usbhost.c revision e533c5f1005e8913f577d2aeac5a26f88f55a249 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17// #define DEBUG 1
18#if DEBUG
19
20#ifdef USE_LIBLOG
21#define LOG_TAG "usbhost"
22#include "utils/Log.h"
23#define D LOGD
24#else
25#define D printf
26#endif
27
28#else
29#define D(...)
30#endif
31
32#include <stdio.h>
33#include <stdlib.h>
34#include <unistd.h>
35#include <string.h>
36
37#include <sys/ioctl.h>
38#include <sys/types.h>
39#include <sys/time.h>
40#include <sys/inotify.h>
41#include <dirent.h>
42#include <fcntl.h>
43#include <errno.h>
44#include <ctype.h>
45#include <pthread.h>
46
47#include <linux/usbdevice_fs.h>
48#include <asm/byteorder.h>
49
50#include "usbhost/usbhost.h"
51
52#define USB_FS_DIR "/dev/bus/usb"
53#define USB_FS_ID_SCANNER   "/dev/bus/usb/%d/%d"
54#define USB_FS_ID_FORMAT    "/dev/bus/usb/%03d/%03d"
55
56
57struct usb_host_context {
58    int fd;
59};
60
61struct usb_device {
62    char dev_name[64];
63    unsigned char desc[256];
64    int desc_length;
65    int fd;
66    int writeable;
67};
68
69static inline int badname(const char *name)
70{
71    while(*name) {
72        if(!isdigit(*name++)) return 1;
73    }
74    return 0;
75}
76
77/* returns true if one of the callbacks indicates we are done */
78static int find_existing_devices(usb_device_added_cb added_cb,
79                                  usb_device_removed_cb removed_cb,
80                                  void *client_data)
81{
82    char busname[32], devname[32];
83    DIR *busdir , *devdir ;
84    struct dirent *de;
85    int done = 0;
86
87    busdir = opendir(USB_FS_DIR);
88    if(busdir == 0) return 1;
89
90    while ((de = readdir(busdir)) != 0 && !done) {
91        if(badname(de->d_name)) continue;
92
93        snprintf(busname, sizeof busname, "%s/%s", USB_FS_DIR, de->d_name);
94        devdir = opendir(busname);
95        if(devdir == 0) continue;
96
97        while ((de = readdir(devdir)) && !done) {
98            if(badname(de->d_name)) continue;
99
100            snprintf(devname, sizeof devname, "%s/%s", busname, de->d_name);
101            done = added_cb(devname, client_data);
102        } // end of devdir while
103        closedir(devdir);
104    } //end of busdir while
105    closedir(busdir);
106
107    return done;
108}
109
110struct usb_host_context *usb_host_init()
111{
112    struct usb_host_context *context = calloc(1, sizeof(struct usb_host_context));
113    if (!context) {
114        fprintf(stderr, "out of memory in usb_host_context\n");
115        return NULL;
116    }
117    context->fd = inotify_init();
118    if (context->fd < 0) {
119        fprintf(stderr, "inotify_init failed\n");
120        free(context);
121        return NULL;
122    }
123    return context;
124}
125
126void usb_host_cleanup(struct usb_host_context *context)
127{
128    close(context->fd);
129    free(context);
130}
131
132void usb_host_run(struct usb_host_context *context,
133                  usb_device_added_cb added_cb,
134                  usb_device_removed_cb removed_cb,
135                  usb_discovery_done_cb discovery_done_cb,
136                  void *client_data)
137{
138    struct inotify_event* event;
139    char event_buf[512];
140    char path[100];
141    int i, ret, done = 0;
142    int wd, wds[10];
143    int wd_count = sizeof(wds) / sizeof(wds[0]);
144
145    D("Created device discovery thread\n");
146
147    /* watch for files added and deleted within USB_FS_DIR */
148    memset(wds, 0, sizeof(wds));
149    /* watch the root for new subdirectories */
150    wds[0] = inotify_add_watch(context->fd, USB_FS_DIR, IN_CREATE | IN_DELETE);
151    if (wds[0] < 0) {
152        fprintf(stderr, "inotify_add_watch failed\n");
153        if (discovery_done_cb)
