xref: /qemu/hw/usb/core.c (revision 618c169b577db64ac6589ad48825d2e11760d1a6)
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 /**********************/
53 
54 /* generic USB device helpers (you are not forced to use them when
55    writing your USB device driver, but they help handling the
56    protocol)
57 */
58 
59 #define SETUP_STATE_IDLE 0
60 #define SETUP_STATE_DATA 1
61 #define SETUP_STATE_ACK  2
62 
63 static int do_token_setup(USBDevice *s, USBPacket *p)
64 {
65     int request, value, index;
66     int ret = 0;
67 
68     if (p->len != 8)
69         return USB_RET_STALL;
70 
71     memcpy(s->setup_buf, p->data, 8);
72     s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
73     s->setup_index = 0;
74 
75     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
76     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
77     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
78 
79     if (s->setup_buf[0] & USB_DIR_IN) {
80         ret = s->info->handle_control(s, request, value, index,
81                                       s->setup_len, s->data_buf);
82         if (ret < 0)
83             return ret;
84 
85         if (ret < s->setup_len)
86             s->setup_len = ret;
87         s->setup_state = SETUP_STATE_DATA;
88     } else {
89         if (s->setup_len == 0)
90             s->setup_state = SETUP_STATE_ACK;
91         else
92             s->setup_state = SETUP_STATE_DATA;
93     }
94 
95     return ret;
96 }
97 
98 static int do_token_in(USBDevice *s, USBPacket *p)
99 {
100     int request, value, index;
101     int ret = 0;
102 
103     if (p->devep != 0)
104         return s->info->handle_data(s, p);
105 
106     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
107     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
108     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
109 
110     switch(s->setup_state) {
111     case SETUP_STATE_ACK:
112         if (!(s->setup_buf[0] & USB_DIR_IN)) {
113             s->setup_state = SETUP_STATE_IDLE;
114             ret = s->info->handle_control(s, request, value, index,
115                                           s->setup_len, s->data_buf);
116             if (ret > 0)
117                 return 0;
118             return ret;
119         }
120 
121         /* return 0 byte */
122         return 0;
123 
124     case SETUP_STATE_DATA:
125         if (s->setup_buf[0] & USB_DIR_IN) {
126             int len = s->setup_len - s->setup_index;
127             if (len > p->len)
128                 len = p->len;
129             memcpy(p->data, s->data_buf + s->setup_index, len);
130             s->setup_index += len;
131             if (s->setup_index >= s->setup_len)
132                 s->setup_state = SETUP_STATE_ACK;
133             return len;
134         }
135 
136         s->setup_state = SETUP_STATE_IDLE;
137         return USB_RET_STALL;
138 
139     default:
140         return USB_RET_STALL;
141     }
142 }
143 
144 static int do_token_out(USBDevice *s, USBPacket *p)
145 {
146     if (p->devep != 0)
147         return s->info->handle_data(s, p);
148 
149     switch(s->setup_state) {
150     case SETUP_STATE_ACK:
151         if (s->setup_buf[0] & USB_DIR_IN) {
152             s->setup_state = SETUP_STATE_IDLE;
153             /* transfer OK */
154         } else {
155             /* ignore additional output */
156         }
157         return 0;
158 
159     case SETUP_STATE_DATA:
160         if (!(s->setup_buf[0] & USB_DIR_IN)) {
161             int len = s->setup_len - s->setup_index;
162             if (len > p->len)
163                 len = p->len;
164             memcpy(s->data_buf + s->setup_index, p->data, len);
165             s->setup_index += len;
166             if (s->setup_index >= s->setup_len)
167                 s->setup_state = SETUP_STATE_ACK;
168             return len;
169         }
170 
171         s->setup_state = SETUP_STATE_IDLE;
172         return USB_RET_STALL;
173 
174     default:
175         return USB_RET_STALL;
176     }
177 }
178 
179 /*
180  * Generic packet handler.
181  * Called by the HC (host controller).
182  *
183  * Returns length of the transaction or one of the USB_RET_XXX codes.
184  */
185 int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
186 {
187     switch(p->pid) {
188     case USB_MSG_ATTACH:
189         s->state = USB_STATE_ATTACHED;
190         return 0;
191 
192     case USB_MSG_DETACH:
193         s->state = USB_STATE_NOTATTACHED;
194         return 0;
195 
196     case USB_MSG_RESET:
197         s->remote_wakeup = 0;
198         s->addr = 0;
199         s->state = USB_STATE_DEFAULT;
200         s->info->handle_reset(s);
201         return 0;
202     }
203 
204     /* Rest of the PIDs must match our address */
205     if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
206         return USB_RET_NODEV;
207 
208     switch (p->pid) {
209     case USB_TOKEN_SETUP:
210         return do_token_setup(s, p);
211 
212     case USB_TOKEN_IN:
213         return do_token_in(s, p);
214 
215     case USB_TOKEN_OUT:
216         return do_token_out(s, p);
217 
218     default:
219         return USB_RET_STALL;
220     }
221 }
222 
223 /* XXX: fix overflow */
224 int set_usb_string(uint8_t *buf, const char *str)
225 {
226     int len, i;
227     uint8_t *q;
228 
229     q = buf;
230     len = strlen(str);
231     *q++ = 2 * len + 2;
232     *q++ = 3;
233     for(i = 0; i < len; i++) {
234         *q++ = str[i];
235         *q++ = 0;
236     }
237     return q - buf;
238 }
239 
240 /* Send an internal message to a USB device.  */
241 void usb_send_msg(USBDevice *dev, int msg)
242 {
243     USBPacket p;
244     memset(&p, 0, sizeof(p));
245     p.pid = msg;
246     dev->info->handle_packet(dev, &p);
247 
248     /* This _must_ be synchronous */
249 }
250