usbhost.c revision e15af09876c5e0301084f46b8036aed147cf9c24 
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 <linux/version.h>
49#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 20)
50#include <linux/usb/ch9.h>
51#else
52#include <linux/usb_ch9.h>
53#endif
54#include <asm/byteorder.h>
55
56#include "usbhost/usbhost.h"
57
58#define USB_FS_DIR "/dev/bus/usb"
59#define USB_FS_ID_SCANNER   "/dev/bus/usb/%d/%d"
60
61
62struct usb_host_context {
63    usb_device_added_cb     added_cb;
64    usb_device_removed_cb   removed_cb;
65    void                    *client_data;
66};
67
68struct usb_device {
69    char dev_name[64];
70    unsigned char desc[256];
71    int desc_length;
72    int fd;
73    int writeable;
74};
75
76struct usb_endpoint
77{
78    struct usb_device *dev;
79    struct usb_endpoint_descriptor  desc;
80    struct usbdevfs_urb urb;
81};
82
83static inline int badname(const char *name)
84{
85    while(*name) {
86        if(!isdigit(*name++)) return 1;
87    }
88    return 0;
89}
90
91static void find_existing_devices(struct usb_host_context *context)
92{
93    char busname[32], devname[32];
94    DIR *busdir , *devdir ;
95    struct dirent *de;
96
97    busdir = opendir(USB_FS_DIR);
98    if(busdir == 0) return;
99
100    while((de = readdir(busdir)) != 0) {
101        if(badname(de->d_name)) continue;
102
103        snprintf(busname, sizeof busname, "%s/%s", USB_FS_DIR, de->d_name);
104        devdir = opendir(busname);
105        if(devdir == 0) continue;
106
107        while((de = readdir(devdir))) {
108            if(badname(de->d_name)) continue;
109
110            snprintf(devname, sizeof devname, "%s/%s", busname, de->d_name);
111            context->added_cb(devname, context->client_data);
112        } // end of devdir while
113        closedir(devdir);
114    } //end of busdir while
115    closedir(busdir);
116}
117
118static void* device_discovery_thread(void *client_data)
119{
120    struct usb_host_context *context = (struct usb_host_context *)client_data;
121    struct inotify_event* event;
122    char event_buf[512];
123    char path[100];
124    int i, fd, ret;
125    int wd, wds[10];
126    int wd_count = sizeof(wds) / sizeof(wds[0]);
127
128    D("Created device discovery thread\n");
129
130    fd = inotify_init();
131    if (fd < 0) {
132        fprintf(stderr, "inotify_init failed\n");
133        return NULL;
134    }
135
136    /* watch for files added and deleted within USB_FS_DIR */
137    memset(wds, 0, sizeof(wds));
138    /* watch the root for new subdirectories */
139    wds[0] = inotify_add_watch(fd, USB_FS_DIR, IN_CREATE | IN_DELETE);
140    if (wds[0] < 0) {
141        fprintf(stderr, "inotify_add_watch failed\n");
142        return NULL;
143    }
144
145    /* watch existing subdirectories of USB_FS_DIR */
146    for (i = 1; i < wd_count; i++) {
147        snprintf(path, sizeof(path), "%s/%03d", USB_FS_DIR, i);
148        ret = inotify_add_watch(fd, path, IN_CREATE | IN_DELETE);
149        if (ret > 0)
150            wds[i] = ret;
151    }
152
153    /* check for existing devices first, after we have inotify set up */
154    find_existing_devices(context);
155
156    while (1) {
157        ret = read(fd, event_buf, sizeof(event_buf));
158        if (ret >= (int)sizeof(struct inotify_event)) {
159            event = (struct inotify_event *)event_buf;
160            wd = event->wd;
161            if (wd == wds[0]) {
162                i = atoi(event->name);
163                snprintf(path, sizeof(path), "%s/%s", USB_FS_DIR, event->name);
164                D("new subdirectory %s: index: %d\n", path, i);
165                if (i > 0 && i < wd_count) {
166                ret = inotify_add_watch(fd, path, IN_CREATE | IN_DELETE);
167                if (ret > 0)
168                    wds[i] = ret;
169                }
170            } else {
171                for (i = 1; i < wd_count; i++) {
172                    if (wd == wds[i]) {
173                        snprintf(path, sizeof(path), "%s/%03d/%s", USB_FS_DIR, i, event->name);
174                        if (event->mask == IN_CREATE) {
175                            D("new device %s\n", path);
176                            context->added_cb(path, context->client_data);
177                        } else if (event->mask == IN_DELETE) {
178                            D("gone device %s\n", path);
179                            context->removed_cb(path, context->client_data);
180                        }
181                    }
182                }
183            }
