iio: dac: Add AD5413 support by BruceTsaoADI · Pull Request #2786 · analogdevicesinc/linux

BruceTsaoADI · 2025-05-18T17:35:45Z

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

New driver: ad5413.c under drivers/iio/dac/
Devicetree binding: adi,ad5413.yaml under Documentation/devicetree/bindings/iio/dac/
Integrated with Kconfig and Makefile

Datasheet:

https://www.analog.com/media/en/technical-documentation/data-sheets/ad5413.pdf

PR Description

Please replace this comment with a summary of your changes, and add any context
necessary to understand them. List any dependencies required for this change.
To check the checkboxes below, insert a 'x' between square brackets (without
any space), or simply check them after publishing the PR.
If you changes include a breaking change, please specify dependent PRs in the
description and try to push all related PRs simultaneously.

PR Type

Bug fix (a change that fixes an issue)
New feature (a change that adds new functionality)
Breaking change (a change that affects other repos or cause CIs to fail)

PR Checklist

I have conducted a self-review of my own code changes
I have tested the changes on the relevant hardware
I have updated the documentation outside this repo accordingly (if there is the case)

gastmaier

Added the warnings that caused the ci to exit with an error but were not logged

gastmaier · 2025-07-04T12:31:19Z

Hi, sorry for the pr failure, I updated the checkout strategy to retry by deepening the fetch until the rebase succeeds.
(It is not mega clear to me why it was failing in the first place, the total depth should be 7 (ahead + behind), but rebase only succeeds with around 24 or so.)

please see CI output, checkpatch is failing for example

BruceTsaoADI · 2025-09-06T14:39:55Z

Hi @dlech, @mhennerich, @nunojsa,

All feedback so far has been addressed in the latest commits.
CI still shows some false positives (e.g. checkpatch whitespace), but local checks pass with --strict and no errors.

Could you kindly take a look and let me know if anything else is required for approval?

Thanks!

nunojsa · 2026-04-27T19:11:48Z

@BruceTsaoADI please properly rebase your patches on top of the target branch.

Replace mutex_lock() and mutex_unlock() calls in rm3100-core.c with the more modern guard(mutex)() family. This will help modernize the driver and bring it up-to-date with modern available macros/functions. While replacing mutex_lock() and mutex_unlock(), the critical sections of rm3100_read_mag() and rm3100_get_samp_freq() have been extended to include negligible operations for cleaner logic. Add new helper-wrapper function rm3100_guarded_regmap_bulk_read() to help keep rm3100_trigger_handler() switch-cases clean while maintaining mutex locking and avoiding re-entrancy risks from potential callbacks. While at it, remove redundant gotos where applicable, and use direct returns instead. In addition, remove regmap variable in rm3100_trigger_handler() as its references have been replaced with variable data. Suggested-by: Jonathan Cameron <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Maxwell Doose <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>

Rewrite MCP3422_CHANNEL_MASK, MCP3422_SRATE_MASK, MCP3422_PGA_MASK and MCP3422_CONT_SAMPLING using GENMASK() and BIT() macros from bits.h. The other macros MCP3422_SRATE_{240, 60, 15, 3} were not changed because they are also used as array indices. Signed-off-by: Marcelo Machado Lage <[email protected]> Co-developed-by: Vinicius Lira <[email protected]> Signed-off-by: Vinicius Lira <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>

Replace manual bit manipulations with FIELD_GET(), FIELD_PREP() and FIELD_MODIFY() calls. The resulting code is more readable and maintainable, and 6 macros previously defined in the header are not needed anymore. Signed-off-by: Marcelo Machado Lage <[email protected]> Co-developed-by: Vinicius Lira <[email protected]> Signed-off-by: Vinicius Lira <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>

Use guard(mutex)() for handling mutex lock instead of manually locking and unlocking the mutex. This prevents forgotten locks due to early exits and removes the need of gotos. Signed-off-by: Pedro Barletta Gennari <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>

Handle errors as early as possible by replacing 'if (!ret)' with the more common form 'if (ret)'. This makes the code easier to read. Signed-off-by: Pedro Barletta Gennari <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]>

patch ci Signed-off-by: CSE CI <[email protected]>

Document the devicetree bindings for the Analog Devices AD5413, a single-channel precision DAC controlled via SPI. The device supports voltage or current output modes and programmable slew-rate control. Signed-off-by: Bruce Tsao <[email protected]>

Signed-off-by: Bruce Tsao <[email protected]>

BruceTsaoADI · 2026-05-06T10:07:15Z

@BruceTsaoADI please properly rebase your patches on top of the target branch.

Thanks @nunojsa .

I fetched the latest mirror_ci/jic23/iio/testing target branch and rebased the two AD5413 patches on top of fdad854.

