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       = "Philips/Sagemcom PicoPix 1020",
  81                 .vendor_id  = 0x21e7,
  82                 .product_id = 0x000e,
  83         },
  84 };
  85
  86 /* The header size on the wire is known to be always 24 bytes, regardless of
  87  * the memory configuration enforced by different architectures or compilers
  88  * for struct am7xxx_header
  89  */
  90 #define AM7XXX_HEADER_WIRE_SIZE 24
  91
  92 struct _am7xxx_device {
  93         libusb_device_handle *usb_device;
  94         uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
  95         am7xxx_context *ctx;
  96         am7xxx_device *next;
  97 };
  98
  99 struct _am7xxx_context {
 100         libusb_context *usb_context;
 101         int log_level;
 102         am7xxx_device *devices_list;
 103 };
 104
 105 typedef enum {
 106         AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
 107         AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
 108         AM7XXX_PACKET_TYPE_POWER   = 0x04,
 109         AM7XXX_PACKET_TYPE_UNKNOWN = 0x05,
 110 } am7xxx_packet_type;
 111
 112 struct am7xxx_generic_header {
 113         uint32_t field0;
 114         uint32_t field1;
 115         uint32_t field2;
 116         uint32_t field3;
 117 };
 118
 119 struct am7xxx_devinfo_header {
 120         uint32_t native_width;
 121         uint32_t native_height;
 122         uint32_t unknown0;
 123         uint32_t unknown1;
 124 };
 125
 126 struct am7xxx_image_header {
 127         uint32_t format;
 128         uint32_t width;
 129         uint32_t height;
 130         uint32_t image_size;
 131 };
 132
 133 struct am7xxx_power_header {
 134         uint32_t bit2;
 135         uint32_t bit1;
 136         uint32_t bit0;
 137 };
 138
 139 /*
 140  * Examples of packet headers:
 141  *
 142  * Image header:
 143  * 02 00 00 00 00 10 3e 10 01 00 00 00 20 03 00 00 e0 01 00 00 53 E8 00 00
 144  *
 145  * Power header:
 146  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 147  */
 148
 149 struct am7xxx_header {
 150         uint32_t packet_type;
 151         uint8_t unknown0;
 152         uint8_t header_data_len;
 153         uint8_t unknown2;
 154         uint8_t unknown3;
 155         union {
 156                 struct am7xxx_generic_header data;
 157                 struct am7xxx_devinfo_header devinfo;
 158                 struct am7xxx_image_header image;
 159                 struct am7xxx_power_header power;
 160         } header_data;
 161 };
 162
 163
 164 #ifdef DEBUG
 165 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 166 {
 167         if (ctx == NULL || d == NULL)
 168                 return;
 169
 170         debug(ctx, "Info header:\n");
 171         debug(ctx, "\tnative_width:  0x%08x (%u)\n", d->native_width, d->native_width);
 172         debug(ctx, "\tnative_height: 0x%08x (%u)\n", d->native_height, d->native_height);
 173         debug(ctx, "\tunknown0:      0x%08x (%u)\n", d->unknown0, d->unknown0);
 174         debug(ctx, "\tunknown1:      0x%08x (%u)\n", d->unknown1, d->unknown1);
 175 }
 176
 177 static void debug_dump_image_header(am7xxx_context *ctx, struct am7xxx_image_header *i)
 178 {
 179         if (ctx == NULL || i == NULL)
 180                 return;
 181
 182         debug(ctx, "Image header:\n");
 183         debug(ctx, "\tformat:     0x%08x (%u)\n", i->format, i->format);
 184         debug(ctx, "\twidth:      0x%08x (%u)\n", i->width, i->width);
 185         debug(ctx, "\theight:     0x%08x (%u)\n", i->height, i->height);
 186         debug(ctx, "\timage size: 0x%08x (%u)\n", i->image_size, i->image_size);
 187 }
 188
 189 static void debug_dump_power_header(am7xxx_context *ctx, struct am7xxx_power_header *p)
 190 {
 191         if (ctx == NULL || p == NULL)
 192                 return;
 193
 194         debug(ctx, "Power header:\n");
 195         debug(ctx, "\tbit2: 0x%08x (%u)\n", p->bit2, p->bit2);
 196         debug(ctx, "\tbit1: 0x%08x (%u)\n", p->bit1, p->bit1);
 197         debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 198 }
 199
 200 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 201 {
 202         if (ctx == NULL || h == NULL)
 203                 return;
 204
 205         debug(ctx, "BEGIN\n");
 206         debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
 207         debug(ctx, "unknown0:        0x%02hhx (%hhu)\n", h->unknown0, h->unknown0);
