major, this field should
 *	be unused.  The driver should set this value in the probe()
 *	function of the driver, after it has been assigned a minor
 *	number from the USB core by calling usb_register_dev().
 * @condition: binding state of the interface: not bound, binding
 *	(in probe()), bound to a driver, or unbinding (in disconnect())
 * @dev: driver model's view of this device
 * @class_dev: driver model's class view of this device.
 *
 * USB device drivers attach to interfaces on a physical device.  Each
 * interface encapsulates a single high level function, such as feeding
 * an audio stream to a speaker or reporting a change in a volume control.
 * Many USB devices only have one interface.  The protocol used to talk to
 * an interface's endpoints can be defined in a usb "class" specification,
 * or by a product's vendor.  The (default) control endpoint is part of
 * every interface, but is never listed among the interface's descriptors.
 *
 * The driver that is bound to the interface can use standard driver model
 * calls such as dev_get_drvdata() on the dev member of this structure.
 *
 * Each interface may have alternate settings.  The initial configuration
 * of a device sets altsetting 0, but the device driver can change
 * that setting using usb_set_interface().  Alternate settings are often
 * used to control the the use of periodic endpoints, such as by having
 * different endpoints use different amounts of reserved USB bandwidth.
 * All standards-conformant USB devices that use isochronous endpoints
 * will use them in non-default settings.
 *
 * The USB specification says that alternate setting numbers must run from
 * 0 to one less than the total number of alternate settings.  But some
 * devices manage to mess this up, and the structures aren't necessarily
 * stored in numerical order anyhow.  Use usb_altnum_to_altsetting() to
 * look up an alternate setting in the altsetting array based on its number.
 */
struct usb_interface {
	/* array of alternate settings for this interface,
	 * stored in no particular order */
	struct usb_host_interface *altsetting;

	struct usb_host_interface *cur_altsetting;	/* the currently
					 * active alternate setting */
	unsigned num_altsetting;	/* number of alternate settings */

	int minor;			/* minor number this interface is bound to */
	enum usb_interface_condition condition;		/* state of binding */
	struct device dev;		/* interface specific device info */
	struct class_device *class_dev;
};
#define	to_usb_interface(d) container_of(d, struct usb_interface, dev)
#define	interface_to_usbdev(intf) \
	container_of(intf->dev.parent, struct usb_device, dev)

static inline void *usb_get_intfdata (struct usb_interface *intf)
{
	return dev_get_drvdata (&intf->dev);
}

static inline void usb_set_intfdata (struct usb_interface *intf, void *data)
{
	dev_set_drvdata(&intf->dev, data);
}

struct usb_interface *usb_get_intf(struct usb_interface *intf);
void usb_put_intf(struct usb_interface *intf);

/* this maximum is arbitrary */
#define USB_MAXINTERFACES	32

/**
 * struct usb_interface_cache - long-term representation of a device interface
 * @num_altsetting: number of altsettings defined.
 * @ref: reference counter.
 * @altsetting: variable-length array of interface structures, one for
 *	each alternate setting that may be selected.  Each one includes a
 *	set of endpoint configurations.  They will be in no particular order.
 *
 * These structures persist for the lifetime of a usb_device, unlike
 * struct usb_interface (which persists only as long as its configuration
 * is installed).  The altsetting arrays can be accessed through these
 * structures at any time, permitting comparison of configurations and
 * providing support for the /proc/bus/usb/devices pseudo-file.
 */
struct usb_interface_cache {
	unsigned num_altsetting;	/* number of alternate settings */
	struct kref ref;		/* reference counter */

	/* variable-length array of alternate settings for this interface,
	 * stored in no particular order */
	struct usb_host_interface altsetting[0];
};
#define	ref_to_usb_interface_cache(r) \
		container_of(r, struct usb_interface_cache, ref)
#define	altsetting_to_usb_interface_cache(a) \
		container_of(a, struct usb_interface_cache, altsetting[0])

