src/am7xxx.c

   1 /* am7xxx - communication with AM7xxx based USB Pico Projectors and DPFs
   2  *
   3  * Copyright (C) 2012  Antonio Ospite <ospite@studenti.unina.it>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <stdarg.h>
  23 #include <errno.h>
  24 #include <libusb.h>
  25 #include <math.h>
  26
  27 #include "am7xxx.h"
  28 #include "serialize.h"
  29
  30 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  31
  32 /* If we're not using GNU C, elide __attribute__
  33  * taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
  34  */
  35 #ifndef __GNUC__
  36 #  define  __attribute__(x)  /*NOTHING*/
  37 #endif
  38
  39 /* Control shared library symbols visibility */
  40 #if defined _WIN32 || defined __CYGWIN__
  41         #define AM7XXX_PUBLIC __declspec(dllexport)
  42         #define AM7XXX_LOCAL
  43 #else
  44         #if __GNUC__ >= 4
  45                 #define AM7XXX_PUBLIC __attribute__ ((visibility ("default")))
  46                 #define AM7XXX_LOCAL  __attribute__ ((visibility ("hidden")))
  47         #else
  48                 #define AM7XXX_PUBLIC
  49                 #define AM7XXX_LOCAL
  50         #endif
  51 #endif
  52
  53 static void log_message(am7xxx_context *ctx,
  54                         int level,
  55                         const char *function,
  56                         int line,
  57                         const char *fmt,
  58                         ...) __attribute__ ((format (printf, 5, 6)));
  59
  60 #define fatal(...)        log_message(NULL, AM7XXX_LOG_FATAL,   __func__, __LINE__, __VA_ARGS__)
  61 #define error(ctx, ...)   log_message(ctx,  AM7XXX_LOG_ERROR,   __func__, __LINE__, __VA_ARGS__)
  62 #define warning(ctx, ...) log_message(ctx,  AM7XXX_LOG_WARNING, __func__, 0,        __VA_ARGS__)
  63 #define info(ctx, ...)    log_message(ctx,  AM7XXX_LOG_INFO,    __func__, 0,        __VA_ARGS__)
  64 #define debug(ctx, ...)   log_message(ctx,  AM7XXX_LOG_DEBUG,   __func__, 0,        __VA_ARGS__)
  65 #define trace(ctx, ...)   log_message(ctx,  AM7XXX_LOG_TRACE,   NULL,     0,        __VA_ARGS__)
  66
  67 struct am7xxx_usb_device_descriptor {
  68         const char *name;
  69         uint16_t vendor_id;
  70         uint16_t product_id;
  71 };
  72
  73 static struct am7xxx_usb_device_descriptor supported_devices[] = {
  74         {
  75                 .name       = "Acer C110",
  76                 .vendor_id  = 0x1de1,
  77                 .product_id = 0xc101,
  78         },
  79         {
  80                 .name       = "Acer C112",
  81                 .vendor_id  = 0x1de1,
  82                 .product_id = 0x5501,
  83         },
  84         {
  85                 .name       ="Aiptek PocketCinema T25",
  86                 .vendor_id  = 0x08ca,
  87                 .product_id = 0x2144,
  88         },
  89         {
  90                 .name       = "Philips/Sagemcom PicoPix 1020",
  91                 .vendor_id  = 0x21e7,
  92                 .product_id = 0x000e,
  93         },
  94         {
  95                 .name       = "Philips/Sagemcom PicoPix 2055",
  96                 .vendor_id  = 0x21e7,
  97                 .product_id = 0x0016,
  98         },
  99 };
 100
 101 /* The header size on the wire is known to be always 24 bytes, regardless of
 102  * the memory configuration enforced by different architectures or compilers
 103  * for struct am7xxx_header
 104  */
 105 #define AM7XXX_HEADER_WIRE_SIZE 24
 106
 107 struct _am7xxx_device {
 108         libusb_device_handle *usb_device;
 109         uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
 110         am7xxx_context *ctx;
 111         am7xxx_device *next;
 112 };
 113
 114 struct _am7xxx_context {
