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     if (dev != NULL) {
  32         /* attach */
  33         if (port->dev) {
  34             usb_attach(port, NULL);
  35         }
  36         dev->port = port;
  37         port->dev = dev;
  38         port->ops->attach(port);
  39         usb_send_msg(dev, USB_MSG_ATTACH);
  40     } else {
  41         /* detach */
  42         dev = port->dev;
  43         port->ops->detach(port);
  44         if (dev) {
  45             usb_send_msg(dev, USB_MSG_DETACH);
  46             dev->port = NULL;
  47             port->dev = NULL;
  48         }
  49     }
  50 }
  51
  52 void usb_wakeup(USBDevice *dev)
  53 {
  54     if (dev->remote_wakeup && dev->port && dev->port->ops->wakeup) {
  55         dev->port->ops->wakeup(dev);
  56     }
  57 }
  58
  59 /**********************/
  60
  61 /* generic USB device helpers (you are not forced to use them when
  62    writing your USB device driver, but they help handling the
  63    protocol)
  64 */
  65
  66 #define SETUP_STATE_IDLE 0
  67 #define SETUP_STATE_DATA 1
  68 #define SETUP_STATE_ACK  2
  69
  70 static int do_token_setup(USBDevice *s, USBPacket *p)
  71 {
  72     int request, value, index;
  73     int ret = 0;
  74
  75     if (p->len != 8)
  76         return USB_RET_STALL;
  77
  78     memcpy(s->setup_buf, p->data, 8);
  79     s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
  80     s->setup_index = 0;
  81
  82     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
  83     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
  84     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
  85
  86     if (s->setup_buf[0] & USB_DIR_IN) {
  87         ret = s->info->handle_control(s, request, value, index,
  88                                       s->setup_len, s->data_buf);
  89         if (ret < 0)
  90             return ret;
  91
  92         if (ret < s->setup_len)
  93             s->setup_len = ret;
  94         s->setup_state = SETUP_STATE_DATA;
  95     } else {
  96         if (s->setup_len == 0)
  97             s->setup_state = SETUP_STATE_ACK;
  98         else
  99             s->setup_state = SETUP_STATE_DATA;
 100     }
 101
 102     return ret;
 103 }
 104
 105 static int do_token_in(USBDevice *s, USBPacket *p)
 106 {
 107     int request, value, index;
 108     int ret = 0;
 109
 110     if (p->devep != 0)
 111         return s->info->handle_data(s, p);
 112
 113     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
 114     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
 115     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
 116
 117     switch(s->setup_state) {
 118     case SETUP_STATE_ACK:
 119         if (!(s->setup_buf[0] & USB_DIR_IN)) {
 120             s->setup_state = SETUP_STATE_IDLE;
 121             ret = s->info->handle_control(s, request, value, index,
 122                                           s->setup_len, s->data_buf);
 123             if (ret > 0)
 124                 return 0;
 125             return ret;
 126         }
 127
 128         /* return 0 byte */
 129         return 0;
 130
 131     case SETUP_STATE_DATA:
 132         if (s->setup_buf[0] & USB_DIR_IN) {
 133             int len = s->setup_len - s->setup_index;
 134             if (len > p->len)
 135                 len = p->len;
 136             memcpy(p->data, s->data_buf + s->setup_index, len);
 137             s->setup_index += len;
 138             if (s->setup_index >= s->setup_len)
 139                 s->setup_state = SETUP_STATE_ACK;
 140             return len;
 141         }
 142
 143         s->setup_state = SETUP_STATE_IDLE;
 144         return USB_RET_STALL;
 145
 146     default:
 147         return USB_RET_STALL;
 148     }
 149 }
 150
 151 static int do_token_out(USBDevice *s, USBPacket *p)
 152 {
 153     if (p->devep != 0)
 154         return s->info->handle_data(s, p);
 155
 156     switch(s->setup_state) {
 157     case SETUP_STATE_ACK:
 158         if (s->setup_buf[0] & USB_DIR_IN) {
 159             s->setup_state = SETUP_STATE_IDLE;
 160             /* transfer OK */
 161         } else {
 162             /* ignore additional output */
 163         }
 164         return 0;
 165
 166     case SETUP_STATE_DATA:
 167         if (!(s->setup_buf[0] & USB_DIR_IN)) {
 168             int len = s->setup_len - s->setup_index;
 169             if (len > p->len)
 170                 len = p->len;
 171             memcpy(s->data_buf + s->setup_index, p->data, len);
 172             s->setup_index += len;
 173             if (s->setup_index >= s->setup_len)
 174                 s->setup_state = SETUP_STATE_ACK;
 175             return len;
 176         }
 177
 178         s->setup_state = SETUP_STATE_IDLE;
 179         return USB_RET_STALL;
 180
 181     default:
 182         return USB_RET_STALL;
 183     }
 184 }
 185
 186 /*
 187  * Generic packet handler.
 188  * Called by the HC (host controller).
 189  *
 190  * Returns length of the transaction or one of the USB_RET_XXX codes.
 191  */
 192 int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
 193 {
 194     switch(p->pid) {
 195     case USB_MSG_ATTACH:
 196         s->state = USB_STATE_ATTACHED;
 197         return 0;
 198
 199     case USB_MSG_DETACH:
 200         s->state = USB_STATE_NOTATTACHED;
 201         return 0;
 202
 203     case USB_MSG_RESET:
 204         s->remote_wakeup = 0;
 205         s->addr = 0;
 206         s->state = USB_STATE_DEFAULT;
 207         s->info->handle_reset(s);
 208         return 0;
 209     }
 210
 211     /* Rest of the PIDs must match our address */
 212     if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
 213         return USB_RET_NODEV;
 214
 215     switch (p->pid) {
 216     case USB_TOKEN_SETUP:
 217         return do_token_setup(s, p);
 218
 219     case USB_TOKEN_IN:
 220         return do_token_in(s, p);
 221
 222     case USB_TOKEN_OUT:
 223         return do_token_out(s, p);
 224
 225     default:
 226         return USB_RET_STALL;
 227     }
 228 }
 229
 230 /* XXX: fix overflow */
 231 int set_usb_string(uint8_t *buf, const char *str)
 232 {
 233     int len, i;
 234     uint8_t *q;
 235
 236     q = buf;
 237     len = strlen(str);
 238     *q++ = 2 * len + 2;
 239     *q++ = 3;
 240     for(i = 0; i < len; i++) {
 241         *q++ = str[i];
 242         *q++ = 0;
 243     }
 244     return q - buf;
 245 }
 246
 247 /* Send an internal message to a USB device.  */
 248 void usb_send_msg(USBDevice *dev, int msg)
 249 {
 250     USBPacket p;
 251     memset(&p, 0, sizeof(p));
 252     p.pid = msg;
 253     dev->info->handle_packet(dev, &p);
 254
 255     /* This _must_ be synchronous */
 256 }