usbhost.c revision 7a96ba436c9a2bacc64e712bdb53bd7accc5c3a9
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 int fd; 64}; 65 66struct usb_device { 67 char dev_name[64]; 68 unsigned char desc[256]; 69 int desc_length; 70 int fd; 71 int writeable; 72}; 73 74struct usb_endpoint 75{ 76 struct usb_device *dev; 77 struct usb_endpoint_descriptor desc; 78 struct usbdevfs_urb urb; 79}; 80 81static inline int badname(const char *name) 82{ 83 while(*name) { 84 if(!isdigit(*name++)) return 1; 85 } 86 return 0; 87} 88 89/* returns true if one of the callbacks indicates we are done */ 90static int find_existing_devices(usb_device_added_cb added_cb, 91 usb_device_removed_cb removed_cb, 92 void *client_data) 93{ 94 char busname[32], devname[32]; 95 DIR *busdir , *devdir ; 96 struct dirent *de; 97 int done = 0; 98 99 busdir = opendir(USB_FS_DIR); 100 if(busdir == 0) return 1; 101 102 while ((de = readdir(busdir)) != 0 && !done) { 103 if(badname(de->d_name)) continue; 104 105 snprintf(busname, sizeof busname, "%s/%s", USB_FS_DIR, de->d_name); 106 devdir = opendir(busname); 107 if(devdir == 0) continue; 108 109 while ((de = readdir(devdir)) && !done) { 110 if(badname(de->d_name)) continue; 111 112 snprintf(devname, sizeof devname, "%s/%s", busname, de->d_name); 113 done = added_cb(devname, client_data); 114 } // end of devdir while 115 closedir(devdir); 116 } //end of busdir while 117 closedir(busdir); 118 119 return done; 120} 121 122struct usb_host_context *usb_host_init() 123{ 124 struct usb_host_context *context = calloc(1, sizeof(struct usb_host_context)); 125 if (!context) { 126 fprintf(stderr, "out of memory in usb_host_context\n"); 127 return NULL; 128 } 129 context->fd = inotify_init(); 130 if (context->fd < 0) { 131 fprintf(stderr, "inotify_init failed\n"); 132 free(context); 133 return NULL; 134 } 135 return context; 136} 137 138void usb_host_cleanup(struct usb_host_context *context) 139{ 140 close(context->fd); 141 free(context); 142} 143 144void usb_host_run(struct usb_host_context *context, 145 usb_device_added_cb added_cb, 146 usb_device_removed_cb removed_cb, 147 void *client_data) 148{ 149 struct inotify_event* event; 150 char event_buf[512]; 151 char path[100]; 152 int i, ret, done = 0; 153 int wd, wds[10]; 154 int wd_count = sizeof(wds) / sizeof(wds[0]); 155 156 D("Created device discovery thread\n"); 157 158 /* watch for files added and deleted within USB_FS_DIR */ 159 memset(wds, 0, sizeof(wds)); 160 /* watch the root for new subdirectories */ 161 wds[0] = inotify_add_watch(context->fd, USB_FS_DIR, IN_CREATE | IN_DELETE); 162 if (wds[0] < 0) { 163 fprintf(stderr, "inotify_add_watch failed\n"); 164 return; 165 } 166 167 /* watch existing subdirectories of USB_FS_DIR */ 168 for (i = 1; i < wd_count; i++) { 169 snprintf(path, sizeof(path), "%s/%03d", USB_FS_DIR, i); 170 ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE); 171 if (ret > 0) 172 wds[i] = ret; 173 } 174 175 /* check for existing devices first, after we have inotify set up */ 176 done = find_existing_devices(added_cb, removed_cb, client_data); 177 178 while (!done) { 179 ret = read(context->fd, event_buf, sizeof(event_buf)); 180 if (ret >= (int)sizeof(struct inotify_event)) { 181 event = (struct inotify_event *)event_buf; 182 wd = event->wd; 183 if (wd == wds[0]) { 184 i = atoi(event->name); 185 snprintf(path, sizeof(path), "%s/%s", USB_FS_DIR, event->name); 186 D("new subdirectory %s: index: %d\n", path, i); 187 if (i > 0 && i < wd_count) { 188 ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE); 189 if (ret > 0) 190 wds[i] = ret; 191 } 192 } else { 193 for (i = 1; i < wd_count && !done; i++) { 194 if (wd == wds[i]) { 195 snprintf(path, sizeof(path), "%s/%03d/%s", USB_FS_DIR, i, event->name); 196 if (event->mask == IN_CREATE) { 