 115         libusb_context *usb_context;
 116         int log_level;
 117         am7xxx_device *devices_list;
 118 };
 119
 120 typedef enum {
 121         AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
 122         AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
 123         AM7XXX_PACKET_TYPE_POWER   = 0x04,
 124         AM7XXX_PACKET_TYPE_ZOOM    = 0x05,
 125 } am7xxx_packet_type;
 126
 127 struct am7xxx_generic_header {
 128         uint32_t field0;
 129         uint32_t field1;
 130         uint32_t field2;
 131         uint32_t field3;
 132 };
 133
 134 struct am7xxx_devinfo_header {
 135         uint32_t native_width;
 136         uint32_t native_height;
 137         uint32_t unknown0;
 138         uint32_t unknown1;
 139 };
 140
 141 struct am7xxx_image_header {
 142         uint32_t format;
 143         uint32_t width;
 144         uint32_t height;
 145         uint32_t image_size;
 146 };
 147
 148 struct am7xxx_power_header {
 149         uint32_t bit2;
 150         uint32_t bit1;
 151         uint32_t bit0;
 152 };
 153
 154 struct am7xxx_zoom_header {
 155         uint32_t bit1;
 156         uint32_t bit0;
 157 };
 158
 159 /*
 160  * Examples of packet headers:
 161  *
 162  * Image header:
 163  * 02 00 00 00 00 10 3e 10 01 00 00 00 20 03 00 00 e0 01 00 00 53 E8 00 00
 164  *
 165  * Power header:
 166  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 167  */
 168
 169 /* Direction of the communication from the host point of view */
 170 #define AM7XXX_DIRECTION_OUT 0 /* host -> device */
 171 #define AM7XXX_DIRECTION_IN  1 /* host <- device */
 172
 173 struct am7xxx_header {
 174         uint32_t packet_type;
 175         uint8_t direction;
 176         uint8_t header_data_len;
 177         uint8_t unknown2;
 178         uint8_t unknown3;
 179         union {
 180                 struct am7xxx_generic_header data;
 181                 struct am7xxx_devinfo_header devinfo;
 182                 struct am7xxx_image_header image;
 183                 struct am7xxx_power_header power;
 184                 struct am7xxx_zoom_header zoom;
 185         } header_data;
 186 };
 187
 188
 189 #ifdef DEBUG
 190 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 191 {
 192         if (ctx == NULL || d == NULL)
 193                 return;
 194
 195         debug(ctx, "Info header:\n");
 196         debug(ctx, "\tnative_width:  0x%08x (%u)\n", d->native_width, d->native_width);
 197         debug(ctx, "\tnative_height: 0x%08x (%u)\n", d->native_height, d->native_height);
 198         debug(ctx, "\tunknown0:      0x%08x (%u)\n", d->unknown0, d->unknown0);
 199         debug(ctx, "\tunknown1:      0x%08x (%u)\n", d->unknown1, d->unknown1);
 200 }
 201
 202 static void debug_dump_image_header(am7xxx_context *ctx, struct am7xxx_image_header *i)
 203 {
 204         if (ctx == NULL || i == NULL)
 205                 return;
 206
 207         debug(ctx, "Image header:\n");
 208         debug(ctx, "\tformat:     0x%08x (%u)\n", i->format, i->format);
 209         debug(ctx, "\twidth:      0x%08x (%u)\n", i->width, i->width);
 210         debug(ctx, "\theight:     0x%08x (%u)\n", i->height, i->height);
 211         debug(ctx, "\timage size: 0x%08x (%u)\n", i->image_size, i->image_size);
 212 }
 213
 214 static void debug_dump_power_header(am7xxx_context *ctx, struct am7xxx_power_header *p)
 215 {
 216         if (ctx == NULL || p == NULL)
 217                 return;
 218
 219         debug(ctx, "Power header:\n");
 220         debug(ctx, "\tbit2: 0x%08x (%u)\n", p->bit2, p->bit2);
 221         debug(ctx, "\tbit1: 0x%08x (%u)\n", p->bit1, p->bit1);
 222         debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 223 }
 224