 208         debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
 209         debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
 210         debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
 211
 212         switch(h->packet_type) {
 213         case AM7XXX_PACKET_TYPE_DEVINFO:
 214                 debug_dump_devinfo_header(ctx, &(h->header_data.devinfo));
 215                 break;
 216
 217         case AM7XXX_PACKET_TYPE_IMAGE:
 218                 debug_dump_image_header(ctx, &(h->header_data.image));
 219                 break;
 220
 221         case AM7XXX_PACKET_TYPE_POWER:
 222                 debug_dump_power_header(ctx, &(h->header_data.power));
 223                 break;
 224
 225         default:
 226                 debug(ctx, "Packet type not supported!\n");
 227                 break;
 228         }
 229         debug(ctx, "END\n\n");
 230 }
 231
 232 static inline unsigned int in_80chars(unsigned int i)
 233 {
 234         /* The 3 below is the length of "xx " where xx is the hex string
 235          * representation of a byte */
 236         return ((i+1) % (80/3));
 237 }
 238
 239 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 240                               uint8_t *buffer, unsigned int len)
 241 {
 242         unsigned int i;
 243
 244         if (ctx == NULL || buffer == NULL || len == 0)
 245                 return;
 246
 247         trace(ctx, "\n");
 248         if (message)
 249                 trace(ctx, "%s\n", message);
 250
 251         for (i = 0; i < len; i++) {
 252                 trace(ctx, "%02hhX%c", buffer[i], (in_80chars(i) && (i < len - 1)) ? ' ' : '\n');
 253         }
 254         trace(ctx, "\n");
 255 }
 256 #else
 257 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 258 {
 259         (void)ctx;
 260         (void)h;
 261 }
 262
 263 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 264                               uint8_t *buffer, unsigned int len)
 265 {
 266         (void)ctx;
 267         (void)message;
 268         (void)buffer;
 269         (void)len;
 270 }
 271 #endif /* DEBUG */
 272
 273 static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 274 {
 275         int ret;
 276         int transferred = 0;
 277
 278         ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
 279         if (ret != 0 || (unsigned int)transferred != len) {
 280                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 281                       ret, transferred, len);
 282                 return ret;
 283         }
 284
 285         trace_dump_buffer(dev->ctx, "<-- received", buffer, len);
 286
 287         return 0;
 288 }
 289
 290 static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 291 {
 292         int ret;
 293         int transferred = 0;
 294
 295         trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 296
 297         ret = libusb_bulk_transfer(dev->usb_device, 1, buffer, len, &transferred, 0);
 298         if (ret != 0 || (unsigned int)transferred != len) {
 299                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 300                       ret, transferred, len);
 301                 return ret;
 302         }
 303
 304         return 0;
 305 }
 306
 307 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 308 {
 309         uint8_t **buffer_iterator = &buffer;
 310
 311         put_le32(h->packet_type, buffer_iterator);
 312         put_8(h->unknown0, buffer_iterator);
 313         put_8(h->header_data_len, buffer_iterator);
 314         put_8(h->unknown2, buffer_iterator);
 315         put_8(h->unknown3, buffer_iterator);
 316         put_le32(h->header_data.data.field0, buffer_iterator);
 317         put_le32(h->header_data.data.field1, buffer_iterator);
 318         put_le32(h->header_data.data.field2, buffer_iterator);
 319         put_le32(h->header_data.data.field3, buffer_iterator);
 320 }
 321
 322 static void unserialize_header(uint8_t *buffer, struct am7xxx_header *h)
 323 {
 324         uint8_t **buffer_iterator = &buffer;
 325
 326         h->packet_type = get_le32(buffer_iterator);
 327         h->unknown0 = get_8(buffer_iterator);
 328         h->header_data_len = get_8(buffer_iterator);
 329         h->unknown2 = get_8(buffer_iterator);
 330         h->unknown3 = get_8(buffer_iterator);
 331         h->header_data.data.field0 = get_le32(buffer_iterator);
 332         h->header_data.data.field1 = get_le32(buffer_iterator);
