Document the new touch API.
Signed-off-by: Nick Dyer <nick@shmanahar.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: fix up videodev2.h.rst.exceptions]
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
- .. row 11
+ .. _MEDIA-INTF-T-V4L-TOUCH:
+
+ - ``MEDIA_INTF_T_V4L_TOUCH``
+
+ - Device node interface for Touch device (V4L)
+
+ - typically, /dev/v4l-touch?
+
+ - .. row 12
+
.. _MEDIA-INTF-T-ALSA-PCM-CAPTURE:
- ``MEDIA_INTF_T_ALSA_PCM_CAPTURE``
- typically, /dev/snd/pcmC?D?c
- - .. row 12
+ - .. row 13
.. _MEDIA-INTF-T-ALSA-PCM-PLAYBACK:
- typically, /dev/snd/pcmC?D?p
- - .. row 13
+ - .. row 14
.. _MEDIA-INTF-T-ALSA-CONTROL:
- typically, /dev/snd/controlC?
- - .. row 14
+ - .. row 15
.. _MEDIA-INTF-T-ALSA-COMPRESS:
- typically, /dev/snd/compr?
- - .. row 15
+ - .. row 16
.. _MEDIA-INTF-T-ALSA-RAWMIDI:
- typically, /dev/snd/midi?
- - .. row 16
+ - .. row 17
.. _MEDIA-INTF-T-ALSA-HWDEP:
- typically, /dev/snd/hwC?D?
- - .. row 17
+ - .. row 18
.. _MEDIA-INTF-T-ALSA-SEQUENCER:
- typically, /dev/snd/seq
- - .. row 18
+ - .. row 19
.. _MEDIA-INTF-T-ALSA-TIMER:
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _touch:
+
+*************
+Touch Devices
+*************
+
+Touch devices are accessed through character device special files named
+``/dev/v4l-touch0`` to ``/dev/v4l-touch255`` with major number 81 and
+dynamically allocated minor numbers 0 to 255.
+
+Overview
+========
+
+Sensors may be Optical, or Projected Capacitive touch (PCT).
+
+Processing is required to analyse the raw data and produce input events. In
+some systems, this may be performed on the ASIC and the raw data is purely a
+side-channel for diagnostics or tuning. In other systems, the ASIC is a simple
+analogue front end device which delivers touch data at high rate, and any touch
+processing must be done on the host.
+
+For capacitive touch sensing, the touchscreen is composed of an array of
+horizontal and vertical conductors (alternatively called rows/columns, X/Y
+lines, or tx/rx). Mutual Capacitance measured is at the nodes where the
+conductors cross. Alternatively, Self Capacitance measures the signal from each
+column and row independently.
+
+A touch input may be determined by comparing the raw capacitance measurement to
+a no-touch reference (or "baseline") measurement:
+
+Delta = Raw - Reference
+
+The reference measurement takes account of variations in the capacitance across
+the touch sensor matrix, for example manufacturing irregularities,
+environmental or edge effects.
+
+Querying Capabilities
+=====================
+
+Devices supporting the touch interface set the ``V4L2_CAP_VIDEO_CAPTURE`` flag
+and the ``V4L2_CAP_TOUCH`` flag in the ``capabilities`` field of
+:ref:`v4l2_capability <v4l2-capability>` returned by the
+:ref:`VIDIOC_QUERYCAP` ioctl.
+
+At least one of the read/write or streaming I/O methods must be
+supported.
+
+The formats supported by touch devices are documented in
+:ref:`Touch Formats <tch-formats>`.
+
+Data Format Negotiation
+=======================
+
+A touch device may support any I/O method.
dev-radio
dev-rds
dev-sdr
+ dev-touch
dev-event
dev-subdev
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _V4L2-TCH-FMT-DELTA-TD08:
+
+********************************
+V4L2_TCH_FMT_DELTA_TD08 ('TD08')
+********************************
+
+*man V4L2_TCH_FMT_DELTA_TD08(2)*
+
+8-bit signed Touch Delta
+
+Description
+===========
+
+This format represents delta data from a touch controller.
+
+Delta values may range from -128 to 127. Typically the values will vary through
+a small range depending on whether the sensor is touched or not. The full value
+may be seen if one of the touchscreen nodes has a fault or the line is not
+connected.
+
+**Byte Order.**
+Each cell is one byte.
