src/am7xxx.c

   1 /* am7xxx - communication with AM7xxx based USB Pico Projectors and DPFs
   2  *
   3  * Copyright (C) 2012  Antonio Ospite <ospite@studenti.unina.it>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <stdarg.h>
  23 #include <errno.h>
  24 #include <libusb.h>
  25 #include <math.h>
  26
  27 #include "am7xxx.h"
  28 #include "serialize.h"
  29
  30 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  31
  32 /* If we're not using GNU C, elide __attribute__
  33  * taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
  34  */
  35 #ifndef __GNUC__
  36 #  define  __attribute__(x)  /*NOTHING*/
  37 #endif
  38
  39 /* Control shared library symbols visibility */
  40 #if defined _WIN32 || defined __CYGWIN__
  41         #define AM7XXX_PUBLIC __declspec(dllexport)
  42         #define AM7XXX_LOCAL
  43 #else
  44         #if __GNUC__ >= 4
  45                 #define AM7XXX_PUBLIC __attribute__ ((visibility ("default")))
  46                 #define AM7XXX_LOCAL  __attribute__ ((visibility ("hidden")))
  47         #else
  48                 #define AM7XXX_PUBLIC
  49                 #define AM7XXX_LOCAL
  50         #endif
  51 #endif
  52
  53 static void log_message(am7xxx_context *ctx,
  54                         int level,
  55                         const char *function,
  56                         int line,
  57                         const char *fmt,
  58                         ...) __attribute__ ((format (printf, 5, 6)));
  59
  60 #define fatal(...)        log_message(NULL, AM7XXX_LOG_FATAL,   __func__, __LINE__, __VA_ARGS__)
  61 #define error(ctx, ...)   log_message(ctx,  AM7XXX_LOG_ERROR,   __func__, __LINE__, __VA_ARGS__)
  62 #define warning(ctx, ...) log_message(ctx,  AM7XXX_LOG_WARNING, __func__, 0,        __VA_ARGS__)
  63 #define info(ctx, ...)    log_message(ctx,  AM7XXX_LOG_INFO,    __func__, 0,        __VA_ARGS__)
  64 #define debug(ctx, ...)   log_message(ctx,  AM7XXX_LOG_DEBUG,   __func__, 0,        __VA_ARGS__)
  65 #define trace(ctx, ...)   log_message(ctx,  AM7XXX_LOG_TRACE,   NULL,     0,        __VA_ARGS__)
  66
  67 struct am7xxx_usb_device_descriptor {
  68         const char *name;
  69         uint16_t vendor_id;
  70         uint16_t product_id;
  71 };
  72
  73 static struct am7xxx_usb_device_descriptor supported_devices[] = {
  74         {
  75                 .name       = "Acer C110",
  76                 .vendor_id  = 0x1de1,
  77                 .product_id = 0xc101,
  78         },
  79         {
  80                 .name       = "Acer C112",
  81                 .vendor_id  = 0x1de1,
  82                 .product_id = 0x5501,
  83         },
  84         {
  85                 .name       ="Aiptek PocketCinema T25",
  86                 .vendor_id  = 0x08ca,
  87                 .product_id = 0x2144,
  88         },
  89         {
  90                 .name       = "Philips/Sagemcom PicoPix 1020",
  91                 .vendor_id  = 0x21e7,
  92                 .product_id = 0x000e,
  93         },
  94         {
  95                 .name       = "Philips/Sagemcom PicoPix 2055",
  96                 .vendor_id  = 0x21e7,
  97                 .product_id = 0x0016,
  98         },
  99 };
 100
 101 /* The header size on the wire is known to be always 24 bytes, regardless of
 102  * the memory configuration enforced by different architectures or compilers
 103  * for struct am7xxx_header
 104  */
 105 #define AM7XXX_HEADER_WIRE_SIZE 24
 106
 107 struct _am7xxx_device {
 108         libusb_device_handle *usb_device;
 109         uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
 110         am7xxx_device_info *device_info;
 111         am7xxx_context *ctx;
 112         am7xxx_device *next;
 113 };
 114
 115 struct _am7xxx_context {
 116         libusb_context *usb_context;
 117         int log_level;
 118         am7xxx_device *devices_list;
 119 };
 120
 121 typedef enum {
 122         AM7XXX_PACKET_TYPE_DEVINFO = 0x01,
 123         AM7XXX_PACKET_TYPE_IMAGE   = 0x02,
 124         AM7XXX_PACKET_TYPE_POWER   = 0x04,
 125         AM7XXX_PACKET_TYPE_ZOOM    = 0x05,
 126 } am7xxx_packet_type;
 127
 128 struct am7xxx_generic_header {
 129         uint32_t field0;
 130         uint32_t field1;
 131         uint32_t field2;
 132         uint32_t field3;
 133 };
 134
 135 struct am7xxx_devinfo_header {
 136         uint32_t native_width;
