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
  96 /* The header size on the wire is known to be always 24 bytes, regardless of
  97  * the memory configuration enforced by different architectures or compilers
  98  * for struct am7xxx_header
  99  */
 100 #define AM7XXX_HEADER_WIRE_SIZE 24
 101
 102 struct _am7xxx_device {
 103         libusb_device_handle *usb_device;
 104         uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
 105         am7xxx_context *ctx;
 106         am7xxx_device *next;
 107 };
 108
 109 struct _am7xxx_context {
 110         libusb_context *usb_context;
 111         int log_level;
 112         am7xxx_device *devices_list;
 113 };
 114
 115 typedef enum {
 116         AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
 117         AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
 118         AM7XXX_PACKET_TYPE_POWER   = 0x04,
 119         AM7XXX_PACKET_TYPE_UNKNOWN = 0x05,
 120 } am7xxx_packet_type;
 121
 122 struct am7xxx_generic_header {
 123         uint32_t field0;
 124         uint32_t field1;
 125         uint32_t field2;
 126         uint32_t field3;
 127 };
 128
 129 struct am7xxx_devinfo_header {
 130         uint32_t native_width;
 131         uint32_t native_height;
 132         uint32_t unknown0;
 133         uint32_t unknown1;
 134 };
 135
 136 struct am7xxx_image_header {
 137         uint32_t format;
 138         uint32_t width;
 139         uint32_t height;
 140         uint32_t image_size;
 141 };
 142
 143 struct am7xxx_power_header {
 144         uint32_t bit2;
 145         uint32_t bit1;
 146         uint32_t bit0;
 147 };
 148
 149 /*
 150  * Examples of packet headers:
 151  *
 152  * Image header:
 153  * 02 00 00 00 00 10 3e 10 01 00 00 00 20 03 00 00 e0 01 00 00 53 E8 00 00
 154  *
 155  * Power header:
 156  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 157  */
 158
 159 /* Direction of the communication from the host point of view */
 160 #define AM7XXX_DIRECTION_OUT 0 /* host -> device */
 161 #define AM7XXX_DIRECTION_IN  1 /* host <- device */
 162
 163 struct am7xxx_header {
 164         uint32_t packet_type;
 165         uint8_t direction;
 166         uint8_t header_data_len;
 167         uint8_t unknown2;
 168         uint8_t unknown3;
 169         union {
 170                 struct am7xxx_generic_header data;
 171                 struct am7xxx_devinfo_header devinfo;
 172                 struct am7xxx_image_header image;
 173                 struct am7xxx_power_header power;
 174         } header_data;
 175 };
 176
 177
 178 #ifdef DEBUG
 179 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 180 {
 181         if (ctx == NULL || d == NULL)
 182                 return;
 183
 184         debug(ctx, "Info header:\n");
 185         debug(ctx, "\tnative_width:  0x%08x (%u)\n", d->native_width, d->native_width);
 186         debug(ctx, "\tnative_height: 0x%08x (%u)\n", d->native_height, d->native_height);
 187         debug(ctx, "\tunknown0:      0x%08x (%u)\n", d->unknown0, d->unknown0);
 188         debug(ctx, "\tunknown1:      0x%08x (%u)\n", d->unknown1, d->unknown1);
 189 }
 190
 191 static void debug_dump_image_header(am7xxx_context *ctx, struct am7xxx_image_header *i)
 192 {
 193         if (ctx == NULL || i == NULL)
 194                 return;
 195
 196         debug(ctx, "Image header:\n");
 197         debug(ctx, "\tformat:     0x%08x (%u)\n", i->format, i->format);
 198         debug(ctx, "\twidth:      0x%08x (%u)\n", i->width, i->width);
 199         debug(ctx, "\theight:     0x%08x (%u)\n", i->height, i->height);
 200         debug(ctx, "\timage size: 0x%08x (%u)\n", i->image_size, i->image_size);
 201 }
 202
 203 static void debug_dump_power_header(am7xxx_context *ctx, struct am7xxx_power_header *p)
 204 {
 205         if (ctx == NULL || p == NULL)
 206                 return;
 207
 208         debug(ctx, "Power header:\n");
 209         debug(ctx, "\tbit2: 0x%08x (%u)\n", p->bit2, p->bit2);
 210         debug(ctx, "\tbit1: 0x%08x (%u)\n", p->bit1, p->bit1);
 211         debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 212 }
 213
 214 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 215 {
 216         if (ctx == NULL || h == NULL)
 217                 return;
 218
 219         debug(ctx, "BEGIN\n");
 220         debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
 221         debug(ctx, "direction:       0x%02hhx (%hhu)\n", h->direction, h->direction);
 222         debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
