diff options
Diffstat (limited to 'Documentation/iio')
| -rw-r--r-- | Documentation/iio/ad7380.rst | 16 | ||||
| -rw-r--r-- | Documentation/iio/ad7606.rst | 144 | ||||
| -rw-r--r-- | Documentation/iio/ad7625.rst | 91 | ||||
| -rw-r--r-- | Documentation/iio/bno055.rst | 2 | ||||
| -rw-r--r-- | Documentation/iio/index.rst | 2 |
5 files changed, 254 insertions, 1 deletions
diff --git a/Documentation/iio/ad7380.rst b/Documentation/iio/ad7380.rst index 6f70b49b9ef2..c46127700e14 100644 --- a/Documentation/iio/ad7380.rst +++ b/Documentation/iio/ad7380.rst @@ -27,6 +27,8 @@ The following chips are supported by this driver: * `AD7386-4 <https://www.analog.com/en/products/ad7386-4.html>`_ * `AD7387-4 <https://www.analog.com/en/products/ad7387-4.html>`_ * `AD7388-4 <https://www.analog.com/en/products/ad7388-4.html>`_ +* `ADAQ4370-4 <https://www.analog.com/en/products/adaq4370-4.html>`_ +* `ADAQ4380-4 <https://www.analog.com/en/products/adaq4380-4.html>`_ Supported features @@ -47,6 +49,12 @@ ad7380-4 ad7380-4 supports only an external reference voltage (2.5V to 3.3V). It must be declared in the device tree as ``refin-supply``. +ADAQ devices +~~~~~~~~~~~~ + +adaq4370-4 and adaq4380-4 don't have an external reference, but use a 3.3V +internal reference derived from one of its supplies (``refin-supply``) + All other devices from ad738x family ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -121,6 +129,14 @@ Example for AD7386/7/8 (2 channels parts): When enabling sequencer mode, the effective sampling rate is divided by two. +Gain (ADAQ devices only) +~~~~~~~~~~~~~~~~~~~~~~~~ + +ADAQ devices have a pin selectable gain in front of each ADC. The appropriate +gain is selectable from device tree using the ``adi,gain-milli`` property. +Refer to the typical connection diagrams section of the datasheet for pin +wiring. + Unimplemented features ---------------------- diff --git a/Documentation/iio/ad7606.rst b/Documentation/iio/ad7606.rst new file mode 100644 index 000000000000..930199e03c67 --- /dev/null +++ b/Documentation/iio/ad7606.rst @@ -0,0 +1,144 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +============= +AD7606 driver +============= + +ADC driver for Analog Devices Inc. AD7606 and similar devices. The module name +is ``ad7606``. + +Supported devices +================= + +The following chips are supported by this driver: + +* `AD7605 <https://www.analog.com/en/products/ad7605.html>`_ +* `AD7606 <https://www.analog.com/en/products/ad7606.html>`_ +* `AD7606B <https://www.analog.com/en/products/ad7606b.html>`_ +* `AD7616 <https://www.analog.com/en/products/ad7616.html>`_ + +Supported features +================== + +SPI wiring modes +---------------- + +These ADCs can output data on several SDO lines (1/2/4/8). The driver +currently supports only 1 SDO line. + +Parallel wiring mode +-------------------- + +There is also a parallel interface, with 16 lines (that can be reduced to 8 in +byte mode). The parallel interface is selected by declaring the device as +platform in the device tree (with no io-backends node defined, see below). + +IIO-backend mode +---------------- + +This mode allows to reach the best sample rates, but it requires an external +hardware (eg HDL or APU) to handle the low level communication. +The backend mode is enabled when through the definition of the "io-backends" +property in the device tree. + +The reference configuration for the current implementation of IIO-backend mode +is the HDL reference provided by ADI: +https://wiki.analog.com/resources/eval/user-guides/ad7606x-fmc/hdl + +This implementation embeds an IIO-backend compatible IP (adi-axi-adc) and a PWM +connected to the conversion trigger pin. + +.. code-block:: + + +---+ +---------------------------- + | | +-------+ |AD76xx + | A | controls | | | + | D |-------------->| PWM |-------------->| cnvst + | 7 | | | | + | 6 | +-------+ | + | 0 | controls +-----------+-----------+ | + | 6 |---------->| | |<--| frstdata + | | | Backend | Backend |<--| busy + | D | | Driver | | | + | R | | | |-->| clk + | I | requests |+---------+| DMA | | + | V |----------->| Buffer ||<---- |<=>| DATA + | E | |+---------+| | | + | R | +-----------+-----------+ | + | |-------------------------------------->| reset/configuration gpios + +---+ +----------------------------- + + +Software and hardware modes +--------------------------- + +While all the AD7606/AD7616 series parts can be configured using GPIOs, some of +them can be configured using register. + +The chips that support software mode have more values available for configuring +the device, as well as more settings, and allow to control the range and +calibration per channel. + +The following settings are available per channel in software mode: + - Scale + +Also, there is a broader choice of oversampling ratios in software mode. + +Conversion triggering +--------------------- + +The conversion can be triggered by two distinct ways: + + - A GPIO is connected to the conversion trigger pin, and this GPIO is controlled + by the driver directly. In this configuration, the driver sets back the + conversion trigger pin to high as soon as it has read all the conversions. + + - An external source is connected to the conversion trigger pin. In the + current implementation, it must be a PWM. In this configuration, the driver + does not control directly the conversion trigger pin. Instead, it can + control the PWM's frequency. This trigger is enabled only for iio-backend. + +Reference voltage +----------------- + +2 possible reference voltage sources are supported: + + - Internal reference (2.5V) + - External reference (2.5V) + +The source is determined by the device tree. If ``refin-supply`` is present, +then the external reference is used, otherwise the internal reference is used. + +Oversampling +------------ + +This family supports oversampling to improve SNR. +In software mode, the following ratios are available: +1 (oversampling disabled)/2/4/8/16/32/64/128/256. + +Unimplemented features +---------------------- + +- 2/4/8 SDO lines +- CRC indication +- Calibration + +Device buffers +============== + +IIO triggered buffer +-------------------- + +This driver supports IIO triggered buffers, with a "built in" trigger, i.e the +trigger is allocated and linked by the driver, and a new conversion is triggered +as soon as the samples are transferred, and a timestamp channel is added to make +up for the potential jitter induced by the delays in the interrupt handling. + +IIO backend buffer +------------------ + +When IIO backend is used, the trigger is not needed, and the sample rate is +considered as stable. There is no timestamp channel. The communication is +delegated to an external logic, called a backend, and the backend's driver +handles the buffer. When this mode is enabled, the driver cannot control the +conversion pin, because the busy pin is bound to the backend. diff --git a/Documentation/iio/ad7625.rst b/Documentation/iio/ad7625.rst new file mode 100644 index 000000000000..61761e3b75c3 --- /dev/null +++ b/Documentation/iio/ad7625.rst @@ -0,0 +1,91 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +==================== +AD7625 driver +==================== + +ADC driver for Analog Devices Inc. AD7625, AD7626, AD7960, and AD7961 +devices. The module name is ``ad7625``. + +Supported devices +================= + +The following chips are supported by this driver: + +* `AD7625 <https://www.analog.com/AD7625>`_ +* `AD7626 <https://www.analog.com/AD7626>`_ +* `AD7960 <https://www.analog.com/AD7960>`_ +* `AD7961 <https://www.analog.com/AD7961>`_ + +The driver requires use of the Pulsar LVDS HDL project: + +* `Pulsar LVDS HDL <http://analogdevicesinc.github.io/hdl/projects/pulsar_lvds/index.html>`_ + +To trigger conversions and enable subsequent data transfer, the devices +require coupled PWM signals with a phase offset. + +Supported features +================== + +Conversion control modes +------------------------ + +The driver currently supports one of two possible LVDS conversion control methods. + +Echoed-Clock interface mode +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. code-block:: + + +----------------+ + +xxxxxxxxxxxxxxxxxxxxxxxxxx| CNV | + X | | + v | HOST | + +----------------------------+ | | + | CNV+/CNV- DCO+/DCO- |xxxxxxx>| CLK_IN | + | | | | + | | | | + | AD7625 D+/D- |xxxxxxx>| DATA_IN | + | | | | + | | | | + | CLK+/CLK- |<xxxxxxx| CLK & CLK_GATE | + +----------------------------+ | | + +----------------+ + +Reference voltage +----------------- + +Three possible reference voltage sources are supported: + +- Internal reference (only available on AD7625 and AD7626) +- External reference and internal buffer +- External reference + +The source is determined by the device tree. If ``ref-supply`` is present, then +the external reference is used. If ``refin-supply`` is present, then the internal +buffer is used. If neither is present, then the internal reference is used. + +Unimplemented features +---------------------- + +- Self-clocked mode + + +Device attributes +================= + +The AD762x is a fully-differential ADC and has the following attributes: + ++---------------------------------------+--------------------------------------------------------------+ +| Attribute | Description | ++=======================================+==============================================================+ +| ``scale`` | Scale factor to convert raw value from buffered reads to mV. | ++---------------------------------------+--------------------------------------------------------------+ + + +Device buffers +============== + +This driver supports IIO triggered buffers. + +See :doc:`iio_devbuf` for more information. diff --git a/Documentation/iio/bno055.rst b/Documentation/iio/bno055.rst index 9a489a79d8f5..f1111ff3fe2e 100644 --- a/Documentation/iio/bno055.rst +++ b/Documentation/iio/bno055.rst @@ -22,7 +22,7 @@ This driver supports also IIO buffers. The IMU continuously performs an autocalibration procedure if (and only if) operating in fusion mode. The magnetometer autocalibration can however be -disabled writing 0 in the sysfs in_magn_calibration_fast_enable attribute. +disabled by writing 0 in the sysfs in_magn_calibration_fast_enable attribute. The driver provides access to autocalibration flags (i.e. you can known if the IMU has successfully autocalibrated) and to the calibration data blob. diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst index dfcf9618568a..074dbbf7ba0a 100644 --- a/Documentation/iio/index.rst +++ b/Documentation/iio/index.rst @@ -21,6 +21,8 @@ Industrial I/O Kernel Drivers ad4000 ad4695 ad7380 + ad7606 + ad7625 ad7944 adis16475 adis16480 |