184        }
185    }
186    return NULL;
187}
188
189int usb_host_init(usb_device_added_cb added_cb, usb_device_removed_cb removed_cb, void *client_data)
190{
191    struct usb_host_context *context;
192    pthread_t tid;
193    pthread_attr_t   attr;
194
195    if (!added_cb || !removed_cb)
196        return -EINVAL;
197
198    context = calloc(1, sizeof(struct usb_host_context));
199    context->added_cb = added_cb;
200    context->removed_cb = removed_cb;
201    context->client_data = client_data;
202
203    pthread_attr_init(&attr);
204    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
205    return pthread_create(&tid, &attr, device_discovery_thread, context);
206}
207
208struct usb_device *usb_device_open(const char *dev_name)
209{
210    struct usb_device *device = calloc(1, sizeof(struct usb_device));
211    int fd, length, did_retry = 0;
212
213    strcpy(device->dev_name, dev_name);
214    device->writeable = 1;
215
216retry:
217    fd = open(dev_name, O_RDWR);
218    if (fd < 0) {
219        /* if we fail, see if have read-only access */
220        fd = open(dev_name, O_RDONLY);
221        D("usb_device_open open returned %d errno %d\n", fd, errno);
222        if (fd < 0 && (errno == EACCES || errno == ENOENT) && !did_retry) {
223            /* work around race condition between inotify and permissions management */
224            sleep(1);
225            did_retry = 1;
226            goto retry;
227        }
228
229        if (fd < 0) goto fail;
230        device->writeable = 0;
231        D("[ usb open read-only %s fd = %d]\n", dev_name, fd);
232    }
233
234    length = read(fd, device->desc, sizeof(device->desc));
235    D("usb_device_open read returned %d errno %d\n", fd, errno);
236    if (length < 0)
237        goto fail;
238
239    device->fd = fd;
240    device->desc_length = length;
241    return device;
242fail:
243    close(fd);
244    free(device);
245    return NULL;
246}
247
248void usb_device_close(struct usb_device *device)
249{
250    close(device->fd);
251    free(device);
252}
253
254const char* usb_device_get_name(struct usb_device *device)
255{
256    return device->dev_name;
257}
258
259int usb_device_get_unique_id(struct usb_device *device)
260{
261    int bus = 0, dev = 0;
262    sscanf(device->dev_name, USB_FS_ID_SCANNER, &bus, &dev);
263    return bus * 1000 + dev;
264}
265
266uint16_t usb_device_get_vendor_id(struct usb_device *device)
267{
268    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
269    return __le16_to_cpu(desc->idVendor);
270}
271
272uint16_t usb_device_get_product_id(struct usb_device *device)
273{
274    struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc;
275    return __le16_to_cpu(desc->idProduct);
276}
277
278char* usb_device_get_string(struct usb_device *device, int id)
279{
280    char string[256];
281    struct usbdevfs_ctrltransfer  ctrl;
282    __u16 buffer[128];
283    __u16 languages[128];
284    int i, result;
285    int languageCount = 0;
286
287    string[0] = 0;
288
289    // reading the string requires read/write permission
290    if (!device->writeable) {
291        int fd = open(device->dev_name, O_RDWR);
292        if (fd > 0) {
293            close(device->fd);
294            device->fd = fd;
295            device->writeable = 1;
296        } else {
297            return NULL;
298        }
299    }
300
301    memset(languages, 0, sizeof(languages));
302    memset(&ctrl, 0, sizeof(ctrl));
303
304    // read list of supported languages
305    ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE;
306    ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
307    ctrl.wValue = (USB_DT_STRING << 8) | 0;
308    ctrl.wIndex = 0;
309    ctrl.wLength = sizeof(languages);
310    ctrl.data = languages;
311
312    result = ioctl(device->fd, USBDEVFS_CONTROL, &ctrl);
313    if (result > 0)
314        languageCount = (result - 2) / 2;
315
316    for (i = 1; i <= languageCount; i++) {
317        memset(buffer, 0, sizeof(buffer));
318        memset(&ctrl, 0, sizeof(ctrl));
319
320        ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE;
321        ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
322        ctrl.wValue = (USB_DT_STRING << 8) | id;
323        ctrl.wIndex = languages[i];
324        ctrl.wLength = sizeof(buffer);
325        ctrl.data = buffer;
326
327        result = ioctl(device->fd, USBDEVFS_CONTROL, &ctrl);
328        if (result > 0) {
329            int i;
330            // skip first word, and copy the rest to the string, changing shorts to bytes.