 333         h->header_data.data.field2 = get_le32(buffer_iterator);
 334         h->header_data.data.field3 = get_le32(buffer_iterator);
 335 }
 336
 337 static int read_header(am7xxx_device *dev, struct am7xxx_header *h)
 338 {
 339         int ret;
 340
 341         ret = read_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 342         if (ret < 0)
 343                 goto out;
 344
 345         unserialize_header(dev->buffer, h);
 346
 347         debug_dump_header(dev->ctx, h);
 348
 349         ret = 0;
 350
 351 out:
 352         return ret;
 353 }
 354
 355 static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 356 {
 357         int ret;
 358
 359         debug_dump_header(dev->ctx, h);
 360
 361         serialize_header(h, dev->buffer);
 362         ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 363         if (ret < 0)
 364                 error(dev->ctx, "failed to send data\n");
 365
 366         return ret;
 367 }
 368
 369 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
 370  * and print the message unconditionally, this makes it possible to print
 371  * fatal messages even early on initialization, before the context has been
 372  * set up */
 373 static void log_message(am7xxx_context *ctx,
 374                         int level,
 375                         const char *function,
 376                         int line,
 377                         const char *fmt,
 378                         ...)
 379 {
 380         va_list ap;
 381
 382         if (level == AM7XXX_LOG_FATAL || (ctx && level <= ctx->log_level)) {
 383                 if (function) {
 384                         fprintf(stderr, "%s", function);
 385                         if (line)
 386                                 fprintf(stderr, "[%d]", line);
 387                         fprintf(stderr, ": ");
 388                 }
 389
 390                 va_start(ap, fmt);
 391                 vfprintf(stderr, fmt, ap);
 392                 va_end(ap);
 393         }
 394
 395         return;
 396 }
 397
 398 static am7xxx_device *add_new_device(am7xxx_context *ctx)
 399 {
 400         am7xxx_device **devices_list;
 401         am7xxx_device *new_device;
 402
 403         if (ctx == NULL) {
 404                 fatal("context must not be NULL!\n");
 405                 return NULL;
 406         }
 407
 408         devices_list = &(ctx->devices_list);
 409
 410         new_device = malloc(sizeof(*new_device));
 411         if (new_device == NULL) {
 412                 fatal("cannot allocate a new device (%s)\n", strerror(errno));
 413                 return NULL;
 414         }
 415         memset(new_device, 0, sizeof(*new_device));
 416
 417         new_device->ctx = ctx;
 418
 419         if (*devices_list == NULL) {
 420                 *devices_list = new_device;
 421         } else {
 422                 am7xxx_device *prev = *devices_list;
 423                 while (prev->next)
 424                         prev = prev->next;
 425                 prev->next = new_device;
 426         }
 427         return new_device;
 428 }
 429
 430 static am7xxx_device *find_device(am7xxx_context *ctx,
 431                                   unsigned int device_index)
 432 {
 433         unsigned int i = 0;
 434         am7xxx_device *current;
 435
 436         if (ctx == NULL) {
 437                 fatal("context must not be NULL!\n");
 438                 return NULL;
 439         }
 440
 441         current = ctx->devices_list;
 442         while (current && i++ < device_index)
 443                 current = current->next;
 444
 445         return current;
 446 }
 447
 448 typedef enum {
 449         SCAN_OP_BUILD_DEVLIST,
 450         SCAN_OP_OPEN_DEVICE,
 451 } scan_op;
 452
 453 /**
 454  * This is where the central logic of multi-device support is.
 455  *
 456  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
 457  * 'dev' are ignored; the function returns 0 on success and a negative value
 458  * on error.
 459  *
 460  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
 461  * device with index 'open_device_index' and returns the correspondent
 462  * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
 463  * 1 if the device was already open and a negative value on error.
 464  *
 465  * NOTES:
 466  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
 467  * the caller might want to call am7xxx_shutdown() in order to remove
 468  * devices possibly added before the failure.