 223         debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
 224         debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
 225
 226         switch(h->packet_type) {
 227         case AM7XXX_PACKET_TYPE_DEVINFO:
 228                 debug_dump_devinfo_header(ctx, &(h->header_data.devinfo));
 229                 break;
 230
 231         case AM7XXX_PACKET_TYPE_IMAGE:
 232                 debug_dump_image_header(ctx, &(h->header_data.image));
 233                 break;
 234
 235         case AM7XXX_PACKET_TYPE_POWER:
 236                 debug_dump_power_header(ctx, &(h->header_data.power));
 237                 break;
 238
 239         default:
 240                 debug(ctx, "Packet type not supported!\n");
 241                 break;
 242         }
 243         debug(ctx, "END\n\n");
 244 }
 245
 246 static inline unsigned int in_80chars(unsigned int i)
 247 {
 248         /* The 3 below is the length of "xx " where xx is the hex string
 249          * representation of a byte */
 250         return ((i+1) % (80/3));
 251 }
 252
 253 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 254                               uint8_t *buffer, unsigned int len)
 255 {
 256         unsigned int i;
 257
 258         if (ctx == NULL || buffer == NULL || len == 0)
 259                 return;
 260
 261         trace(ctx, "\n");
 262         if (message)
 263                 trace(ctx, "%s\n", message);
 264
 265         for (i = 0; i < len; i++) {
 266                 trace(ctx, "%02hhX%c", buffer[i], (in_80chars(i) && (i < len - 1)) ? ' ' : '\n');
 267         }
 268         trace(ctx, "\n");
 269 }
 270 #else
 271 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 272 {
 273         (void)ctx;
 274         (void)h;
 275 }
 276
 277 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 278                               uint8_t *buffer, unsigned int len)
 279 {
 280         (void)ctx;
 281         (void)message;
 282         (void)buffer;
 283         (void)len;
 284 }
 285 #endif /* DEBUG */
 286
 287 static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 288 {
 289         int ret;
 290         int transferred = 0;
 291
 292         ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
 293         if (ret != 0 || (unsigned int)transferred != len) {
 294                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 295                       ret, transferred, len);
 296                 return ret;
 297         }
 298
 299         trace_dump_buffer(dev->ctx, "<-- received", buffer, len);
 300
 301         return 0;
 302 }
 303
 304 static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 305 {
 306         int ret;
 307         int transferred = 0;
 308
 309         trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 310
 311         ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
 312         if (ret != 0 || (unsigned int)transferred != len) {
 313                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 314                       ret, transferred, len);
 315                 return ret;
 316         }
 317
 318         return 0;
 319 }
 320
 321 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 322 {
 323         uint8_t **buffer_iterator = &buffer;
 324
 325         put_le32(h->packet_type, buffer_iterator);
 326         put_8(h->direction, buffer_iterator);
 327         put_8(h->header_data_len, buffer_iterator);
 328         put_8(h->unknown2, buffer_iterator);
 329         put_8(h->unknown3, buffer_iterator);
 330         put_le32(h->header_data.data.field0, buffer_iterator);
 331         put_le32(h->header_data.data.field1, buffer_iterator);
 332         put_le32(h->header_data.data.field2, buffer_iterator);
 333         put_le32(h->header_data.data.field3, buffer_iterator);
 334 }
 335
 336 static void unserialize_header(uint8_t *buffer, struct am7xxx_header *h)
 337 {
 338         uint8_t **buffer_iterator = &buffer;
 339
 340         h->packet_type = get_le32(buffer_iterator);
 341         h->direction = get_8(buffer_iterator);
 342         h->header_data_len = get_8(buffer_iterator);
 343         h->unknown2 = get_8(buffer_iterator);
 344         h->unknown3 = get_8(buffer_iterator);
 345         h->header_data.data.field0 = get_le32(buffer_iterator);
 346         h->header_data.data.field1 = get_le32(buffer_iterator);
 347         h->header_data.data.field2 = get_le32(buffer_iterator);
 348         h->header_data.data.field3 = get_le32(buffer_iterator);
 349 }
 350
 351 static int read_header(am7xxx_device *dev, struct am7xxx_header *h)