154            discovery_done_cb(client_data);
155        return;
156    }
157
158    /* watch existing subdirectories of USB_FS_DIR */
159    for (i = 1; i < wd_count; i++) {
160        snprintf(path, sizeof(path), "%s/%03d", USB_FS_DIR, i);
161        ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
162        if (ret > 0)
163            wds[i] = ret;
164    }
165
166    /* check for existing devices first, after we have inotify set up */
167    done = find_existing_devices(added_cb, removed_cb, client_data);
168    if (discovery_done_cb)
169        done |= discovery_done_cb(client_data);
170
171    while (!done) {
172        ret = read(context->fd, event_buf, sizeof(event_buf));
173        if (ret >= (int)sizeof(struct inotify_event)) {
174            event = (struct inotify_event *)event_buf;
175            wd = event->wd;
176            if (wd == wds[0]) {
177                i = atoi(event->name);
178                snprintf(path, sizeof(path), "%s/%s", USB_FS_DIR, event->name);
179                D("new subdirectory %s: index: %d\n", path, i);
180                if (i > 0 && i < wd_count) {
181                ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
182                if (ret > 0)
183                    wds[i] = ret;
184                }
185            } else {
186                for (i = 1; i < wd_count && !done; i++) {
187                    if (wd == wds[i]) {
188                        snprintf(path, sizeof(path), "%s/%03d/%s", USB_FS_DIR, i, event->name);
189                        if (event->mask == IN_CREATE) {
190                            D("new device %s\n", path);
191                            done = added_cb(path, client_data);
192                        } else if (event->mask == IN_DELETE) {
193                            D("gone device %s\n", path);
194                            done = removed_cb(path, client_data);
195                        }
196                    }
197                }
198            }
199        }
200    }
201}
202
203struct usb_device *usb_device_open(const char *dev_name)
204{
205    int fd, did_retry = 0, writeable = 1;
206
207retry:
208    fd = open(dev_name, O_RDWR);
209    if (fd < 0) {
210        /* if we fail, see if have read-only access */
211        fd = open(dev_name, O_RDONLY);
212        D("usb_device_open open returned %d errno %d\n", fd, errno);
213        if (fd < 0 && (errno == EACCES || errno == ENOENT) && !did_retry) {
214            /* work around race condition between inotify and permissions management */
215            sleep(1);
216            did_retry = 1;
217            goto retry;
218        }
219
220        if (fd < 0)
221            return NULL;
222        writeable = 0;
223        D("[ usb open read-only %s fd = %d]\n", dev_name, fd);
224    }
225
226    struct usb_device* result = usb_device_new(dev_name, fd);
227    if (result)
228        result->writeable = writeable;
229    return result;
230}
231
232void usb_device_close(struct usb_device *device)
233{
234    close(device->fd);
235    free(device);
236}
237
238struct usb_device *usb_device_new(const char *dev_name, int fd)
239{
240    struct usb_device *device = calloc(1, sizeof(struct usb_device));
241    int length;
242
243    if (lseek(fd, 0, SEEK_SET) != 0)
244        goto failed;
245    length = read(fd, device->desc, sizeof(device->desc));
246    D("usb_device_new read returned %d errno %d\n", fd, errno);
247    if (length < 0)
248        goto failed;
249
250    strncpy(device->dev_name, dev_name, sizeof(device->dev_name) - 1);
251    device->fd = fd;
252    device->desc_length = length;
253    // assume we are writeable, since usb_device_get_fd will only return writeable fds
254    device->writeable = 1;
255    return device;
256
257failed:
258    close(fd);