/**
 * struct usb_host_config - representation of a device's configuration
 * @desc: the device's configuration descriptor.
 * @string: pointer to the cached version of the iConfiguration string, if
 *	present for this configuration.
 * @interface: array of pointers to usb_interface structures, one for each
 *	interface in the configuration.  The number of interfaces is stored
 *	in desc.bNumInterfaces.  These pointers are valid only while the
 *	the configuration is active.
 * @intf_cache: array of pointers to usb_interface_cache structures, one
 *	for each interface in the configuration.  These structures exist
 *	for the entire life of the device.
 * @extra: pointer to buffer containing all extra descriptors associated
 *	with this configuration (those preceding the first interface
 *	descriptor).
 * @extralen: length of the extra descriptors buffer.
 *
 * USB devices may have multiple configurations, but only one can be active
 * at any time.  Each encapsulates a different operational environment;
 * for example, a dual-speed device would have separate configurations for
 * full-speed and high-speed operation.  The number of configurations
 * available is stored in the device descriptor as bNumConfigurations.
 *
 * A configuration can contain multiple interfaces.  Each corresponds to
 * a different function of the USB device, and all are available whenever
 * the configuration is active.  The USB standard says that interfaces
 * are supposed to be numbered from 0 to desc.bNumInterfaces-1, but a lot
 * of devices get this wrong.  In addition, the interface array is not
 * guaranteed to be sorted in numerical order.  Use usb_ifnum_to_if() to
 * look up an interface entry based on its number.
 *
 * Device drivers should not attempt to activate configurations.  The choice
 * of which configuration to install is a policy decision based on such
 * considerations as available power, functionality provided, and the user's
 * desires (expressed through hotplug scripts).  However, drivers can call
 * usb_reset_configuration() to reinitialize the current configuration and
 * all its interfaces.
 */
struct usb_host_config {
	struct usb_config_descriptor	desc;

	char *string;
	/* the interfaces associated with this configuration,
	 * stored in no particular order */
	struct usb_interface *interface[USB_MAXINTERFACES];

	/* Interface information available even when this is not the
	 * active configuration */
	struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];

	unsigned char *extra;   /* Extra descriptors */
	int extralen;
};

int __usb_get_extra_descriptor(char *buffer, unsigned size,
	unsigned char type, void **ptr);
#define usb_get_extra_descriptor(ifpoint,type,ptr)\
	__usb_get_extra_descriptor((ifpoint)->extra,(ifpoint)->extralen,\
		type,(void**)ptr)

/* -------------------------------------------------------------------------- */

struct usb_operations;

/* USB device number allocation bitmap */
struct usb_devmap {
	unsigned long devicemap[128 / (8*sizeof(unsigned long))];
};

/*
 * Allocated per bus (tree of devices) we have:
 */
struct usb_bus {
	struct device *controller;	/* host/master side hardware */
	int busnum;			/* Bus number (in order of reg) */
	char *bus_name;			/* stable id (PCI slot_name etc) */
	u8 otg_port;			/* 0, or number of OTG/HNP port */
	unsigned is_b_host:1;		/* true during some HNP roleswitches */
	unsigned b_hnp_enable:1;	/* OTG: did A-Host enable HNP? */

	int devnum_next;		/* Next open device number in round-robin allocation */

	struct usb_devmap devmap;	/* device address allocation map */
	struct usb_operations *op;	/* Operations (specific to the HC) */
	struct usb_device *root_hub;	/* Root hub */
	struct list_head bus_list;	/* list of busses */
	void *hcpriv;                   /* Host Controller private data */

	int bandwidth_allocated;	/* on this bus: how much of the time
					 * reserved for periodic (intr/iso)
					 * requests is used, on average?
					 * Units: microseconds/frame.
					 * Limits: Full/low speed reserve 90%,
					 * while high speed reserves 80%.
					 */
	int bandwidth_int_reqs;		/* number of Interrupt requests */
	int bandwidth_isoc_reqs;	/* number of Isoc. requests */

	struct dentry *usbfs_dentry;	/* usbfs dentry entry for the bus */

	struct class_device *class_dev;	/* class device for this bus */
	struct kref kref;		/* handles reference counting this bus */
	void (*release)(struct usb_bus *bus);	/* function to destroy this bus's memory */
#if defined(CONFIG_USB_MON)
	struct mon_bus *mon_bus;	/* non-null when associated */
	int monitored;			/* non-zero when monitored */
#endif
};

/* -------------------------------------------------------------------------- */

/* This is arbitrary.
 * From USB 2.0 spec Table 11-13, offset 7, a hub can
 * have up to 255 ports. The most yet reported is 10.
 */
#define USB_MAXCHILDREN		(16)

struct usb_tt;

