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1.. SPDX-License-Identifier: GPL-2.0-only2 3=============4AD4000 driver5=============6 7Device driver for Analog Devices Inc. AD4000 series of ADCs.8 9Supported devices10=================11 12* `AD4000 <https://www.analog.com/AD4000>`_13* `AD4001 <https://www.analog.com/AD4001>`_14* `AD4002 <https://www.analog.com/AD4002>`_15* `AD4003 <https://www.analog.com/AD4003>`_16* `AD4004 <https://www.analog.com/AD4004>`_17* `AD4005 <https://www.analog.com/AD4005>`_18* `AD4006 <https://www.analog.com/AD4006>`_19* `AD4007 <https://www.analog.com/AD4007>`_20* `AD4008 <https://www.analog.com/AD4008>`_21* `AD4010 <https://www.analog.com/AD4010>`_22* `AD4011 <https://www.analog.com/AD4011>`_23* `AD4020 <https://www.analog.com/AD4020>`_24* `AD4021 <https://www.analog.com/AD4021>`_25* `AD4022 <https://www.analog.com/AD4022>`_26* `ADAQ4001 <https://www.analog.com/ADAQ4001>`_27* `ADAQ4003 <https://www.analog.com/ADAQ4003>`_28 29Wiring connections30------------------31 32Devices of the AD4000 series can be connected to the SPI host controller in a33few different modes.34 35CS mode, 3-wire turbo mode36^^^^^^^^^^^^^^^^^^^^^^^^^^37 38Datasheet "3-wire" mode is what most resembles standard SPI connection which,39for these devices, comprises of connecting the controller CS line to device CNV40pin and other SPI lines as usual. This configuration is (misleadingly) called41"CS Mode, 3-Wire Turbo Mode" connection in datasheets.42NOTE: The datasheet definition of 3-wire mode for the AD4000 series is NOT the43same of standard spi-3wire mode.44This is the only connection mode that allows configuration register access but45it requires the SPI controller to support the ``SPI_MOSI_IDLE_HIGH`` feature.46 47Omit the ``adi,sdi-pin`` property in device tree to select this mode.48 49::50 51 +-------------+52 + ----------------------------------| SDO |53 | | |54 | +-------------------| CS |55 | v | |56 | +--------------------+ | HOST |57 | | CNV | | |58 +--->| SDI AD4000 SDO |-------->| SDI |59 | SCK | | |60 +--------------------+ | |61 ^ | |62 +--------------------| SCLK |63 +-------------+64 65CS mode, 3-wire, without busy indicator66^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^67 68Another wiring configuration supported as "3-wire" mode has the SDI pin69hard-wired to digital input/output interface supply (VIO). In this setup, the70controller is not required to support ``SPI_MOSI_IDLE_HIGH`` but register access71is not possible. This connection mode saves one wire and works with any SPI72controller.73 74Set the ``adi,sdi-pin`` device tree property to ``"high"`` to select this mode.75 76::77 78 +-------------+79 +--------------------| CS |80 v | |81 VIO +--------------------+ | HOST |82 | | CNV | | |83 +--->| SDI AD4000 SDO |-------->| SDI |84 | SCK | | |85 +--------------------+ | |86 ^ | |87 +--------------------| SCLK |88 +-------------+89 90Alternatively, a GPIO may be connected to the device CNV pin. This is similar to91the previous wiring configuration but saves the use of a CS line.92 93::94 95 +-------------+96 +--------------------| GPIO |97 v | |98 VIO +--------------------+ | HOST |99 | | CNV | | |100 +--->| SDI AD4000 SDO |-------->| SDI |101 | SCK | | |102 +--------------------+ | |103 ^ | |104 +--------------------| SCLK |105 +-------------+106 107CS mode, 4-wire without busy indicator108^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^109 110In datasheet "4-wire" mode, the controller CS line is connected to the ADC SDI111pin and a GPIO is connected to the ADC CNV pin. This connection mode may better112suit scenarios where multiple ADCs can share one CNV trigger.113 114Set ``adi,sdi-pin`` to ``"cs"`` to select this mode.115 116 117::118 119 +-------------+120 + ----------------------------------| CS |121 | | |122 | +-------------------| GPIO |123 | v | |124 | +--------------------+ | HOST |125 | | CNV | | |126 +--->| SDI AD4000 SDO |-------->| SDI |127 | SCK | | |128 +--------------------+ | |129 ^ | |130 +--------------------| SCLK |131 +-------------+132