iio: dac: Add AD5413 support #2786
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The AD5413 is a single-channel, 14-bit DAC with programmable current or voltage output. It communicates via SPI at clock rates up to 50 MHz. The output can be configured as either voltage or current and is available on a single terminal. Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ad5413.pdf Signed-off-by: Bruce Tsao <[email protected]>
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nunojsa,
mhennerich,
dbogdan,
btogorean,
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amiclaus,
rbolboac,
danmois,
CiprianRegus and
machschmitt
as code owners
| { | ||
| unsigned int tmp, tmparray[2], size; | ||
| const struct ad5413_range *range; | ||
| int *index, ret; |
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drivers/iio/dac/ad5413.c: In function 'ad5413_parse_dt':
::warning file=drivers/iio/dac/ad5413.c,line=590,col=14::gcc_fanalayzer: unused variable 'index' [-Wunused-variable]
590 | int *index, ret;
| ^~~~~
| else | ||
| indio_dev->channels = ad5413_current_ch; | ||
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| ret = ad5413_init(st); | ||
| if (ret < 0) { | ||
| dev_err(&spi->dev, "AD5413 init failed\n"); | ||
| return ret; | ||
| } | ||
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| return devm_iio_device_register(&st->spi->dev, indio_dev); |
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drivers/iio/dac/ad5413.c: In function 'ad5413_probe':
::warning file=drivers/iio/dac/ad5413.c,line=724,col=5::gcc_fanalayzer: this 'else' clause does not guard... [-Wmisleading-indentation]
724 | else
| ^~~~
drivers/iio/dac/ad5413.c:727:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
727 | ret = ad5413_init(st);
| ^~~
| enum: | ||
| - [-10500000, 10500000] | ||
| - [-12600000, 12600000] |
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enum doesn't work like that. See other bindings that already have this same property for what works.
| enum: | |
| - [-10500000, 10500000] | |
| - [-12600000, 12600000] | |
| adi,range-microvolt: | |
| description: Voltage output range specified as <minimum, maximum> | |
| oneOf: | |
| - items: | |
| - const: -10500000 | |
| - const: 10500000 | |
| - items: | |
| - const: -12600000 | |
| - const: 12600000 |
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| adi,range-microamp: | ||
| description: Current output range <min, max> in microamps | ||
| enum: |
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Same here.
Will also want to call out in the commit message why there is only one option here (and why adi,range-microvolt doesn't have a default: - the same reason - but it isn't obvious until later, so best to mention it before)
| description: | | ||
| Output digital slew control time in microseconds |
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| description: | | |
| Output digital slew control time in microseconds | |
| description: Output digital slew control time in microseconds |
| allOf: | ||
| - $ref: /schemas/spi/spi-peripheral-props.yaml# | ||
| - if: | ||
| required: [adi, range-microamp] |
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| required: [adi, range-microamp] | |
| required: [ 'adi,range-microamp' ] |
| properties: | ||
| adi,range-microvolt: false | ||
| - if: | ||
| required: [adi, range-microvolt] |
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| required: [adi, range-microvolt] | |
| required: [ 'adi,range-microvolt' ] |
| if (regval < 0) | ||
| return regval; | ||
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| /* Clear all the error flags */ |
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The reset doesn't do this already?
| /* 3) read slew-time（optional） */ | ||
| ret = device_property_read_u32(&st->spi->dev, | ||
| "adi,slew-time-us", &tmp); | ||
| if (ret) { |
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Checking all of the device_property_ returns in this function could be more strict. There are different errors for "property is missing" (-EINAL) and other error caused, e.g. by typos in the .dts file (e.g. a not enough items in the array).
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| #define AD5413_DAC_CHAN(_chan_type) { \ | ||
| .type = (_chan_type), \ | ||
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_RAW) | \ |
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IIO_CHAN_INFO_RAW is for sure separate, not shared_by_type. Since there aren't versions of this chip with more than one channel, it isn't clear if SCALE and OFFSET should also be separate, so could go either way on those.
| int *index, ret; | ||
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| /* 1) voltage */ | ||
| ret = device_property_read_u32_array(&st->spi->dev, |
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This will allow the +/- 12.6 range to be given in the devicetree but set up the chip for +/-10.5V, but OVRNG_EN isn't implemented yet. So we should not allow that or now or implement OVRNG_EN.
It also wouldn't hurt to check the current values as well (even if there is only one option, someone might try to put something else in the .dts file)
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| struct ad5413_range { | ||
| int reg; | ||
| int min; |
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Upstream prefers units on macros and variables, e.g. min_uv here.
Same applies throughout the driver. (It would especially help to make the raw_read function easier to understand)
Summary
This PR adds initial support for the Analog Devices AD5413, a 14-bit single-channel DAC capable of voltage and current output.
Key changes
ad5413.cunderdrivers/iio/dac/adi,ad5413.yamlunderDocumentation/devicetree/bindings/iio/dac/Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/ad5413.pdf
PR Description
necessary to understand them. List any dependencies required for this change.
any space), or simply check them after publishing the PR.
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PR Type
PR Checklist