1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/media/video-interface-devices.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Common Properties for Video Receiver and Transmitter Devices 8 9maintainers: 10 - Jacopo Mondi <jacopo@jmondi.org> 11 - Sakari Ailus <sakari.ailus@linux.intel.com> 12 13properties: 14 flash-leds: 15 $ref: /schemas/types.yaml#/definitions/phandle-array 16 description: 17 An array of phandles, each referring to a flash LED, a sub-node of the LED 18 driver device node. 19 20 leds: 21 minItems: 1 22 maxItems: 1 23 24 led-names: 25 enum: 26 - privacy 27 28 lens-focus: 29 $ref: /schemas/types.yaml#/definitions/phandle 30 description: 31 A phandle to the node of the focus lens controller. 32 33 rotation: 34 $ref: /schemas/types.yaml#/definitions/uint32 35 enum: [ 0, 90, 180, 270 ] 36 description: | 37 The camera rotation is expressed as the angular difference in degrees 38 between two reference systems, one relative to the camera module, and one 39 defined on the external world scene to be captured when projected on the 40 image sensor pixel array. 41 42 A camera sensor has a 2-dimensional reference system 'Rc' defined by its 43 pixel array read-out order. The origin is set to the first pixel being 44 read out, the X-axis points along the column read-out direction towards 45 the last columns, and the Y-axis along the row read-out direction towards 46 the last row. 47 48 A typical example for a sensor with a 2592x1944 pixel array matrix 49 observed from the front is: 50 51 2591 X-axis 0 52 <------------------------+ 0 53 .......... ... ..........! 54 .......... ... ..........! Y-axis 55 ... ! 56 .......... ... ..........! 57 .......... ... ..........! 1943 58 V 59 60 The external world scene reference system 'Rs' is a 2-dimensional 61 reference system on the focal plane of the camera module. The origin is 62 placed on the top-left corner of the visible scene, the X-axis points 63 towards the right, and the Y-axis points towards the bottom of the scene. 64 The top, bottom, left and right directions are intentionally not defined 65 and depend on the environment in which the camera is used. 66 67 A typical example of a (very common) picture of a shark swimming from left 68 to right, as seen from the camera, is: 69 70 0 X-axis 71 0 +-------------------------------------> 72 ! 73 ! 74 ! 75 ! |\____)\___ 76 ! ) _____ __`< 77 ! |/ )/ 78 ! 79 ! 80 ! 81 V 82 Y-axis 83 84 with the reference system 'Rs' placed on the camera focal plane: 85 86 ¸.·˙! 87 ¸.·˙ ! 88 _ ¸.·˙ ! 89 +-/ \-+¸.·˙ ! 90 | (o) | ! Camera focal plane 91 +-----+˙·.¸ ! 92 ˙·.¸ ! 93 ˙·.¸ ! 94 ˙·.¸! 95 96 When projected on the sensor's pixel array, the image and the associated 97 reference system 'Rs' are typically (but not always) inverted, due to the 98 camera module's lens optical inversion effect. 99 100 Assuming the above represented scene of the swimming shark, the lens 101 inversion projects the scene and its reference system onto the sensor 102 pixel array, seen from the front of the camera sensor, as follows: 103 104 Y-axis 105 ^ 106 ! 107 ! 108 ! 109 ! |\_____)\__ 110 ! ) ____ ___.< 111 ! |/ )/ 112 ! 113 ! 114 ! 115 0 +-------------------------------------> 116 0 X-axis 117 118 Note the shark being upside-down. 119 120 The resulting projected reference system is named 'Rp'. 121 122 The camera rotation property is then defined as the angular difference in 123 the counter-clockwise direction between the camera reference system 'Rc' 124 and the projected scene reference system 'Rp'. It is expressed in degrees 125 as a number in the range [0, 360[. 126 127 Examples 128 129 0 degrees camera rotation: 130 131 132 Y-Rp 133 ^ 134 Y-Rc ! 135 ^ ! 136 ! ! 137 ! ! 138 ! ! 139 ! ! 140 ! ! 141 ! ! 142 ! ! 143 ! 0 +-------------------------------------> 144 ! 0 X-Rp 145 0 +-------------------------------------> 146 0 X-Rc 147 148 149 X-Rc 0 150 <------------------------------------+ 0 151 X-Rp 0 ! 152 <------------------------------------+ 0 ! 153 ! ! 154 ! ! 155 ! ! 156 ! ! 157 ! ! 158 ! ! 159 ! ! 160 ! V 161 ! Y-Rc 162 V 163 Y-Rp 164 165 90 degrees camera rotation: 166 167 0 Y-Rc 168 0 +--------------------> 169 ! Y-Rp 170 ! ^ 171 ! ! 172 ! ! 173 ! ! 174 ! ! 175 ! ! 176 ! ! 177 ! ! 178 ! ! 179 ! ! 180 ! 0 +-------------------------------------> 181 ! 0 X-Rp 182 ! 183 ! 184 ! 185 ! 186 V 187 X-Rc 188 189 180 degrees camera rotation: 190 191 0 192 <------------------------------------+ 0 193 X-Rc ! 194 Y-Rp ! 195 ^ ! 196 ! ! 197 ! ! 198 ! ! 199 ! ! 200 ! ! 201 ! ! 202 ! V 203 ! Y-Rc 204 0 +-------------------------------------> 205 0 X-Rp 206 207 270 degrees camera rotation: 208 209 0 Y-Rc 210 0 +--------------------> 211 ! 