tools/usb/ffs-aio-example/simple/device_app/aio_simple.c

   1 #define _BSD_SOURCE /* for endian.h */
   2
   3 #include <endian.h>
   4 #include <errno.h>
   5 #include <fcntl.h>
   6 #include <stdarg.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/stat.h>
  12 #include <sys/types.h>
  13 #include <sys/poll.h>
  14 #include <unistd.h>
  15 #include <stdbool.h>
  16 #include <sys/eventfd.h>
  17
  18 #include "libaio.h"
  19 #define IOCB_FLAG_RESFD         (1 << 0)
  20
  21 #include <linux/usb/functionfs.h>
  22
  23 #define BUF_LEN         8192
  24
  25 /******************** Descriptors and Strings *******************************/
  26
  27 static const struct {
  28         struct usb_functionfs_descs_head header;
  29         struct {
  30                 struct usb_interface_descriptor intf;
  31                 struct usb_endpoint_descriptor_no_audio bulk_sink;
  32                 struct usb_endpoint_descriptor_no_audio bulk_source;
  33         } __attribute__ ((__packed__)) fs_descs, hs_descs;
  34 } __attribute__ ((__packed__)) descriptors = {
  35         .header = {
  36                 .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC),
  37                 .length = htole32(sizeof(descriptors)),
  38                 .fs_count = 3,
  39                 .hs_count = 3,
  40         },
  41         .fs_descs = {
  42                 .intf = {
  43                         .bLength = sizeof(descriptors.fs_descs.intf),
  44                         .bDescriptorType = USB_DT_INTERFACE,
  45                         .bNumEndpoints = 2,
  46                         .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
  47                         .iInterface = 1,
  48                 },
  49                 .bulk_sink = {
  50                         .bLength = sizeof(descriptors.fs_descs.bulk_sink),
  51                         .bDescriptorType = USB_DT_ENDPOINT,
  52                         .bEndpointAddress = 1 | USB_DIR_IN,
  53                         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  54                 },
  55                 .bulk_source = {
  56                         .bLength = sizeof(descriptors.fs_descs.bulk_source),
  57                         .bDescriptorType = USB_DT_ENDPOINT,
  58                         .bEndpointAddress = 2 | USB_DIR_OUT,
  59                         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  60                 },
  61         },
  62         .hs_descs = {
  63                 .intf = {
  64                         .bLength = sizeof(descriptors.hs_descs.intf),
  65                         .bDescriptorType = USB_DT_INTERFACE,
  66                         .bNumEndpoints = 2,
  67                         .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
  68                         .iInterface = 1,
  69                 },
  70                 .bulk_sink = {
  71                         .bLength = sizeof(descriptors.hs_descs.bulk_sink),
  72                         .bDescriptorType = USB_DT_ENDPOINT,
  73                         .bEndpointAddress = 1 | USB_DIR_IN,
  74                         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  75                 },
  76                 .bulk_source = {
  77                         .bLength = sizeof(descriptors.hs_descs.bulk_source),
  78                         .bDescriptorType = USB_DT_ENDPOINT,
  79                         .bEndpointAddress = 2 | USB_DIR_OUT,
  80                         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  81                 },
  82         },
  83 };
  84
  85 #define STR_INTERFACE "AIO Test"
  86
  87 static const struct {
  88         struct usb_functionfs_strings_head header;
  89         struct {
  90                 __le16 code;
  91                 const char str1[sizeof(STR_INTERFACE)];
  92         } __attribute__ ((__packed__)) lang0;
  93 } __attribute__ ((__packed__)) strings = {
  94         .header = {
  95                 .magic = htole32(FUNCTIONFS_STRINGS_MAGIC),
  96                 .length = htole32(sizeof(strings)),
  97                 .str_count = htole32(1),
  98                 .lang_count = htole32(1),
  99         },
 100         .lang0 = {
 101                 htole16(0x0409), /* en-us */
 102                 STR_INTERFACE,
 103         },
 104 };
 105
