hw/usb.c

   1 /*
   2  * QEMU USB emulation
   3  *
   4  * Copyright (c) 2005 Fabrice Bellard
   5  *
   6  * 2008 Generic packet handler rewrite by Max Krasnyansky
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24  * THE SOFTWARE.
  25  */
  26 #include "qemu-common.h"
  27 #include "usb.h"
  28
  29 void usb_attach(USBPort *port, USBDevice *dev)
  30 {
  31     port->attach(port, dev);
  32 }
  33
  34 /**********************/
  35
  36 /* generic USB device helpers (you are not forced to use them when
  37    writing your USB device driver, but they help handling the
  38    protocol)
  39 */
  40
  41 #define SETUP_STATE_IDLE 0
  42 #define SETUP_STATE_DATA 1
  43 #define SETUP_STATE_ACK  2
  44
  45 static int do_token_setup(USBDevice *s, USBPacket *p)
  46 {
  47     int request, value, index;
  48     int ret = 0;
  49
  50     if (p->len != 8)
  51         return USB_RET_STALL;
  52
  53     memcpy(s->setup_buf, p->data, 8);
  54     s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
  55     s->setup_index = 0;
  56
  57     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
  58     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
  59     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
  60
  61     if (s->setup_buf[0] & USB_DIR_IN) {
  62         ret = s->info->handle_control(s, request, value, index,
  63                                       s->setup_len, s->data_buf);
  64         if (ret < 0)
  65             return ret;
  66
  67         if (ret < s->setup_len)
  68             s->setup_len = ret;
  69         s->setup_state = SETUP_STATE_DATA;
  70     } else {
  71         if (s->setup_len == 0)
  72             s->setup_state = SETUP_STATE_ACK;
  73         else
  74             s->setup_state = SETUP_STATE_DATA;
  75     }
  76
  77     return ret;
  78 }
  79
  80 static int do_token_in(USBDevice *s, USBPacket *p)
  81 {
  82     int request, value, index;
  83     int ret = 0;
  84
  85     if (p->devep != 0)
  86         return s->info->handle_data(s, p);
  87
  88     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
  89     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
  90     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
  91
  92     switch(s->setup_state) {
  93     case SETUP_STATE_ACK:
  94         if (!(s->setup_buf[0] & USB_DIR_IN)) {
  95             s->setup_state = SETUP_STATE_IDLE;
  96             ret = s->info->handle_control(s, request, value, index,
  97                                           s->setup_len, s->data_buf);
  98             if (ret > 0)
  99                 return 0;
 100             return ret;
 101         }
 102
 103         /* return 0 byte */
 104         return 0;
 105
 106     case SETUP_STATE_DATA:
 107         if (s->setup_buf[0] & USB_DIR_IN) {
 108             int len = s->setup_len - s->setup_index;
 109             if (len > p->len)
 110                 len = p->len;
 111             memcpy(p->data, s->data_buf + s->setup_index, len);
 112             s->setup_index += len;
 113             if (s->setup_index >= s->setup_len)
 114                 s->setup_state = SETUP_STATE_ACK;
 115             return len;
 116         }
 117
 118         s->setup_state = SETUP_STATE_IDLE;
 119         return USB_RET_STALL;
 120
 121     default:
 122         return USB_RET_STALL;
 123     }
 124 }
 125
 126 static int do_token_out(USBDevice *s, USBPacket *p)
 127 {
 128     if (p->devep != 0)
 129         return s->info->handle_data(s, p);
 130
 131     switch(s->setup_state) {
 132     case SETUP_STATE_ACK:
 133         if (s->setup_buf[0] & USB_DIR_IN) {
 134             s->setup_state = SETUP_STATE_IDLE;
 135             /* transfer OK */
 136         } else {
 137             /* ignore additional output */
 138         }
 139         return 0;
 140
 141     case SETUP_STATE_DATA:
 142         if (!(s->setup_buf[0] & USB_DIR_IN)) {
 143             int len = s->setup_len - s->setup_index;
 144             if (len > p->len)
 145                 len = p->len;
 146             memcpy(s->data_buf + s->setup_index, p->data, len);
 147             s->setup_index += len;
 148             if (s->setup_index >= s->setup_len)
 149                 s->setup_state = SETUP_STATE_ACK;
 150             return len;
 151         }
 152
 153         s->setup_state = SETUP_STATE_IDLE;
 154         return USB_RET_STALL;
 155
 156     default:
 157         return USB_RET_STALL;
 158     }
 159 }
 160
 161 /*
 162  * Generic packet handler.
 163  * Called by the HC (host controller).
 164  *
 165  * Returns length of the transaction or one of the USB_RET_XXX codes.
 166  */
 167 int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
 168 {
 169     switch(p->pid) {
 170     case USB_MSG_ATTACH:
 171         s->state = USB_STATE_ATTACHED;
 172         return 0;
 173
 174     case USB_MSG_DETACH:
 175         s->state = USB_STATE_NOTATTACHED;
 176         return 0;
 177
 178     case USB_MSG_RESET:
 179         s->remote_wakeup = 0;
 180         s->addr = 0;
 181         s->state = USB_STATE_DEFAULT;
 182         s->info->handle_reset(s);
 183         return 0;
 184     }
 185
 186     /* Rest of the PIDs must match our address */
 187     if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
 188         return USB_RET_NODEV;
 189
 190     switch (p->pid) {
 191     case USB_TOKEN_SETUP:
 192         return do_token_setup(s, p);
 193
 194     case USB_TOKEN_IN:
 195         return do_token_in(s, p);
 196
 197     case USB_TOKEN_OUT:
 198         return do_token_out(s, p);
 199
 200     default:
 201         return USB_RET_STALL;
 202     }
 203 }
 204
 205 /* XXX: fix overflow */
 206 int set_usb_string(uint8_t *buf, const char *str)
 207 {
 208     int len, i;
 209     uint8_t *q;
 210
 211     q = buf;
 212     len = strlen(str);
 213     *q++ = 2 * len + 2;
 214     *q++ = 3;
 215     for(i = 0; i < len; i++) {
 216         *q++ = str[i];
 217         *q++ = 0;
 218     }
 219     return q - buf;
 220 }
 221
 222 /* Send an internal message to a USB device.  */
 223 void usb_send_msg(USBDevice *dev, int msg)
 224 {
 225     USBPacket p;
 226     memset(&p, 0, sizeof(p));
 227     p.pid = msg;
 228     dev->info->handle_packet(dev, &p);
 229
 230     /* This _must_ be synchronous */
 231 }