Re: [PATCH] iio: amplifiers: ad8366: add support for HMC792A Attenuator

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 21 Jul 2023 20:10:38 +0800
Kim Seer Paller <kimseer.paller@analog.com> wrote:

> This change adds support for the HMC792A Digital Attenuator. The
> HMC792A is a broadband 6-bit GaAs MMIC Digital Attenuator operating
> from DC to 6.0 GHz with 15.75 dB attenuation control range in 0.25 dB steps.
> 
> Datasheet link:
>   https://www.analog.com/media/en/technical-documentation/data-sheets/hmc792a.pdf
Should be part of the tag block as
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/hmc792a.pdf

I tidied that up whilst applying.

Applied to the togreg branch of iio.git and pushed out as testing for
all the normal reasons.

Thanks,

Jonathan

> 
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> ---
>  drivers/iio/amplifiers/Kconfig  |  1 +
>  drivers/iio/amplifiers/ad8366.c | 15 +++++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/iio/amplifiers/Kconfig b/drivers/iio/amplifiers/Kconfig
> index f217a2a1e..b54fe0173 100644
> --- a/drivers/iio/amplifiers/Kconfig
> +++ b/drivers/iio/amplifiers/Kconfig
> @@ -18,6 +18,7 @@ config AD8366
>  	    AD8366 Dual-Digital Variable Gain Amplifier (VGA)
>  	    ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
>  	    ADL5240 Digitally controlled variable gain amplifier (VGA)
> +	    HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
>  	    HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
>  
>  	  To compile this driver as a module, choose M here: the
> diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
> index 8d8c8ea94..31564afb1 100644
> --- a/drivers/iio/amplifiers/ad8366.c
> +++ b/drivers/iio/amplifiers/ad8366.c
> @@ -5,6 +5,7 @@
>   *   AD8366 Dual-Digital Variable Gain Amplifier (VGA)
>   *   ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
>   *   ADL5240 Digitally controlled variable gain amplifier (VGA)
> + *   HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
>   *   HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
>   *
>   * Copyright 2012-2019 Analog Devices Inc.
> @@ -28,6 +29,7 @@ enum ad8366_type {
>  	ID_AD8366,
>  	ID_ADA4961,
>  	ID_ADL5240,
> +	ID_HMC792,
>  	ID_HMC1119,
>  };
>  
> @@ -64,6 +66,10 @@ static struct ad8366_info ad8366_infos[] = {
>  		.gain_min = -11500,
>  		.gain_max = 20000,
>  	},
> +	[ID_HMC792] = {
> +		.gain_min = -15750,
> +		.gain_max = 0,
> +	},
>  	[ID_HMC1119] = {
>  		.gain_min = -31750,
>  		.gain_max = 0,
> @@ -90,6 +96,7 @@ static int ad8366_write(struct iio_dev *indio_dev,
>  	case ID_ADL5240:
>  		st->data[0] = (ch_a & 0x3F);
>  		break;
> +	case ID_HMC792:
>  	case ID_HMC1119:
>  		st->data[0] = ch_a;
>  		break;
> @@ -127,6 +134,9 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
>  		case ID_ADL5240:
>  			gain = 20000 - 31500 + code * 500;
>  			break;
> +		case ID_HMC792:
> +			gain = -1 * code * 500;
> +			break;
>  		case ID_HMC1119:
>  			gain = -1 * code * 250;
>  			break;
> @@ -176,6 +186,9 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
>  	case ID_ADL5240:
>  		code = ((gain - 500 - 20000) / 500) & 0x3F;
>  		break;
> +	case ID_HMC792:
> +		code = (abs(gain) / 500) & 0x3F;
> +		break;
>  	case ID_HMC1119:
>  		code = (abs(gain) / 250) & 0x7F;
>  		break;
> @@ -261,6 +274,7 @@ static int ad8366_probe(struct spi_device *spi)
>  		break;
>  	case ID_ADA4961:
>  	case ID_ADL5240:
> +	case ID_HMC792:
>  	case ID_HMC1119:
>  		st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_HIGH);
>  		if (IS_ERR(st->reset_gpio)) {
> @@ -314,6 +328,7 @@ static const struct spi_device_id ad8366_id[] = {
>  	{"ad8366",  ID_AD8366},
>  	{"ada4961", ID_ADA4961},
>  	{"adl5240", ID_ADL5240},
> +	{"hmc792a", ID_HMC792},
>  	{"hmc1119", ID_HMC1119},
>  	{}
>  };
> 
> base-commit: f7e3a1bafdea735050dfde00523cf505dc7fd309