 106 /******************** Endpoints handling *******************************/
 107
 108 static void display_event(struct usb_functionfs_event *event)
 109 {
 110         static const char *const names[] = {
 111                 [FUNCTIONFS_BIND] = "BIND",
 112                 [FUNCTIONFS_UNBIND] = "UNBIND",
 113                 [FUNCTIONFS_ENABLE] = "ENABLE",
 114                 [FUNCTIONFS_DISABLE] = "DISABLE",
 115                 [FUNCTIONFS_SETUP] = "SETUP",
 116                 [FUNCTIONFS_SUSPEND] = "SUSPEND",
 117                 [FUNCTIONFS_RESUME] = "RESUME",
 118         };
 119         switch (event->type) {
 120         case FUNCTIONFS_BIND:
 121         case FUNCTIONFS_UNBIND:
 122         case FUNCTIONFS_ENABLE:
 123         case FUNCTIONFS_DISABLE:
 124         case FUNCTIONFS_SETUP:
 125         case FUNCTIONFS_SUSPEND:
 126         case FUNCTIONFS_RESUME:
 127                 printf("Event %s\n", names[event->type]);
 128         }
 129 }
 130
 131 static void handle_ep0(int ep0, bool *ready)
 132 {
 133         struct usb_functionfs_event event;
 134         int ret;
 135
 136         struct pollfd pfds[1];
 137         pfds[0].fd = ep0;
 138         pfds[0].events = POLLIN;
 139
 140         ret = poll(pfds, 1, 0);
 141
 142         if (ret && (pfds[0].revents & POLLIN)) {
 143                 ret = read(ep0, &event, sizeof(event));
 144                 if (!ret) {
 145                         perror("unable to read event from ep0");
 146                         return;
 147                 }
 148                 display_event(&event);
 149                 switch (event.type) {
 150                 case FUNCTIONFS_SETUP:
 151                         if (event.u.setup.bRequestType & USB_DIR_IN)
 152                                 write(ep0, NULL, 0);
 153                         else
 154                                 read(ep0, NULL, 0);
 155                         break;
 156
 157                 case FUNCTIONFS_ENABLE:
 158                         *ready = true;
 159                         break;
 160
 161                 case FUNCTIONFS_DISABLE:
 162                         *ready = false;
 163                         break;
 164
 165                 default:
 166                         break;
 167                 }
 168         }
 169 }
 170
 171 int main(int argc, char *argv[])
 172 {
 173         int i, ret;
 174         char *ep_path;
 175
 176         int ep0;
 177         int ep[2];
 178
 179         io_context_t ctx;
 180
 181         int evfd;
 182         fd_set rfds;
 183
 184         char *buf_in, *buf_out;
 185         struct iocb *iocb_in, *iocb_out;
 186         int req_in = 0, req_out = 0;
 187         bool ready;
 188
 189         if (argc != 2) {
 190                 printf("ffs directory not specified!\n");
 191                 return 1;
 192         }
 193
 194         ep_path = malloc(strlen(argv[1]) + 4 /* "/ep#" */ + 1 /* '\0' */);
 195         if (!ep_path) {
 196                 perror("malloc");
 197                 return 1;
 198         }
 199
 200         /* open endpoint files */
 201         sprintf(ep_path, "%s/ep0", argv[1]);
 202         ep0 = open(ep_path, O_RDWR);
 203         if (ep0 < 0) {
 204                 perror("unable to open ep0");
 205                 return 1;
 206         }
 207         if (write(ep0, &descriptors, sizeof(descriptors)) < 0) {
 208                 perror("unable do write descriptors");
 209                 return 1;
 210         }
 211         if (write(ep0, &strings, sizeof(strings)) < 0) {
 212                 perror("unable to write strings");
 213                 return 1;
 214         }
 215         for (i = 0; i < 2; ++i) {
 216                 sprintf(ep_path, "%s/ep%d", argv[1], i+1);
 217                 ep[i] = open(ep_path, O_RDWR);
 218                 if (ep[i] < 0) {
 219                         printf("unable to open ep%d: %s\n", i+1,
 220                                strerror(errno));
 221                         return 1;
 222                 }
 223         }
 224
 225         free(ep_path);
 226
 227         memset(&ctx, 0, sizeof(ctx));
 228         /* setup aio context to handle up to 2 requests */
 229         if (io_setup(2, &ctx) < 0) {
 230                 perror("unable to setup aio");
 231                 return 1;
 232         }
 233
 234         evfd = eventfd(0, 0);
 235         if (evfd < 0) {
