| Message ID | e553a7c6ba88b3d8ae2db0963212fdce0919805a.1719351923.git.marcelo.schmitt@analog.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add support for AD4000 series of ADCs | expand |
On 6/25/24 4:55 PM, Marcelo Schmitt wrote: > Document wiring configurations for the AD4000 series of ADCs. > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> > --- > Documentation/iio/ad4000.rst | 131 +++++++++++++++++++++++++++++++++++ > Documentation/iio/index.rst | 1 + > MAINTAINERS | 1 + > 3 files changed, 133 insertions(+) > create mode 100644 Documentation/iio/ad4000.rst > > diff --git a/Documentation/iio/ad4000.rst b/Documentation/iio/ad4000.rst > new file mode 100644 > index 000000000000..de8fd3ae6e62 > --- /dev/null > +++ b/Documentation/iio/ad4000.rst > @@ -0,0 +1,131 @@ > +.. SPDX-License-Identifier: GPL-2.0-only > + > +============= > +AD4000 driver > +============= > + > +Device driver for Analog Devices Inc. AD4000 series of ADCs. > + > +Supported devices > +================= > + > +* `AD4000 <https://www.analog.com/AD4000>`_ > +* `AD4001 <https://www.analog.com/AD4001>`_ > +* `AD4002 <https://www.analog.com/AD4002>`_ > +* `AD4003 <https://www.analog.com/AD4003>`_ > +* `AD4004 <https://www.analog.com/AD4004>`_ > +* `AD4005 <https://www.analog.com/AD4005>`_ > +* `AD4006 <https://www.analog.com/AD4006>`_ > +* `AD4007 <https://www.analog.com/AD4007>`_ > +* `AD4008 <https://www.analog.com/AD4008>`_ > +* `AD4010 <https://www.analog.com/AD4010>`_ > +* `AD4011 <https://www.analog.com/AD4011>`_ > +* `AD4020 <https://www.analog.com/AD4020>`_ > +* `AD4021 <https://www.analog.com/AD4021>`_ > +* `AD4022 <https://www.analog.com/AD4022>`_ > +* `ADAQ4001 <https://www.analog.com/ADAQ4001>`_ > +* `ADAQ4003 <https://www.analog.com/ADAQ4003>`_ > + > +Wiring connections > +------------------ > + > +Devices of the AD4000 series can be connected to the SPI host controller in a > +few different modes. > + > +CS mode, 3-wire turbo mode > +^^^^^^^^^^^^^^^^^^^^^^^^^^ The datasheet also has the same diagram in _Figure 55. CS Mode, 4-Wire Turbo Mode Connection Diagram_. So maybe we should call this "register support mode" or something like that instead of mentioning 3 or 4-wire? > + > +Datasheet "3-wire" mode is what most resembles standard SPI connection which, > +for these devices, comprises of connecting the controller CS line to device CNV > +pin and other SPI lines as usual. This configuration is (misleadingly) called > +"CS Mode, 3-Wire Turbo Mode" connection in datasheets. > +NOTE: The datasheet definition of 3-wire mode for the AD4000 series is NOT the > +same of standard spi-3wire mode. > +This is the only connection mode that allows configuration register access but > +it requires the SPI controller to support the ``SPI_MOSI_IDLE_HIGH`` feature. > + > +Omit the ``adi,sdi-pin`` property in device tree to select this mode. > + > +:: > + > + +-------------+ > + + ----------------------------------| SDO | > + | | | > + | +-------------------| CS | > + | v | | > + | +--------------------+ | HOST | > + | | CNV | | | > + +--->| SDI AD4000 SDO |-------->| SDI | > + | SCK | | | > + +--------------------+ | | > + ^ | | > + +--------------------| SCLK | > + +-------------+ > + I think the rest of the explanations are good.