 225 static void debug_dump_zoom_header(am7xxx_context *ctx, struct am7xxx_zoom_header *z)
 226 {
 227         if (ctx == NULL || z == NULL)
 228                 return;
 229
 230         debug(ctx, "Zoom header:\n");
 231         debug(ctx, "\tbit1: 0x%08x (%u)\n", z->bit1, z->bit1);
 232         debug(ctx, "\tbit0: 0x%08x (%u)\n", z->bit0, z->bit0);
 233 }
 234
 235 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 236 {
 237         if (ctx == NULL || h == NULL)
 238                 return;
 239
 240         debug(ctx, "BEGIN\n");
 241         debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
 242         debug(ctx, "direction:       0x%02hhx (%hhu) (%s)\n", h->direction, h->direction,
 243               h->direction == AM7XXX_DIRECTION_IN ? "IN" :
 244               h->direction == AM7XXX_DIRECTION_OUT ? "OUT" :
 245               "UNKNOWN");
 246         debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
 247         debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
 248         debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
 249
 250         switch(h->packet_type) {
 251         case AM7XXX_PACKET_TYPE_DEVINFO:
 252                 debug_dump_devinfo_header(ctx, &(h->header_data.devinfo));
 253                 break;
 254
 255         case AM7XXX_PACKET_TYPE_IMAGE:
 256                 debug_dump_image_header(ctx, &(h->header_data.image));
 257                 break;
 258
 259         case AM7XXX_PACKET_TYPE_POWER:
 260                 debug_dump_power_header(ctx, &(h->header_data.power));
 261                 break;
 262
 263         case AM7XXX_PACKET_TYPE_ZOOM:
 264                 debug_dump_zoom_header(ctx, &(h->header_data.zoom));
 265                 break;
 266
 267         default:
 268                 debug(ctx, "Packet type not supported!\n");
 269                 break;
 270         }
 271         debug(ctx, "END\n\n");
 272 }
 273
 274 static inline unsigned int in_80chars(unsigned int i)
 275 {
 276         /* The 3 below is the length of "xx " where xx is the hex string
 277          * representation of a byte */
 278         return ((i+1) % (80/3));
 279 }
 280
 281 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 282                               uint8_t *buffer, unsigned int len)
 283 {
 284         unsigned int i;
 285
 286         if (ctx == NULL || buffer == NULL || len == 0)
 287                 return;
 288
 289         trace(ctx, "\n");
 290         if (message)
 291                 trace(ctx, "%s\n", message);
 292
 293         for (i = 0; i < len; i++) {
 294                 trace(ctx, "%02hhX%c", buffer[i], (in_80chars(i) && (i < len - 1)) ? ' ' : '\n');
 295         }
 296         trace(ctx, "\n");
 297 }
 298 #else
 299 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 300 {
 301         (void)ctx;
 302         (void)h;
 303 }
 304
 305 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 306                               uint8_t *buffer, unsigned int len)
 307 {
 308         (void)ctx;
 309         (void)message;
 310         (void)buffer;
 311         (void)len;
 312 }
 313 #endif /* DEBUG */
 314
 315 static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 316 {
 317         int ret;
 318         int transferred = 0;
 319
 320         ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
 321         if (ret != 0 || (unsigned int)transferred != len) {
 322                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 323                       ret, transferred, len);
 324                 return ret;
 325         }
 326
 327         trace_dump_buffer(dev->ctx, "<-- received", buffer, len);
 328
 329         return 0;
 330 }
 331
 332 static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 333 {