259    free(device);
260    return NULL;
261}
262
263static int usb_device_reopen_writeable(struct usb_device *device)
264{
265    if (device->writeable)
266        return 1;
267
268    int fd = open(device->dev_name, O_RDWR);
269    if (fd >= 0) {
270        close(device->fd);
271        device->fd = fd;
272        device->writeable = 1;
273        return 1;
274    }
275    D("usb_device_reopen_writeable failed errno %d\n", errno);
276    return 0;
277}
278
279int usb_device_get_fd(struct usb_device *device)
280{
281    if (!usb_device_reopen_writeable(device))
282        return -1;
283    return device->fd;
284}
285
286const char* usb_device_get_name(struct usb_device *device)
287{
288    return device->dev_name;
289}
290
291int usb_device_get_unique_id(struct usb_device *device)
292{
293    int bus = 0, dev = 0;
294    sscanf(device->dev_name, USB_FS_ID_SCANNER, &bus, &dev);
295    return bus * 1000 + dev;
296}
297
298int usb_device_get_unique_id_from_name(const char* name)
299{
300    int bus = 0, dev = 0;
301    sscanf(name, USB_FS_ID_SCANNER, &bus, &dev);
302    return bus * 1000 + dev;
303}
304
305char* usb_device_get_name_from_unique_id(int id)
306{
307    int bus = id / 1000;
308    int dev = id % 1000;
309    char* result = (char *)calloc(1, strlen(USB_FS_ID_FORMAT));
310    snprintf(result, strlen(USB_FS_ID_FORMAT) - 1, USB_FS_ID_FORMAT, bus, dev);
311    return result;
312}
313
314uint16_t usb_device_get_vendor_id(struct usb_device *device)
315{
316    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
317    return __le16_to_cpu(desc->idVendor);
318}
319
320uint16_t usb_device_get_product_id(struct usb_device *device)
321{
322    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
323    return __le16_to_cpu(desc->idProduct);
324}
325
326const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device)
327{
328    return (struct usb_device_descriptor*)device->desc;
329}
330
331int usb_device_send_control(struct usb_device *device,
332                            int requestType,
333                            int request,
334                            int value,
335                            int index,
336                            int length,
337                            void* buffer)
338{
339    struct usbdevfs_ctrltransfer  ctrl;
340
341    // this usually requires read/write permission
342    if (!usb_device_reopen_writeable(device))
343        return -1;
344
345    memset(&ctrl, 0, sizeof(ctrl));
346    ctrl.bRequestType = requestType;
347    ctrl.bRequest = request;
348    ctrl.wValue = value;
349    ctrl.wIndex = index;
350    ctrl.wLength = length;
351    ctrl.data = buffer;
352    return ioctl(device->fd, USBDEVFS_CONTROL, &ctrl);
353}
354
355char* usb_device_get_string(struct usb_device *device, int id)
356{
357    char string[256];
358    __u16 buffer[128];
359    __u16 languages[128];
360    int i, result;
361    int languageCount = 0;
362
363    string[0] = 0;
364    memset(languages, 0, sizeof(languages));
365
366    // read list of supported languages
367    result = usb_device_send_control(device,
368            USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
369            (USB_DT_STRING << 8) | 0, 0, sizeof(languages), languages);
370    if (result > 0)
371        languageCount = (result - 2) / 2;
372
373    for (i = 1; i <= languageCount; i++) {
374        memset(buffer, 0, sizeof(buffer));
375
376        result = usb_device_send_control(device,
377                USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
378                (USB_DT_STRING << 8) | id, languages[i], sizeof(buffer), buffer);
379        if (result > 0) {
380            int i;
381            // skip first word, and copy the rest to the string, changing shorts to bytes.
