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 /* Fill in a struct v4l2_queryctrl */ 84 int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 _min, s32 _max, s32 _step, s32 _def) 85 { 86 const char *name; 87 s64 min = _min; 88 s64 max = _max; 89 u64 step = _step; 90 s64 def = _def; 91 92 v4l2_ctrl_fill(qctrl->id, &name, &qctrl->type, 93 &min, &max, &step, &def, &qctrl->flags); 94 95 if (name == NULL) 96 return -EINVAL; 97 98 qctrl->minimum = min; 99 qctrl->maximum = max; 100 qctrl->step = step; 101 qctrl->default_value = def; 102 qctrl->reserved[0] = qctrl->reserved[1] = 0; 103 strlcpy(qctrl->name, name, sizeof(qctrl->name)); 104 return 0; 105 } 106 EXPORT_SYMBOL(v4l2_ctrl_query_fill); 107 108 /* I2C Helper functions */ 109 110 #if IS_ENABLED(CONFIG_I2C) 111 112 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client, 113 const struct v4l2_subdev_ops *ops) 114 { 115 v4l2_subdev_init(sd, ops); 116 sd->flags |= V4L2_SUBDEV_FL_IS_I2C; 117 /* the owner is the same as the i2c_client's driver owner */ 118 sd->owner = client->dev.driver->owner; 119 sd->dev = &client->dev; 120 /* i2c_client and v4l2_subdev point to one another */ 121 v4l2_set_subdevdata(sd, client); 122 i2c_set_clientdata(client, sd); 123 /* initialize name */ 124 snprintf(sd->name, sizeof(sd->name), "%s %d-%04x", 125 client->dev.driver->name, i2c_adapter_id(client->adapter), 126 client->addr); 127 } 128 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init); 129 130 /* Load an i2c sub-device. */ 131 struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev, 132 struct i2c_adapter *adapter, struct i2c_board_info *info, 133 const unsigned short *probe_addrs) 134 { 135 struct v4l2_subdev *sd = NULL; 136 struct i2c_client *client; 137 138 BUG_ON(!v4l2_dev); 139 140 request_module(I2C_MODULE_PREFIX "%s", info->type); 141 142 /* Create the i2c client */ 143 if (info->addr == 0 && probe_addrs) 144 client = i2c_new_probed_device(adapter, info, probe_addrs, 145 NULL); 146 else 147 client = i2c_new_device(adapter, info); 148 149 /* Note: by loading the module first we are certain that c->driver 150 will be set if the driver was found. If the module was not loaded 151 first, then the i2c core tries to delay-load the module for us, 152 and then c->driver is still NULL until the module is finally 153 loaded. This delay-load mechanism doesn't work if other drivers 154 want to use the i2c device, so explicitly loading the module 155 is the best alternative. */ 156 if (client == NULL || client->dev.driver == NULL) 157 goto error; 158 159 /* Lock the module so we can safely get the v4l2_subdev pointer */ 160 if (!try_module_get(client->dev.driver->owner)) 161 goto error; 162 sd = i2c_get_clientdata(client); 163 164 /* Register with the v4l2_device which increases the module's 165 use count as well. */ 166 if (v4l2_device_register_subdev(v4l2_dev, sd)) 167 sd = NULL; 168 /* Decrease the module use count to match the first try_module_get. */ 169 module_put(client->dev.driver->owner); 170 171 error: 172 /* If we have a client but no subdev, then something went wrong and 173 we must unregister the client. */ 174 if (client && sd == NULL) 175 i2c_unregister_device(client); 176 return sd; 177 } 178 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board); 179 180 struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev, 181 struct i2c_adapter *adapter, const char *client_type, 182 u8 addr, const unsigned short *probe_addrs) 183 { 184 struct i2c_board_info info; 185 186 /* Setup the i2c board info with the device type and 187 the device address. */ 188 memset(&info, 0, sizeof(info)); 189 strlcpy(info.type, client_type, sizeof(info.type)); 190 info.addr = addr; 191 192 return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, probe_addrs); 193 } 194 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev); 195 196 /* Return i2c client address of v4l2_subdev. */ 197 unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd) 198 { 199 struct i2c_client *client = v4l2_get_subdevdata(sd); 200 201 return client ? client->addr : I2C_CLIENT_END; 202 } 203 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr); 204 205 /* Return a list of I2C tuner addresses to probe. Use only if the tuner 206 addresses are unknown. */ 207 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type) 208 { 209 static const unsigned short radio_addrs[] = { 210 #if IS_ENABLED(CONFIG_MEDIA_TUNER_TEA5761) 211 0x10, 212 #endif 213 0x60, 214 I2C_CLIENT_END 215 }; 216 static const unsigned short demod_addrs[] = { 217 0x42, 0x43, 0x4a, 0x4b, 218 I2C_CLIENT_END 219 }; 220 static const unsigned short tv_addrs[] = { 221 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */ 222 0x60, 0x61, 0x62, 0x63, 0x64, 223 I2C_CLIENT_END 224 }; 225 226 switch (type) { 227 case ADDRS_RADIO: 228 return radio_addrs; 229 case ADDRS_DEMOD: 230 return demod_addrs; 231 case ADDRS_TV: 232 return tv_addrs; 233 case ADDRS_TV_WITH_DEMOD: 234 return tv_addrs + 4; 235 } 236 return NULL; 237 } 238 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs); 239 240 #endif /* defined(CONFIG_I2C) */ 241 242 #if defined(CONFIG_SPI) 243 244 /* Load an spi sub-device. */ 245 246 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi, 247 const struct