 137         uint32_t native_height;
 138         uint32_t unknown0;
 139         uint32_t unknown1;
 140 };
 141
 142 struct am7xxx_image_header {
 143         uint32_t format;
 144         uint32_t width;
 145         uint32_t height;
 146         uint32_t image_size;
 147 };
 148
 149 struct am7xxx_power_header {
 150         uint32_t bit2;
 151         uint32_t bit1;
 152         uint32_t bit0;
 153 };
 154
 155 struct am7xxx_zoom_header {
 156         uint32_t bit1;
 157         uint32_t bit0;
 158 };
 159
 160 /*
 161  * Examples of packet headers:
 162  *
 163  * Image header:
 164  * 02 00 00 00 00 10 3e 10 01 00 00 00 20 03 00 00 e0 01 00 00 53 E8 00 00
 165  *
 166  * Power header:
 167  * 04 00 00 00 00 0c ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 168  */
 169
 170 /* Direction of the communication from the host point of view */
 171 #define AM7XXX_DIRECTION_OUT 0 /* host -> device */
 172 #define AM7XXX_DIRECTION_IN  1 /* host <- device */
 173
 174 struct am7xxx_header {
 175         uint32_t packet_type;
 176         uint8_t direction;
 177         uint8_t header_data_len;
 178         uint8_t unknown2;
 179         uint8_t unknown3;
 180         union {
 181                 struct am7xxx_generic_header data;
 182                 struct am7xxx_devinfo_header devinfo;
 183                 struct am7xxx_image_header image;
 184                 struct am7xxx_power_header power;
 185                 struct am7xxx_zoom_header zoom;
 186         } header_data;
 187 };
 188
 189
 190 #ifdef DEBUG
 191 static void debug_dump_devinfo_header(am7xxx_context *ctx, struct am7xxx_devinfo_header *d)
 192 {
 193         if (ctx == NULL || d == NULL)
 194                 return;
 195
 196         debug(ctx, "Info header:\n");
 197         debug(ctx, "\tnative_width:  0x%08x (%u)\n", d->native_width, d->native_width);
 198         debug(ctx, "\tnative_height: 0x%08x (%u)\n", d->native_height, d->native_height);
 199         debug(ctx, "\tunknown0:      0x%08x (%u)\n", d->unknown0, d->unknown0);
 200         debug(ctx, "\tunknown1:      0x%08x (%u)\n", d->unknown1, d->unknown1);
 201 }
 202
 203 static void debug_dump_image_header(am7xxx_context *ctx, struct am7xxx_image_header *i)
 204 {
 205         if (ctx == NULL || i == NULL)
 206                 return;
 207
 208         debug(ctx, "Image header:\n");
 209         debug(ctx, "\tformat:     0x%08x (%u)\n", i->format, i->format);
 210         debug(ctx, "\twidth:      0x%08x (%u)\n", i->width, i->width);
 211         debug(ctx, "\theight:     0x%08x (%u)\n", i->height, i->height);
 212         debug(ctx, "\timage size: 0x%08x (%u)\n", i->image_size, i->image_size);
 213 }
 214
 215 static void debug_dump_power_header(am7xxx_context *ctx, struct am7xxx_power_header *p)
 216 {
 217         if (ctx == NULL || p == NULL)
 218                 return;
 219
 220         debug(ctx, "Power header:\n");
 221         debug(ctx, "\tbit2: 0x%08x (%u)\n", p->bit2, p->bit2);
 222         debug(ctx, "\tbit1: 0x%08x (%u)\n", p->bit1, p->bit1);
 223         debug(ctx, "\tbit0: 0x%08x (%u)\n", p->bit0, p->bit0);
 224 }
 225
 226 static void debug_dump_zoom_header(am7xxx_context *ctx, struct am7xxx_zoom_header *z)
 227 {
 228         if (ctx == NULL || z == NULL)
 229                 return;
 230
 231         debug(ctx, "Zoom header:\n");
 232         debug(ctx, "\tbit1: 0x%08x (%u)\n", z->bit1, z->bit1);
 233         debug(ctx, "\tbit0: 0x%08x (%u)\n", z->bit0, z->bit0);
 234 }
 235
 236 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 237 {
 238         if (ctx == NULL || h == NULL)
 239                 return;
 240
 241         debug(ctx, "BEGIN\n");
 242         debug(ctx, "packet_type:     0x%08x (%u)\n", h->packet_type, h->packet_type);
 243         debug(ctx, "direction:       0x%02hhx (%hhu) (%s)\n", h->direction, h->direction,
 244               h->direction == AM7XXX_DIRECTION_IN ? "IN" :
 245               h->direction == AM7XXX_DIRECTION_OUT ? "OUT" :
 246               "UNKNOWN");
 247         debug(ctx, "header_data_len: 0x%02hhx (%hhu)\n", h->header_data_len, h->header_data_len);
 248         debug(ctx, "unknown2:        0x%02hhx (%hhu)\n", h->unknown2, h->unknown2);
 249         debug(ctx, "unknown3:        0x%02hhx (%hhu)\n", h->unknown3, h->unknown3);
 250
 251         switch(h->packet_type) {
