/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
* 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
* - 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/types.h> /* __u8 etc */
#include <asm/byteorder.h> /* le16_to_cpu */
/*-------------------------------------------------------------------------*/
/* CONTROL REQUEST SUPPORT */
* This bit flag is used in endpoint descriptors' bEndpointAddress field.
* It's also one of three fields in control requests bRequestType.
#define USB_DIR_OUT 0 /* to device */
#define USB_DIR_IN 0x80 /* to host */
* USB types, the second of three bRequestType fields
#define USB_TYPE_MASK (0x03 << 5)
#define USB_TYPE_STANDARD (0x00 << 5)
#define USB_TYPE_CLASS (0x01 << 5)
#define USB_TYPE_VENDOR (0x02 << 5)
#define USB_TYPE_RESERVED (0x03 << 5)
* USB recipients, the third of three bRequestType fields
#define USB_RECIP_MASK 0x1f
#define USB_RECIP_DEVICE 0x00
#define USB_RECIP_INTERFACE 0x01
#define USB_RECIP_ENDPOINT 0x02
#define USB_RECIP_OTHER 0x03
/* From Wireless USB 1.0 */
#define USB_RECIP_PORT 0x04
#define USB_RECIP_RPIPE 0x05
* Standard requests, for the bRequest field of a SETUP packet.
* These are qualified by the bRequestType field, so that for example
* TYPE_CLASS or TYPE_VENDOR specific feature flags could be retrieved
* by a GET_STATUS request.
#define USB_REQ_GET_STATUS 0x00
#define USB_REQ_CLEAR_FEATURE 0x01
#define USB_REQ_SET_FEATURE 0x03
#define USB_REQ_SET_ADDRESS 0x05
#define USB_REQ_GET_DESCRIPTOR 0x06
#define USB_REQ_SET_DESCRIPTOR 0x07
#define USB_REQ_GET_CONFIGURATION 0x08
#define USB_REQ_SET_CONFIGURATION 0x09
#define USB_REQ_GET_INTERFACE 0x0A
#define USB_REQ_SET_INTERFACE 0x0B
#define USB_REQ_SYNCH_FRAME 0x0C
#define USB_REQ_SET_SEL 0x30
#define USB_REQ_SET_ISOCH_DELAY 0x31
#define USB_REQ_SET_ENCRYPTION 0x0D /* Wireless USB */
#define USB_REQ_GET_ENCRYPTION 0x0E
#define USB_REQ_RPIPE_ABORT 0x0E
#define USB_REQ_SET_HANDSHAKE 0x0F
#define USB_REQ_RPIPE_RESET 0x0F
#define USB_REQ_GET_HANDSHAKE 0x10
#define USB_REQ_SET_CONNECTION 0x11
#define USB_REQ_SET_SECURITY_DATA 0x12
#define USB_REQ_GET_SECURITY_DATA 0x13
#define USB_REQ_SET_WUSB_DATA 0x14
#define USB_REQ_LOOPBACK_DATA_WRITE 0x15
#define USB_REQ_LOOPBACK_DATA_READ 0x16
#define USB_REQ_SET_INTERFACE_DS 0x17
/* specific requests for USB Power Delivery */
#define USB_REQ_GET_PARTNER_PDO 20
#define USB_REQ_GET_BATTERY_STATUS 21
#define USB_REQ_SET_PDO 22
#define USB_REQ_GET_VDM 23
#define USB_REQ_SEND_VDM 24
/* The Link Power Management (LPM) ECN defines USB_REQ_TEST_AND_SET command,
* used by hubs to put ports into a new L1 suspend state, except that it
* forgot to define its number ...
* USB feature flags are written using USB_REQ_{CLEAR,SET}_FEATURE, and
* are read as a bit array returned by USB_REQ_GET_STATUS. (So there
* are at most sixteen features of each type.) Hubs may also support a
* new USB_REQ_TEST_AND_SET_FEATURE to put ports into L1 suspend.