 334         int ret;
 335         int transferred = 0;
 336
 337         trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 338
 339         ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
 340         if (ret != 0 || (unsigned int)transferred != len) {
 341                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 342                       ret, transferred, len);
 343                 return ret;
 344         }
 345
 346         return 0;
 347 }
 348
 349 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 350 {
 351         uint8_t **buffer_iterator = &buffer;
 352
 353         put_le32(h->packet_type, buffer_iterator);
 354         put_8(h->direction, buffer_iterator);
 355         put_8(h->header_data_len, buffer_iterator);
 356         put_8(h->unknown2, buffer_iterator);
 357         put_8(h->unknown3, buffer_iterator);
 358         put_le32(h->header_data.data.field0, buffer_iterator);
 359         put_le32(h->header_data.data.field1, buffer_iterator);
 360         put_le32(h->header_data.data.field2, buffer_iterator);
 361         put_le32(h->header_data.data.field3, buffer_iterator);
 362 }
 363
 364 static void unserialize_header(uint8_t *buffer, struct am7xxx_header *h)
 365 {
 366         uint8_t **buffer_iterator = &buffer;
 367
 368         h->packet_type = get_le32(buffer_iterator);
 369         h->direction = get_8(buffer_iterator);
 370         h->header_data_len = get_8(buffer_iterator);
 371         h->unknown2 = get_8(buffer_iterator);
 372         h->unknown3 = get_8(buffer_iterator);
 373         h->header_data.data.field0 = get_le32(buffer_iterator);
 374         h->header_data.data.field1 = get_le32(buffer_iterator);
 375         h->header_data.data.field2 = get_le32(buffer_iterator);
 376         h->header_data.data.field3 = get_le32(buffer_iterator);
 377 }
 378
 379 static int read_header(am7xxx_device *dev, struct am7xxx_header *h)
 380 {
 381         int ret;
 382
 383         ret = read_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 384         if (ret < 0)
 385                 goto out;
 386
 387         unserialize_header(dev->buffer, h);
 388
 389         if (h->direction == AM7XXX_DIRECTION_IN) {
 390                 ret = 0;
 391         } else {
 392                 error(dev->ctx,
 393                       "Expected an AM7XXX_DIRECTION_IN packet, got one with direction = %d. Weird!\n",
 394                       h->direction);
 395                 ret = -EINVAL;
 396         }
 397
 398         debug_dump_header(dev->ctx, h);
 399
 400 out:
 401         return ret;
 402 }
 403
 404 static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 405 {
 406         int ret;
 407
 408         debug_dump_header(dev->ctx, h);
 409
 410         /* For symmetry with read_header() we should check here for
 411          * h->direction == AM7XXX_DIRECTION_OUT but we just ensure that in all
 412          * the callers and save some cycles here.
 413          */
 414
 415         serialize_header(h, dev->buffer);
 416
 417         ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 418         if (ret < 0)
 419                 error(dev->ctx, "failed to send data\n");
 420
 421         return ret;
 422 }
 423
 424 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
 425  * and print the message unconditionally, this makes it possible to print
 426  * fatal messages even early on initialization, before the context has been
 427  * set up */
 428 static void log_message(am7xxx_context *ctx,
 429                         int level,
 430                         const char *function,
 431                         int line,
 432                         const char *fmt,
 433                         ...)
