[PATCH v2] iio: amplifiers: ad8366: add support for HMC1119 Attenuator

From: Alexandru Ardelean
Date: Fri Feb 21 2020 - 11:18:35 EST


From: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>

This change adds support for the HMC1119 Silicon Digial Attenuator. The
HMC1119 is a broadband, highly accurate, 7-bit digital attenuator,
operating from 0.1 GHz to 6.0 GHz with 31.5 dB attenuation control range
in 0.25 dB steps.

Link: https://www.analog.com/media/en/technical-documentation/data-sheets/hmc1119.pdf

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
---
drivers/iio/amplifiers/ad8366.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
index 95972ab60f42..62167b87caea 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)
+ * HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
*
* Copyright 2012-2019 Analog Devices Inc.
*/
@@ -27,6 +28,7 @@ enum ad8366_type {
ID_AD8366,
ID_ADA4961,
ID_ADL5240,
+ ID_HMC1119,
};

struct ad8366_info {
@@ -62,6 +64,10 @@ static struct ad8366_info ad8366_infos[] = {
.gain_min = -11500,
.gain_max = 20000,
},
+ [ID_HMC1119] = {
+ .gain_min = -31750,
+ .gain_max = 0,
+ },
};

static int ad8366_write(struct iio_dev *indio_dev,
@@ -84,6 +90,9 @@ static int ad8366_write(struct iio_dev *indio_dev,
case ID_ADL5240:
st->data[0] = (ch_a & 0x3F);
break;
+ case ID_HMC1119:
+ st->data[0] = ch_a;
+ break;
}

ret = spi_write(st->spi, st->data, indio_dev->num_channels);
@@ -118,6 +127,9 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
case ID_ADL5240:
gain = 20000 - 31500 + code * 500;
break;
+ case ID_HMC1119:
+ gain = -1 * code * 250;
+ break;
}

/* Values in dB */
@@ -164,6 +176,9 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
case ID_ADL5240:
code = ((gain - 500 - 20000) / 500) & 0x3F;
break;
+ case ID_HMC1119:
+ code = (abs(gain) / 250) & 0x7F;
+ break;
}

mutex_lock(&st->lock);
@@ -246,6 +261,7 @@ static int ad8366_probe(struct spi_device *spi)
break;
case ID_ADA4961:
case ID_ADL5240:
+ case ID_HMC1119:
st->reset_gpio = devm_gpiod_get(&spi->dev, "reset",
GPIOD_OUT_HIGH);
indio_dev->channels = ada4961_channels;
@@ -298,6 +314,7 @@ static const struct spi_device_id ad8366_id[] = {
{"ad8366", ID_AD8366},
{"ada4961", ID_ADA4961},
{"adl5240", ID_ADL5240},
+ {"hmc1119", ID_HMC1119},
{}
};
MODULE_DEVICE_TABLE(spi, ad8366_id);
--
2.20.1