331            result /= 2;
332            for (i = 1; i < result; i++)
333                string[i - 1] = buffer[i];
334            string[i - 1] = 0;
335            return strdup(string);
336        }
337    }
338
339    return NULL;
340}
341
342char* usb_device_get_manufacturer_name(struct usb_device *device)
343{
344    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
345
346    if (desc->iManufacturer)
347        return usb_device_get_string(device, desc->iManufacturer);
348    else
349        return NULL;
350}
351
352char* usb_device_get_product_name(struct usb_device *device)
353{
354    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
355
356    if (desc->iProduct)
357        return usb_device_get_string(device, desc->iProduct);
358    else
359        return NULL;
360}
361
362char* usb_device_get_serial(struct usb_device *device)
363{
364    struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc;
365
366    if (desc->iSerialNumber)
367        return usb_device_get_string(device, desc->iSerialNumber);
368    else
369        return NULL;
370}
371
372int usb_device_is_writeable(struct usb_device *device)
373{
374    return device->writeable;
375}
376
377void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter)
378{
379    iter->config = device->desc;
380    iter->config_end = device->desc + device->desc_length;
381    iter->curr_desc = device->desc;
382}
383
384struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter)
385{
386    struct usb_descriptor_header* next;
387    if (iter->curr_desc >= iter->config_end)
388        return NULL;
389    next = (struct usb_descriptor_header*)iter->curr_desc;
390    iter->curr_desc += next->bLength;
391    return next;
392}
393
394int usb_device_claim_interface(struct usb_device *device, unsigned int interface)
395{
396    return ioctl(device->fd, USBDEVFS_CLAIMINTERFACE, &interface);
397}
398
399int usb_device_release_interface(struct usb_device *device, unsigned int interface)
400{
401    return ioctl(device->fd, USBDEVFS_RELEASEINTERFACE, &interface);
402}
403
404struct usb_endpoint *usb_endpoint_open(struct usb_device *dev,
405        const struct usb_endpoint_descriptor *desc)
406{
407    struct usb_endpoint *ep = calloc(1, sizeof(struct usb_endpoint));
408    memcpy(&ep->desc, desc, sizeof(ep->desc));
409    ep->dev = dev;
410    return ep;
411}
412
413void usb_endpoint_close(struct usb_endpoint *ep)
414{
415    // cancel IO here?
416    free(ep);
417}
418
419int usb_endpoint_queue(struct usb_endpoint *ep, void *data, int len)
420{
421    struct usbdevfs_urb *urb = &ep->urb;
422    int res;
423
424    D("usb_endpoint_queue\n");
425    memset(urb, 0, sizeof(*urb));
426    urb->type = USBDEVFS_URB_TYPE_BULK;
427    urb->endpoint = ep->desc.bEndpointAddress;
428    urb->status = -1;
429    urb->buffer = data;
430    urb->buffer_length = len;
431
432    do {
433        res = ioctl(ep->dev->fd, USBDEVFS_SUBMITURB, urb);
434    } while((res < 0) && (errno == EINTR));
435
436    return res;
437}
438
439int usb_endpoint_wait(struct usb_device *dev, int *out_ep_num)
440{
441    struct usbdevfs_urb *out = NULL;
442    int res;
443
444    while (1) {
445        res = ioctl(dev->fd, USBDEVFS_REAPURB, &out);
446        D("USBDEVFS_REAPURB returned %d\n", res);
447        if (res < 0) {
448            if(errno == EINTR) {
449                continue;
450            }
451            D("[ reap urb - error ]\n");
452            *out_ep_num = -1;
453        } else {
454            D("[ urb @%p status = %d, actual = %d ]\n",
455                out, out->status, out->actual_length);
456            res = out->actual_length;
457            *out_ep_num = out->endpoint;
458        }
459        break;
460    }
461    return res;
462}
463
464int usb_endpoint_cancel(struct usb_endpoint *ep)
465{
466    return ioctl(ep->dev->fd, USBDEVFS_DISCARDURB, &ep->urb);
467}
468
469struct usb_device *usb_endpoint_get_device(struct usb_endpoint *ep)
470{
471    return ep->dev;
472}
473
474int usb_endpoint_number(struct usb_endpoint *ep)
475{
476    return ep->desc.bEndpointAddress;
477}
478
479int usb_endpoint_max_packet(struct usb_endpoint *ep)
480{
481    return __le16_to_cpu(ep->desc.wMaxPacketSize);
482}
483
484