 352 {
 353         int ret;
 354
 355         ret = read_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 356         if (ret < 0)
 357                 goto out;
 358
 359         unserialize_header(dev->buffer, h);
 360
 361         debug_dump_header(dev->ctx, h);
 362
 363         if (h->direction == AM7XXX_DIRECTION_IN) {
 364                 ret = 0;
 365         } else {
 366                 error(dev->ctx,
 367                       "Received a packet with direction AM7XXX_DIRECTION_OUT, weird!\n");
 368                 ret = -EINVAL;
 369         }
 370
 371 out:
 372         return ret;
 373 }
 374
 375 static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 376 {
 377         int ret;
 378
 379         debug_dump_header(dev->ctx, h);
 380
 381         serialize_header(h, dev->buffer);
 382         ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 383         if (ret < 0)
 384                 error(dev->ctx, "failed to send data\n");
 385
 386         return ret;
 387 }
 388
 389 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
 390  * and print the message unconditionally, this makes it possible to print
 391  * fatal messages even early on initialization, before the context has been
 392  * set up */
 393 static void log_message(am7xxx_context *ctx,
 394                         int level,
 395                         const char *function,
 396                         int line,
 397                         const char *fmt,
 398                         ...)
 399 {
 400         va_list ap;
 401
 402         if (level == AM7XXX_LOG_FATAL || (ctx && level <= ctx->log_level)) {
 403                 if (function) {
 404                         fprintf(stderr, "%s", function);
 405                         if (line)
 406                                 fprintf(stderr, "[%d]", line);
 407                         fprintf(stderr, ": ");
 408                 }
 409
 410                 va_start(ap, fmt);
 411                 vfprintf(stderr, fmt, ap);
 412                 va_end(ap);
 413         }
 414
 415         return;
 416 }
 417
 418 static am7xxx_device *add_new_device(am7xxx_context *ctx)
 419 {
 420         am7xxx_device **devices_list;
 421         am7xxx_device *new_device;
 422
 423         if (ctx == NULL) {
 424                 fatal("context must not be NULL!\n");
 425                 return NULL;
 426         }
 427
 428         devices_list = &(ctx->devices_list);
 429
 430         new_device = malloc(sizeof(*new_device));
 431         if (new_device == NULL) {
 432                 fatal("cannot allocate a new device (%s)\n", strerror(errno));
 433                 return NULL;
 434         }
 435         memset(new_device, 0, sizeof(*new_device));
 436
 437         new_device->ctx = ctx;
 438
 439         if (*devices_list == NULL) {
 440                 *devices_list = new_device;
 441         } else {
 442                 am7xxx_device *prev = *devices_list;
 443                 while (prev->next)
 444                         prev = prev->next;
 445                 prev->next = new_device;
 446         }
 447         return new_device;
 448 }
 449
 450 static am7xxx_device *find_device(am7xxx_context *ctx,
 451                                   unsigned int device_index)
 452 {
 453         unsigned int i = 0;
 454         am7xxx_device *current;
 455
 456         if (ctx == NULL) {
 457                 fatal("context must not be NULL!\n");
 458                 return NULL;
 459         }
 460
 461         current = ctx->devices_list;
 462         while (current && i++ < device_index)
 463                 current = current->next;
 464
 465         return current;
 466 }
 467
 468 typedef enum {
 469         SCAN_OP_BUILD_DEVLIST,
 470         SCAN_OP_OPEN_DEVICE,
 471 } scan_op;
 472
 473 /**
 474  * This is where the central logic of multi-device support is.
 475  *
 476  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
 477  * 'dev' are ignored; the function returns 0 on success and a negative value
 478  * on error.
 479  *
 480  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
 481  * device with index 'open_device_index' and returns the correspondent
 482  * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
 483  * 1 if the device was already open and a negative value on error.
 484  *
 485  * NOTES:
 486  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
 487  * the caller might want to call am7xxx_shutdown() in order to remove
 488  * devices possibly added before the failure.