 434 {
 435         va_list ap;
 436
 437         if (level == AM7XXX_LOG_FATAL || (ctx && level <= ctx->log_level)) {
 438                 if (function) {
 439                         fprintf(stderr, "%s", function);
 440                         if (line)
 441                                 fprintf(stderr, "[%d]", line);
 442                         fprintf(stderr, ": ");
 443                 }
 444
 445                 va_start(ap, fmt);
 446                 vfprintf(stderr, fmt, ap);
 447                 va_end(ap);
 448         }
 449
 450         return;
 451 }
 452
 453 static am7xxx_device *add_new_device(am7xxx_context *ctx)
 454 {
 455         am7xxx_device **devices_list;
 456         am7xxx_device *new_device;
 457
 458         if (ctx == NULL) {
 459                 fatal("context must not be NULL!\n");
 460                 return NULL;
 461         }
 462
 463         new_device = malloc(sizeof(*new_device));
 464         if (new_device == NULL) {
 465                 fatal("cannot allocate a new device (%s)\n", strerror(errno));
 466                 return NULL;
 467         }
 468         memset(new_device, 0, sizeof(*new_device));
 469
 470         new_device->ctx = ctx;
 471
 472         devices_list = &(ctx->devices_list);
 473
 474         if (*devices_list == NULL) {
 475                 *devices_list = new_device;
 476         } else {
 477                 am7xxx_device *prev = *devices_list;
 478                 while (prev->next)
 479                         prev = prev->next;
 480                 prev->next = new_device;
 481         }
 482         return new_device;
 483 }
 484
 485 static am7xxx_device *find_device(am7xxx_context *ctx,
 486                                   unsigned int device_index)
 487 {
 488         unsigned int i = 0;
 489         am7xxx_device *current;
 490
 491         if (ctx == NULL) {
 492                 fatal("context must not be NULL!\n");
 493                 return NULL;
 494         }
 495
 496         current = ctx->devices_list;
 497         while (current && i++ < device_index)
 498                 current = current->next;
 499
 500         return current;
 501 }
 502
 503 typedef enum {
 504         SCAN_OP_BUILD_DEVLIST,
 505         SCAN_OP_OPEN_DEVICE,
 506 } scan_op;
 507
 508 /**
 509  * This is where the central logic of multi-device support is.
 510  *
 511  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
 512  * 'dev' are ignored; the function returns 0 on success and a negative value
 513  * on error.
 514  *
 515  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
 516  * device with index 'open_device_index' and returns the correspondent
 517  * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
 518  * 1 if the device was already open and a negative value on error.
 519  *
 520  * NOTES:
 521  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
 522  * the caller might want to call am7xxx_shutdown() in order to remove
 523  * devices possibly added before the failure.
 524  */
 525 static int scan_devices(am7xxx_context *ctx, scan_op op,
 526                         unsigned int open_device_index, am7xxx_device **dev)
 527 {
 528         int num_devices;
 529         libusb_device** list;
 530         unsigned int current_index;
 531         int i;
 532         int ret;
 533
 534         if (ctx == NULL) {
 535                 fatal("context must not be NULL!\n");
 536                 return -EINVAL;
 537         }
 538         if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
 539                 error(ctx, "device scan done already? Abort!\n");
 540                 return -EINVAL;
 541         }
 542
 543         num_devices = libusb_get_device_list(ctx->usb_context, &list);
 544         if (num_devices < 0) {
 545                 ret = -ENODEV;
 546                 goto out;
 547         }
 548
 549         current_index = 0;
 550         for (i = 0; i < num_devices; i++) {
 551                 struct libusb_device_descriptor desc;
 552                 unsigned int j;
 553
 554                 ret = libusb_get_device_descriptor(list[i], &desc);
 555                 if (ret < 0)
 556                         continue;
 557
 558                 for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
 559                         if (desc.idVendor == supported_devices[j].vendor_id
 560                             && desc.idProduct == supported_devices[j].product_id) {
 561
 562                                 if (op == SCAN_OP_BUILD_DEVLIST) {
 563                                         am7xxx_device *new_device;
 564                                         info(ctx, "am7xxx device found, index: %d, name: %s\n",
 565                                              current_index,
 566                                              supported_devices[j].name);
 567                                         new_device = add_new_device(ctx);
 568                                         if (new_device == NULL) {
 569                                                 /* XXX, the caller may want
