xref: /qemu/hw/usb/core.c (revision 4f4321c11ff6e98583846bfd6f0e81954924b003)
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 #include "iov.h"
29 
30 void usb_attach(USBPort *port, USBDevice *dev)
31 {
32     if (dev != NULL) {
33         /* attach */
34         if (port->dev) {
35             usb_attach(port, NULL);
36         }
37         dev->port = port;
38         port->dev = dev;
39         port->ops->attach(port);
40         usb_send_msg(dev, USB_MSG_ATTACH);
41     } else {
42         /* detach */
43         dev = port->dev;
44         assert(dev);
45         port->ops->detach(port);
46         usb_send_msg(dev, USB_MSG_DETACH);
47         dev->port = NULL;
48         port->dev = NULL;
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->port);
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_SETUP 1
68 #define SETUP_STATE_DATA  2
69 #define SETUP_STATE_ACK   3
70 
71 static int do_token_setup(USBDevice *s, USBPacket *p)
72 {
73     int request, value, index;
74     int ret = 0;
75 
76     if (p->iov.size != 8) {
77         return USB_RET_STALL;
78     }
79 
80     usb_packet_copy(p, s->setup_buf, p->iov.size);
81     s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
82     s->setup_index = 0;
83 
84     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
85     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
86     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
87 
88     if (s->setup_buf[0] & USB_DIR_IN) {
89         ret = s->info->handle_control(s, p, request, value, index,
90                                       s->setup_len, s->data_buf);
91         if (ret == USB_RET_ASYNC) {
92              s->setup_state = SETUP_STATE_SETUP;
93              return USB_RET_ASYNC;
94         }
95         if (ret < 0)
96             return ret;
97 
98         if (ret < s->setup_len)
99             s->setup_len = ret;
100         s->setup_state = SETUP_STATE_DATA;
101     } else {
102         if (s->setup_len > sizeof(s->data_buf)) {
103             fprintf(stderr,
104                 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
105                 s->setup_len, sizeof(s->data_buf));
106             return USB_RET_STALL;
107         }
108         if (s->setup_len == 0)
109             s->setup_state = SETUP_STATE_ACK;
110         else
111             s->setup_state = SETUP_STATE_DATA;
112     }
113 
114     return ret;
115 }
116 
117 static int do_token_in(USBDevice *s, USBPacket *p)
118 {
119     int request, value, index;
120     int ret = 0;
121 
122     if (p->devep != 0)
123         return s->info->handle_data(s, p);
124 
125     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
126     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
127     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
128 
129     switch(s->setup_state) {
130     case SETUP_STATE_ACK:
131         if (!(s->setup_buf[0] & USB_DIR_IN)) {
132             ret = s->info->handle_control(s, p, request, value, index,
133                                           s->setup_len, s->data_buf);
134             if (ret == USB_RET_ASYNC) {
135                 return USB_RET_ASYNC;
136             }
137             s->setup_state = SETUP_STATE_IDLE;
138             if (ret > 0)
139                 return 0;
140             return ret;
141         }
142 
143         /* return 0 byte */
144         return 0;
145 
146     case SETUP_STATE_DATA:
147         if (s->setup_buf[0] & USB_DIR_IN) {
148             int len = s->setup_len - s->setup_index;
149             if (len > p->iov.size) {
150                 len = p->iov.size;
151             }
152             usb_packet_copy(p, s->data_buf + s->setup_index, len);
153             s->setup_index += len;
154             if (s->setup_index >= s->setup_len)
155                 s->setup_state = SETUP_STATE_ACK;
156             return len;
157         }
158 
159         s->setup_state = SETUP_STATE_IDLE;
160         return USB_RET_STALL;
161 
162     default:
163         return USB_RET_STALL;
164     }
165 }
166 
167 static int do_token_out(USBDevice *s, USBPacket *p)
168 {
169     if (p->devep != 0)
170         return s->info->handle_data(s, p);
171 
172     switch(s->setup_state) {
173     case SETUP_STATE_ACK:
174         if (s->setup_buf[0] & USB_DIR_IN) {
175             s->setup_state = SETUP_STATE_IDLE;
176             /* transfer OK */
177         } else {
178             /* ignore additional output */
179         }
180         return 0;
181 
182     case SETUP_STATE_DATA:
183         if (!(s->setup_buf[0] & USB_DIR_IN)) {
184             int len = s->setup_len - s->setup_index;
185             if (len > p->iov.size) {
186                 len = p->iov.size;
187             }
188             usb_packet_copy(p, s->data_buf + s->setup_index, len);
189             s->setup_index += len;
190             if (s->setup_index >= s->setup_len)
191                 s->setup_state = SETUP_STATE_ACK;
192             return len;
193         }
194 
195         s->setup_state = SETUP_STATE_IDLE;
196         return USB_RET_STALL;
197 
198     default:
199         return USB_RET_STALL;
200     }
201 }
202 
203 /*
204  * Generic packet handler.
205  * Called by the HC (host controller).
206  *
207  * Returns length of the transaction or one of the USB_RET_XXX codes.