 252         case AM7XXX_PACKET_TYPE_DEVINFO:
 253                 debug_dump_devinfo_header(ctx, &(h->header_data.devinfo));
 254                 break;
 255
 256         case AM7XXX_PACKET_TYPE_IMAGE:
 257                 debug_dump_image_header(ctx, &(h->header_data.image));
 258                 break;
 259
 260         case AM7XXX_PACKET_TYPE_POWER:
 261                 debug_dump_power_header(ctx, &(h->header_data.power));
 262                 break;
 263
 264         case AM7XXX_PACKET_TYPE_ZOOM:
 265                 debug_dump_zoom_header(ctx, &(h->header_data.zoom));
 266                 break;
 267
 268         default:
 269                 debug(ctx, "Packet type not supported!\n");
 270                 break;
 271         }
 272         debug(ctx, "END\n\n");
 273 }
 274
 275 static inline unsigned int in_80chars(unsigned int i)
 276 {
 277         /* The 3 below is the length of "xx " where xx is the hex string
 278          * representation of a byte */
 279         return ((i+1) % (80/3));
 280 }
 281
 282 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 283                               uint8_t *buffer, unsigned int len)
 284 {
 285         unsigned int i;
 286
 287         if (ctx == NULL || buffer == NULL || len == 0)
 288                 return;
 289
 290         trace(ctx, "\n");
 291         if (message)
 292                 trace(ctx, "%s\n", message);
 293
 294         for (i = 0; i < len; i++) {
 295                 trace(ctx, "%02hhX%c", buffer[i], (in_80chars(i) && (i < len - 1)) ? ' ' : '\n');
 296         }
 297         trace(ctx, "\n");
 298 }
 299 #else
 300 static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
 301 {
 302         (void)ctx;
 303         (void)h;
 304 }
 305
 306 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
 307                               uint8_t *buffer, unsigned int len)
 308 {
 309         (void)ctx;
 310         (void)message;
 311         (void)buffer;
 312         (void)len;
 313 }
 314 #endif /* DEBUG */
 315
 316 static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 317 {
 318         int ret;
 319         int transferred = 0;
 320
 321         ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
 322         if (ret != 0 || (unsigned int)transferred != len) {
 323                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 324                       ret, transferred, len);
 325                 return ret;
 326         }
 327
 328         trace_dump_buffer(dev->ctx, "<-- received", buffer, len);
 329
 330         return 0;
 331 }
 332
 333 static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
 334 {
 335         int ret;
 336         int transferred = 0;
 337
 338         trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 339
 340         ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
 341         if (ret != 0 || (unsigned int)transferred != len) {
 342                 error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
 343                       ret, transferred, len);
 344                 return ret;
 345         }
 346
 347         return 0;
 348 }
 349
 350 static void serialize_header(struct am7xxx_header *h, uint8_t *buffer)
 351 {
 352         uint8_t **buffer_iterator = &buffer;
 353
 354         put_le32(h->packet_type, buffer_iterator);
 355         put_8(h->direction, buffer_iterator);
 356         put_8(h->header_data_len, buffer_iterator);
 357         put_8(h->unknown2, buffer_iterator);
 358         put_8(h->unknown3, buffer_iterator);
 359         put_le32(h->header_data.data.field0, buffer_iterator);
 360         put_le32(h->header_data.data.field1, buffer_iterator);
 361         put_le32(h->header_data.data.field2, buffer_iterator);
 362         put_le32(h->header_data.data.field3, buffer_iterator);
 363 }
 364
 365 static void unserialize_header(uint8_t *buffer, struct am7xxx_header *h)
 366 {
 367         uint8_t **buffer_iterator = &buffer;
 368
 369         h->packet_type = get_le32(buffer_iterator);
 370         h->direction = get_8(buffer_iterator);
 371         h->header_data_len = get_8(buffer_iterator);
 372         h->unknown2 = get_8(buffer_iterator);
 373         h->unknown3 = get_8(buffer_iterator);
 374         h->header_data.data.field0 = get_le32(buffer_iterator);
 375         h->header_data.data.field1 = get_le32(buffer_iterator);
