Re: [PATCH v2 2/3] iio: amplifiers: adl8113: add driver support

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 8 Nov 2025 17:43:53 +0000
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add support for adl8113 10MHz to 12GHz Low Noise Amplifier with
> 10MHz to 14GHz bypass switches.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Hi Antoniu

I think we need to come up with an innovative solution for the "mode".
I'm not sure what it is yet though so very much looking for some discussion.

thanks,

Jonathan

> diff --git a/drivers/iio/amplifiers/adl8113.c b/drivers/iio/amplifiers/adl8113.c
> new file mode 100644
> index 000000000000..8c234f0a1b6a
> --- /dev/null
> +++ b/drivers/iio/amplifiers/adl8113.c
> @@ -0,0 +1,213 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ADL8113 Low Noise Amplifier with integrated bypass switches
> + *
> + * Copyright 2025 Analog Devices Inc.
> + */
> +
> +#include <linux/array_size.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>

Not sure if this file is being used.  It is rare to see it needed in a modern drive.

> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>

> +
> +static int adl8113_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct adl8113_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_HARDWAREGAIN:
> +		switch (st->current_mode) {
> +		case ADL8113_INTERNAL_AMPLIFIER:
> +			*val = 14;
> +			*val2 = 0;
> +			ret = IIO_VAL_INT_PLUS_MICRO_DB;
return ...

> +			break;
> +		case ADL8113_INTERNAL_BYPASS:
> +			*val = 0;
> +			*val2 = 0;
gain of bypass = 1.0 rather than 0.0 which is open circuit gain.

> +			ret = IIO_VAL_INT_PLUS_MICRO_DB;
return IIO_VAL_INT...

> +			break;
> +		case ADL8113_EXTERNAL_BYPASS_A:
> +		case ADL8113_EXTERNAL_BYPASS_B:
> +		default:
> +			ret = -EINVAL;
return -EINVAL;

Early returns save a line of code here and I general think make
for much more readable code.

> +		}
> +		return ret;
> +	default:
> +		return -EINVAL;
> +	}
> +}