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