 236                 perror("unable to open eventfd");
 237                 return 1;
 238         }
 239
 240         /* alloc buffers and requests */
 241         buf_in = malloc(BUF_LEN);
 242         buf_out = malloc(BUF_LEN);
 243         iocb_in = malloc(sizeof(*iocb_in));
 244         iocb_out = malloc(sizeof(*iocb_out));
 245
 246         while (1) {
 247                 FD_ZERO(&rfds);
 248                 FD_SET(ep0, &rfds);
 249                 FD_SET(evfd, &rfds);
 250
 251                 ret = select(((ep0 > evfd) ? ep0 : evfd)+1,
 252                              &rfds, NULL, NULL, NULL);
 253                 if (ret < 0) {
 254                         if (errno == EINTR)
 255                                 continue;
 256                         perror("select");
 257                         break;
 258                 }
 259
 260                 if (FD_ISSET(ep0, &rfds))
 261                         handle_ep0(ep0, &ready);
 262
 263                 /* we are waiting for function ENABLE */
 264                 if (!ready)
 265                         continue;
 266
 267                 /* if something was submitted we wait for event */
 268                 if (FD_ISSET(evfd, &rfds)) {
 269                         uint64_t ev_cnt;
 270                         ret = read(evfd, &ev_cnt, sizeof(ev_cnt));
 271                         if (ret < 0) {
 272                                 perror("unable to read eventfd");
 273                                 break;
 274                         }
 275
 276                         struct io_event e[2];
 277                         /* we wait for one event */
 278                         ret = io_getevents(ctx, 1, 2, e, NULL);
 279                         /* if we got event */
 280                         for (i = 0; i < ret; ++i) {
 281                                 if (e[i].obj->aio_fildes == ep[0]) {
 282                                         printf("ev=in; ret=%lu\n", e[i].res);
 283                                         req_in = 0;
 284                                 } else if (e[i].obj->aio_fildes == ep[1]) {
 285                                         printf("ev=out; ret=%lu\n", e[i].res);
 286                                         req_out = 0;
 287                                 }
 288                         }
 289                 }
 290
 291                 if (!req_in) { /* if IN transfer not requested*/
 292                         /* prepare write request */
 293                         io_prep_pwrite(iocb_in, ep[0], buf_in, BUF_LEN, 0);
 294                         /* enable eventfd notification */
 295                         iocb_in->u.c.flags |= IOCB_FLAG_RESFD;
 296                         iocb_in->u.c.resfd = evfd;
 297                         /* submit table of requests */
 298                         ret = io_submit(ctx, 1, &iocb_in);
 299                         if (ret >= 0) { /* if ret > 0 request is queued */
 300                                 req_in = 1;
 301                                 printf("submit: in\n");
 302                         } else
 303                                 perror("unable to submit request");
 304                 }
 305                 if (!req_out) { /* if OUT transfer not requested */
 306                         /* prepare read request */
 307                         io_prep_pread(iocb_out, ep[1], buf_out, BUF_LEN, 0);
 308                         /* enable eventfs notification */
 309                         iocb_out->u.c.flags |= IOCB_FLAG_RESFD;
 310                         iocb_out->u.c.resfd = evfd;
 311                         /* submit table of requests */
 312                         ret = io_submit(ctx, 1, &iocb_out);
 313                         if (ret >= 0) { /* if ret > 0 request is queued */
 314                                 req_out = 1;
 315                                 printf("submit: out\n");
 316                         } else
 317                                 perror("unable to submit request");
 318                 }
 319         }
 320
 321         /* free resources */
 322
 323         io_destroy(ctx);
 324
 325         free(buf_in);
 326         free(buf_out);
 327         free(iocb_in);
 328         free(iocb_out);
 329
 330         for (i = 0; i < 2; ++i)
 331                 close(ep[i]);
 332         close(ep0);
 333
 334         return 0;
 335 }