#define USB_DEVICE_SELF_POWERED 0 /* (read only) */
#define USB_DEVICE_REMOTE_WAKEUP 1 /* dev may initiate wakeup */
#define USB_DEVICE_TEST_MODE 2 /* (wired high speed only) */
#define USB_DEVICE_BATTERY 2 /* (wireless) */
#define USB_DEVICE_B_HNP_ENABLE 3 /* (otg) dev may initiate HNP */
#define USB_DEVICE_WUSB_DEVICE 3 /* (wireless)*/
#define USB_DEVICE_A_HNP_SUPPORT 4 /* (otg) RH port supports HNP */
#define USB_DEVICE_A_ALT_HNP_SUPPORT 5 /* (otg) other RH port does */
#define USB_DEVICE_DEBUG_MODE 6 /* (special devices only) */
* See USB 2.0 spec Table 9-7
#define USB_STATUS_TYPE_STANDARD 0
#define USB_STATUS_TYPE_PTM 1
* New Feature Selectors as added by USB 3.0
* See USB 3.0 spec Table 9-7
#define USB_DEVICE_U1_ENABLE 48 /* dev may initiate U1 transition */
#define USB_DEVICE_U2_ENABLE 49 /* dev may initiate U2 transition */
#define USB_DEVICE_LTM_ENABLE 50 /* dev may send LTM */
#define USB_INTRF_FUNC_SUSPEND 0 /* function suspend */
#define USB_INTR_FUNC_SUSPEND_OPT_MASK 0xFF00
* Suspend Options, Table 9-8 USB 3.0 spec
#define USB_INTRF_FUNC_SUSPEND_LP (1 << (8 + 0))
#define USB_INTRF_FUNC_SUSPEND_RW (1 << (8 + 1))
* Interface status, Figure 9-5 USB 3.0 spec
#define USB_INTRF_STAT_FUNC_RW_CAP 1
#define USB_INTRF_STAT_FUNC_RW 2
#define USB_ENDPOINT_HALT 0 /* IN/OUT will STALL */
/* Bit array elements as returned by the USB_REQ_GET_STATUS request. */
#define USB_DEV_STAT_U1_ENABLED 2 /* transition into U1 state */
#define USB_DEV_STAT_U2_ENABLED 3 /* transition into U2 state */
#define USB_DEV_STAT_LTM_ENABLED 4 /* Latency tolerance messages */
* Feature selectors from Table 9-8 USB Power Delivery spec
#define USB_DEVICE_BATTERY_WAKE_MASK 40
#define USB_DEVICE_OS_IS_PD_AWARE 41
#define USB_DEVICE_POLICY_MODE 42
#define USB_PORT_PR_SWAP 43
#define USB_PORT_GOTO_MIN 44
#define USB_PORT_RETURN_POWER 45
#define USB_PORT_ACCEPT_PD_REQUEST 46
#define USB_PORT_REJECT_PD_REQUEST 47
#define USB_PORT_PORT_PD_RESET 48
#define USB_PORT_C_PORT_PD_CHANGE 49
#define USB_PORT_CABLE_PD_RESET 50
#define USB_DEVICE_CHARGING_POLICY 54
* struct usb_ctrlrequest - SETUP data for a USB device control request
* @bRequestType: matches the USB bmRequestType field
* @bRequest: matches the USB bRequest field
* @wValue: matches the USB wValue field (le16 byte order)
* @wIndex: matches the USB wIndex field (le16 byte order)
* @wLength: matches the USB wLength field (le16 byte order)
* This structure is used to send control requests to a USB device. It matches
* the different fields of the USB 2.0 Spec section 9.3, table 9-2. See the
* USB spec for a fuller description of the different fields, and what they are
* Note that the driver for any interface can issue control requests.
* For most devices, interfaces don't coordinate with each other, so
* such requests may be made at any time.
} __attribute__ ((packed));
/*-------------------------------------------------------------------------*/
* STANDARD DESCRIPTORS ... as returned by GET_DESCRIPTOR, or
* (rarely) accepted by SET_DESCRIPTOR.
* Note that all multi-byte values here are encoded in little endian
* byte order "on the wire". Within the kernel and when exposed
* through the Linux-USB APIs, they are not converted to cpu byte
* order; it is the responsibility of the client code to do this.
* The single exception is when device and configuration descriptors (but
* not other descriptors) are read from character devices
* (i.e. /dev/bus/usb/BBB/DDD);
* in this case the fields are converted to host endianness by the kernel.
