On Fri, Jun 23, 2017 at 04:04:04PM -0700, Ismail Kose wrote:
> From: "Ismail H. Kose" <ihk...@gmail.com>
>
> Add iio driver for DS4422/DS4424 chips that support two/four channel 7-bit
> Sink/Source Current DAC.
>
> The driver supports device tree and platfrom files for the configurations.
>
> Datasheet publicly available at:
> https://datasheets.maximintegrated.com/en/ds/DS4422-DS4424.pdf
>
> Signed-off-by: Ismail Kose <ismail.k...@maximintegrated.com>
> ---
> .../devicetree/bindings/iio/dac/ds4424.txt | 41 ++
Please make the binding a separate patch.
> drivers/iio/dac/Kconfig | 9 +
> drivers/iio/dac/Makefile | 1 +
> drivers/iio/dac/ds4424.c | 733
> +++++++++++++++++++++
> include/linux/iio/dac/ds4424.h | 29 +
> 5 files changed, 813 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/dac/ds4424.txt
> create mode 100644 drivers/iio/dac/ds4424.c
> create mode 100644 include/linux/iio/dac/ds4424.h
>
> diff --git a/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> new file mode 100644
> index 000000000000..03c1b575a6db
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ds4424.txt
> @@ -0,0 +1,41 @@
> +Maxim Integrated DS4422/DS4424 DAC device driver
Bindings describe h/w not device drivers.
> +
> +Required properties:
> + - compatible: Must be "maxim,ds4422" or "maxim,ds4424"
> + - reg: Should contain the DAC I2C address
> + - min_rfs, max_rfs: In order to get the correct processed data values,
Don't use '_' in property names, and these all need vendor prefixes.
> + these resistor values should be changed to the correct values
> + that match the user's system resistor values for RFS0 to
> RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm
> units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
Just use ohms (adding a suffix). Perhaps do a 2 value property with min
and max values.
> + - ifs_scale: 61000*100 = 6100000 = 100,000,000 * .976/16
> + - max_picoamp: Should contain DAC maximum pico amper value.
Add any new units to property-units.txt.
> + - rfs_resistor: Should contain reference resistor
unit suffix?
> + - iio map: Should contain IIO Map info
Can't have a space in property names.
> +
> +Optional properties:
> + - vcc-supply: Power supply us optional. If not defined, driver will
> ignore it.
> +
> +Example:
> + ds4224@10 {
> + compatible = "maxim,ds4424";
> + reg = <0x10>; /* When A0, A1 pins are ground */
> + vcc-supply = "dac_vcc_3v3";
> + max-picoamp = <200000000>; /* 200uA */
> + ifs-scale = <61000>;
> + /* In order to get the correct processed data values,
> + these resistor values should be changed to the correct
> values that match the
> + user's system resistor values for RFS0 to RFS1.
> + Resistance values for rfs_resistor are listed in 100 Ohm
> units;
> + ie, 800 is 80K. Acceptable RFS values are 40K to 160K.
> + */
> + min-rfs = <400>;
> + max-rfs = <1600>;
> + rfs-resistors = <400 800 1000 1600>;
> + dac-iio-map =
Doesn't match above doc.
> + /* consumer_dev_name, consumer_channel, adc_channel_label
> */
> + "ds4424_dac-consumer-dev_name-1", "ds4424_dac1", "OUT1",
> + "ds4424_dac-consumer-dev_name-2", "ds4424_dac2", "OUT2",
> + "ds4424_dac-consumer-dev_name-3", "ds4424_dac3", "OUT3",
> + "ds4424_dac-consumer-dev_name-4", "ds4424_dac4", "OUT4";
> + };
