1 /* 2 * Video for Linux Two 3 * 4 * A generic video device interface for the LINUX operating system 5 * using a set of device structures/vectors for low level operations. 6 * 7 * This file replaces the videodev.c file that comes with the 8 * regular kernel distribution. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 * 15 * Author: Bill Dirks <bill@thedirks.org> 16 * based on code by Alan Cox, <alan@cymru.net> 17 * 18 */ 19 20 /* 21 * Video capture interface for Linux 22 * 23 * A generic video device interface for the LINUX operating system 24 * using a set of device structures/vectors for low level operations. 25 * 26 * This program is free software; you can redistribute it and/or 27 * modify it under the terms of the GNU General Public License 28 * as published by the Free Software Foundation; either version 29 * 2 of the License, or (at your option) any later version. 30 * 31 * Author: Alan Cox, <alan@lxorguk.ukuu.org.uk> 32 * 33 * Fixes: 34 */ 35 36 /* 37 * Video4linux 1/2 integration by Justin Schoeman 38 * <justin@suntiger.ee.up.ac.za> 39 * 2.4 PROCFS support ported from 2.4 kernels by 40 * Iñaki García Etxebarria <garetxe@euskalnet.net> 41 * Makefile fix by "W. Michael Petullo" <mike@flyn.org> 42 * 2.4 devfs support ported from 2.4 kernels by 43 * Dan Merillat <dan@merillat.org> 44 * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman) 45 */ 46 47 #include <linux/module.h> 48 #include <linux/types.h> 49 #include <linux/kernel.h> 50 #include <linux/mm.h> 51 #include <linux/string.h> 52 #include <linux/errno.h> 53 #include <linux/i2c.h> 54 #if defined(CONFIG_SPI) 55 #include <linux/spi/spi.h> 56 #endif 57 #include <asm/uaccess.h> 58 #include <asm/pgtable.h> 59 #include <asm/io.h> 60 #include <asm/div64.h> 61 #include <media/v4l2-common.h> 62 #include <media/v4l2-device.h> 63 #include <media/v4l2-ctrls.h> 64 65 #include <linux/videodev2.h> 66 67 MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr"); 68 MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers"); 69 MODULE_LICENSE("GPL"); 70 71 /* 72 * 73 * V 4 L 2 D R I V E R H E L P E R A P I 74 * 75 */ 76 77 /* 78 * Video Standard Operations (contributed by Michael Schimek) 79 */ 80 81 /* Helper functions for control handling */ 82 83 /* Check for correctness of the ctrl's value based on the data from 84 struct v4l2_queryctrl and the available menu items. Note that 85 menu_items may be NULL, in that case it is ignored. */ 86 int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl, 87 const char * const *menu_items) 88 { 89 if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED) 90 return -EINVAL; 91 if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED) 92 return -EBUSY; 93 if (qctrl->type == V4L2_CTRL_TYPE_STRING) 94 return 0; 95 if (qctrl->type == V4L2_CTRL_TYPE_BUTTON || 96 qctrl->type == V4L2_CTRL_TYPE_INTEGER64 || 97 qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS) 98 return 0; 99 if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum) 100 return -ERANGE; 101 if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) { 102 if (menu_items[ctrl->value] == NULL || 103 menu_items[ctrl->value][0] == '\0') 104 return -EINVAL; 105 } 106 if (qctrl->type == V4L2_CTRL_TYPE_BITMASK && 107 (ctrl->value & ~qctrl->maximum)) 108 return -ERANGE; 109 return 0; 110 } 111 EXPORT_SYMBOL(v4l2_ctrl_check); 112 113 /* Fill in a struct v4l2_queryctrl */ 114 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 _min, s32 _max, s32 _step, s32 _def) 115 { 116 const char *name; 117 s64 min = _min; 118 s64 max = _max; 119 u64 step = _step; 120 s64 def = _def; 121 122 v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type, 123 &min, &max, &step, &def, &qctrl->flags); 124 125 if (name == NULL) 126 return -EINVAL; 127 128 qctrl->minimum = min; 129 qctrl->maximum = max; 130 qctrl->step = step; 131 qctrl->default_value = def; 132 qctrl->reserved[0] = qctrl->reserved[1] = 0; 133 strlcpy(qctrl->name, name, sizeof(qctrl->name)); 134 return 0; 135 } 136 EXPORT_SYMBOL(v4l2_ctrl_query_fill); 137 138 /* Fill in a struct v4l2_querymenu based on the struct v4l2_queryctrl and 139 the menu. The qctrl pointer may be NULL, in which case it is ignored. 