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      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->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->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->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->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->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->handle_packet(dev, &p);
    229 
    230     /* This _must_ be synchronous */
    231 }
    232