 469  */
 470 static int scan_devices(am7xxx_context *ctx, scan_op op,
 471                         unsigned int open_device_index, am7xxx_device **dev)
 472 {
 473         int num_devices;
 474         libusb_device** list;
 475         unsigned int current_index;
 476         int i;
 477         int ret;
 478
 479         if (ctx == NULL) {
 480                 fatal("context must not be NULL!\n");
 481                 return -EINVAL;
 482         }
 483         if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
 484                 error(ctx, "device scan done already? Abort!\n");
 485                 return -EINVAL;
 486         }
 487
 488         num_devices = libusb_get_device_list(ctx->usb_context, &list);
 489         if (num_devices < 0) {
 490                 ret = -ENODEV;
 491                 goto out;
 492         }
 493
 494         current_index = 0;
 495         for (i = 0; i < num_devices; i++) {
 496                 struct libusb_device_descriptor desc;
 497                 unsigned int j;
 498
 499                 ret = libusb_get_device_descriptor(list[i], &desc);
 500                 if (ret < 0)
 501                         continue;
 502
 503                 for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
 504                         if (desc.idVendor == supported_devices[j].vendor_id
 505                             && desc.idProduct == supported_devices[j].product_id) {
 506
 507                                 if (op == SCAN_OP_BUILD_DEVLIST) {
 508                                         am7xxx_device *new_device;
 509                                         info(ctx, "am7xxx device found, index: %d, name: %s\n",
 510                                              current_index,
 511                                              supported_devices[j].name);
 512                                         new_device = add_new_device(ctx);
 513                                         if (new_device == NULL) {
 514                                                 /* XXX, the caller may want
 515                                                  * to call am7xxx_shutdown() if
 516                                                  * we fail here, as we may have
 517                                                  * added some devices already
 518                                                  */
 519                                                 debug(ctx, "Cannot create a new device\n");
 520                                                 ret = -ENODEV;
 521                                                 goto out;
 522                                         }
 523                                 } else if (op == SCAN_OP_OPEN_DEVICE &&
 524                                            current_index == open_device_index) {
 525
 526                                         *dev = find_device(ctx, open_device_index);
 527                                         if (*dev == NULL) {
 528                                                 ret = -ENODEV;
 529                                                 goto out;
 530                                         }
 531
 532                                         /* the usb device has already been opened */
 533                                         if ((*dev)->usb_device) {
 534                                                 debug(ctx, "(*dev)->usb_device already set\n");
 535                                                 ret = 1;
 536                                                 goto out;
 537                                         }
 538
 539                                         ret = libusb_open(list[i], &((*dev)->usb_device));
 540                                         if (ret < 0) {
 541                                                 debug(ctx, "libusb_open failed\n");
 542                                                 goto out;
 543                                         }
 544
 545                                         libusb_set_configuration((*dev)->usb_device, 1);
 546                                         libusb_claim_interface((*dev)->usb_device, 0);
 547                                         goto out;
 548                                 }
 549                                 current_index++;
 550                         }
 551                 }
 552         }
 553
 554         /* if we made it up to here we didn't find any device to open */
 555         if (op == SCAN_OP_OPEN_DEVICE) {
 556                 error(ctx, "Cannot find any device to open\n");
 557                 ret = -ENODEV;
 558                 goto out;
 559         }
 560
 561         /* everything went fine when building the device list */
 562         ret = 0;
 563 out:
 564         libusb_free_device_list(list, 1);
 565         return ret;
 566 }
 567
 568 /* Public API */
 569
 570 AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 571 {
 572         int ret = 0;
 573
 574         *ctx = malloc(sizeof(**ctx));
 575         if (*ctx == NULL) {
 576                 fatal("cannot allocate the context (%s)\n", strerror(errno));
 577                 ret = -ENOMEM;
 578                 goto out;
 579         }