+
+
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 2 1 1 1 1
+
+
+ - .. row 1
+
+ - start + 0:
+
+ - D'\ :sub:`00`
+
+ - D'\ :sub:`01`
+
+ - D'\ :sub:`02`
+
+ - D'\ :sub:`03`
+
+ - .. row 2
+
+ - start + 4:
+
+ - D'\ :sub:`10`
+
+ - D'\ :sub:`11`
+
+ - D'\ :sub:`12`
+
+ - D'\ :sub:`13`
+
+ - .. row 3
+
+ - start + 8:
+
+ - D'\ :sub:`20`
+
+ - D'\ :sub:`21`
+
+ - D'\ :sub:`22`
+
+ - D'\ :sub:`23`
+
+ - .. row 4
+
+ - start + 12:
+
+ - D'\ :sub:`30`
+
+ - D'\ :sub:`31`
+
+ - D'\ :sub:`32`
+
+ - D'\ :sub:`33`
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _V4L2-TCH-FMT-DELTA-TD16:
+
+********************************
+V4L2_TCH_FMT_DELTA_TD16 ('TD16')
+********************************
+
+*man V4L2_TCH_FMT_DELTA_TD16(2)*
+
+16-bit signed Touch Delta
+
+
+Description
+===========
+
+This format represents delta data from a touch controller.
+
+Delta values may range from -32768 to 32767. Typically the values will vary
+through a small range depending on whether the sensor is touched or not. The
+full value may be seen if one of the touchscreen nodes has a fault or the line
+is not connected.
+
+**Byte Order.**
+Each cell is one byte.
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 2 1 1 1 1 1 1 1 1
+
+
+ - .. row 1
+
+ - start + 0:
+
+ - D'\ :sub:`00high`
+
+ - D'\ :sub:`00low`
+
+ - D'\ :sub:`01high`
+
+ - D'\ :sub:`01low`
+
+ - D'\ :sub:`02high`
+
+ - D'\ :sub:`02low`
+
+ - D'\ :sub:`03high`
+
+ - D'\ :sub:`03low`
+
+ - .. row 2
+
+ - start + 8:
+
+ - D'\ :sub:`10high`
+
+ - D'\ :sub:`10low`
+
+ - D'\ :sub:`11high`
+
+ - D'\ :sub:`11low`
+
+ - D'\ :sub:`12high`
+
+ - D'\ :sub:`12low`
+
+ - D'\ :sub:`13high`
+
+ - D'\ :sub:`13low`
+
+ - .. row 3
+
+ - start + 16:
+
+ - D'\ :sub:`20high`
+
+ - D'\ :sub:`20low`
+
+ - D'\ :sub:`21high`
+
+ - D'\ :sub:`21low`
+
+ - D'\ :sub:`22high`
+
+ - D'\ :sub:`22low`
+
+ - D'\ :sub:`23high`
+
+ - D'\ :sub:`23low`
+
+ - .. row 4
+
+ - start + 24:
+
+ - D'\ :sub:`30high`
+
+ - D'\ :sub:`30low`
+
+ - D'\ :sub:`31high`
+
+ - D'\ :sub:`31low`
+
+ - D'\ :sub:`32high`
+
+ - D'\ :sub:`32low`
+
+ - D'\ :sub:`33high`
+
+ - D'\ :sub:`33low`
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _V4L2-TCH-FMT-TU08:
+
+**************************
+V4L2_TCH_FMT_TU08 ('TU08')
+**************************
+
+*man V4L2_TCH_FMT_TU08(2)*
+
+8-bit unsigned raw touch data
+
+Description
+===========
+
+This format represents unsigned 8-bit data from a touch controller.
+
+This may be used for output for raw and reference data. Values may range from
+0 to 255.
+
+**Byte Order.**
+Each cell is one byte.