/*
 * struct usb_device - kernel's representation of a USB device
 *
 * FIXME: Write the kerneldoc!
 *
 * Usbcore drivers should not set usbdev->state directly.  Instead use
 * usb_set_device_state().
 */
struct usb_device {
	int		devnum;		/* Address on USB bus */
	char		devpath [16];	/* Use in messages: /port/port/... */
	enum usb_device_state	state;	/* configured, not attached, etc */
	enum usb_device_speed	speed;	/* high/full/low (or error) */

	struct usb_tt	*tt; 		/* low/full speed dev, highspeed hub */
	int		ttport;		/* device port on that tt hub */

	struct semaphore serialize;

	unsigned int toggle[2];		/* one bit for each endpoint ([0] = IN, [1] = OUT) */

	struct usb_device *parent;	/* our hub, unless we're the root */
	struct usb_bus *bus;		/* Bus we're part of */
	struct usb_host_endpoint ep0;

	struct device dev;		/* Generic device interface */

	struct usb_device_descriptor descriptor;/* Descriptor */
	struct usb_host_config *config;	/* All of the configs */

	struct usb_host_config *actconfig;/* the active configuration */
	struct usb_host_endpoint *ep_in[16];
	struct usb_host_endpoint *ep_out[16];

	char **rawdescriptors;		/* Raw descriptors for each config */

	int have_langid;		/* whether string_langid is valid yet */
	int string_langid;		/* language ID for strings */

	char *product;
	char *manufacturer;
	char *serial;			/* static strings from the device */
	struct list_head filelist;
	struct class_device *class_dev;
	struct dentry *usbfs_dentry;	/* usbfs dentry entry for the device */

	/*
	 * Child devices - these can be either new devices
	 * (if this is a hub device), or different instances
	 * of this same device.
	 *
	 * Each instance needs its own set of data structures.
	 */

	int maxchild;			/* Number of ports if hub */
	struct usb_device *children[USB_MAXCHILDREN];
};
#define	to_usb_device(d) container_of(d, struct usb_device, dev)

extern struct usb_device *usb_get_dev(struct usb_device *dev);
extern void usb_put_dev(struct usb_device *dev);

extern void usb_lock_device(struct usb_device *udev);
extern int usb_trylock_device(struct usb_device *udev);
extern int usb_lock_device_for_reset(struct usb_device *udev,
		struct usb_interface *iface);
extern void usb_unlock_device(struct usb_device *udev);

/* USB port reset for device reinitialization */
extern int usb_reset_device(struct usb_device *dev);

extern struct usb_device *usb_find_device(u16 vendor_id, u16 product_id);

/*-------------------------------------------------------------------------*/

/* for drivers using iso endpoints */
extern int usb_get_current_frame_number (struct usb_device *usb_dev);

/* used these for multi-interface device registration */
extern int usb_driver_claim_interface(struct usb_driver *driver,
			struct usb_interface *iface, void* priv);

/**
 * usb_interface_claimed - returns true iff an interface is claimed
 * @iface: the interface being checked
 *
 * Returns true (nonzero) iff the interface is claimed, else false (zero).
 * Callers must own the driver model's usb bus readlock.  So driver
 * probe() entries don't need extra locking, but other call contexts
 * may need to explicitly claim that lock.
 *
 */
static inline int usb_interface_claimed(struct usb_interface *iface) {
	return (iface->dev.driver != NULL);
}

extern void usb_driver_release_interface(struct usb_driver *driver,
			struct usb_interface *iface);
const struct usb_device_id *usb_match_id(struct usb_interface *interface,
					 const struct usb_device_id *id);

extern struct usb_interface *usb_find_interface(struct usb_driver *drv,
		int minor);
extern struct usb_interface *usb_ifnum_to_if(struct usb_device *dev,
		unsigned ifnum);
extern struct usb_host_interface *usb_altnum_to_altsetting(
		struct usb_interface *intf, unsigned int altnum);


