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diff --git a/Documentation/devicetree/bindings/media/video-interface-devices.yaml b/Documentation/devicetree/bindings/media/video-interface-devices.yaml new file mode 100644 index 000000000..4527f56a5 --- /dev/null +++ b/Documentation/devicetree/bindings/media/video-interface-devices.yaml @@ -0,0 +1,406 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/media/video-interface-devices.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common bindings for video receiver and transmitter devices + +maintainers: + - Jacopo Mondi <jacopo@jmondi.org> + - Sakari Ailus <sakari.ailus@linux.intel.com> + +properties: + flash-leds: + $ref: /schemas/types.yaml#/definitions/phandle-array + description: + An array of phandles, each referring to a flash LED, a sub-node of the LED + driver device node. + + lens-focus: + $ref: /schemas/types.yaml#/definitions/phandle + description: + A phandle to the node of the focus lens controller. + + rotation: + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [ 0, 90, 180, 270 ] + description: | + The camera rotation is expressed as the angular difference in degrees + between two reference systems, one relative to the camera module, and one + defined on the external world scene to be captured when projected on the + image sensor pixel array. + + A camera sensor has a 2-dimensional reference system 'Rc' defined by its + pixel array read-out order. The origin is set to the first pixel being + read out, the X-axis points along the column read-out direction towards + the last columns, and the Y-axis along the row read-out direction towards + the last row. + + A typical example for a sensor with a 2592x1944 pixel array matrix + observed from the front is: + + 2591 X-axis 0 + <------------------------+ 0 + .......... ... ..........! + .......... ... ..........! Y-axis + ... ! + .......... ... ..........! + .......... ... ..........! 1943 + V + + The external world scene reference system 'Rs' is a 2-dimensional + reference system on the focal plane of the camera module. The origin is + placed on the top-left corner of the visible scene, the X-axis points + towards the right, and the Y-axis points towards the bottom of the scene. + The top, bottom, left and right directions are intentionally not defined + and depend on the environment in which the camera is used. + + A typical example of a (very common) picture of a shark swimming from left + to right, as seen from the camera, is: + + 0 X-axis + 0 +-------------------------------------> + ! + ! + ! + ! |\____)\___ + ! ) _____ __`< + ! |/ )/ + ! + ! + ! + V + Y-axis + + with the reference system 'Rs' placed on the camera focal plane: + + ¸.·˙! + ¸.·˙ ! + _ ¸.·˙ ! + +-/ \-+¸.·˙ ! + | (o) | ! Camera focal plane + +-----+˙·.¸ ! + ˙·.¸ ! + ˙·.¸ ! + ˙·.¸! + + When projected on the sensor's pixel array, the image and the associated + reference system 'Rs' are typically (but not always) inverted, due to the + camera module's lens optical inversion effect. + + Assuming the above represented scene of the swimming shark, the lens + inversion projects the scene and its reference system onto the sensor + pixel array, seen from the front of the camera sensor, as follows: + + Y-axis + ^ + ! + ! + ! + ! |\_____)\__ + ! ) ____ ___.< + ! |/ )/ + ! + ! + ! + 0 +-------------------------------------> + 0 X-axis + + Note the shark being upside-down. + + The resulting projected reference system is named 'Rp'. + + The camera rotation property is then defined as the angular difference in + the counter-clockwise direction between the camera reference system 'Rc' + and the projected scene reference system 'Rp'. It is expressed in degrees + as a number in the range [0, 360[. + + Examples + + 0 degrees camera rotation: + + + Y-Rp + ^ + Y-Rc ! + ^ ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! 0 +-------------------------------------> + ! 0 X-Rp + 0 +-------------------------------------> + 0 X-Rc + + + X-Rc 0 + <------------------------------------+ 0 + X-Rp 0 ! + <------------------------------------+ 0 ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! V + ! Y-Rc + V + Y-Rp + + 90 degrees camera rotation: + + 0 Y-Rc + 0 +--------------------> + ! Y-Rp + ! ^ + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! 0 +-------------------------------------> + ! 