* Descriptor types ... USB 2.0 spec table 9.5
#define USB_DT_DEVICE 0x01
#define USB_DT_CONFIG 0x02
#define USB_DT_STRING 0x03
#define USB_DT_INTERFACE 0x04
#define USB_DT_ENDPOINT 0x05
#define USB_DT_DEVICE_QUALIFIER 0x06
#define USB_DT_OTHER_SPEED_CONFIG 0x07
#define USB_DT_INTERFACE_POWER 0x08
/* these are from a minor usb 2.0 revision (ECN) */
#define USB_DT_DEBUG 0x0a
#define USB_DT_INTERFACE_ASSOCIATION 0x0b
/* these are from the Wireless USB spec */
#define USB_DT_SECURITY 0x0c
#define USB_DT_ENCRYPTION_TYPE 0x0e
#define USB_DT_DEVICE_CAPABILITY 0x10
#define USB_DT_WIRELESS_ENDPOINT_COMP 0x11
#define USB_DT_WIRE_ADAPTER 0x21
#define USB_DT_RPIPE 0x22
#define USB_DT_CS_RADIO_CONTROL 0x23
/* From the T10 UAS specification */
#define USB_DT_PIPE_USAGE 0x24
/* From the USB 3.0 spec */
#define USB_DT_SS_ENDPOINT_COMP 0x30
/* From the USB 3.1 spec */
#define USB_DT_SSP_ISOC_ENDPOINT_COMP 0x31
/* Conventional codes for class-specific descriptors. The convention is
* defined in the USB "Common Class" Spec (3.11). Individual class specs
* are authoritative for their usage, not the "common class" writeup.
#define USB_DT_CS_DEVICE (USB_TYPE_CLASS | USB_DT_DEVICE)
#define USB_DT_CS_CONFIG (USB_TYPE_CLASS | USB_DT_CONFIG)
#define USB_DT_CS_STRING (USB_TYPE_CLASS | USB_DT_STRING)
#define USB_DT_CS_INTERFACE (USB_TYPE_CLASS | USB_DT_INTERFACE)
#define USB_DT_CS_ENDPOINT (USB_TYPE_CLASS | USB_DT_ENDPOINT)
/* All standard descriptors have these 2 fields at the beginning */
struct usb_descriptor_header {
} __attribute__ ((packed));
/*-------------------------------------------------------------------------*/
/* USB_DT_DEVICE: Device descriptor */
struct usb_device_descriptor {
} __attribute__ ((packed));
#define USB_DT_DEVICE_SIZE 18
* Device and/or Interface Class codes
* as found in bDeviceClass or bInterfaceClass
* and defined by www.usb.org documents
#define USB_CLASS_PER_INTERFACE 0 /* for DeviceClass */
#define USB_CLASS_AUDIO 1
#define USB_CLASS_PHYSICAL 5
#define USB_CLASS_STILL_IMAGE 6
#define USB_CLASS_PRINTER 7
#define USB_CLASS_MASS_STORAGE 8
#define USB_CLASS_CDC_DATA 0x0a
#define USB_CLASS_CSCID 0x0b /* chip+ smart card */
#define USB_CLASS_CONTENT_SEC 0x0d /* content security */
#define USB_CLASS_VIDEO 0x0e
#define USB_CLASS_WIRELESS_CONTROLLER 0xe0
#define USB_CLASS_PERSONAL_HEALTHCARE 0x0f
#define USB_CLASS_AUDIO_VIDEO 0x10
#define USB_CLASS_BILLBOARD 0x11
#define USB_CLASS_USB_TYPE_C_BRIDGE 0x12
#define USB_CLASS_MISC 0xef
#define USB_CLASS_APP_SPEC 0xfe
#define USB_CLASS_VENDOR_SPEC 0xff
#define USB_SUBCLASS_VENDOR_SPEC 0xff
/*-------------------------------------------------------------------------*/
/* USB_DT_CONFIG: Configuration descriptor information.