+
+
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 2 1 1 1 1
+
+
+ - .. row 1
+
+ - start + 0:
+
+ - R'\ :sub:`00`
+
+ - R'\ :sub:`01`
+
+ - R'\ :sub:`02`
+
+ - R'\ :sub:`03`
+
+ - .. row 2
+
+ - start + 4:
+
+ - R'\ :sub:`10`
+
+ - R'\ :sub:`11`
+
+ - R'\ :sub:`12`
+
+ - R'\ :sub:`13`
+
+ - .. row 3
+
+ - start + 8:
+
+ - R'\ :sub:`20`
+
+ - R'\ :sub:`21`
+
+ - R'\ :sub:`22`
+
+ - R'\ :sub:`23`
+
+ - .. row 4
+
+ - start + 12:
+
+ - R'\ :sub:`30`
+
+ - R'\ :sub:`31`
+
+ - R'\ :sub:`32`
+
+ - R'\ :sub:`33`
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _V4L2-TCH-FMT-TU16:
+
+********************************
+V4L2_TCH_FMT_TU16 ('TU16')
+********************************
+
+*man V4L2_TCH_FMT_TU16(2)*
+
+16-bit unsigned raw touch data
+
+
+Description
+===========
+
+This format represents unsigned 16-bit data from a touch controller.
+
+This may be used for output for raw and reference data. Values may range from
+0 to 65535.
+
+**Byte Order.**
+Each cell is one byte.
+
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 2 1 1 1 1 1 1 1 1
+
+
+ - .. row 1
+
+ - start + 0:
+
+ - R'\ :sub:`00high`
+
+ - R'\ :sub:`00low`
+
+ - R'\ :sub:`01high`
+
+ - R'\ :sub:`01low`
+
+ - R'\ :sub:`02high`
+
+ - R'\ :sub:`02low`
+
+ - R'\ :sub:`03high`
+
+ - R'\ :sub:`03low`
+
+ - .. row 2
+
+ - start + 8:
+
+ - R'\ :sub:`10high`
+
+ - R'\ :sub:`10low`
+
+ - R'\ :sub:`11high`
+
+ - R'\ :sub:`11low`
+
+ - R'\ :sub:`12high`
+
+ - R'\ :sub:`12low`
+
+ - R'\ :sub:`13high`
+
+ - R'\ :sub:`13low`
+
+ - .. row 3
+
+ - start + 16:
+
+ - R'\ :sub:`20high`
+
+ - R'\ :sub:`20low`
+
+ - R'\ :sub:`21high`
+
+ - R'\ :sub:`21low`
+
+ - R'\ :sub:`22high`
+
+ - R'\ :sub:`22low`
+
+ - R'\ :sub:`23high`
+
+ - R'\ :sub:`23low`
+
+ - .. row 4
+
+ - start + 24:
+
+ - R'\ :sub:`30high`
+
+ - R'\ :sub:`30low`
+
+ - R'\ :sub:`31high`
+
+ - R'\ :sub:`31low`
+
+ - R'\ :sub:`32high`
+
+ - R'\ :sub:`32low`
+
+ - R'\ :sub:`33high`
+
+ - R'\ :sub:`33low`
depth-formats
pixfmt-013
sdr-formats
+ tch-formats
pixfmt-reserved
--- /dev/null
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _tch-formats:
+
+*************
+Touch Formats
+*************
+
+These formats are used for :ref:`touch` interface only.
+
+
+.. toctree::
+ :maxdepth: 1
+
+ pixfmt-tch-td16
+ pixfmt-tch-td08
+ pixfmt-tch-tu16
+ pixfmt-tch-tu08
- Analog baseband input, for example CVBS / Composite Video,
S-Video, RGB.
+ - .. row 3
+
+ - ``V4L2_INPUT_TYPE_TOUCH``
+
+ - 3
+
+ - This input is a touch device for capturing raw touch data.
+
.. tabularcolumns:: |p{4.8cm}|p{2.6cm}|p{10.1cm}|
- .. row 26
+ - ``V4L2_CAP_TOUCH``
+
+ - 0x10000000
+
+ - This is a touch device.
+
+ - .. row 27
+
- ``V4L2_CAP_DEVICE_CAPS``
- 0x80000000
replace define V4L2_CAP_ASYNCIO device-capabilities
replace define V4L2_CAP_STREAMING device-capabilities
replace define V4L2_CAP_DEVICE_CAPS device-capabilities
+replace define V4L2_CAP_TOUCH device-capabilities
# V4L2 pix flags
replace define V4L2_PIX_FMT_PRIV_MAGIC v4l2-pix-format
replace define V4L2_INPUT_TYPE_TUNER input-type
replace define V4L2_INPUT_TYPE_CAMERA input-type
+replace define V4L2_INPUT_TYPE_TOUCH input-type
replace define V4L2_IN_ST_NO_POWER input-status
replace define V4L2_IN_ST_NO_SIGNAL input-status