[deliverable/linux.git] / include / linux / usb / ch9.h

/*
 * This file holds USB constants and structures that are needed for
 * USB device APIs.  These are used by the USB device model, which is
 * defined in chapter 9 of the USB 2.0 specification and in the
 * Wireless USB 1.0 (spread around).  Linux has several APIs in C that
 * need these:
 *
 * - the master/host side Linux-USB kernel driver API;
 * - the "usbfs" user space API; and
 * - the Linux "gadget" slave/device/peripheral side driver API.
 *
 * USB 2.0 adds an additional "On The Go" (OTG) mode, which lets systems
 * act either as a USB master/host or as a USB slave/device.  That means
 * the master and slave side APIs benefit from working well together.
 *
 * There's also "Wireless USB", using low power short range radios for
 * peripheral interconnection but otherwise building on the USB framework.
 *
 * Note all descriptors are declared '__attribute__((packed))' so that:
 *
 * [a] they never get padded, either internally (USB spec writers
 *     probably handled that) or externally;
 *
 * [b] so that accessing bigger-than-a-bytes fields will never
 *     generate bus errors on any platform, even when the location of
 *     its descriptor inside a bundle isn't "naturally aligned", and
 *
 * [c] for consistency, removing all doubt even when it appears to
 *     someone that the two other points are non-issues for that
 *     particular descriptor type.
 */
#ifndef __LINUX_USB_CH9_H
#define __LINUX_USB_CH9_H

#include <linux/device.h>
#include <uapi/linux/usb/ch9.h>

/**
 * usb_speed_string() - Returns human readable-name of the speed.
 * @speed: The speed to return human-readable name for.  If it's not
 *   any of the speeds defined in usb_device_speed enum, string for
 *   USB_SPEED_UNKNOWN will be returned.
 */
extern const char *usb_speed_string(enum usb_device_speed speed);

/**
 * usb_get_maximum_speed - Get maximum requested speed for a given USB
 * controller.
 * @dev: Pointer to the given USB controller device
 *
 * The function gets the maximum speed string from property "maximum-speed",
 * and returns the corresponding enum usb_device_speed.
 */
extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);

/**
 * usb_state_string - Returns human readable name for the state.
 * @state: The state to return a human-readable name for. If it's not
 *	any of the states devices in usb_device_state_string enum,
 *	the string UNKNOWN will be returned.
 */
extern const char *usb_state_string(enum usb_device_state state);

#endif /* __LINUX_USB_CH9_H */
Commit	Line	Data
1da177e4	1	/*
672027a3 IPG	2	* This file holds USB constants and structures that are needed for
	3	* USB device APIs. These are used by the USB device model, which is
	4	* defined in chapter 9 of the USB 2.0 specification and in the
	5	* Wireless USB 1.0 (spread around). Linux has several APIs in C that
	6	* need these:
1da177e4 LT	7	*
	8	* - the master/host side Linux-USB kernel driver API;
	9	* - the "usbfs" user space API; and
5da0106f	10	* - the Linux "gadget" slave/device/peripheral side driver API.
1da177e4 LT	11	*
	12	* USB 2.0 adds an additional "On The Go" (OTG) mode, which lets systems
	13	* act either as a USB master/host or as a USB slave/device. That means
5da0106f DB	14	* the master and slave side APIs benefit from working well together.
	15	*
	16	* There's also "Wireless USB", using low power short range radios for
	17	* peripheral interconnection but otherwise building on the USB framework.
672027a3 IPG	18	*
	19	* Note all descriptors are declared '__attribute__((packed))' so that:
	20	*
	21	* [a] they never get padded, either internally (USB spec writers
	22	* probably handled that) or externally;
	23	*
	24	* [b] so that accessing bigger-than-a-bytes fields will never
	25	* generate bus errors on any platform, even when the location of
	26	* its descriptor inside a bundle isn't "naturally aligned", and
	27	*
	28	* [c] for consistency, removing all doubt even when it appears to
	29	* someone that the two other points are non-issues for that
	30	* particular descriptor type.
1da177e4	31	*/
1da177e4 LT	32	#ifndef __LINUX_USB_CH9_H
	33	#define __LINUX_USB_CH9_H
	34
63863b98	35	#include <linux/device.h>
5e1ddb48	36	#include <uapi/linux/usb/ch9.h>
1da177e4	37
e538dfda MN	38	/**
	39	* usb_speed_string() - Returns human readable-name of the speed.
	40	* @speed: The speed to return human-readable name for. If it's not
	41	* any of the speeds defined in usb_device_speed enum, string for
	42	* USB_SPEED_UNKNOWN will be returned.
	43	*/
	44	extern const char *usb_speed_string(enum usb_device_speed speed);
	45
63863b98 HK	46	/**
	47	* usb_get_maximum_speed - Get maximum requested speed for a given USB
	48	* controller.
	49	* @dev: Pointer to the given USB controller device
	50	*
	51	* The function gets the maximum speed string from property "maximum-speed",
	52	* and returns the corresponding enum usb_device_speed.
	53	*/
	54	extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
d1e3d757 FB	55
	56	/**
	57	* usb_state_string - Returns human readable name for the state.
	58	* @state: The state to return a human-readable name for. If it's not
	59	* any of the states devices in usb_device_state_string enum,
	60	* the string UNKNOWN will be returned.
	61	*/
	62	extern const char *usb_state_string(enum usb_device_state state);
	63
dda43a0e	64	#endif /* __LINUX_USB_CH9_H */