208  */
209 int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
210 {
211     switch(p->pid) {
212     case USB_MSG_ATTACH:
213         s->state = USB_STATE_ATTACHED;
214         if (s->info->handle_attach) {
215             s->info->handle_attach(s);
216         }
217         return 0;
218 
219     case USB_MSG_DETACH:
220         s->state = USB_STATE_NOTATTACHED;
221         return 0;
222 
223     case USB_MSG_RESET:
224         s->remote_wakeup = 0;
225         s->addr = 0;
226         s->state = USB_STATE_DEFAULT;
227         if (s->info->handle_reset) {
228             s->info->handle_reset(s);
229         }
230         return 0;
231     }
232 
233     /* Rest of the PIDs must match our address */
234     if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
235         return USB_RET_NODEV;
236 
237     switch (p->pid) {
238     case USB_TOKEN_SETUP:
239         return do_token_setup(s, p);
240 
241     case USB_TOKEN_IN:
242         return do_token_in(s, p);
243 
244     case USB_TOKEN_OUT:
245         return do_token_out(s, p);
246 
247     default:
248         return USB_RET_STALL;
249     }
250 }
251 
252 /* ctrl complete function for devices which use usb_generic_handle_packet and
253    may return USB_RET_ASYNC from their handle_control callback. Device code
254    which does this *must* call this function instead of the normal
255    usb_packet_complete to complete their async control packets. */
256 void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p)
257 {
258     if (p->result < 0) {
259         s->setup_state = SETUP_STATE_IDLE;
260     }
261 
262     switch (s->setup_state) {
263     case SETUP_STATE_SETUP:
264         if (p->result < s->setup_len) {
265             s->setup_len = p->result;
266         }
267         s->setup_state = SETUP_STATE_DATA;
268         p->result = 8;
269         break;
270 
271     case SETUP_STATE_ACK:
272         s->setup_state = SETUP_STATE_IDLE;
273         p->result = 0;
274         break;
275 
276     default:
277         break;
278     }
279     usb_packet_complete(s, p);
280 }
281 
282 /* XXX: fix overflow */
283 int set_usb_string(uint8_t *buf, const char *str)
284 {
285     int len, i;
286     uint8_t *q;
287 
288     q = buf;
289     len = strlen(str);
290     *q++ = 2 * len + 2;
291     *q++ = 3;
292     for(i = 0; i < len; i++) {
293         *q++ = str[i];
294         *q++ = 0;
295     }
296     return q - buf;
297 }
298 
299 /* Send an internal message to a USB device.  */
300 void usb_send_msg(USBDevice *dev, int msg)
301 {
302     USBPacket p;
303     int ret;
304 
305     memset(&p, 0, sizeof(p));
306     p.pid = msg;
307     ret = usb_handle_packet(dev, &p);
308     /* This _must_ be synchronous */
309     assert(ret != USB_RET_ASYNC);
310 }
311 
312 /* Hand over a packet to a device for processing.  Return value
313    USB_RET_ASYNC indicates the processing isn't finished yet, the
314    driver will call usb_packet_complete() when done processing it. */
315 int usb_handle_packet(USBDevice *dev, USBPacket *p)
316 {
317     int ret;
318 
319     assert(p->owner == NULL);
320     ret = dev->info->handle_packet(dev, p);
321     if (ret == USB_RET_ASYNC) {
322         if (p->owner == NULL) {
323             p->owner = dev;
324         } else {
325             /* We'll end up here when usb_handle_packet is called
326              * recursively due to a hub being in the chain.  Nothing
327              * to do.  Leave p->owner pointing to the device, not the
328              * hub. */;
329         }
330     }
331     return ret;
332 }
333 
334 /* Notify the controller that an async packet is complete.  This should only
335    be called for packets previously deferred by returning USB_RET_ASYNC from
336    handle_packet. */
337 void usb_packet_complete(USBDevice *dev, USBPacket *p)
338 {
339     /* Note: p->owner != dev is possible in case dev is a hub */
340     assert(p->owner != NULL);
341     dev->port->ops->complete(dev->port, p);
342     p->owner = NULL;
343 }
344 
345 /* Cancel an active packet.  The packed must have been deferred by
346    returning USB_RET_ASYNC from handle_packet, and not yet
347    completed.  */
348 void usb_cancel_packet(USBPacket * p)
349 {
350     assert(p->owner != NULL);
351     p->owner->info->cancel_packet(p->owner, p);
352     p->owner = NULL;
353 }
354 
355 
356 void usb_packet_init(USBPacket *p)
357 {
358     qemu_iovec_init(&p->iov, 1);
359 }
360 
361 void usb_packet_setup(USBPacket *p, int pid, uint8_t addr, uint8_t ep)
362 {
363     p->pid = pid;
364     p->devaddr = addr;
365     p->devep = ep;
366     p->result = 0;
367     qemu_iovec_reset(&p->iov);
368 }
369 
370 void usb_packet_addbuf(USBPacket *p, void *ptr, size_t len)
371 {
372     qemu_iovec_add(&p->iov, ptr, len);
373 }
374 
375 void usb_packet_copy(USBPacket *p, void *ptr, size_t bytes)
376 {
377     assert(p->result >= 0);
378     assert(p->result + bytes <= p->iov.size);
379     switch (p->pid) {
380     case USB_TOKEN_SETUP:
381     case USB_TOKEN_OUT:
382         iov_to_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
383         break;
384     case USB_TOKEN_IN:
385         iov_from_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
386         break;
387     default:
388         fprintf(stderr, "%s: invalid pid: %x\n", __func__, p->pid);
389         abort();
390     }
391     p->result += bytes;
392 }
393 
394 void usb_packet_skip(USBPacket *p, size_t bytes)
395 {
396     assert(p->result >= 0);
397     assert(p->result + bytes <= p->iov.size);
398     if (p->pid == USB_TOKEN_IN) {
399         iov_clear(p->iov.iov, p->iov.niov, p->result, bytes);
400     }
401     p->result += bytes;
402 }
403 
404 void usb_packet_cleanup(USBPacket *p)
405 {
406     qemu_iovec_destroy(&p->iov);
407 }
408