* USB_DT_OTHER_SPEED_CONFIG is the same descriptor, except that the
* descriptor type is different. Highspeed-capable devices can look
* different depending on what speed they're currently running. Only
* devices with a USB_DT_DEVICE_QUALIFIER have any OTHER_SPEED_CONFIG
struct usb_config_descriptor {
__u8 bConfigurationValue;
} __attribute__ ((packed));
#define USB_DT_CONFIG_SIZE 9
/* from config descriptor bmAttributes */
#define USB_CONFIG_ATT_ONE (1 << 7) /* must be set */
#define USB_CONFIG_ATT_SELFPOWER (1 << 6) /* self powered */
#define USB_CONFIG_ATT_WAKEUP (1 << 5) /* can wakeup */
#define USB_CONFIG_ATT_BATTERY (1 << 4) /* battery powered */
/*-------------------------------------------------------------------------*/
/* USB String descriptors can contain at most 126 characters. */
#define USB_MAX_STRING_LEN 126
/* USB_DT_STRING: String descriptor */
struct usb_string_descriptor {
__le16 wData[1]; /* UTF-16LE encoded */
} __attribute__ ((packed));
/* note that "string" zero is special, it holds language codes that
* the device supports, not Unicode characters.
/*-------------------------------------------------------------------------*/
/* USB_DT_INTERFACE: Interface descriptor */
struct usb_interface_descriptor {
} __attribute__ ((packed));
#define USB_DT_INTERFACE_SIZE 9
/*-------------------------------------------------------------------------*/
/* USB_DT_ENDPOINT: Endpoint descriptor */
struct usb_endpoint_descriptor {
/* NOTE: these two are _only_ in audio endpoints. */
/* use USB_DT_ENDPOINT*_SIZE in bLength, not sizeof. */
} __attribute__ ((packed));
#define USB_DT_ENDPOINT_SIZE 7
#define USB_DT_ENDPOINT_AUDIO_SIZE 9 /* Audio extension */
#define USB_ENDPOINT_NUMBER_MASK 0x0f /* in bEndpointAddress */
#define USB_ENDPOINT_DIR_MASK 0x80
#define USB_ENDPOINT_XFERTYPE_MASK 0x03 /* in bmAttributes */
#define USB_ENDPOINT_XFER_CONTROL 0
#define USB_ENDPOINT_XFER_ISOC 1
#define USB_ENDPOINT_XFER_BULK 2
#define USB_ENDPOINT_XFER_INT 3
#define USB_ENDPOINT_MAX_ADJUSTABLE 0x80
#define USB_ENDPOINT_MAXP_MASK 0x07ff
#define USB_EP_MAXP_MULT_SHIFT 11
#define USB_EP_MAXP_MULT_MASK (3 << USB_EP_MAXP_MULT_SHIFT)
#define USB_EP_MAXP_MULT(m) \
(((m) & USB_EP_MAXP_MULT_MASK) >> USB_EP_MAXP_MULT_SHIFT)
/* The USB 3.0 spec redefines bits 5:4 of bmAttributes as interrupt ep type. */
#define USB_ENDPOINT_INTRTYPE 0x30
#define USB_ENDPOINT_INTR_PERIODIC (0 << 4)
#define USB_ENDPOINT_INTR_NOTIFICATION (1 << 4)
#define USB_ENDPOINT_SYNCTYPE 0x0c
#define USB_ENDPOINT_SYNC_NONE (0 << 2)
#define USB_ENDPOINT_SYNC_ASYNC (1 << 2)
#define USB_ENDPOINT_SYNC_ADAPTIVE (2 << 2)
#define USB_ENDPOINT_SYNC_SYNC (3 << 2)
#define USB_ENDPOINT_USAGE_MASK 0x30
#define USB_ENDPOINT_USAGE_DATA 0x00
#define USB_ENDPOINT_USAGE_FEEDBACK 0x10
#define USB_ENDPOINT_USAGE_IMPLICIT_FB 0x20 /* Implicit feedback Data endpoint */
/*-------------------------------------------------------------------------*/
* usb_endpoint_num - get the endpoint's number
* @epd: endpoint to be checked
* Returns @epd's number: 0 to 15.
static __inline__ int usb_endpoint_num(const struct usb_endpoint_descriptor *epd)
return epd->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
* usb_endpoint_type - get the endpoint's transfer type
* @epd: endpoint to be checked
* Returns one of USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT} according
* to @epd's transfer type.
static __inline__ int usb_endpoint_type(const struct usb_endpoint_descriptor *epd)
return epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
* usb_endpoint_dir_in - check if the endpoint has IN direction
* @epd: endpoint to be checked
* Returns true if the endpoint is of type IN, otherwise it returns false.
static __inline__ int usb_endpoint_dir_in(const struct usb_endpoint_descriptor *epd)
return ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN);
* usb_endpoint_dir_out - check if the endpoint has OUT direction
* @epd: endpoint to be checked