 570                                                  * to call am7xxx_shutdown() if
 571                                                  * we fail here, as we may have
 572                                                  * added some devices already
 573                                                  */
 574                                                 debug(ctx, "Cannot create a new device\n");
 575                                                 ret = -ENODEV;
 576                                                 goto out;
 577                                         }
 578                                 } else if (op == SCAN_OP_OPEN_DEVICE &&
 579                                            current_index == open_device_index) {
 580
 581                                         *dev = find_device(ctx, open_device_index);
 582                                         if (*dev == NULL) {
 583                                                 ret = -ENODEV;
 584                                                 goto out;
 585                                         }
 586
 587                                         /* the usb device has already been opened */
 588                                         if ((*dev)->usb_device) {
 589                                                 debug(ctx, "(*dev)->usb_device already set\n");
 590                                                 ret = 1;
 591                                                 goto out;
 592                                         }
 593
 594                                         ret = libusb_open(list[i], &((*dev)->usb_device));
 595                                         if (ret < 0) {
 596                                                 debug(ctx, "libusb_open failed\n");
 597                                                 goto out;
 598                                         }
 599
 600                                         libusb_set_configuration((*dev)->usb_device, 2);
 601                                         libusb_claim_interface((*dev)->usb_device, 0);
 602                                         goto out;
 603                                 }
 604                                 current_index++;
 605                         }
 606                 }
 607         }
 608
 609         /* if we made it up to here we didn't find any device to open */
 610         if (op == SCAN_OP_OPEN_DEVICE) {
 611                 error(ctx, "Cannot find any device to open\n");
 612                 ret = -ENODEV;
 613                 goto out;
 614         }
 615
 616         /* everything went fine when building the device list */
 617         ret = 0;
 618 out:
 619         libusb_free_device_list(list, 1);
 620         return ret;
 621 }
 622
 623 /* Public API */
 624
 625 AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 626 {
 627         int ret = 0;
 628
 629         *ctx = malloc(sizeof(**ctx));
 630         if (*ctx == NULL) {
 631                 fatal("cannot allocate the context (%s)\n", strerror(errno));
 632                 ret = -ENOMEM;
 633                 goto out;
 634         }
 635         memset(*ctx, 0, sizeof(**ctx));
 636
 637         /* Set the highest log level during initialization */
 638         (*ctx)->log_level = AM7XXX_LOG_TRACE;
 639
 640         ret = libusb_init(&((*ctx)->usb_context));
 641         if (ret < 0)
 642                 goto out_free_context;
 643
 644         libusb_set_debug((*ctx)->usb_context, 3);
 645
 646         ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
 647         if (ret < 0) {
 648                 error(*ctx, "scan_devices() failed\n");
 649                 am7xxx_shutdown(*ctx);
 650                 goto out;
 651         }
 652
 653         /* Set a quieter log level as default for normal operation */
 654         (*ctx)->log_level = AM7XXX_LOG_ERROR;
 655         return 0;
 656
 657 out_free_context:
 658         free(*ctx);
 659         *ctx = NULL;
 660 out:
 661         return ret;
 662 }
 663
 664 AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 665 {
 666         am7xxx_device *current;
 667
 668         if (ctx == NULL) {
 669                 fatal("context must not be NULL!\n");
 670                 return;
 671         }
 672
 673         current = ctx->devices_list;
 674         while (current) {
 675                 am7xxx_device *next = current->next;
 676                 am7xxx_close_device(current);
 677                 free(current);
 678                 current = next;
 679         }
 680
 681         libusb_exit(ctx->usb_context);
 682         free(ctx);
 683         ctx = NULL;
 684 }
 685
 686 AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 687 {
 688         ctx->log_level = log_level;
 689 }
 690
 691 AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 692                        unsigned int device_index)
 693 {
 694         int ret;
 695
 696         if (ctx == NULL) {
 697                 fatal("context must not be NULL!\n");