v4l2_subdev_ops *ops) 248 { 249 v4l2_subdev_init(sd, ops); 250 sd->flags |= V4L2_SUBDEV_FL_IS_SPI; 251 /* the owner is the same as the spi_device's driver owner */ 252 sd->owner = spi->dev.driver->owner; 253 sd->dev = &spi->dev; 254 /* spi_device and v4l2_subdev point to one another */ 255 v4l2_set_subdevdata(sd, spi); 256 spi_set_drvdata(spi, sd); 257 /* initialize name */ 258 strlcpy(sd->name, spi->dev.driver->name, sizeof(sd->name)); 259 } 260 EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init); 261 262 struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev, 263 struct spi_master *master, struct spi_board_info *info) 264 { 265 struct v4l2_subdev *sd = NULL; 266 struct spi_device *spi = NULL; 267 268 BUG_ON(!v4l2_dev); 269 270 if (info->modalias[0]) 271 request_module(info->modalias); 272 273 spi = spi_new_device(master, info); 274 275 if (spi == NULL || spi->dev.driver == NULL) 276 goto error; 277 278 if (!try_module_get(spi->dev.driver->owner)) 279 goto error; 280 281 sd = spi_get_drvdata(spi); 282 283 /* Register with the v4l2_device which increases the module's 284 use count as well. */ 285 if (v4l2_device_register_subdev(v4l2_dev, sd)) 286 sd = NULL; 287 288 /* Decrease the module use count to match the first try_module_get. */ 289 module_put(spi->dev.driver->owner); 290 291 error: 292 /* If we have a client but no subdev, then something went wrong and 293 we must unregister the client. */ 294 if (spi && sd == NULL) 295 spi_unregister_device(spi); 296 297 return sd; 298 } 299 EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev); 300 301 #endif /* defined(CONFIG_SPI) */ 302 303 /* Clamp x to be between min and max, aligned to a multiple of 2^align. min 304 * and max don't have to be aligned, but there must be at least one valid 305 * value. E.g., min=17,max=31,align=4 is not allowed as there are no multiples 306 * of 16 between 17 and 31. */ 307 static unsigned int clamp_align(unsigned int x, unsigned int min, 308 unsigned int max, unsigned int align) 309 { 310 /* Bits that must be zero to be aligned */ 311 unsigned int mask = ~((1 << align) - 1); 312 313 /* Clamp to aligned min and max */ 314 x = clamp(x, (min + ~mask) & mask, max & mask); 315 316 /* Round to nearest aligned value */ 317 if (align) 318 x = (x + (1 << (align - 1))) & mask; 319 320 return x; 321 } 322 323 /* Bound an image to have a width between wmin and wmax, and height between 324 * hmin and hmax, inclusive. Additionally, the width will be a multiple of 325 * 2^walign, the height will be a multiple of 2^halign, and the overall size 326 * (width*height) will be a multiple of 2^salign. The image may be shrunk 327 * or enlarged to fit the alignment constraints. 328 * 329 * The width or height maximum must not be smaller than the corresponding 330 * minimum. The alignments must not be so high there are no possible image 331 * sizes within the allowed bounds. wmin and hmin must be at least 1 332 * (don't use 0). If you don't care about a certain alignment, specify 0, 333 * as 2^0 is 1 and one byte alignment is equivalent to no alignment. If 334 * you only want to adjust downward, specify a maximum that's the same as 335 * the initial value. 336 */ 337 void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax, 338 unsigned int walign, 339 u32 *h, unsigned int hmin, unsigned int hmax, 340 unsigned int halign, unsigned int salign) 341 { 342 *w = clamp_align(*w, wmin, wmax, walign); 343 *h = clamp_align(*h, hmin, hmax, halign); 344 345 /* Usually we don't need to align the size and are done now. */ 346 if (!salign) 347 return; 348 349 /* How much alignment do we have? */ 350 walign = __ffs(*w); 351 halign = __ffs(*h); 352 /* Enough to satisfy the image alignment? */ 353 if (walign + halign < salign) { 354 /* Max walign where there is still a valid width */ 355 unsigned int wmaxa = __fls(wmax ^ (wmin - 1)); 356 /* Max halign where there is still a valid height */ 357 unsigned int hmaxa = __fls(hmax ^ (hmin - 1)); 358 359 /* up the smaller alignment until we have enough */ 360 do { 361 if (halign >= hmaxa || 362 (walign <= halign && walign < wmaxa)) { 363 *w = clamp_align(*w, wmin, wmax, walign + 1); 364 walign = __ffs(*w); 365 } else { 366 *h = clamp_align(*h, hmin, hmax, halign + 1); 367 halign = __ffs(*h); 368 } 369 } while (halign + walign < salign); 370 } 371 } 372 EXPORT_SYMBOL_GPL(v4l_bound_align_image); 373 374 const struct v4l2_frmsize_discrete *v4l2_find_nearest_format( 375 const struct v4l2_discrete_probe *probe, 376 s32 width, s32 height) 377 { 378 int i; 379 u32 error, min_error = UINT_MAX; 380 const struct v4l2_frmsize_discrete *size, *best = NULL; 381 382 if (!probe) 383 return best; 384 385 for (i = 0, size = probe->sizes; i < probe->num_sizes; i++, size++) { 386 error = abs(size->width - width) + abs(size->height - height); 387 if (error < min_error) { 388 min_error = error; 389 best = size; 390 } 391 if (!error) 392 break; 393 } 394 395 return best; 396 } 397 EXPORT_SYMBOL_GPL(v4l2_find_nearest_format); 398 399 void v4l2_get_timestamp(struct timeval *tv) 400 { 401 struct timespec ts; 402 403 ktime_get_ts(&ts); 404 tv->tv_sec = ts.tv_sec; 405 tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC; 406 } 407 EXPORT_SYMBOL_GPL(v4l2_get_timestamp); 408