197 D("new device %s\n", path); 198 done = added_cb(path, client_data); 199 } else if (event->mask == IN_DELETE) { 200 D("gone device %s\n", path); 201 done = removed_cb(path, client_data); 202 } 203 } 204 } 205 } 206 } 207 } 208} 209 210struct usb_device *usb_device_open(const char *dev_name) 211{ 212 struct usb_device *device = calloc(1, sizeof(struct usb_device)); 213 int fd, length, did_retry = 0; 214 215 strcpy(device->dev_name, dev_name); 216 device->writeable = 1; 217 218retry: 219 fd = open(dev_name, O_RDWR); 220 if (fd < 0) { 221 /* if we fail, see if have read-only access */ 222 fd = open(dev_name, O_RDONLY); 223 D("usb_device_open open returned %d errno %d\n", fd, errno); 224 if (fd < 0 && (errno == EACCES || errno == ENOENT) && !did_retry) { 225 /* work around race condition between inotify and permissions management */ 226 sleep(1); 227 did_retry = 1; 228 goto retry; 229 } 230 231 if (fd < 0) goto fail; 232 device->writeable = 0; 233 D("[ usb open read-only %s fd = %d]\n", dev_name, fd); 234 } 235 236 length = read(fd, device->desc, sizeof(device->desc)); 237 D("usb_device_open read returned %d errno %d\n", fd, errno); 238 if (length < 0) 239 goto fail; 240 241 device->fd = fd; 242 device->desc_length = length; 243 return device; 244fail: 245 close(fd); 246 free(device); 247 return NULL; 248} 249 250void usb_device_close(struct usb_device *device) 251{ 252 close(device->fd); 253 free(device); 254} 255 256const char* usb_device_get_name(struct usb_device *device) 257{ 258 return device->dev_name; 259} 260 261int usb_device_get_unique_id(struct usb_device *device) 262{ 263 int bus = 0, dev = 0; 264 sscanf(device->dev_name, USB_FS_ID_SCANNER, &bus, &dev); 265 return bus * 1000 + dev; 266} 267 268uint16_t usb_device_get_vendor_id(struct usb_device *device) 269{ 270 struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc; 271 return __le16_to_cpu(desc->idVendor); 272} 273 274uint16_t usb_device_get_product_id(struct usb_device *device) 275{ 276 struct usb_device_descriptor* desc = (struct usb_device_descriptor*)device->desc; 277 return __le16_to_cpu(desc->idProduct); 278} 279 280char* usb_device_get_string(struct usb_device *device, int id) 281{ 282 char string[256]; 283 struct usbdevfs_ctrltransfer ctrl; 284 __u16 buffer[128]; 285 __u16 languages[128]; 286 int i, result; 287 int languageCount = 0; 288 289 string[0] = 0; 290 291 // reading the string requires read/write permission 292 if (!device->writeable) { 293 int fd = open(device->dev_name, O_RDWR); 294 if (fd > 0) { 295 close(device->fd); 296 device->fd = fd; 297 device->writeable = 1; 298 } else { 299 return NULL; 300 } 301 } 302 303 memset(languages, 0, sizeof(languages)); 304 memset(&ctrl, 0, sizeof(ctrl)); 305 306 // read list of supported languages 307 ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE; 308 ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; 309 ctrl.wValue = (USB_DT_STRING << 8) | 0; 310 ctrl.wIndex = 0; 311 ctrl.wLength = sizeof(languages); 312 ctrl.data = languages; 313 314 result = ioctl(device->fd, USBDEVFS_CONTROL, &ctrl); 315 if (result > 0) 316 languageCount = (result - 2) / 2; 317 318 for (i = 1; i <= languageCount; i++) { 319 memset(buffer, 0, sizeof(buffer)); 320 memset(&ctrl, 0, sizeof(ctrl)); 321 322 ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE; 323 ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; 324 ctrl.wValue = (USB_DT_STRING << 8) | id; 325 ctrl.wIndex = languages[i]; 326 ctrl.wLength = sizeof(buffer); 327 ctrl.data = buffer; 328 329 result = ioctl(device->fd, USBDEVFS_CONTROL, &ctrl); 330 if (result > 0) { 331 int i; 332 // skip first word, and copy the rest to the string, changing shorts to bytes. 