0 212 ! <-----------------------------------+ 0 213 ! X-Rp ! 214 ! ! 215 ! ! 216 ! ! 217 ! ! 218 ! ! 219 ! ! 220 ! ! 221 ! ! 222 ! V 223 ! Y-Rp 224 ! 225 ! 226 ! 227 ! 228 V 229 X-Rc 230 231 232 Example one - Webcam 233 234 A camera module installed on the user facing part of a laptop screen 235 casing used for video calls. The captured images are meant to be displayed 236 in landscape mode (width > height) on the laptop screen. 237 238 The camera is typically mounted upside-down to compensate the lens optical 239 inversion effect: 240 241 Y-Rp 242 Y-Rc ^ 243 ^ ! 244 ! ! 245 ! ! |\_____)\__ 246 ! ! ) ____ ___.< 247 ! ! |/ )/ 248 ! ! 249 ! ! 250 ! ! 251 ! 0 +-------------------------------------> 252 ! 0 X-Rp 253 0 +-------------------------------------> 254 0 X-Rc 255 256 The two reference systems are aligned, the resulting camera rotation is 257 0 degrees, no rotation correction needs to be applied to the resulting 258 image once captured to memory buffers to correctly display it to users: 259 260 +--------------------------------------+ 261 ! ! 262 ! ! 263 ! ! 264 ! |\____)\___ ! 265 ! ) _____ __`< ! 266 ! |/ )/ ! 267 ! ! 268 ! ! 269 ! ! 270 +--------------------------------------+ 271 272 If the camera sensor is not mounted upside-down to compensate for the lens 273 optical inversion, the two reference systems will not be aligned, with 274 'Rp' being rotated 180 degrees relatively to 'Rc': 275 276 277 X-Rc 0 278 <------------------------------------+ 0 279 ! 280 Y-Rp ! 281 ^ ! 282 ! ! 283 ! |\_____)\__ ! 284 ! ) ____ ___.< ! 285 ! |/ )/ ! 286 ! ! 287 ! ! 288 ! V 289 ! Y-Rc 290 0 +-------------------------------------> 291 0 X-Rp 292 293 The image once captured to memory will then be rotated by 180 degrees: 294 295 +--------------------------------------+ 296 ! ! 297 ! ! 298 ! ! 299 ! __/(_____/| ! 300 ! >.___ ____ ( ! 301 ! \( \| ! 302 ! ! 303 ! ! 304 ! ! 305 +--------------------------------------+ 306 307 A software rotation correction of 180 degrees should be applied to 308 correctly display the image: 309 310 +--------------------------------------+ 311 ! ! 312 ! ! 313 ! ! 314 ! |\____)\___ ! 315 ! ) _____ __`< ! 316 ! |/ )/ ! 317 ! ! 318 ! ! 319 ! ! 320 +--------------------------------------+ 321 322 Example two - Phone camera 323 324 A camera installed on the back side of a mobile device facing away from 325 the user. The captured images are meant to be displayed in portrait mode 326 (height > width) to match the device screen orientation and the device 327 usage orientation used when taking the picture. 328 329 The camera sensor is typically mounted with its pixel array longer side 330 aligned to the device longer side, upside-down mounted to compensate for 331 the lens optical inversion effect: 332 333 0 Y-Rc 334 0 +--------------------> 335 ! Y-Rp 336 ! ^ 337 ! ! 338 ! ! 339 ! ! 340 ! ! |\_____)\__ 341 ! ! ) ____ ___.< 342 ! ! |/ )/ 343 ! ! 344 ! ! 345 ! ! 346 ! 0 +-------------------------------------> 347 ! 0 X-Rp 348 ! 349 ! 350 ! 351 ! 352 V 353 X-Rc 354 355 The two reference systems are not aligned and the 'Rp' reference system is 356 rotated by 90 degrees in the counter-clockwise direction relatively to the 357 'Rc' reference system. 358 359 The image once captured to memory will be rotated: 360 361 +-------------------------------------+ 362 | _ _ | 363 | \ / | 364 | | | | 365 | | | | 366 | | > | 367 | < | | 368 | | | | 369 | . | 370 | V | 371 +-------------------------------------+ 372 373 A correction of 90 degrees in counter-clockwise direction has to be 374 applied to correctly display the image in portrait mode on the device 375 screen: 376 377 +--------------------+ 378 | | 379 | | 380 | | 381 | | 382 | | 383 | | 384 | |\____)\___ | 385 | ) _____ __`< | 386 | |/ )/ | 387 | | 388 | | 389 | | 390 | | 391 | | 392 +--------------------+ 393 394 orientation: 395 description: 396 The orientation of a device (typically an image sensor or a flash LED) 397 describing its mounting position relative to the usage orientation of the 398 system where the device is installed on. 399 $ref: /schemas/types.yaml#/definitions/uint32 400 enum: 401 # Front. The device is mounted on the front facing side of the system. For 402 # mobile devices such as smartphones, tablets and laptops the front side 403 # is the user facing side. 404 - 0 405 # Back. The device is mounted on the back side of the system, which is 406 # defined as the opposite side of the front facing one. 407 - 1 408 # External. The device is not attached directly to the system but is 409 # attached in a way that allows it to move freely. 410 - 2 411 412additionalProperties: true 413 414... 415