 698                 return -EINVAL;
 699         }
 700
 701         ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
 702         if (ret < 0) {
 703                 errno = ENODEV;
 704         } else if (ret > 0) {
 705                 warning(ctx, "device %d already open\n", device_index);
 706                 errno = EBUSY;
 707                 ret = -EBUSY;
 708         }
 709
 710         return ret;
 711 }
 712
 713 AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 714 {
 715         if (dev == NULL) {
 716                 fatal("dev must not be NULL!\n");
 717                 return -EINVAL;
 718         }
 719         if (dev->usb_device) {
 720                 libusb_release_interface(dev->usb_device, 0);
 721                 libusb_close(dev->usb_device);
 722                 dev->usb_device = NULL;
 723         }
 724         return 0;
 725 }
 726
 727 AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 728                            am7xxx_device_info *device_info)
 729 {
 730         int ret;
 731         struct am7xxx_header h = {
 732                 .packet_type     = AM7XXX_PACKET_TYPE_DEVINFO,
 733                 .direction       = AM7XXX_DIRECTION_OUT,
 734                 .header_data_len = 0x00,
 735                 .unknown2        = 0x3e,
 736                 .unknown3        = 0x10,
 737                 .header_data = {
 738                         .devinfo = {
 739                                 .native_width  = 0,
 740                                 .native_height = 0,
 741                                 .unknown0      = 0,
 742                                 .unknown1      = 0,
 743                         },
 744                 },
 745         };
 746
 747         ret = send_header(dev, &h);
 748         if (ret < 0)
 749                 return ret;
 750
 751         ret = read_header(dev, &h);
 752         if (ret < 0)
 753                 return ret;
 754
 755         device_info->native_width = h.header_data.devinfo.native_width;
 756         device_info->native_height = h.header_data.devinfo.native_height;
 757 #if 0
 758         /* No reason to expose these in the public API until we know what they mean */
 759         device_info->unknown0 = h.header_data.devinfo.unknown0;
 760         device_info->unknown1 = h.header_data.devinfo.unknown1;
 761 #endif
 762
 763         return 0;
 764 }
 765
 766 AM7XXX_PUBLIC int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
 767                                         unsigned int upscale,
 768                                         unsigned int original_width,
 769                                         unsigned int original_height,
 770                                         unsigned int *scaled_width,
 771                                         unsigned int *scaled_height)
 772 {
 773
 774         am7xxx_device_info device_info;
 775         float width_ratio;
 776         float height_ratio;
 777         int ret;
 778
 779         ret = am7xxx_get_device_info(dev, &device_info);
 780         if (ret < 0) {
 781                 error(dev->ctx, "cannot get device info\n");
 782                 return ret;
 783         }
 784
 785         /*
 786          * Check if we need to rescale; if the input image fits the native
 787          * dimensions there is no need to, unless we want to upscale.
 788          */
 789         if (!upscale &&
 790             original_width <= device_info.native_width &&
 791             original_height <= device_info.native_height ) {
 792                 debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
 793                 *scaled_width = original_width;
 794                 *scaled_height = original_height;
 795                 return 0;
 796         }
 797
 798         /* Input dimensions relative to the device native dimensions */
 799         width_ratio =  (float)original_width / device_info.native_width;
 800         height_ratio = (float)original_height / device_info.native_height;
 801
 802         if (width_ratio > height_ratio) {
 803                 /*
 804                  * The input is proportionally "wider" than the device viewport
 805                  * so its height needs to be adjusted
 806                  */
 807                 debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
 808                 *scaled_width = device_info.native_width;
 809                 *scaled_height = (unsigned int)lroundf(original_height / width_ratio);
 810         } else if (width_ratio < height_ratio) {
 811                 /*
 812                  * The input is proportionally "taller" than the device viewport
 813                  * so its width needs to be adjusted
 814                  */
 815                 debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
 816                 *scaled_width = (unsigned int)lroundf(original_width / height_ratio);
 817                 *scaled_height = device_info.native_height;
 818         } else {
 819                 debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