 489  */
 490 static int scan_devices(am7xxx_context *ctx, scan_op op,
 491                         unsigned int open_device_index, am7xxx_device **dev)
 492 {
 493         int num_devices;
 494         libusb_device** list;
 495         unsigned int current_index;
 496         int i;
 497         int ret;
 498
 499         if (ctx == NULL) {
 500                 fatal("context must not be NULL!\n");
 501                 return -EINVAL;
 502         }
 503         if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
 504                 error(ctx, "device scan done already? Abort!\n");
 505                 return -EINVAL;
 506         }
 507
 508         num_devices = libusb_get_device_list(ctx->usb_context, &list);
 509         if (num_devices < 0) {
 510                 ret = -ENODEV;
 511                 goto out;
 512         }
 513
 514         current_index = 0;
 515         for (i = 0; i < num_devices; i++) {
 516                 struct libusb_device_descriptor desc;
 517                 unsigned int j;
 518
 519                 ret = libusb_get_device_descriptor(list[i], &desc);
 520                 if (ret < 0)
 521                         continue;
 522
 523                 for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
 524                         if (desc.idVendor == supported_devices[j].vendor_id
 525                             && desc.idProduct == supported_devices[j].product_id) {
 526
 527                                 if (op == SCAN_OP_BUILD_DEVLIST) {
 528                                         am7xxx_device *new_device;
 529                                         info(ctx, "am7xxx device found, index: %d, name: %s\n",
 530                                              current_index,
 531                                              supported_devices[j].name);
 532                                         new_device = add_new_device(ctx);
 533                                         if (new_device == NULL) {
 534                                                 /* XXX, the caller may want
 535                                                  * to call am7xxx_shutdown() if
 536                                                  * we fail here, as we may have
 537                                                  * added some devices already
 538                                                  */
 539                                                 debug(ctx, "Cannot create a new device\n");
 540                                                 ret = -ENODEV;
 541                                                 goto out;
 542                                         }
 543                                 } else if (op == SCAN_OP_OPEN_DEVICE &&
 544                                            current_index == open_device_index) {
 545
 546                                         *dev = find_device(ctx, open_device_index);
 547                                         if (*dev == NULL) {
 548                                                 ret = -ENODEV;
 549                                                 goto out;
 550                                         }
 551
 552                                         /* the usb device has already been opened */
 553                                         if ((*dev)->usb_device) {
 554                                                 debug(ctx, "(*dev)->usb_device already set\n");
 555                                                 ret = 1;
 556                                                 goto out;
 557                                         }
 558
 559                                         ret = libusb_open(list[i], &((*dev)->usb_device));
 560                                         if (ret < 0) {
 561                                                 debug(ctx, "libusb_open failed\n");
 562                                                 goto out;
 563                                         }
 564
 565                                         libusb_set_configuration((*dev)->usb_device, 2);
 566                                         libusb_claim_interface((*dev)->usb_device, 0);
 567                                         goto out;
 568                                 }
 569                                 current_index++;
 570                         }
 571                 }
 572         }
 573
 574         /* if we made it up to here we didn't find any device to open */
 575         if (op == SCAN_OP_OPEN_DEVICE) {
 576                 error(ctx, "Cannot find any device to open\n");
 577                 ret = -ENODEV;
 578                 goto out;
 579         }
 580
 581         /* everything went fine when building the device list */
 582         ret = 0;
 583 out:
 584         libusb_free_device_list(list, 1);
 585         return ret;
 586 }
 587
 588 /* Public API */
 589
 590 AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 591 {
 592         int ret = 0;
 593
 594         *ctx = malloc(sizeof(**ctx));
 595         if (*ctx == NULL) {
 596                 fatal("cannot allocate the context (%s)\n", strerror(errno));
 597                 ret = -ENOMEM;
 598                 goto out;
 599         }
 600         memset(*ctx, 0, sizeof(**ctx));