 580         memset(*ctx, 0, sizeof(**ctx));
 581
 582         /* Set the highest log level during initialization */
 583         (*ctx)->log_level = AM7XXX_LOG_TRACE;
 584
 585         ret = libusb_init(&((*ctx)->usb_context));
 586         if (ret < 0)
 587                 goto out_free_context;
 588
 589         libusb_set_debug((*ctx)->usb_context, 3);
 590
 591         ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
 592         if (ret < 0) {
 593                 error(*ctx, "scan_devices() failed\n");
 594                 am7xxx_shutdown(*ctx);
 595                 goto out;
 596         }
 597
 598         /* Set a quieter log level as default for normal operation */
 599         (*ctx)->log_level = AM7XXX_LOG_ERROR;
 600         return 0;
 601
 602 out_free_context:
 603         free(*ctx);
 604         *ctx = NULL;
 605 out:
 606         return ret;
 607 }
 608
 609 AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 610 {
 611         am7xxx_device *current;
 612
 613         if (ctx == NULL) {
 614                 fatal("context must not be NULL!\n");
 615                 return;
 616         }
 617
 618         current = ctx->devices_list;
 619         while (current) {
 620                 am7xxx_device *next = current->next;
 621                 am7xxx_close_device(current);
 622                 free(current);
 623                 current = next;
 624         }
 625
 626         libusb_exit(ctx->usb_context);
 627         free(ctx);
 628         ctx = NULL;
 629 }
 630
 631 AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 632 {
 633         ctx->log_level = log_level;
 634 }
 635
 636 AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 637                        unsigned int device_index)
 638 {
 639         int ret;
 640
 641         if (ctx == NULL) {
 642                 fatal("context must not be NULL!\n");
 643                 return -EINVAL;
 644         }
 645
 646         ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
 647         if (ret < 0) {
 648                 errno = ENODEV;
 649         } else if (ret > 0) {
 650                 warning(ctx, "device %d already open\n", device_index);
 651                 errno = EBUSY;
 652                 ret = -EBUSY;
 653         }
 654
 655         return ret;
 656 }
 657
 658 AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 659 {
 660         if (dev == NULL) {
 661                 fatal("dev must not be NULL!\n");
 662                 return -EINVAL;
 663         }
 664         if (dev->usb_device) {
 665                 libusb_release_interface(dev->usb_device, 0);
 666                 libusb_close(dev->usb_device);
 667                 dev->usb_device = NULL;
 668         }
 669         return 0;
 670 }
 671
 672 AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 673                            am7xxx_device_info *device_info)
 674 {
 675         int ret;
 676         struct am7xxx_header h = {
 677                 .packet_type     = AM7XXX_PACKET_TYPE_DEVINFO,
 678                 .unknown0        = 0x00,
 679                 .header_data_len = 0x00,
 680                 .unknown2        = 0x3e,
 681                 .unknown3        = 0x10,
 682                 .header_data = {
 683                         .devinfo = {
 684                                 .native_width  = 0,
 685                                 .native_height = 0,
 686                                 .unknown0      = 0,
 687                                 .unknown1      = 0,
 688                         },
 689                 },
 690         };
 691
 692         ret = send_header(dev, &h);
 693         if (ret < 0)
 694                 return ret;
 695
 696         ret = read_header(dev, &h);
 697         if (ret < 0)
 698                 return ret;
 699
 700         device_info->native_width = h.header_data.devinfo.native_width;
 701         device_info->native_height = h.header_data.devinfo.native_height;
 702 #if 0
 703         /* No reason to expose these in the public API until we know what they mean */
 704         device_info->unknown0 = h.header_data.devinfo.unknown0;
 705         device_info->unknown1 = h.header_data.devinfo.unknown1;
 706 #endif
 707
 708         return 0;
 709 }
 710
 711 AM7XXX_PUBLIC int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
 712                                         unsigned int upscale,
 713                                         unsigned int original_width,
 714                                         unsigned int original_height,
 715                                         unsigned int *scaled_width,
 716                                         unsigned int *scaled_height)
 717 {
 718
 719         am7xxx_device_info device_info;
 720         float width_ratio;
 721         float height_ratio;
 722         int ret;
 723
 724         ret = am7xxx_get_device_info(dev, &device_info);
 725         if (ret < 0) {
 726                 error(dev->ctx, "cannot get device info\n");
 727                 return ret;
 728         }
 729
 730         /*
 731          * Check if we need to rescale; if the input image fits the native
 732          * dimensions there is no need to, unless we want to upscale.