0 X-Rp + ! + ! + ! + ! + V + X-Rc + + 180 degrees camera rotation: + + 0 + <------------------------------------+ 0 + X-Rc ! + Y-Rp ! + ^ ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! V + ! Y-Rc + 0 +-------------------------------------> + 0 X-Rp + + 270 degrees camera rotation: + + 0 Y-Rc + 0 +--------------------> + ! 0 + ! <-----------------------------------+ 0 + ! X-Rp ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! ! + ! V + ! Y-Rp + ! + ! + ! + ! + V + X-Rc + + + Example one - Webcam + + A camera module installed on the user facing part of a laptop screen + casing used for video calls. The captured images are meant to be displayed + in landscape mode (width > height) on the laptop screen. + + The camera is typically mounted upside-down to compensate the lens optical + inversion effect: + + Y-Rp + Y-Rc ^ + ^ ! + ! ! + ! ! |\_____)\__ + ! ! ) ____ ___.< + ! ! |/ )/ + ! ! + ! ! + ! ! + ! 0 +-------------------------------------> + ! 0 X-Rp + 0 +-------------------------------------> + 0 X-Rc + + The two reference systems are aligned, the resulting camera rotation is + 0 degrees, no rotation correction needs to be applied to the resulting + image once captured to memory buffers to correctly display it to users: + + +--------------------------------------+ + ! ! + ! ! + ! ! + ! |\____)\___ ! + ! ) _____ __`< ! + ! |/ )/ ! + ! ! + ! ! + ! ! + +--------------------------------------+ + + If the camera sensor is not mounted upside-down to compensate for the lens + optical inversion, the two reference systems will not be aligned, with + 'Rp' being rotated 180 degrees relatively to 'Rc': + + + X-Rc 0 + <------------------------------------+ 0 + ! + Y-Rp ! + ^ ! + ! ! + ! |\_____)\__ ! + ! ) ____ ___.< ! + ! |/ )/ ! + ! ! + ! ! + ! V + ! Y-Rc + 0 +-------------------------------------> + 0 X-Rp + + The image once captured to memory will then be rotated by 180 degrees: + + +--------------------------------------+ + ! ! + ! ! + ! ! + ! __/(_____/| ! + ! >.___ ____ ( ! + ! \( \| ! + ! ! + ! ! + ! ! + +--------------------------------------+ + + A software rotation correction of 180 degrees should be applied to + correctly display the image: + + +--------------------------------------+ + ! ! + ! ! + ! ! + ! |\____)\___ ! + ! ) _____ __`< ! + ! |/ )/ ! + ! ! + ! ! + ! ! + +--------------------------------------+ + + Example two - Phone camera + + A camera installed on the back side of a mobile device facing away from + the user. The captured images are meant to be displayed in portrait mode + (height > width) to match the device screen orientation and the device + usage orientation used when taking the picture. + + The camera sensor is typically mounted with its pixel array longer side + aligned to the device longer side, upside-down mounted to compensate for + the lens optical inversion effect: + + 0 Y-Rc + 0 +--------------------> + ! Y-Rp + ! ^ + ! ! + ! ! + ! ! + ! ! |\_____)\__ + ! ! ) ____ ___.< + ! ! |/ )/ + ! ! + ! ! + ! ! + ! 0 +-------------------------------------> + ! 0 X-Rp + ! + ! + ! + ! + V + X-Rc + + The two reference systems are not aligned and the 'Rp' reference system is + rotated by 90 degrees in the counter-clockwise direction relatively to the + 'Rc' reference system. + + The image once captured to memory will be rotated: + + +-------------------------------------+ + | _ _ | + | \ / | + | | | | + | | | | + | | > | + | < | | + | | | | + | . | + | V | + +-------------------------------------+ + + A correction of 90 degrees in counter-clockwise direction has to be + applied to correctly display the image in portrait mode on the device + screen: + + +--------------------+ + | | + | | + | | + | | + | | + | | + | |\____)\___ | + | ) _____ __`< | + | |/ )/ | + | | + | | + | | + | | + | | + +--------------------+ + + orientation: + description: + The orientation of a device (typically an image sensor or a flash LED) + describing its mounting position relative to the usage orientation of the + system where the device is installed on. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: + # Front. The device is mounted on the front facing side of the system. For + # mobile devices such as smartphones, tablets and laptops the front side + # is the user facing side. + - 0 + # Back. The device is mounted on the back side of the system, which is + # defined as the opposite side of the front facing one. + - 1 + # External. The device is not attached directly to the system but is + # attached in a way that allows it to move freely. + - 2 + +additionalProperties: true + +... |