 601
 602         /* Set the highest log level during initialization */
 603         (*ctx)->log_level = AM7XXX_LOG_TRACE;
 604
 605         ret = libusb_init(&((*ctx)->usb_context));
 606         if (ret < 0)
 607                 goto out_free_context;
 608
 609         libusb_set_debug((*ctx)->usb_context, 3);
 610
 611         ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
 612         if (ret < 0) {
 613                 error(*ctx, "scan_devices() failed\n");
 614                 am7xxx_shutdown(*ctx);
 615                 goto out;
 616         }
 617
 618         /* Set a quieter log level as default for normal operation */
 619         (*ctx)->log_level = AM7XXX_LOG_ERROR;
 620         return 0;
 621
 622 out_free_context:
 623         free(*ctx);
 624         *ctx = NULL;
 625 out:
 626         return ret;
 627 }
 628
 629 AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 630 {
 631         am7xxx_device *current;
 632
 633         if (ctx == NULL) {
 634                 fatal("context must not be NULL!\n");
 635                 return;
 636         }
 637
 638         current = ctx->devices_list;
 639         while (current) {
 640                 am7xxx_device *next = current->next;
 641                 am7xxx_close_device(current);
 642                 free(current);
 643                 current = next;
 644         }
 645
 646         libusb_exit(ctx->usb_context);
 647         free(ctx);
 648         ctx = NULL;
 649 }
 650
 651 AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 652 {
 653         ctx->log_level = log_level;
 654 }
 655
 656 AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 657                        unsigned int device_index)
 658 {
 659         int ret;
 660
 661         if (ctx == NULL) {
 662                 fatal("context must not be NULL!\n");
 663                 return -EINVAL;
 664         }
 665
 666         ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
 667         if (ret < 0) {
 668                 errno = ENODEV;
 669         } else if (ret > 0) {
 670                 warning(ctx, "device %d already open\n", device_index);
 671                 errno = EBUSY;
 672                 ret = -EBUSY;
 673         }
 674
 675         return ret;
 676 }
 677
 678 AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 679 {
 680         if (dev == NULL) {
 681                 fatal("dev must not be NULL!\n");
 682                 return -EINVAL;
 683         }
 684         if (dev->usb_device) {
 685                 libusb_release_interface(dev->usb_device, 0);
 686                 libusb_close(dev->usb_device);
 687                 dev->usb_device = NULL;
 688         }
 689         return 0;
 690 }
 691
 692 AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 693                            am7xxx_device_info *device_info)
 694 {
 695         int ret;
 696         struct am7xxx_header h = {
 697                 .packet_type     = AM7XXX_PACKET_TYPE_DEVINFO,
 698                 .direction       = AM7XXX_DIRECTION_OUT,
 699                 .header_data_len = 0x00,
 700                 .unknown2        = 0x3e,
 701                 .unknown3        = 0x10,
 702                 .header_data = {
 703                         .devinfo = {
 704                                 .native_width  = 0,
 705                                 .native_height = 0,
 706                                 .unknown0      = 0,
 707                                 .unknown1      = 0,
 708                         },
 709                 },
 710         };
 711
 712         ret = send_header(dev, &h);
 713         if (ret < 0)
 714                 return ret;
 715
 716         ret = read_header(dev, &h);
 717         if (ret < 0)
 718                 return ret;
 719
 720         device_info->native_width = h.header_data.devinfo.native_width;
 721         device_info->native_height = h.header_data.devinfo.native_height;
 722 #if 0
 723         /* No reason to expose these in the public API until we know what they mean */
 724         device_info->unknown0 = h.header_data.devinfo.unknown0;
 725         device_info->unknown1 = h.header_data.devinfo.unknown1;
 726 #endif
 727
 728         return 0;
 729 }
 730
 731 AM7XXX_PUBLIC int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
 732                                         unsigned int upscale,
 733                                         unsigned int original_width,
 734                                         unsigned int original_height,
 735                                         unsigned int *scaled_width,
 736                                         unsigned int *scaled_height)
 737 {
 738
 739         am7xxx_device_info device_info;
 740         float width_ratio;
 741         float height_ratio;
 742         int ret;
 743
 744         ret = am7xxx_get_device_info(dev, &device_info);
 745         if (ret < 0) {
 746                 error(dev->ctx, "cannot get device info\n");
 747                 return ret;
 748         }
 749
 750         /*
 751          * Check if we need to rescale; if the input image fits the native
 752          * dimensions there is no need to, unless we want to upscale.