 820                 *scaled_width = device_info.native_width;
 821                 *scaled_height = device_info.native_height;
 822         }
 823         debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
 824
 825         return 0;
 826 }
 827
 828 AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
 829                       am7xxx_image_format format,
 830                       unsigned int width,
 831                       unsigned int height,
 832                       uint8_t *image,
 833                       unsigned int image_size)
 834 {
 835         int ret;
 836         struct am7xxx_header h = {
 837                 .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
 838                 .direction       = AM7XXX_DIRECTION_OUT,
 839                 .header_data_len = sizeof(struct am7xxx_image_header),
 840                 .unknown2        = 0x3e,
 841                 .unknown3        = 0x10,
 842                 .header_data = {
 843                         .image = {
 844                                 .format     = format,
 845                                 .width      = width,
 846                                 .height     = height,
 847                                 .image_size = image_size,
 848                         },
 849                 },
 850         };
 851
 852         ret = send_header(dev, &h);
 853         if (ret < 0)
 854                 return ret;
 855
 856         if (image == NULL || image_size == 0) {
 857                 warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
 858                 return 0;
 859         }
 860
 861         return send_data(dev, image, image_size);
 862 }
 863
 864 AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power)
 865 {
 866         int ret;
 867         struct am7xxx_header h = {
 868                 .packet_type     = AM7XXX_PACKET_TYPE_POWER,
 869                 .direction       = AM7XXX_DIRECTION_OUT,
 870                 .header_data_len = sizeof(struct am7xxx_power_header),
 871                 .unknown2        = 0x3e,
 872                 .unknown3        = 0x10,
 873         };
 874
 875         switch(power) {
 876         case AM7XXX_POWER_OFF:
 877                 h.header_data.power.bit2 = 0;
 878                 h.header_data.power.bit1 = 0;
 879                 h.header_data.power.bit0 = 0;
 880                 break;
 881
 882         case AM7XXX_POWER_LOW:
 883                 h.header_data.power.bit2 = 0;
 884                 h.header_data.power.bit1 = 0;
 885                 h.header_data.power.bit0 = 1;
 886                 break;
 887
 888         case AM7XXX_POWER_MIDDLE:
 889                 h.header_data.power.bit2 = 0;
 890                 h.header_data.power.bit1 = 1;
 891                 h.header_data.power.bit0 = 0;
 892                 break;
 893
 894         case AM7XXX_POWER_HIGH:
 895                 h.header_data.power.bit2 = 0;
 896                 h.header_data.power.bit1 = 1;
 897                 h.header_data.power.bit0 = 1;
 898                 break;
 899
 900         case AM7XXX_POWER_TURBO:
 901                 h.header_data.power.bit2 = 1;
 902                 h.header_data.power.bit1 = 0;
 903                 h.header_data.power.bit0 = 0;
 904                 break;
 905
 906         default:
 907                 error(dev->ctx, "Unsupported power mode.\n");
 908                 return -EINVAL;
 909         };
 910
 911         ret = send_header(dev, &h);
 912         if (ret < 0)
 913                 return ret;
 914
 915         return 0;
 916 }
 917
 918 AM7XXX_PUBLIC int am7xxx_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom)
 919 {
 920         int ret;
 921         struct am7xxx_header h = {
 922                 .packet_type     = AM7XXX_PACKET_TYPE_ZOOM,
 923                 .direction       = AM7XXX_DIRECTION_OUT,
 924                 .header_data_len = sizeof(struct am7xxx_zoom_header),
 925                 .unknown2        = 0x3e,
 926                 .unknown3        = 0x10,
 927         };
 928
 929         switch(zoom) {
 930         case AM7XXX_ZOOM_ORIGINAL:
 931                 h.header_data.zoom.bit1 = 0;
 932                 h.header_data.zoom.bit0 = 0;
 933                 break;
 934
 935         case AM7XXX_ZOOM_H:
 936                 h.header_data.zoom.bit1 = 0;
 937                 h.header_data.zoom.bit0 = 1;
 938                 break;
 939
 940         case AM7XXX_ZOOM_H_V:
 941                 h.header_data.zoom.bit1 = 1;
 942                 h.header_data.zoom.bit0 = 0;
 943                 break;
 944
 945         case AM7XXX_ZOOM_TEST:
 946                 h.header_data.zoom.bit1 = 1;
 947                 h.header_data.zoom.bit0 = 1;
 948                 break;
 949
 950         default:
 951                 error(dev->ctx, "Unsupported zoom mode.\n");
 952                 return -EINVAL;
 953         };
 954
 955         ret = send_header(dev, &h);
 956         if (ret < 0)
 957                 return ret;
 958
 959         return 0;
 960 }