// SPDX-License-Identifier: GPL-2.0
/*
* AD8366 and similar Gain Amplifiers
* This driver supports the following gain amplifiers:
* 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.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/bitrev.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
enum ad8366_type {
ID_AD8366,
ID_ADA4961,
ID_ADL5240,
ID_HMC792,
ID_HMC1119,
};
struct ad8366_info {
int gain_min;
int gain_max;
};
struct ad8366_state {
struct spi_device *spi;
struct regulator *reg;
struct mutex lock; /* protect sensor state */
struct gpio_desc *reset_gpio;
unsigned char ch[2];
enum ad8366_type type;
struct ad8366_info *info;
/*
* DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
unsigned char data[2] __aligned(IIO_DMA_MINALIGN);
};
static struct ad8366_info ad8366_infos[] = {
[ID_AD8366] = {
.gain_min = 4500,
.gain_max = 20500,
},
[ID_ADA4961] = {
.gain_min = -6000,
.gain_max = 15000,
},
[ID_ADL5240] = {
.gain_min = -11500,
.gain_max = 20000,
},
[ID_HMC792] = {
.gain_min = -15750,
.gain_max = 0,
},
[ID_HMC1119] = {
.gain_min = -31750,
.gain_max = 0,
},
};
static int ad8366_write(struct iio_dev *indio_dev,
unsigned char ch_a, unsigned char ch_b)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
switch (st->type) {
case ID_AD8366:
ch_a = bitrev8(ch_a & 0x3F);
ch_b = bitrev8(ch_b & 0x3F);
st->data[0] = ch_b >> 4;
st->data[1] = (ch_b << 4) | (ch_a >> 2);
break;
case ID_ADA4961:
st->data[0] = ch_a & 0x1F;
break;
case ID_ADL5240:
st->data[0] = (ch_a & 0x3F);
break;
case ID_HMC792:
case ID_HMC1119:
st->data[0] = ch_a;
break;
}
ret = spi_write(st->spi, st->data, indio_dev->num_channels);
if (ret < 0)
dev_err(&indio_dev->dev, "write failed (%d)", ret);
return ret;
}
static int ad8366_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad8366_state *st = iio_priv(indio_dev);
int ret;
int code, gain = 0;
mutex_lock(&st->lock);
switch (m) {
case IIO_CHAN_INFO_HARDWAREGAIN:
code = st->ch[chan->channel];
switch (st->type) {
case ID_AD8366:
gain = code * 253 + 4500;
break;
case ID_ADA4961:
gain = 15000 - code * 1000;
break;
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;
}
/* Values in dB */
*val = gain / 1000;
*val2 = (gain % 1000) * 1000;
ret = IIO_VAL_INT_PLUS_MICRO_DB;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&st->lock);
return ret;
};
static int ad8366_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad8366_state *st = iio_priv(indio_dev);
struct ad8366_info *inf = st->info;
int code = 0, gain;
int ret;
/* Values in dB */
if (val < 0)
gain = (val * 1000) - (val2 / 1000);
else
gain = (val * 1000) + (val2 / 1000);
if (gain > inf->gain_max || gain < inf->gain_min)
return -EINVAL;
switch (st->type) {
case ID_AD8366:
code = (gain - 4500) / 253;
break;
case ID_ADA4961:
code = (15000 - gain) / 1000;
break;
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;
}
mutex_lock(&st->lock);
switch (mask) {
case IIO_CHAN_INFO_HARDWAREGAIN:
st->ch[chan->channel] = code;
ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
break;
default:
ret = -EINVAL;
}
mutex_unlock(&st->lock);
return ret;
}
static int ad8366_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
long mask)
{
switch (mask) {
case IIO_CHAN_INFO_HARDWAREGAIN:
return IIO_VAL_INT_PLUS_MICRO_DB;
default:
return -EINVAL;
}
}
static const struct iio_info ad8366_info = {
.read_raw = &ad8366_read_raw,
.write_raw = &ad8366_write_raw,
.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
};
#define AD8366_CHAN(_channel) { \
.type = IIO_VOLTAGE, \
.output = 1, \
.indexed = 1, \
.channel = _channel, \
.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
}
static const struct iio_chan_spec ad8366_channels[] = {
AD8366_CHAN(0),
AD8366_CHAN(1),
};
static const struct iio_chan_spec ada4961_channels[] = {
AD8366_CHAN(0),
};
static int ad8366_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad8366_state *st;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
st->reg = devm_regulator_get(&spi->dev, "vcc");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret)
return ret;
}
spi_set_drvdata(spi, indio_dev);
mutex_init(&st->lock);
st->spi = spi;
st->type = spi_get_device_id(spi)->driver_data;
switch (st->type) {
case ID_AD8366:
indio_dev->channels = ad8366_channels;
indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
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)) {
ret = PTR_ERR(st->reset_gpio);
goto error_disable_reg;
}
indio_dev->channels = ada4961_channels;
indio_dev->num_channels = ARRAY_SIZE(ada4961_channels);
break;
default:
dev_err(&spi->dev, "Invalid device ID\n");
ret = -EINVAL;
goto error_disable_reg;
}
st->info = &ad8366_infos[st->type];
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad8366_info;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = ad8366_write(indio_dev, 0, 0);
if (ret < 0)
goto error_disable_reg;
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
return 0;
error_disable_reg:
if (!IS_ERR(st->reg))
regulator_disable(st->reg);
return ret;
}
static void ad8366_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad8366_state *st = iio_priv(indio_dev);
struct regulator *reg = st->reg;
iio_device_unregister(indio_dev);
if (!IS_ERR(reg))
regulator_disable(reg);
}
static const struct spi_device_id ad8366_id[] = {
{"ad8366", ID_AD8366},
{"ada4961", ID_ADA4961},
{"adl5240", ID_ADL5240},
{"hmc792a", ID_HMC792},
{"hmc1119", ID_HMC1119},
{}
};
MODULE_DEVICE_TABLE(spi, ad8366_id);
static struct spi_driver ad8366_driver = {
.driver = {
.name = KBUILD_MODNAME,
},
.probe = ad8366_probe,
.remove = ad8366_remove,
.id_table = ad8366_id,
};
module_spi_driver(ad8366_driver);
MODULE_AUTHOR("Michael Hennerich <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD8366 and similar Gain Amplifiers");
MODULE_LICENSE("GPL v2");
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