On 06/26, David Lechner wrote: > On 6/25/24 4:55 PM, Marcelo Schmitt wrote: > > Document wiring configurations for the AD4000 series of ADCs. > > > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> > > --- > > Documentation/iio/ad4000.rst | 131 +++++++++++++++++++++++++++++++++++ > > Documentation/iio/index.rst | 1 + > > MAINTAINERS | 1 + ... > > +Wiring connections > > +------------------ > > + > > +Devices of the AD4000 series can be connected to the SPI host controller in a > > +few different modes. > > + > > +CS mode, 3-wire turbo mode > > +^^^^^^^^^^^^^^^^^^^^^^^^^^ > > The datasheet also has the same diagram in _Figure 55. CS Mode, 4-Wire Turbo Mode > Connection Diagram_. So maybe we should call this "register support mode" or > something like that instead of mentioning 3 or 4-wire? > Humm, ADAQ4003 datasheet has the same figure for CS Mode, 4-wire turbo mode and CS mode, 4-wire with busy indicator although other datasheets have MOSI to SDI in 4-wire turbo as you said. The register read/write functionality sections say CNV must be brought low to access the configuration register. I'll leave it as it is for now as I have not tested reg access with CNV high. We can update this in the future if find out reg access to work in 4-wire mode. > > + > > +Datasheet "3-wire" mode is what most resembles standard SPI connection which, > > +for these devices, comprises of connecting the controller CS line to device CNV > > +pin and other SPI lines as usual. This configuration is (misleadingly) called > > +"CS Mode, 3-Wire Turbo Mode" connection in datasheets. > > +NOTE: The datasheet definition of 3-wire mode for the AD4000 series is NOT the > > +same of standard spi-3wire mode. > > +This is the only connection mode that allows configuration register access but > > +it requires the SPI controller to support the ``SPI_MOSI_IDLE_HIGH`` feature. > > + > > +Omit the ``adi,sdi-pin`` property in device tree to select this mode. > > + > > +:: > > + > > + +-------------+ > > + + ----------------------------------| SDO | > > + | | | > > + | +-------------------| CS | > > + | v | | > > + | +--------------------+ | HOST | > > + | | CNV | | | > > + +--->| SDI AD4000 SDO |-------->| SDI | > > + | SCK | | | > > + +--------------------+ | | > > + ^ | | > > + +--------------------| SCLK | > > + +-------------+ > > + > > I think the rest of the explanations are good. >
diff --git a/Documentation/iio/ad4000.rst b/Documentation/iio/ad4000.rst new file mode 100644 index 000000000000..de8fd3ae6e62 --- /dev/null +++ b/Documentation/iio/ad4000.rst @@ -0,0 +1,131 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +============= +AD4000 driver +============= + +Device driver for Analog Devices Inc. AD4000 series of ADCs. + +Supported devices +================= + +* `AD4000 <https://www.analog.com/AD4000>`_ +* `AD4001 <https://www.analog.com/AD4001>`_ +* `AD4002 <https://www.analog.com/AD4002>`_ +* `AD4003 <https://www.analog.com/AD4003>`_ +* `AD4004 <https://www.analog.com/AD4004>`_ +* `AD4005 <https://www.analog.com/AD4005>`_ +* `AD4006 <https://www.analog.com/AD4006>`_ +* `AD4007 <https://www.analog.com/AD4007>`_ +* `AD4008 <https://www.analog.com/AD4008>`_ +* `AD4010 <https://www.analog.com/AD4010>`_ +* `AD4011 <https://www.analog.com/AD4011>`_ +* `AD4020 <https://www.analog.com/AD4020>`_ +* `AD4021 <https://www.analog.com/AD4021>`_ +* `AD4022 <https://www.analog.com/AD4022>`_ +* `ADAQ4001 <https://www.analog.com/ADAQ4001>`_ +* `ADAQ4003 <https://www.analog.com/ADAQ4003>`_ + +Wiring connections +------------------ + +Devices of the AD4000 series can be connected to the SPI host controller in a +few different modes. + +CS mode, 3-wire turbo mode +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Datasheet "3-wire" mode is what most resembles standard SPI connection which, +for these devices, comprises of connecting the controller CS line to device CNV +pin and other SPI lines as usual. This configuration is (misleadingly) called +"CS Mode, 3-Wire Turbo Mode" connection in datasheets. +NOTE: The datasheet definition of 3-wire mode for the AD4000 series is NOT the +same of standard spi-3wire mode. +This is the only connection mode that allows configuration register access but +it requires the SPI controller to support the ``SPI_MOSI_IDLE_HIGH`` feature. + +Omit the ``adi,sdi-pin`` property in device tree to select this mode. + +:: + + +-------------+ + + ----------------------------------| SDO | + | | | + | +-------------------| CS | + | v | | + | +--------------------+ | HOST | + | | CNV | | | + +--->| SDI AD4000 SDO |-------->| SDI | + | SCK | | | + +--------------------+ | | + ^ | | + +--------------------| SCLK | + +-------------+ + +CS mode, 3-wire, without busy indicator +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Another wiring configuration supported as "3-wire" mode has the SDI pin +hard-wired to digital input/output interface supply (VIO). In this setup, the +controller is not required to support ``SPI_MOSI_IDLE_HIGH`` but register access +is not possible. This connection mode saves one wire and works with any SPI +controller. + +Set the ``adi,sdi-pin`` device tree property to ``"high"`` to select this mode. + +:: + + +-------------+ + +--------------------| CS | + v | | + VIO +--------------------+ | HOST | + | | CNV | | | + +--->| SDI AD4000 SDO |-------->| SDI | + | SCK | | | + +--------------------+ | | + ^ | | + +--------------------| SCLK | + +-------------+ + +Alternatively, a GPIO may be connected to the device CNV pin. This is similar to +the previous wiring configuration but saves the use of a CS line. + +:: + + +-------------+ + +--------------------| GPIO | + v | | + VIO +--------------------+ | HOST | + | | CNV | | | + +--->| SDI AD4000 SDO |-------->| SDI | + | SCK | | | + +--------------------+ | | + ^ | | + +--------------------| SCLK | + +-------------+ + +CS mode, 4-wire without busy indicator +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In datasheet "4-wire" mode, the controller CS line is connected to the ADC SDI +pin and a GPIO is connected to the ADC CNV pin. This connection mode may better +suit scenarios where multiple ADCs can share one CNV trigger. + +Set ``adi,sdi-pin`` to ``"cs"`` to select this mode. + + +:: + + +-------------+ + + ----------------------------------| CS | + | | | + | +-------------------| GPIO | + | v | | + | +--------------------+ | HOST | + | | CNV | | | + +--->| SDI AD4000 SDO |-------->| SDI | + | SCK | | | + +--------------------+ | | + ^ | | + +--------------------| SCLK | + +-------------+ diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst index 4c13bfa2865c..5df157a44923 100644 --- a/Documentation/iio/index.rst +++ b/Documentation/iio/index.rst @@ -17,6 +17,7 @@ Industrial I/O Kernel Drivers .. toctree:: :maxdepth: 1 + ad4000 ad7944 adis16475 adis16480 diff --git a/MAINTAINERS b/MAINTAINERS index f4ffedada8ea..a03b3db9157c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1205,6 +1205,7 @@ L: linux-iio@vger.kernel.org S: Supported W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml +F: Documentation/iio/ad4000.rst F: drivers/iio/adc/ad4000.c ANALOG DEVICES INC AD4130 DRIVER
Document wiring configurations for the AD4000 series of ADCs. Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> --- Documentation/iio/ad4000.rst | 131 +++++++++++++++++++++++++++++++++++ Documentation/iio/index.rst | 1 + MAINTAINERS | 1 + 3 files changed, 133 insertions(+) create mode 100644 Documentation/iio/ad4000.rst