/**
 * usb_make_path - returns stable device path in the usb tree
 * @dev: the device whose path is being constructed
 * @buf: where to put the string
 * @size: how big is "buf"?
 *
 * Returns length of the string (> 0) or negative if size was too small.
 *
 * This identifier is intended to be "stable", reflecting physical paths in
 * hardware such as physical bus addresses for host controllers or ports on
 * USB hubs.  That makes it stay the same until systems are physically
 * reconfigured, by re-cabling a tree of USB devices or by moving USB host
 * controllers.  Adding and removing devices, including virtual root hubs
 * in host controller driver modules, does not change these path identifers;
 * neither does rebooting or re-enumerating.  These are more useful identifiers
 * than changeable ("unstable") ones like bus numbers or device addresses.
 *
 * With a partial exception for devices connected to USB 2.0 root hubs, these
 * identifiers are also predictable.  So long as the device tree isn't changed,
 * plugging any USB device into a given hub port always gives it the same path.
 * Because of the use of "companion" controllers, devices connected to ports on
 * USB 2.0 root hubs (EHCI host controllers) will get one path ID if they are
 * high speed, and a different one if they are full or low speed.
 */
static inline int usb_make_path (struct usb_device *dev, char *buf, size_t size)
{
	int actual;
	actual = snprintf (buf, size, "usb-%s-%s", dev->bus->bus_name, dev->devpath);
	return (actual >= (int)size) ? -1 : actual;
}

/*-------------------------------------------------------------------------*/

#define USB_DEVICE_ID_MATCH_DEVICE		(USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT)
#define USB_DEVICE_ID_MATCH_DEV_RANGE		(USB_DEVICE_ID_MATCH_DEV_LO | USB_DEVICE_ID_MATCH_DEV_HI)
#define USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION	(USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_RANGE)
#define USB_DEVICE_ID_MATCH_DEV_INFO \
	(USB_DEVICE_ID_MATCH_DEV_CLASS | USB_DEVICE_ID_MATCH_DEV_SUBCLASS | USB_DEVICE_ID_MATCH_DEV_PROTOCOL)
#define USB_DEVICE_ID_MATCH_INT_INFO \
	(USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS | USB_DEVICE_ID_MATCH_INT_PROTOCOL)

/**
 * USB_DEVICE - macro used to describe a specific usb device
 * @vend: the 16 bit USB Vendor ID
 * @prod: the 16 bit USB Product ID
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific device.
 */
#define USB_DEVICE(vend,prod) \
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE, .idVendor = (vend), .idProduct = (prod)
/**
 * USB_DEVICE_VER - macro used to describe a specific usb device with a version range
 * @vend: the 16 bit USB Vendor ID
 * @prod: the 16 bit USB Product ID
 * @lo: the bcdDevice_lo value
 * @hi: the bcdDevice_hi value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific device, with a version range.
 */
#define USB_DEVICE_VER(vend,prod,lo,hi) \
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION, .idVendor = (vend), .idProduct = (prod), .bcdDevice_lo = (lo), .bcdDevice_hi = (hi)

/**
 * USB_DEVICE_INFO - macro used to describe a class of usb devices
 * @cl: bDeviceClass value
 * @sc: bDeviceSubClass value
 * @pr: bDeviceProtocol value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific class of devices.
 */
#define USB_DEVICE_INFO(cl,sc,pr) \
	.match_flags = USB_DEVICE_ID_MATCH_DEV_INFO, .bDeviceClass = (cl), .bDeviceSubClass = (sc), .bDeviceProtocol = (pr)

/**
 * USB_INTERFACE_INFO - macro used to describe a class of usb interfaces 
 * @cl: bInterfaceClass value
 * @sc: bInterfaceSubClass value
 * @pr: bInterfaceProtocol value
 *
 * This macro is used to create a struct usb_device_id that matches a
 * specific class of interfaces.
 */
#define USB_INTERFACE_INFO(cl,sc,pr) \
	.match_flags = USB_DEVICE_ID_MATCH_INT_INFO, .bInterfaceClass = (cl), .bInterfaceSubClass = (sc), .bInterfaceProtocol = (pr)

/* -------------------------------------------------------------------------- */

/**
 * struct usb_driver - identifies USB driver to usbcore
 * @owner: Pointer to the module owner of this driver; initialize
 *	it using THIS_MODULE.
 * @name: The driver name should be unique among USB drivers,
 *	and should normally be the same as the module name.
 * @probe: Called to see if the driver is willing to manage a particular
 *	interface on a device.  If it is, probe returns zero and uses
 *	dev_set_drvdata() to associate driver-specific data with the
 *	interface.  It may also use usb_set_interface() to specify the
 *	appropriate altsetting.  If unwilling to manage the interface,
 *	return a negative errno value.
 * @disconnect: Called when the interface is no longer accessible, usually
 *	because its device has been (or is being) disconnected or the
 *	driver module is being unloaded.
 * @ioctl: