docs: iio: ad7380: add support for single-ended parts

The AD7380 family has some compatible single-ended chips: AD7386/7/8(-4).
These single-ended chips have a  2:1 multiplexer in front of each ADC.
They also include additional configuration registers that allow for either
manual selection or automatic switching (sequencer mode), of the
multiplexer inputs. Add a section to describe this.

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240731-ad7380-add-single-ended-chips-v2-7-cd63bf05744c@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Julien Stephan 2024-07-31 09:05:48 +02:00 committed by Jonathan Cameron
parent d4c6ff182d
commit 1ca99efa17

View file

@ -17,10 +17,16 @@ The following chips are supported by this driver:
* `AD7381 <https://www.analog.com/en/products/ad7381.html>`_
* `AD7383 <https://www.analog.com/en/products/ad7383.html>`_
* `AD7384 <https://www.analog.com/en/products/ad7384.html>`_
* `AD7386 <https://www.analog.com/en/products/ad7386.html>`_
* `AD7387 <https://www.analog.com/en/products/ad7387.html>`_
* `AD7388 <https://www.analog.com/en/products/ad7388.html>`_
* `AD7380-4 <https://www.analog.com/en/products/ad7380-4.html>`_
* `AD7381-4 <https://www.analog.com/en/products/ad7381-4.html>`_
* `AD7383-4 <https://www.analog.com/en/products/ad7383-4.html>`_
* `AD7384-4 <https://www.analog.com/en/products/ad7384-4.html>`_
* `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>`_
Supported features
@ -69,6 +75,42 @@ must restart iiod using the following command:
root:~# systemctl restart iiod
Channel selection and sequencer (single-end chips only)
-------------------------------------------------------
Single-ended chips of this family (ad7386/7/8(-4)) have a 2:1 multiplexer in
front of each ADC. They also include additional configuration registers that
allow for either manual selection or automatic switching (sequencer mode), of
the multiplexer inputs.
From an IIO point of view, all inputs are exported, i.e ad7386/7/8
export 4 channels and ad7386-4/7-4/8-4 export 8 channels.
Inputs ``AinX0`` of multiplexers correspond to the first half of IIO channels (i.e
0-1 or 0-3) and inputs ``AinX1`` correspond to second half (i.e 2-3 or 4-7).
Example for AD7386/7/8 (2 channels parts):
.. code-block::
IIO | AD7386/7/8
| +----------------------------
| | _____ ______
| | | | | |
voltage0 | AinA0 --|--->| | | |
| | | mux |----->| ADCA |---
voltage2 | AinA1 --|--->| | | |
| | |_____| |_____ |
| | _____ ______
| | | | | |
voltage1 | AinB0 --|--->| | | |
| | | mux |----->| ADCB |---
voltage3 | AinB1 --|--->| | | |
| | |_____| |______|
| |
| +----------------------------
When enabling sequencer mode, the effective sampling rate is divided by two.
Unimplemented features
----------------------