333 result /= 2; 334 for (i = 1; i < result; i++) 335 string[i - 1] = buffer[i]; 336 string[i - 1] = 0; 337 return strdup(string); 338 } 339 } 340 341 return NULL; 342} 343 344char* usb_device_get_manufacturer_name(struct usb_device *device) 345{ 346 struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc; 347 348 if (desc->iManufacturer) 349 return usb_device_get_string(device, desc->iManufacturer); 350 else 351 return NULL; 352} 353 354char* usb_device_get_product_name(struct usb_device *device) 355{ 356 struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc; 357 358 if (desc->iProduct) 359 return usb_device_get_string(device, desc->iProduct); 360 else 361 return NULL; 362} 363 364char* usb_device_get_serial(struct usb_device *device) 365{ 366 struct usb_device_descriptor *desc = (struct usb_device_descriptor *)device->desc; 367 368 if (desc->iSerialNumber) 369 return usb_device_get_string(device, desc->iSerialNumber); 370 else 371 return NULL; 372} 373 374int usb_device_is_writeable(struct usb_device *device) 375{ 376 return device->writeable; 377} 378 379void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter) 380{ 381 iter->config = device->desc; 382 iter->config_end = device->desc + device->desc_length; 383 iter->curr_desc = device->desc; 384} 385 386struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter) 387{ 388 struct usb_descriptor_header* next; 389 if (iter->curr_desc >= iter->config_end) 390 return NULL; 391 next = (struct usb_descriptor_header*)iter->curr_desc; 392 iter->curr_desc += next->bLength; 393 return next; 394} 395 396int usb_device_claim_interface(struct usb_device *device, unsigned int interface) 397{ 398 return ioctl(device->fd, USBDEVFS_CLAIMINTERFACE, &interface); 399} 400 401int usb_device_release_interface(struct usb_device *device, unsigned int interface) 402{ 403 return ioctl(device->fd, USBDEVFS_RELEASEINTERFACE, &interface); 404} 405 406struct usb_endpoint *usb_endpoint_open(struct usb_device *dev, 407 const struct usb_endpoint_descriptor *desc) 408{ 409 struct usb_endpoint *ep = calloc(1, sizeof(struct usb_endpoint)); 410 memcpy(&ep->desc, desc, sizeof(ep->desc)); 411 ep->dev = dev; 412 return ep; 413} 414 415void usb_endpoint_close(struct usb_endpoint *ep) 416{ 417 // cancel IO here? 418 free(ep); 419} 420 421int usb_endpoint_queue(struct usb_endpoint *ep, void *data, int len) 422{ 423 struct usbdevfs_urb *urb = &ep->urb; 424 int res; 425 426 D("usb_endpoint_queue\n"); 427 memset(urb, 0, sizeof(*urb)); 428 urb->type = USBDEVFS_URB_TYPE_BULK; 429 urb->endpoint = ep->desc.bEndpointAddress; 430 urb->status = -1; 431 urb->buffer = data; 432 urb->buffer_length = len; 433 434 do { 435 res = ioctl(ep->dev->fd, USBDEVFS_SUBMITURB, urb); 436 } while((res < 0) && (errno == EINTR)); 437 438 return res; 439} 440 441int usb_endpoint_wait(struct usb_device *dev, int *out_ep_num) 442{ 443 struct usbdevfs_urb *out = NULL; 444 int res; 445 446 while (1) { 447 res = ioctl(dev->fd, USBDEVFS_REAPURB, &out); 448 D("USBDEVFS_REAPURB returned %d\n", res); 449 if (res < 0) { 450 if(errno == EINTR) { 451 continue; 452 } 453 D("[ reap urb - error ]\n"); 454 *out_ep_num = -1; 455 } else { 456 D("[ urb @%p status = %d, actual = %d ]\n", 457 out, out->status, out->actual_length); 458 res = out->actual_length; 459 *out_ep_num = out->endpoint; 460 } 461 break; 462 } 463 return res; 464} 465 466int usb_endpoint_cancel(struct usb_endpoint *ep) 467{ 468 return ioctl(ep->dev->fd, USBDEVFS_DISCARDURB, &ep->urb); 469} 470 471struct usb_device *usb_endpoint_get_device(struct usb_endpoint *ep) 472{ 473 return ep->dev; 474} 475 476int usb_endpoint_number(struct usb_endpoint *ep) 477{ 478 return ep->desc.bEndpointAddress; 479} 480 481int usb_endpoint_max_packet(struct usb_endpoint *ep) 482{ 483 return __le16_to_cpu(ep->desc.wMaxPacketSize); 484} 485 486