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