 376         h->header_data.data.field2 = get_le32(buffer_iterator);
 377         h->header_data.data.field3 = get_le32(buffer_iterator);
 378 }
 379
 380 static int read_header(am7xxx_device *dev, struct am7xxx_header *h)
 381 {
 382         int ret;
 383
 384         ret = read_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 385         if (ret < 0)
 386                 goto out;
 387
 388         unserialize_header(dev->buffer, h);
 389
 390         if (h->direction == AM7XXX_DIRECTION_IN) {
 391                 ret = 0;
 392         } else {
 393                 error(dev->ctx,
 394                       "Expected an AM7XXX_DIRECTION_IN packet, got one with direction = %d. Weird!\n",
 395                       h->direction);
 396                 ret = -EINVAL;
 397         }
 398
 399         debug_dump_header(dev->ctx, h);
 400
 401 out:
 402         return ret;
 403 }
 404
 405 static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
 406 {
 407         int ret;
 408
 409         debug_dump_header(dev->ctx, h);
 410
 411         /* For symmetry with read_header() we should check here for
 412          * h->direction == AM7XXX_DIRECTION_OUT but we just ensure that in all
 413          * the callers and save some cycles here.
 414          */
 415
 416         serialize_header(h, dev->buffer);
 417
 418         ret = send_data(dev, dev->buffer, AM7XXX_HEADER_WIRE_SIZE);
 419         if (ret < 0)
 420                 error(dev->ctx, "failed to send data\n");
 421
 422         return ret;
 423 }
 424
 425 /* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
 426  * and print the message unconditionally, this makes it possible to print
 427  * fatal messages even early on initialization, before the context has been
 428  * set up */
 429 static void log_message(am7xxx_context *ctx,
 430                         int level,
 431                         const char *function,
 432                         int line,
 433                         const char *fmt,
 434                         ...)
 435 {
 436         va_list ap;
 437
 438         if (level == AM7XXX_LOG_FATAL || (ctx && level <= ctx->log_level)) {
 439                 if (function) {
 440                         fprintf(stderr, "%s", function);
 441                         if (line)
 442                                 fprintf(stderr, "[%d]", line);
 443                         fprintf(stderr, ": ");
 444                 }
 445
 446                 va_start(ap, fmt);
 447                 vfprintf(stderr, fmt, ap);
 448                 va_end(ap);
 449         }
 450
 451         return;
 452 }
 453
 454 static am7xxx_device *add_new_device(am7xxx_context *ctx)
 455 {
 456         am7xxx_device **devices_list;
 457         am7xxx_device *new_device;
 458
 459         if (ctx == NULL) {
 460                 fatal("context must not be NULL!\n");
 461                 return NULL;
 462         }
 463
 464         new_device = malloc(sizeof(*new_device));
 465         if (new_device == NULL) {
 466                 fatal("cannot allocate a new device (%s)\n", strerror(errno));
 467                 return NULL;
 468         }
 469         memset(new_device, 0, sizeof(*new_device));
 470
 471         new_device->ctx = ctx;
 472
 473         devices_list = &(ctx->devices_list);
 474
 475         if (*devices_list == NULL) {
 476                 *devices_list = new_device;
 477         } else {
 478                 am7xxx_device *prev = *devices_list;
 479                 while (prev->next)
 480                         prev = prev->next;
 481                 prev->next = new_device;
 482         }
 483         return new_device;
 484 }
 485
 486 static am7xxx_device *find_device(am7xxx_context *ctx,
 487                                   unsigned int device_index)
 488 {
 489         unsigned int i = 0;
 490         am7xxx_device *current;
 491
 492         if (ctx == NULL) {
 493                 fatal("context must not be NULL!\n");
 494                 return NULL;
 495         }
 496
 497         current = ctx->devices_list;
 498         while (current && i++ < device_index)
 499                 current = current->next;
 500
 501         return current;
 502 }
 503
 504 typedef enum {
 505         SCAN_OP_BUILD_DEVLIST,
 506         SCAN_OP_OPEN_DEVICE,
 507 } scan_op;
 508
 509 /**
 510  * This is where the central logic of multi-device support is.