The PR branch has been force-pushed again. CI is now passing and there are no conflicts with the base branch.

nunojsa

Here it goes my review

nunojsa · 2026-05-11T09:19:15Z

+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>


include paths should be in alphabetical order

nunojsa · 2026-05-11T09:19:55Z

+
+MODULE_AUTHOR("Bruce Tsao <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD5413 DAC");
+MODULE_LICENSE("GPL v2");


seems like you have some warnings here

nunojsa · 2026-05-11T09:20:17Z

+{
+	struct ad5413_state *st;
+	struct iio_dev *indio_dev;
+	int ret, i;


nunojsa · 2026-05-11T09:21:40Z

+	return ad5413_spi_write_mask(st,
+					     AD5413_REG_DAC_CONFIG,
+					     AD5413_REG_DAC_CONFIG_OUT_EN_MSK,
+					     FIELD_PREP(AD5413_REG_DAC_CONFIG_OUT_EN_MSK, 1));


still issues with formatting

nunojsa · 2026-05-11T09:25:11Z

+
+		*val = ret;
+		return IIO_VAL_INT;
+		}


nunojsa · 2026-05-11T09:25:56Z

+	if (ret < 0) {
+		return dev_err_probe(&st->spi->dev, ret,
+				     "Failed to initiate a calibration memory refresh\n");
+	}


no need for brackets

nunojsa · 2026-05-11T09:26:27Z

+	/*
+	 * Poll until the bit clears. ad5413_spi_reg_read() returns a negative
+	 * errno on failure, so stop polling on error and propagate it.
+	 */


I would say you don't need to comment what the API does

nunojsa · 2026-05-11T09:27:07Z

+	u32 cmd;
+
+	cmd = (u32)AD5413_WR_FLAG_MSK(AD5413_REG_TWO_STAGE_READBACK_SELECT) << 24;
+	cmd |= (u32)addr << 8;


Same question as before?

nunojsa · 2026-05-11T09:30:11Z

+	if (ret < 0)
+		return ret;
+
+	return (be32_to_cpu(st->d32[2]) >> 8) & 0xFFFF;


Oh just noticed this now. Don't mix error codes (returns) with proper read values. It just makes it weird. Just pass in a proper u16 * pointer as a argument and set it:

*val = be32_to_cpu(st->d32[2]) >> 8

Then no need for the mask as we already have an implicit cast to u16

nunojsa · 2026-05-11T09:31:28Z

@BruceTsaoADI if you rebase again on top of testing so that only your two patches exist, we can trigger a final LLM review on your series before going upstream.

BruceTsaoADI requested review from CiprianRegus, amiclaus, btogorean, buha, chegbeli, danmois, dbogdan, machschmitt, mhennerich, nunojsa and rbolboac as code owners May 18, 2025 17:35

gastmaier reviewed May 19, 2025

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Comment thread drivers/iio/dac/ad5413.c Outdated

Comment thread drivers/iio/dac/ad5413.c Outdated

dlech reviewed May 22, 2025

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dlech reviewed Jun 16, 2025

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BruceTsaoADI force-pushed the add-ad5413-driver branch 3 times, most recently from ba5d87d to 1401608 Compare June 29, 2025 05:51

dlech reviewed Jul 1, 2025

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dlech reviewed Jul 4, 2025

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Comment thread Documentation/devicetree/bindings/iio/dac/adi,ad5413.yaml Outdated

BruceTsaoADI force-pushed the add-ad5413-driver branch 9 times, most recently from 15694b1 to 8174327 Compare September 14, 2025 09:41

gastmaier force-pushed the mirror_ci/jic23/iio/testing branch from 4674362 to 78b10cd Compare April 27, 2026 00:12

gastmaier force-pushed the mirror_ci/jic23/iio/testing branch 8 times, most recently from 6114e4f to e196cfc Compare May 5, 2026 00:12

maxskiier and others added 6 commits May 5, 2026 13:45

deploy: e3efce0

fdad854

patch ci Signed-off-by: CSE CI <[email protected]>

gastmaier force-pushed the mirror_ci/jic23/iio/testing branch from e196cfc to fdad854 Compare May 6, 2026 00:11

BruceTsaoADI added 2 commits May 6, 2026 16:39

iio: dac: add AD5413 driver

f41ce13

Signed-off-by: Bruce Tsao <[email protected]>

BruceTsaoADI force-pushed the add-ad5413-driver branch from d859997 to f41ce13 Compare May 6, 2026 08:42

gastmaier force-pushed the mirror_ci/jic23/iio/testing branch 5 times, most recently from ae283b1 to dcb3553 Compare May 11, 2026 00:14

nunojsa reviewed May 11, 2026

View reviewed changes

gastmaier force-pushed the mirror_ci/jic23/iio/testing branch 2 times, most recently from 1719553 to 55ab0e3 Compare May 13, 2026 00:11

Conversation

BruceTsaoADI commented May 18, 2025

Summary

Key changes

Datasheet:

PR Description

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BruceTsaoADI commented Sep 6, 2025

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nunojsa commented May 11, 2026

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