/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) by Linux Kernel Developers
 *
 * Based on code from the Linux Kernel
 * available at http://www.kernel.org
 * Original file: <kernel>/include/linux/usb/ch9.h
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/*
 * 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).
 *
 * 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 _CH9_H_
#define _CH9_H_

#include <inttypes.h>

/*
 * USB directions
 *
 * 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

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

/**
 * 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)
 */
struct usb_ctrlrequest {
    uint8_t bRequestType;
    uint8_t bRequest;
    uint16_t wValue;
    uint16_t wIndex;
    uint16_t wLength;
} __attribute__ ((packed));

/*
 * 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

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

/*
 * 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".  But when exposed through Linux-USB APIs,
 * they've been converted to cpu byte order.
 */

/*
 * 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_OTG                      0x09
#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_KEY                      0x0d
#define USB_DT_ENCRYPTION_TYPE          0x0e
#define USB_DT_BOS                      0x0f
#define USB_DT_DEVICE_CAPABILITY        0x10
#define USB_DT_WIRELESS_ENDPOINT_COMP   0x11
#define USB_DT_WIRE_ADAPTER             0x21
#define USB_DT_RPIPE                    0x22

/* 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)

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

/* USB_DT_DEVICE: Device descriptor */
struct usb_device_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;
    uint16_t bcdUSB;
    uint8_t  bDeviceClass;
    uint8_t  bDeviceSubClass;
    uint8_t  bDeviceProtocol;
    uint8_t  bMaxPacketSize0;
    uint16_t idVendor;
    uint16_t idProduct;
    uint16_t bcdDevice;
    uint8_t  iManufacturer;
    uint8_t  iProduct;
    uint8_t  iSerialNumber;
    uint8_t  bNumConfigurations;
} __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_COMM                   2
#define USB_CLASS_HID                    3
#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_HUB                    9
#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_MISC                   0xef
#define USB_CLASS_APP_SPEC               0xfe
#define USB_CLASS_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
 * descriptors.
 */
struct usb_config_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;
    uint16_t wTotalLength;
    uint8_t  bNumInterfaces;
    uint8_t  bConfigurationValue;
    uint8_t  iConfiguration;
    uint8_t  bmAttributes;
    uint8_t  bMaxPower;
} __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_DT_STRING: String descriptor */
struct usb_string_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

    uint16_t wString[]; /* 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 {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

    uint8_t  bInterfaceNumber;
    uint8_t  bAlternateSetting;
    uint8_t  bNumEndpoints;
    uint8_t  bInterfaceClass;
    uint8_t  bInterfaceSubClass;
    uint8_t  bInterfaceProtocol;
    uint8_t  iInterface;
} __attribute__ ((packed));

#define USB_DT_INTERFACE_SIZE    9

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

/* USB_DT_ENDPOINT: Endpoint descriptor */
struct usb_endpoint_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

    uint8_t  bEndpointAddress;
    uint8_t  bmAttributes;
    uint16_t wMaxPacketSize;
    uint8_t  bInterval;

	/* NOTE:  these two are _only_ in audio endpoints. */
	/* use USB_DT_ENDPOINT*_SIZE in bLength, not sizeof. */
    //uint8_t  bRefresh;
    //uint8_t  bSynchAddress;
} __attribute__ ((packed));

#define USB_DT_ENDPOINT_SIZE        7
#define USB_DT_ENDPOINT_AUDIO_SIZE  9	/* Audio extension */

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

/* USB_DT_DEVICE_QUALIFIER: Device Qualifier descriptor */
struct usb_qualifier_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

    uint16_t bcdUSB;
    uint8_t  bDeviceClass;
    uint8_t  bDeviceSubClass;
    uint8_t  bDeviceProtocol;
    uint8_t  bMaxPacketSize0;
    uint8_t  bNumConfigurations;
    uint8_t  bRESERVED;
} __attribute__ ((packed));

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

/* USB_DT_OTG (from OTG 1.0a supplement) */
struct usb_otg_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

    uint8_t  bmAttributes;	/* support for HNP, SRP, etc */
} __attribute__ ((packed));

/* from usb_otg_descriptor.bmAttributes */
#define USB_OTG_SRP    (1 << 0)
#define USB_OTG_HNP    (1 << 1) /* swap host/device roles */

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

/* USB_DT_DEBUG:  for special highspeed devices, replacing serial console */
struct usb_debug_descriptor {
    uint8_t  bLength;
    uint8_t  bDescriptorType;

	/* bulk endpoints with 8 byte maxpacket */
    uint8_t  bDebugInEndpoint;
    uint8_t  bDebugOutEndpoint;
};

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

/*
 * Endpoints
 */
#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

enum usb_device_speed {
	USB_SPEED_UNKNOWN = 0,          /* enumerating */
	USB_SPEED_LOW, USB_SPEED_FULL,  /* usb 1.1 */
	USB_SPEED_HIGH,                 /* usb 2.0 */
	USB_SPEED_VARIABLE,             /* wireless (usb 2.5) */
};

enum usb_device_state {
	/* NOTATTACHED isn't in the USB spec, and this state acts
	 * the same as ATTACHED ... but it's clearer this way.
	 */
	USB_STATE_NOTATTACHED = 0,

	/* chapter 9 and authentication (wireless) device states */
	USB_STATE_ATTACHED,
	USB_STATE_POWERED,			/* wired */
	USB_STATE_UNAUTHENTICATED,		/* auth */
	USB_STATE_RECONNECTING,			/* auth */
	USB_STATE_DEFAULT,			/* limited function */
	USB_STATE_ADDRESS,
	USB_STATE_CONFIGURED,			/* most functions */

	USB_STATE_SUSPENDED

	/* NOTE:  there are actually four different SUSPENDED
	 * states, returning to POWERED, DEFAULT, ADDRESS, or
	 * CONFIGURED respectively when SOF tokens flow again.
	 */
};

/* All standard descriptors have these 2 fields at the beginning */
struct usb_descriptor_header {
    uint8_t  bLength;
    uint8_t  bDescriptorType;
} __attribute__ ((packed));

/**
 * struct usb_string - wraps a C string and its USB id
 * @id:the (nonzero) ID for this string
 * @s:the string, in UTF-8 encoding
 *
 * If you're using usb_gadget_get_string(), use this to wrap a string
 * together with its ID.
 */
struct usb_string {
    uint8_t id;
    const char* s;
};

/**
 * struct usb_gadget_strings - a set of USB strings in a given language
 * @language:identifies the strings' language (0x0409 for en-us)
 * @strings:array of strings with their ids
 *
 * If you're using usb_gadget_get_string(), use this to wrap all the
 * strings for a given language.
 */
struct usb_gadget_strings {
    uint16_t language;	/* 0x0409 for en-us */
    struct usb_string* strings;
};

#endif /*_CH9_H_*/