 511  *
 512  * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and
 513  * 'dev' are ignored; the function returns 0 on success and a negative value
 514  * on error.
 515  *
 516  * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB
 517  * device with index 'open_device_index' and returns the correspondent
 518  * am7xxx_device in the 'dev' parameter; the function returns 0 on success,
 519  * 1 if the device was already open and a negative value on error.
 520  *
 521  * NOTES:
 522  * if scan_devices() fails when called with 'op' == SCAN_OP_BUILD_DEVLIST,
 523  * the caller might want to call am7xxx_shutdown() in order to remove
 524  * devices possibly added before the failure.
 525  */
 526 static int scan_devices(am7xxx_context *ctx, scan_op op,
 527                         unsigned int open_device_index, am7xxx_device **dev)
 528 {
 529         int num_devices;
 530         libusb_device** list;
 531         unsigned int current_index;
 532         int i;
 533         int ret;
 534
 535         if (ctx == NULL) {
 536                 fatal("context must not be NULL!\n");
 537                 return -EINVAL;
 538         }
 539         if (op == SCAN_OP_BUILD_DEVLIST && ctx->devices_list != NULL) {
 540                 error(ctx, "device scan done already? Abort!\n");
 541                 return -EINVAL;
 542         }
 543
 544         num_devices = libusb_get_device_list(ctx->usb_context, &list);
 545         if (num_devices < 0) {
 546                 ret = -ENODEV;
 547                 goto out;
 548         }
 549
 550         current_index = 0;
 551         for (i = 0; i < num_devices; i++) {
 552                 struct libusb_device_descriptor desc;
 553                 unsigned int j;
 554
 555                 ret = libusb_get_device_descriptor(list[i], &desc);
 556                 if (ret < 0)
 557                         continue;
 558
 559                 for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
 560                         if (desc.idVendor == supported_devices[j].vendor_id
 561                             && desc.idProduct == supported_devices[j].product_id) {
 562
 563                                 if (op == SCAN_OP_BUILD_DEVLIST) {
 564                                         am7xxx_device *new_device;
 565                                         info(ctx, "am7xxx device found, index: %d, name: %s\n",
 566                                              current_index,
 567                                              supported_devices[j].name);
 568                                         new_device = add_new_device(ctx);
 569                                         if (new_device == NULL) {
 570                                                 /* XXX, the caller may want
 571                                                  * to call am7xxx_shutdown() if
 572                                                  * we fail here, as we may have
 573                                                  * added some devices already
 574                                                  */
 575                                                 debug(ctx, "Cannot create a new device\n");
 576                                                 ret = -ENODEV;
 577                                                 goto out;
 578                                         }
 579                                 } else if (op == SCAN_OP_OPEN_DEVICE &&
 580                                            current_index == open_device_index) {
 581
 582                                         *dev = find_device(ctx, open_device_index);
 583                                         if (*dev == NULL) {
 584                                                 ret = -ENODEV;
 585                                                 goto out;
 586                                         }
 587
 588                                         /* the usb device has already been opened */
 589                                         if ((*dev)->usb_device) {
 590                                                 debug(ctx, "(*dev)->usb_device already set\n");
 591                                                 ret = 1;
 592                                                 goto out;
 593                                         }
 594
 595                                         ret = libusb_open(list[i], &((*dev)->usb_device));
 596                                         if (ret < 0) {
 597                                                 debug(ctx, "libusb_open failed\n");
 598                                                 goto out;
 599                                         }
 600
 601                                         libusb_set_configuration((*dev)->usb_device, 2);
