Re: [PATCH 3/3] iio: accel: adxl372: add support for ADXL371

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 2 Mar 2026 14:20:59 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add support for the Analog Devices ADXL371, a +-200g 3-axis MEMS
> accelerometer sharing the same register map as the ADXL372 but with
> different ODR values (320/640/1280/2560/5120 Hz vs 400/800/1600/3200/
> 6400 Hz), different bandwidth values, and different timer scale
> factors for activity/inactivity detection.
> 
> Due to a silicon anomaly (er001) causing FIFO data misalignment on
> all current ADXL371 silicon, FIFO and triggered buffer support is
> disabled for the ADXL371 - only direct mode reads are supported.

Ouch.

> 

> diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
> index d1f957adea64..10eb5bf14dad 100644
> --- a/drivers/iio/accel/adxl372.c
> +++ b/drivers/iio/accel/adxl372.c
> @@ -1,6 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0+
>  /*
> - * ADXL372 3-Axis Digital Accelerometer core driver
> + * ADXL371/ADXL372 3-Axis Digital Accelerometer core driver
>   *
>   * Copyright 2018 Analog Devices Inc.
>   */
> @@ -182,6 +182,14 @@ enum adxl372_odr {
>  	ADXL372_ODR_6400HZ,
>  };
>  
> +enum adxl371_odr {
> +	ADXL371_ODR_320HZ,
> +	ADXL371_ODR_640HZ,
> +	ADXL371_ODR_1280HZ,
> +	ADXL371_ODR_2560HZ,
> +	ADXL371_ODR_5120HZ,
> +};
> +
>  enum adxl372_bandwidth {
>  	ADXL372_BW_200HZ,
>  	ADXL372_BW_400HZ,
> @@ -222,6 +230,29 @@ static const int adxl372_bw_freq_tbl[5] = {
>  	200, 400, 800, 1600, 3200,
>  };
>  
> +static const int adxl371_samp_freq_tbl[5] = {
> +	320, 640, 1280, 2560, 5120,
It might be a good idea to make the association of ordering an element
explicit via
	[ADXL371_ODR_320HZ] = 320,
etc

> +};
> +
> +static const int adxl371_bw_freq_tbl[5] = {

I assume these are indexed off the odr enum. If so then
	[ADXL371_ODR_320HZ] = 160, 
etc here may make sense as well.

> +	160, 320, 640, 1280, 2560,
> +};

> +		if (st->irq) {
It might be worth factoring out this block (maybe the earlier bit as well)
as a helper function in a precursor patch.  
The indent is getting rather large for such long lines.

> +			st->dready_trig = devm_iio_trigger_alloc(dev,
> +								 "%s-dev%d",
> +								 indio_dev->name,
> +								 iio_device_id(indio_dev));
> +			if (!st->dready_trig)
> +				return -ENOMEM;
> +
> +			st->peak_datardy_trig = devm_iio_trigger_alloc(dev,
> +								       "%s-dev%d-peak",
> +								       indio_dev->name,
> +								       iio_device_id(indio_dev));
> +			if (!st->peak_datardy_trig)
> +				return -ENOMEM;
> +
> +			st->dready_trig->ops = &adxl372_trigger_ops;
> +			st->peak_datardy_trig->ops = &adxl372_peak_data_trigger_ops;
> +			iio_trigger_set_drvdata(st->dready_trig, indio_dev);
> +			iio_trigger_set_drvdata(st->peak_datardy_trig, indio_dev);
> +			ret = devm_iio_trigger_register(dev, st->dready_trig);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = devm_iio_trigger_register(dev, st->peak_datardy_trig);
> +			if (ret < 0)
> +				return ret;
>  
> -		indio_dev->trig = iio_trigger_get(st->dready_trig);
> +			indio_dev->trig = iio_trigger_get(st->dready_trig);
>  
> -		ret = devm_request_irq(dev, st->irq,
> -				       iio_trigger_generic_data_rdy_poll,
> -				       IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
> -				       indio_dev->name, st->dready_trig);
> -		if (ret < 0)
> -			return ret;
> +			ret = devm_request_irq(dev, st->irq,
> +					       iio_trigger_generic_data_rdy_poll,
> +					       IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
> +					       indio_dev->name, st->dready_trig);
> +			if (ret < 0)
> +				return ret;
> +		}
>  	}
>  
>  	return devm_iio_device_register(dev, indio_dev);