 733          */
 734         if (!upscale &&
 735             original_width <= device_info.native_width &&
 736             original_height <= device_info.native_height ) {
 737                 debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
 738                 *scaled_width = original_width;
 739                 *scaled_height = original_height;
 740                 return 0;
 741         }
 742
 743         /* Input dimensions relative to the device native dimensions */
 744         width_ratio =  (float)original_width / device_info.native_width;
 745         height_ratio = (float)original_height / device_info.native_height;
 746
 747         if (width_ratio > height_ratio) {
 748                 /*
 749                  * The input is proportionally "wider" than the device viewport
 750                  * so its height needs to be adjusted
 751                  */
 752                 debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
 753                 *scaled_width = device_info.native_width;
 754                 *scaled_height = (unsigned int)lroundf(original_height / width_ratio);
 755         } else if (width_ratio < height_ratio) {
 756                 /*
 757                  * The input is proportionally "taller" than the device viewport
 758                  * so its width needs to be adjusted
 759                  */
 760                 debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
 761                 *scaled_width = (unsigned int)lroundf(original_width / height_ratio);
 762                 *scaled_height = device_info.native_height;
 763         } else {
 764                 debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
 765                 *scaled_width = device_info.native_width;
 766                 *scaled_height = device_info.native_height;
 767         }
 768         debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
 769
 770         return 0;
 771 }
 772
 773 AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
 774                       am7xxx_image_format format,
 775                       unsigned int width,
 776                       unsigned int height,
 777                       uint8_t *image,
 778                       unsigned int image_size)
 779 {
 780         int ret;
 781         struct am7xxx_header h = {
 782                 .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
 783                 .unknown0        = 0x00,
 784                 .header_data_len = sizeof(struct am7xxx_image_header),
 785                 .unknown2        = 0x3e,
 786                 .unknown3        = 0x10,
 787                 .header_data = {
 788                         .image = {
 789                                 .format     = format,
 790                                 .width      = width,
 791                                 .height     = height,
 792                                 .image_size = image_size,
 793                         },
 794                 },
 795         };
 796
 797         ret = send_header(dev, &h);
 798         if (ret < 0)
 799                 return ret;
 800
 801         if (image == NULL || image_size == 0) {
 802                 warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
 803                 return 0;
 804         }
 805
 806         return send_data(dev, image, image_size);
 807 }
 808
 809 AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode)
 810 {
 811         int ret;
 812         struct am7xxx_header h = {
 813                 .packet_type     = AM7XXX_PACKET_TYPE_POWER,
 814                 .unknown0        = 0x00,
 815                 .header_data_len = sizeof(struct am7xxx_power_header),
 816                 .unknown2        = 0x3e,
 817                 .unknown3        = 0x10,
 818         };
 819
 820         switch(mode) {
 821         case AM7XXX_POWER_OFF:
 822                 h.header_data.power.bit2 = 0;
 823                 h.header_data.power.bit1 = 0;
 824                 h.header_data.power.bit0 = 0;
 825                 break;
 826
 827         case AM7XXX_POWER_LOW:
 828                 h.header_data.power.bit2 = 0;
 829                 h.header_data.power.bit1 = 0;
 830                 h.header_data.power.bit0 = 1;
 831
 832         case AM7XXX_POWER_MIDDLE:
 833                 h.header_data.power.bit2 = 0;
 834                 h.header_data.power.bit1 = 1;
 835                 h.header_data.power.bit0 = 0;
 836                 break;
 837
 838         case AM7XXX_POWER_HIGH:
 839                 h.header_data.power.bit2 = 0;
 840                 h.header_data.power.bit1 = 1;
 841                 h.header_data.power.bit0 = 1;
 842                 break;
 843
 844         case AM7XXX_POWER_TURBO:
 845                 h.header_data.power.bit2 = 1;
 846                 h.header_data.power.bit1 = 0;
 847                 h.header_data.power.bit0 = 0;
 848                 break;
 849
 850         default:
 851                 error(dev->ctx, "Power mode not supported!\n");
 852                 return -EINVAL;
 853         };
 854
 855         ret = send_header(dev, &h);
 856         if (ret < 0)
 857                 return ret;
 858
 859         return 0;
 860 }