 602                                         libusb_claim_interface((*dev)->usb_device, 0);
 603                                         goto out;
 604                                 }
 605                                 current_index++;
 606                         }
 607                 }
 608         }
 609
 610         /* if we made it up to here we didn't find any device to open */
 611         if (op == SCAN_OP_OPEN_DEVICE) {
 612                 error(ctx, "Cannot find any device to open\n");
 613                 ret = -ENODEV;
 614                 goto out;
 615         }
 616
 617         /* everything went fine when building the device list */
 618         ret = 0;
 619 out:
 620         libusb_free_device_list(list, 1);
 621         return ret;
 622 }
 623
 624 /* Public API */
 625
 626 AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 627 {
 628         int ret = 0;
 629
 630         *ctx = malloc(sizeof(**ctx));
 631         if (*ctx == NULL) {
 632                 fatal("cannot allocate the context (%s)\n", strerror(errno));
 633                 ret = -ENOMEM;
 634                 goto out;
 635         }
 636         memset(*ctx, 0, sizeof(**ctx));
 637
 638         /* Set the highest log level during initialization */
 639         (*ctx)->log_level = AM7XXX_LOG_TRACE;
 640
 641         ret = libusb_init(&((*ctx)->usb_context));
 642         if (ret < 0)
 643                 goto out_free_context;
 644
 645         libusb_set_debug((*ctx)->usb_context, 3);
 646
 647         ret = scan_devices(*ctx, SCAN_OP_BUILD_DEVLIST , 0, NULL);
 648         if (ret < 0) {
 649                 error(*ctx, "scan_devices() failed\n");
 650                 am7xxx_shutdown(*ctx);
 651                 goto out;
 652         }
 653
 654         /* Set a quieter log level as default for normal operation */
 655         (*ctx)->log_level = AM7XXX_LOG_ERROR;
 656         return 0;
 657
 658 out_free_context:
 659         free(*ctx);
 660         *ctx = NULL;
 661 out:
 662         return ret;
 663 }
 664
 665 AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 666 {
 667         am7xxx_device *current;
 668
 669         if (ctx == NULL) {
 670                 fatal("context must not be NULL!\n");
 671                 return;
 672         }
 673
 674         current = ctx->devices_list;
 675         while (current) {
 676                 am7xxx_device *next = current->next;
 677                 am7xxx_close_device(current);
 678                 free(current->device_info);
 679                 free(current);
 680                 current = next;
 681         }
 682
 683         libusb_exit(ctx->usb_context);
 684         free(ctx);
 685         ctx = NULL;
 686 }
 687
 688 AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 689 {
 690         ctx->log_level = log_level;
 691 }
 692
 693 AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 694                        unsigned int device_index)
 695 {
 696         int ret;
 697
 698         if (ctx == NULL) {
 699                 fatal("context must not be NULL!\n");
 700                 return -EINVAL;
 701         }
 702
 703         ret = scan_devices(ctx, SCAN_OP_OPEN_DEVICE, device_index, dev);
 704         if (ret < 0) {
 705                 errno = ENODEV;
 706         } else if (ret > 0) {
 707                 warning(ctx, "device %d already open\n", device_index);
 708                 errno = EBUSY;
 709                 ret = -EBUSY;
 710         }
 711
 712         return ret;
 713 }
 714
 715 AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 716 {
 717         if (dev == NULL) {
 718                 fatal("dev must not be NULL!\n");
 719                 return -EINVAL;
 720         }
 721         if (dev->usb_device) {
 722                 libusb_release_interface(dev->usb_device, 0);
 723                 libusb_close(dev->usb_device);
 724                 dev->usb_device = NULL;
 725         }
 726         return 0;
 727 }
 728
 729 AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 730                            am7xxx_device_info *device_info)
 731 {
 732         int ret;
 733         struct am7xxx_header h = {
 734                 .packet_type     = AM7XXX_PACKET_TYPE_DEVINFO,
 735                 .direction       = AM7XXX_DIRECTION_OUT,
 736                 .header_data_len = 0x00,
 737                 .unknown2        = 0x3e,
 738                 .unknown3        = 0x10,
 739                 .header_data = {
 740                         .devinfo = {
 741                                 .native_width  = 0,
 742                                 .native_height = 0,
 743                                 .unknown0      = 0,