 753          */
 754         if (!upscale &&
 755             original_width <= device_info.native_width &&
 756             original_height <= device_info.native_height ) {
 757                 debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
 758                 *scaled_width = original_width;
 759                 *scaled_height = original_height;
 760                 return 0;
 761         }
 762
 763         /* Input dimensions relative to the device native dimensions */
 764         width_ratio =  (float)original_width / device_info.native_width;
 765         height_ratio = (float)original_height / device_info.native_height;
 766
 767         if (width_ratio > height_ratio) {
 768                 /*
 769                  * The input is proportionally "wider" than the device viewport
 770                  * so its height needs to be adjusted
 771                  */
 772                 debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
 773                 *scaled_width = device_info.native_width;
 774                 *scaled_height = (unsigned int)lroundf(original_height / width_ratio);
 775         } else if (width_ratio < height_ratio) {
 776                 /*
 777                  * The input is proportionally "taller" than the device viewport
 778                  * so its width needs to be adjusted
 779                  */
 780                 debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
 781                 *scaled_width = (unsigned int)lroundf(original_width / height_ratio);
 782                 *scaled_height = device_info.native_height;
 783         } else {
 784                 debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
 785                 *scaled_width = device_info.native_width;
 786                 *scaled_height = device_info.native_height;
 787         }
 788         debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
 789
 790         return 0;
 791 }
 792
 793 AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
 794                       am7xxx_image_format format,
 795                       unsigned int width,
 796                       unsigned int height,
 797                       uint8_t *image,
 798                       unsigned int image_size)
 799 {
 800         int ret;
 801         struct am7xxx_header h = {
 802                 .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
 803                 .direction       = AM7XXX_DIRECTION_OUT,
 804                 .header_data_len = sizeof(struct am7xxx_image_header),
 805                 .unknown2        = 0x3e,
 806                 .unknown3        = 0x10,
 807                 .header_data = {
 808                         .image = {
 809                                 .format     = format,
 810                                 .width      = width,
 811                                 .height     = height,
 812                                 .image_size = image_size,
 813                         },
 814                 },
 815         };
 816
 817         ret = send_header(dev, &h);
 818         if (ret < 0)
 819                 return ret;
 820
 821         if (image == NULL || image_size == 0) {
 822                 warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
 823                 return 0;
 824         }
 825
 826         return send_data(dev, image, image_size);
 827 }
 828
 829 AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode)
 830 {
 831         int ret;
 832         struct am7xxx_header h = {
 833                 .packet_type     = AM7XXX_PACKET_TYPE_POWER,
 834                 .direction       = AM7XXX_DIRECTION_OUT,
 835                 .header_data_len = sizeof(struct am7xxx_power_header),
 836                 .unknown2        = 0x3e,
 837                 .unknown3        = 0x10,
 838         };
 839
 840         switch(mode) {
 841         case AM7XXX_POWER_OFF:
 842                 h.header_data.power.bit2 = 0;
 843                 h.header_data.power.bit1 = 0;
 844                 h.header_data.power.bit0 = 0;
 845                 break;
 846
 847         case AM7XXX_POWER_LOW:
 848                 h.header_data.power.bit2 = 0;
 849                 h.header_data.power.bit1 = 0;
 850                 h.header_data.power.bit0 = 1;
 851                 break;
 852
 853         case AM7XXX_POWER_MIDDLE:
 854                 h.header_data.power.bit2 = 0;
 855                 h.header_data.power.bit1 = 1;
 856                 h.header_data.power.bit0 = 0;
 857                 break;
 858
 859         case AM7XXX_POWER_HIGH:
 860                 h.header_data.power.bit2 = 0;
 861                 h.header_data.power.bit1 = 1;
 862                 h.header_data.power.bit0 = 1;
 863                 break;
 864
 865         case AM7XXX_POWER_TURBO:
 866                 h.header_data.power.bit2 = 1;
 867                 h.header_data.power.bit1 = 0;
 868                 h.header_data.power.bit0 = 0;
 869                 break;
 870
 871         default:
 872                 error(dev->ctx, "Power mode not supported!\n");
 873                 return -EINVAL;
 874         };
 875
 876         ret = send_header(dev, &h);
 877         if (ret < 0)
 878                 return ret;
 879
 880         return 0;
 881 }