140 If menu_items is NULL, then the menu items are retrieved using 141 v4l2_ctrl_get_menu. */ 142 int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qctrl, 143 const char * const *menu_items) 144 { 145 int i; 146 147 qmenu->reserved = 0; 148 if (menu_items == NULL) 149 menu_items = v4l2_ctrl_get_menu(qmenu->id); 150 if (menu_items == NULL || 151 (qctrl && (qmenu->index < qctrl->minimum || qmenu->index > qctrl->maximum))) 152 return -EINVAL; 153 for (i = 0; i < qmenu->index && menu_items[i]; i++) ; 154 if (menu_items[i] == NULL || menu_items[i][0] == '\0') 155 return -EINVAL; 156 strlcpy(qmenu->name, menu_items[qmenu->index], sizeof(qmenu->name)); 157 return 0; 158 } 159 EXPORT_SYMBOL(v4l2_ctrl_query_menu); 160 161 /* Fill in a struct v4l2_querymenu based on the specified array of valid 162 menu items (terminated by V4L2_CTRL_MENU_IDS_END). 163 Use this if there are 'holes' in the list of valid menu items. */ 164 int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids) 165 { 166 const char * const *menu_items = v4l2_ctrl_get_menu(qmenu->id); 167 168 qmenu->reserved = 0; 169 if (menu_items == NULL || ids == NULL) 170 return -EINVAL; 171 while (*ids != V4L2_CTRL_MENU_IDS_END) { 172 if (*ids++ == qmenu->index) { 173 strlcpy(qmenu->name, menu_items[qmenu->index], 174 sizeof(qmenu->name)); 175 return 0; 176 } 177 } 178 return -EINVAL; 179 } 180 EXPORT_SYMBOL(v4l2_ctrl_query_menu_valid_items); 181 182 /* ctrl_classes points to an array of u32 pointers, the last element is 183 a NULL pointer. Each u32 array is a 0-terminated array of control IDs. 184 Each array must be sorted low to high and belong to the same control 185 class. The array of u32 pointers must also be sorted, from low class IDs 186 to high class IDs. 187 188 This function returns the first ID that follows after the given ID. 189 When no more controls are available 0 is returned. */ 190 u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id) 191 { 192 u32 ctrl_class = V4L2_CTRL_ID2CLASS(id); 193 const u32 *pctrl; 194 195 if (ctrl_classes == NULL) 196 return 0; 197 198 /* if no query is desired, then check if the ID is part of ctrl_classes */ 199 if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) { 200 /* find class */ 201 while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class) 202 ctrl_classes++; 203 if (*ctrl_classes == NULL) 204 return 0; 205 pctrl = *ctrl_classes; 206 /* find control ID */ 207 while (*pctrl && *pctrl != id) pctrl++; 208 return *pctrl ? id : 0; 209 } 210 id &= V4L2_CTRL_ID_MASK; 211 id++; /* select next control */ 212 /* find first class that matches (or is greater than) the class of 213 the ID */ 214 while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) < ctrl_class) 215 ctrl_classes++; 216 /* no more classes */ 217 if (*ctrl_classes == NULL) 218 return 0; 219 pctrl = *ctrl_classes; 220 /* find first ctrl within the class that is >= ID */ 221 while (*pctrl && *pctrl < id) pctrl++; 222 if (*pctrl) 223 return *pctrl; 224 /* we are at the end of the controls of the current class. */ 225 /* continue with next class if available */ 226 ctrl_classes++; 227 if (*ctrl_classes == NULL) 228 return 0; 229 return **ctrl_classes; 230 } 231 EXPORT_SYMBOL(v4l2_ctrl_next); 232 233 /* I2C Helper functions */ 234 235 #if IS_ENABLED(CONFIG_I2C) 236 237 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client, 238 const struct v4l2_subdev_ops *ops) 239 { 240 v4l2_subdev_init(sd, ops); 241 sd->flags |= V4L2_SUBDEV_FL_IS_I2C; 242 /* the owner is the same as the i2c_client's driver owner */ 243 sd->owner = client->dev.driver->owner; 244 sd->dev = &client->dev; 245 /* i2c_client and v4l2_subdev point to one another */ 246 v4l2_set_subdevdata(sd, client); 247 i2c_set_clientdata(client, sd); 248 /* initialize name */ 249 snprintf(sd->name, sizeof(sd->name), "%s %d-%04x", 250 client->dev.driver->name, i2c_adapter_id(client->adapter), 251 client->addr); 252 } 253 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init); 254 255 /* Load an i2c sub-device. */ 256 struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev, 257 struct i2c_adapter *adapter, struct i2c_board_info *info, 258 const unsigned short *probe_addrs) 259 { 260 struct v4l2_subdev *sd = NULL; 261 struct i2c_client *client; 262 263 BUG_ON(!v4l2_dev); 264 265 request_module(I2C_MODULE_PREFIX "%s", info->type); 266 267 /* Create the i2c client */ 268 if (info->addr == 0 && probe_addrs) 269 client = i2c_new_probed_device(adapter, info, probe_addrs, 270 NULL); 271 else 272 client = i2c_new_device(adapter, info); 273 274 /* Note: by loading the module first we are certain that c->driver 275 will be set if the driver was found. If the module was not loaded 276 first, then the i2c core tries to delay-load the module for us, 277 and then c->driver is still NULL until the module is finally 278 loaded. This delay-load mechanism doesn't work if other drivers 279 want to use the i2c device, so explicitly loading the module 280 is the best alternative. */ 281 if (client == NULL || client->dev.driver == NULL) 282 goto error; 283 284 /* Lock the module so we can safely get the v4l2_subdev pointer */ 285 if (!try_module_get(client->dev.driver->owner)) 286 goto error; 287 sd = i2c_get_clientdata(client); 288 289 /* Register with the v4l2_device which increases the module's 290 use count as well. */ 291 if (v4l2_device_register_subdev(v4l2_dev, sd)) 292 sd = NULL; 293 /* Decrease the module use count to match the first try_module_get. */ 294 module_put(client->dev.driver->owner); 295 296 error: 297 /* If we have a client but no subdev, then something went wrong and 298 we must unregister the client. */ 299 if (client && sd == NULL) 300 i2c_unregister_device(client); 301 return sd; 302 } 303 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board); 304 305 struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev, 306 struct i2c_adapter *adapter, const char *client_type, 307 u8 addr, const unsigned short *probe_addrs) 308 { 309 struct i2c_board_info info; 310 311 /* Setup the i2c board info with the device type and 312 the device address. */ 313 memset(&info, 0, sizeof(info)); 314 strlcpy(info.type, client_type, sizeof(info.type)); 315 info.addr = addr; 316 317 return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs); 318 } 319 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev); 320 321 /* Return i2c client address of v4l2_subdev. */ 322 unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd) 323 { 324 struct i2c_client *client = v4l2_get_subdevdata(sd); 325 326 return client ? client->addr : I2C_CLIENT_END; 327 } 328 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr); 329 330 /* Return a list of I2C tuner addresses to probe. Use only if the tuner 331 addresses are unknown. */ 332 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type) 333 { 334 static const unsigned short radio_addrs[] = { 335 #if IS_ENABLED(CONFIG_MEDIA_TUNER_TEA5761) 336 0x10, 337 #endif 338 0x60, 339 I2C_CLIENT_END 340 }; 341 static const unsigned short demod_addrs[] = { 342 0x42, 0x43, 0x4a, 0x4b, 343 I2C_CLIENT_END 344 }; 345 static const unsigned short tv_addrs[] = { 346 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */ 347 0x60, 0x61, 0x62, 0x63, 0x64, 348 I2C_CLIENT_END 349 }; 350 351 switch (type) { 352 case ADDRS_RADIO: 353 return radio_addrs; 354 case ADDRS_DEMOD: 355 return demod_addrs; 356 case ADDRS_TV: 357 return tv_addrs; 358 case ADDRS_TV_WITH_DEMOD: 359 return tv_addrs + 4; 360 } 361 return NULL; 362 } 363 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs); 364 365 #endif /* defined(CONFIG_I2C) */ 366 367 #if defined(CONFIG_SPI) 368 369 /* Load an spi sub-device. */ 370 371 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi, 372 const struct v4l2_subdev_ops *ops) 373 { 374 v4l2_subdev_init(sd, ops); 375 sd->flags |= V4L2_SUBDEV_FL_IS_SPI; 376 /* the owner is the same as the spi_device's driver owner */ 377 sd->owner = spi->dev.driver->owner; 378 sd->dev = &spi->dev; 379 /* spi_device and v4l2_subdev point to one another */ 380 v4l2_set_subdevdata(sd, spi); 381 spi_set_drvdata(spi, sd); 382 /* initialize name */ 383 strlcpy(sd->name, spi->dev.driver->name, sizeof(sd->name)); 384 } 385 EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init); 386 387 struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev, 388 struct spi_master *master, struct spi_board_info *info) 389 { 390 struct v4l2_subdev *sd = NULL; 391 struct spi_device *spi = NULL; 392 393 BUG_ON(!v4l2_dev); 394 395 if (info->modalias[0]) 396 request_module(info->modalias); 397 398 spi = spi_new_device(master, info); 399 400 if (spi == NULL || spi->dev.driver == NULL) 401 goto error; 402 403 if (!try_module_get(spi->dev.driver->owner)) 404 goto error; 405 406 sd = spi_get_drvdata(spi); 407 408 /* Register with the v4l2_device which increases the module's 409 use count as well. */ 410 if (v4l2_device_register_subdev(v4l2_dev, sd)) 411 sd = NULL; 412 413 /* Decrease the module use count to match the first try_module_get. */ 414 module_put(spi->dev.driver->owner); 415 416 error: 417 /* If we have a client but no subdev, then something went wrong and 418 we must unregister the client. */ 419 if (spi && sd == NULL) 420 spi_unregister_device(spi); 421 422 return sd; 423 } 424 EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev); 425 426 #endif /* defined(CONFIG_SPI) */ 427 428 /* Clamp x to be between min and max, aligned to a multiple of 2^align. min 429 * and max don't have to be aligned, but there must be at least one valid 430 * value. E.g., min=17,max=31,align=4 is not allowed as there are no multiples 431 * of 16 between 17 and 31. */ 432 static unsigned int clamp_align(unsigned int x, unsigned int min, 433 unsigned int max, unsigned int align) 434 { 435 /* Bits that must be zero to be aligned */ 436 unsigned int mask = ~((1 << align) - 1); 437 438 /* Clamp to aligned min and max */ 439 x = clamp(x, (min + ~mask) & mask, max & mask); 440 441 /* Round to nearest aligned value */ 442 if (align) 443 x = (x + (1 << (align - 1))) & mask; 444 445 return x; 446 } 447 448 /* Bound an image to have a width between wmin and wmax, and height between 449 * hmin and hmax, inclusive. Additionally, the width will be a multiple of 450 * 2^walign, the height will be a multiple of 2^halign, and the overall size 451 * (width*height) will be a multiple of 2^salign. The image may be shrunk 452 * or enlarged to fit the alignment constraints. 453 * 454 * The width or height maximum must not be smaller than the corresponding 455 * minimum. The alignments must not be so high there are no possible image 456 * sizes within the allowed bounds. wmin and hmin must be at least 1 457 * (don't use 0). If you don't care about a certain alignment, specify 0, 458 * as 2^0 is 1 and one byte alignment is equivalent to no alignment. If 459 * you only want to adjust downward, specify a maximum that's the same as 460 * the initial value. 461 */ 462 void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax, 463 unsigned int walign, 464 u32 *h, unsigned int hmin, unsigned int hmax, 465 unsigned int halign, unsigned int salign) 466 { 467 *w = clamp_align(*w, wmin, wmax, walign); 468 *h = clamp_align(*h, hmin, hmax, halign); 469 470 /* Usually we don't need to align the size and are done now. */ 471 if (!salign) 472 return; 473 474 /* How much alignment do we have? */ 475 walign = __ffs(*w); 476 halign = __ffs(*h); 477 /* Enough to satisfy the image alignment? */ 478 if (walign + halign < salign) { 479 /* Max walign where there is still a valid width */ 480 unsigned int wmaxa = __fls(wmax ^ (wmin - 1)); 481 /* Max halign where there is still a valid height */ 482 unsigned int hmaxa = __fls(hmax ^ (hmin - 1)); 483 484 /* up the smaller alignment until we have enough */ 485 do { 486 if (halign >= hmaxa || 487 (walign <= halign && walign < wmaxa)) { 488 *w = clamp_align(*w, wmin, wmax, walign + 1); 489 walign = __ffs(*w); 490 } else { 491 *h = clamp_align(*h, hmin, hmax, halign + 1); 492 halign = __ffs(*h); 493 } 494 } while (halign + walign < salign); 495 } 496 } 497 EXPORT_SYMBOL_GPL(v4l_bound_align_image); 498 499 const struct v4l2_frmsize_discrete *v4l2_find_nearest_format( 500 const struct v4l2_discrete_probe *probe, 501 s32 width, s32 height) 502 { 503 int i; 504 u32 error, min_error = UINT_MAX; 505 const struct v4l2_frmsize_discrete *size, *best = NULL; 506 507 if (!probe) 508 return best; 509 510 for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) { 511 error = abs(size->width - width) + abs(size->height - height); 512 if (error < min_error) { 513 min_error = error; 514 best = size; 515 } 516 if (!error) 517 break; 518 } 519 520 return best; 521 } 522 EXPORT_SYMBOL_GPL(v4l2_find_nearest_format); 523 524 void v4l2_get_timestamp(struct timeval *tv) 525 { 526 struct timespec ts; 527 528 ktime_get_ts(&ts); 529 tv->tv_sec = ts.tv_sec; 530 tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC; 531 } 532 EXPORT_SYMBOL_GPL(v4l2_get_timestamp); 533