 744                                 .unknown1      = 0,
 745                         },
 746                 },
 747         };
 748
 749         if (dev->device_info) {
 750                 memcpy(device_info, dev->device_info, sizeof(*device_info));
 751                 return 0;
 752         }
 753
 754         ret = send_header(dev, &h);
 755         if (ret < 0)
 756                 return ret;
 757
 758         ret = read_header(dev, &h);
 759         if (ret < 0)
 760                 return ret;
 761
 762         if (h.packet_type != AM7XXX_PACKET_TYPE_DEVINFO) {
 763                 error(dev->ctx, "expected packet type: %d, got %d instead!\n",
 764                       AM7XXX_PACKET_TYPE_DEVINFO, h.packet_type);
 765                 errno = ENOTSUP;
 766                 return -ENOTSUP;
 767         }
 768
 769         dev->device_info = malloc(sizeof(*dev->device_info));
 770         if (dev->device_info == NULL) {
 771                 error(dev->ctx, "cannot allocate a device info (%s)\n",
 772                        strerror(errno));
 773                 return -ENOMEM;
 774         }
 775         memset(dev->device_info, 0, sizeof(*dev->device_info));
 776
 777         dev->device_info->native_width = h.header_data.devinfo.native_width;
 778         dev->device_info->native_height = h.header_data.devinfo.native_height;
 779 #if 0
 780         /* No reason to expose these in the public API until we know what they mean */
 781         dev->device_info->unknown0 = h.header_data.devinfo.unknown0;
 782         dev->device_info->unknown1 = h.header_data.devinfo.unknown1;
 783 #endif
 784
 785         return 0;
 786 }
 787
 788 AM7XXX_PUBLIC int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
 789                                         unsigned int upscale,
 790                                         unsigned int original_width,
 791                                         unsigned int original_height,
 792                                         unsigned int *scaled_width,
 793                                         unsigned int *scaled_height)
 794 {
 795
 796         am7xxx_device_info device_info;
 797         float width_ratio;
 798         float height_ratio;
 799         int ret;
 800
 801         ret = am7xxx_get_device_info(dev, &device_info);
 802         if (ret < 0) {
 803                 error(dev->ctx, "cannot get device info\n");
 804                 return ret;
 805         }
 806
 807         /*
 808          * Check if we need to rescale; if the input image fits the native
 809          * dimensions there is no need to, unless we want to upscale.
 810          */
 811         if (!upscale &&
 812             original_width <= device_info.native_width &&
 813             original_height <= device_info.native_height ) {
 814                 debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
 815                 *scaled_width = original_width;
 816                 *scaled_height = original_height;
 817                 return 0;
 818         }
 819
 820         /* Input dimensions relative to the device native dimensions */
 821         width_ratio =  (float)original_width / device_info.native_width;
 822         height_ratio = (float)original_height / device_info.native_height;
 823
 824         if (width_ratio > height_ratio) {
 825                 /*
 826                  * The input is proportionally "wider" than the device viewport
 827                  * so its height needs to be adjusted
 828                  */
 829                 debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
 830                 *scaled_width = device_info.native_width;
 831                 *scaled_height = (unsigned int)lroundf(original_height / width_ratio);
 832         } else if (width_ratio < height_ratio) {
 833                 /*
 834                  * The input is proportionally "taller" than the device viewport
 835                  * so its width needs to be adjusted
 836                  */
 837                 debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
 838                 *scaled_width = (unsigned int)lroundf(original_width / height_ratio);
 839                 *scaled_height = device_info.native_height;
 840         } else {
 841                 debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
 842                 *scaled_width = device_info.native_width;
 843                 *scaled_height = device_info.native_height;
 844         }
 845         debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
 846
 847         return 0;
 848 }
 849
 850 AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
 851                       am7xxx_image_format format,