382            result /= 2;
383            for (i = 1; i < result; i++)
384                string[i - 1] = buffer[i];
385            string[i - 1] = 0;
386            return strdup(string);
387        }
388    }
389
390    return NULL;
391}
392
393char* usb_device_get_manufacturer_name(struct usb_device *device)
394{
395    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
396
397    if (desc->iManufacturer)
398        return usb_device_get_string(device, desc->iManufacturer);
399    else
400        return NULL;
401}
402
403char* usb_device_get_product_name(struct usb_device *device)
404{
405    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
406
407    if (desc->iProduct)
408        return usb_device_get_string(device, desc->iProduct);
409    else
410        return NULL;
411}
412
413char* usb_device_get_serial(struct usb_device *device)
414{
415    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
416
417    if (desc->iSerialNumber)
418        return usb_device_get_string(device, desc->iSerialNumber);
419    else
420        return NULL;
421}
422
423int usb_device_is_writeable(struct usb_device *device)
424{
425    return device->writeable;
426}
427
428void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter)
429{
430    iter->config = device->desc;
431    iter->config_end = device->desc + device->desc_length;
432    iter->curr_desc = device->desc;
433}
434
435struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter)
436{
437    struct usb_descriptor_header* next;
438    if (iter->curr_desc >= iter->config_end)
439        return NULL;
440    next = (struct usb_descriptor_header*)iter->curr_desc;
441    iter->curr_desc += next->bLength;
442    return next;
443}
444
445int usb_device_claim_interface(struct usb_device *device, unsigned int interface)
446{
447    return ioctl(device->fd, USBDEVFS_CLAIMINTERFACE, &interface);
448}
449
450int usb_device_release_interface(struct usb_device *device, unsigned int interface)
451{
452    return ioctl(device->fd, USBDEVFS_RELEASEINTERFACE, &interface);
453}
454
455struct usb_request *usb_request_new(struct usb_device *dev,
456        const struct usb_endpoint_descriptor *ep_desc)
457{
458    struct usbdevfs_urb *urb = calloc(1, sizeof(struct usbdevfs_urb));
459    if (!urb)
460        return NULL;
461
462    if ((ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
463        urb->type = USBDEVFS_URB_TYPE_BULK;
464    else if ((ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)
465        urb->type = USBDEVFS_URB_TYPE_INTERRUPT;
466    else {
467        D("Unsupported endpoint type %d", ep_desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
468        free(urb);
469        return NULL;
470    }
471    urb->endpoint = ep_desc->bEndpointAddress;
472
473    struct usb_request *req = calloc(1, sizeof(struct usb_request));
474    if (!req) {
475        free(urb);
476        return NULL;
477    }
478
479    req->dev = dev;
480    req->max_packet_size = __le16_to_cpu(ep_desc->wMaxPacketSize);
481    req->private_data = urb;
482    urb->usercontext = req;
483
484    return req;
485}
486
487void usb_request_free(struct usb_request *req)
488{
489    free(req->private_data);
490    free(req);
491}
492
493int usb_request_queue(struct usb_request *req)
494{
495    struct usbdevfs_urb *urb = (struct usbdevfs_urb*)req->private_data;
496    int res;
497
498    urb->status = -1;
499    urb->buffer = req->buffer;
500    urb->buffer_length = req->buffer_length;
501
502    do {
503        res = ioctl(req->dev->fd, USBDEVFS_SUBMITURB, urb);
504    } while((res < 0) && (errno == EINTR));
505
506    return res;
507}
508
509struct usb_request *usb_request_wait(struct usb_device *dev)
510{
511    struct usbdevfs_urb *urb = NULL;
512    struct usb_request *req = NULL;
513    int res;
514
515    while (1) {
516        int res = ioctl(dev->fd, USBDEVFS_REAPURB, &urb);
517        D("USBDEVFS_REAPURB returned %d\n", res);
518        if (res < 0) {
519            if(errno == EINTR) {
520                continue;
521            }
522            D("[ reap urb - error ]\n");
523            return NULL;
524        } else {
525            D("[ urb @%p status = %d, actual = %d ]\n",
526                urb, urb->status, urb->actual_length);
527            req = (struct usb_request*)urb->usercontext;
528            req->actual_length = urb->actual_length;
529        }
530        break;
531    }
532    return req;
533}
534
535int usb_request_cancel(struct usb_request *req)
536{
537    struct usbdevfs_urb *urb = ((struct usbdevfs_urb*)req->private_data);
538    return ioctl(req->dev->fd, USBDEVFS_DISCARDURB, &urb);
539}
540
541