 852                       unsigned int width,
 853                       unsigned int height,
 854                       uint8_t *image,
 855                       unsigned int image_size)
 856 {
 857         int ret;
 858         struct am7xxx_header h = {
 859                 .packet_type     = AM7XXX_PACKET_TYPE_IMAGE,
 860                 .direction       = AM7XXX_DIRECTION_OUT,
 861                 .header_data_len = sizeof(struct am7xxx_image_header),
 862                 .unknown2        = 0x3e,
 863                 .unknown3        = 0x10,
 864                 .header_data = {
 865                         .image = {
 866                                 .format     = format,
 867                                 .width      = width,
 868                                 .height     = height,
 869                                 .image_size = image_size,
 870                         },
 871                 },
 872         };
 873
 874         ret = send_header(dev, &h);
 875         if (ret < 0)
 876                 return ret;
 877
 878         if (image == NULL || image_size == 0) {
 879                 warning(dev->ctx, "Not sending any data, check the 'image' or 'image_size' parameters\n");
 880                 return 0;
 881         }
 882
 883         return send_data(dev, image, image_size);
 884 }
 885
 886 AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power)
 887 {
 888         int ret;
 889         struct am7xxx_header h = {
 890                 .packet_type     = AM7XXX_PACKET_TYPE_POWER,
 891                 .direction       = AM7XXX_DIRECTION_OUT,
 892                 .header_data_len = sizeof(struct am7xxx_power_header),
 893                 .unknown2        = 0x3e,
 894                 .unknown3        = 0x10,
 895         };
 896
 897         switch(power) {
 898         case AM7XXX_POWER_OFF:
 899                 h.header_data.power.bit2 = 0;
 900                 h.header_data.power.bit1 = 0;
 901                 h.header_data.power.bit0 = 0;
 902                 break;
 903
 904         case AM7XXX_POWER_LOW:
 905                 h.header_data.power.bit2 = 0;
 906                 h.header_data.power.bit1 = 0;
 907                 h.header_data.power.bit0 = 1;
 908                 break;
 909
 910         case AM7XXX_POWER_MIDDLE:
 911                 h.header_data.power.bit2 = 0;
 912                 h.header_data.power.bit1 = 1;
 913                 h.header_data.power.bit0 = 0;
 914                 break;
 915
 916         case AM7XXX_POWER_HIGH:
 917                 h.header_data.power.bit2 = 0;
 918                 h.header_data.power.bit1 = 1;
 919                 h.header_data.power.bit0 = 1;
 920                 break;
 921
 922         case AM7XXX_POWER_TURBO:
 923                 h.header_data.power.bit2 = 1;
 924                 h.header_data.power.bit1 = 0;
 925                 h.header_data.power.bit0 = 0;
 926                 break;
 927
 928         default:
 929                 error(dev->ctx, "Unsupported power mode.\n");
 930                 return -EINVAL;
 931         };
 932
 933         ret = send_header(dev, &h);
 934         if (ret < 0)
 935                 return ret;
 936
 937         return 0;
 938 }
 939
 940 AM7XXX_PUBLIC int am7xxx_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom)
 941 {
 942         int ret;
 943         struct am7xxx_header h = {
 944                 .packet_type     = AM7XXX_PACKET_TYPE_ZOOM,
 945                 .direction       = AM7XXX_DIRECTION_OUT,
 946                 .header_data_len = sizeof(struct am7xxx_zoom_header),
 947                 .unknown2        = 0x3e,
 948                 .unknown3        = 0x10,
 949         };
 950
 951         switch(zoom) {
 952         case AM7XXX_ZOOM_ORIGINAL:
 953                 h.header_data.zoom.bit1 = 0;
 954                 h.header_data.zoom.bit0 = 0;
 955                 break;
 956
 957         case AM7XXX_ZOOM_H:
 958                 h.header_data.zoom.bit1 = 0;
 959                 h.header_data.zoom.bit0 = 1;
 960                 break;
 961
 962         case AM7XXX_ZOOM_H_V:
 963                 h.header_data.zoom.bit1 = 1;
 964                 h.header_data.zoom.bit0 = 0;
 965                 break;
 966
 967         case AM7XXX_ZOOM_TEST:
 968                 h.header_data.zoom.bit1 = 1;
 969                 h.header_data.zoom.bit0 = 1;
 970                 break;
 971
 972         default:
 973                 error(dev->ctx, "Unsupported zoom mode.\n");
 974                 return -EINVAL;
 975         };
 976
 977         ret = send_header(dev, &h);
 978         if (ret < 0)
 979                 return ret;
 980
 981         return 0;
 982 }