Commit 506d2e31 authored by Marcelo Schmitt's avatar Marcelo Schmitt Committed by Jonathan Cameron

iio: adc: Add driver support for AD7292

The AD7292 is a 10-bit monitor and control system with ADC, DACs,
temperature sensor, and GPIOs.

Configure AD7292 devices in direct access mode, enabling single-ended
ADC readings.

Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdfSigned-off-by: default avatarMarcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent d898f9ac
...@@ -906,6 +906,7 @@ M: Marcelo Schmitt <marcelo.schmitt1@gmail.com> ...@@ -906,6 +906,7 @@ M: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
L: linux-iio@vger.kernel.org L: linux-iio@vger.kernel.org
W: http://ez.analog.com/community/linux-device-drivers W: http://ez.analog.com/community/linux-device-drivers
S: Supported S: Supported
F: drivers/iio/adc/ad7292.c
F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
ANALOG DEVICES INC AD7606 DRIVER ANALOG DEVICES INC AD7606 DRIVER
......
...@@ -55,6 +55,16 @@ config AD7291 ...@@ -55,6 +55,16 @@ config AD7291
To compile this driver as a module, choose M here: the To compile this driver as a module, choose M here: the
module will be called ad7291. module will be called ad7291.
config AD7292
tristate "Analog Devices AD7292 ADC driver"
depends on SPI
help
Say yes here to build support for Analog Devices AD7292
8 Channel ADC with temperature sensor.
To compile this driver as a module, choose M here: the
module will be called ad7292.
config AD7298 config AD7298
tristate "Analog Devices AD7298 ADC driver" tristate "Analog Devices AD7298 ADC driver"
depends on SPI depends on SPI
......
...@@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o ...@@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
obj-$(CONFIG_AD7124) += ad7124.o obj-$(CONFIG_AD7124) += ad7124.o
obj-$(CONFIG_AD7266) += ad7266.o obj-$(CONFIG_AD7266) += ad7266.o
obj-$(CONFIG_AD7291) += ad7291.o obj-$(CONFIG_AD7291) += ad7291.o
obj-$(CONFIG_AD7292) += ad7292.o
obj-$(CONFIG_AD7298) += ad7298.o obj-$(CONFIG_AD7298) += ad7298.o
obj-$(CONFIG_AD7923) += ad7923.o obj-$(CONFIG_AD7923) += ad7923.o
obj-$(CONFIG_AD7476) += ad7476.o obj-$(CONFIG_AD7476) += ad7476.o
......
// SPDX-License-Identifier: GPL-2.0
/*
* Analog Devices AD7292 SPI ADC driver
*
* Copyright 2019 Analog Devices Inc.
*/
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#define ADI_VENDOR_ID 0x0018
/* AD7292 registers definition */
#define AD7292_REG_VENDOR_ID 0x00
#define AD7292_REG_CONF_BANK 0x05
#define AD7292_REG_CONV_COMM 0x0E
#define AD7292_REG_ADC_CH(x) (0x10 + (x))
/* AD7292 configuration bank subregisters definition */
#define AD7292_BANK_REG_VIN_RNG0 0x10
#define AD7292_BANK_REG_VIN_RNG1 0x11
#define AD7292_BANK_REG_SAMP_MODE 0x12
#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F))
/* AD7292_REG_ADC_CONVERSION */
#define AD7292_ADC_DATA_MASK GENMASK(15, 6)
#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x)
/* AD7292_CHANNEL_SAMPLING_MODE */
#define AD7292_CH_SAMP_MODE(reg, ch) (((reg) >> 8) & BIT(ch))
/* AD7292_CHANNEL_VIN_RANGE */
#define AD7292_CH_VIN_RANGE(reg, ch) ((reg) & BIT(ch))
#define AD7292_VOLTAGE_CHAN(_chan) \
{ \
.type = IIO_VOLTAGE, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.indexed = 1, \
.channel = _chan, \
}
static const struct iio_chan_spec ad7292_channels[] = {
AD7292_VOLTAGE_CHAN(0),
AD7292_VOLTAGE_CHAN(1),
AD7292_VOLTAGE_CHAN(2),
AD7292_VOLTAGE_CHAN(3),
AD7292_VOLTAGE_CHAN(4),
AD7292_VOLTAGE_CHAN(5),
AD7292_VOLTAGE_CHAN(6),
AD7292_VOLTAGE_CHAN(7)
};
static const struct iio_chan_spec ad7292_channels_diff[] = {
{
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.indexed = 1,
.differential = 1,
.channel = 0,
.channel2 = 1,
},
AD7292_VOLTAGE_CHAN(2),
AD7292_VOLTAGE_CHAN(3),
AD7292_VOLTAGE_CHAN(4),
AD7292_VOLTAGE_CHAN(5),
AD7292_VOLTAGE_CHAN(6),
AD7292_VOLTAGE_CHAN(7)
};
struct ad7292_state {
struct spi_device *spi;
struct regulator *reg;
unsigned short vref_mv;
__be16 d16 ____cacheline_aligned;
u8 d8[2];
};
static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
{
int ret;
st->d8[0] = AD7292_RD_FLAG_MSK(addr);
ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);
if (ret < 0)
return ret;
return be16_to_cpu(st->d16);
}
static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,
unsigned int sub_addr, unsigned int len)
{
unsigned int shift = 16 - (8 * len);
int ret;
st->d8[0] = AD7292_RD_FLAG_MSK(addr);
st->d8[1] = sub_addr;
ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);
if (ret < 0)
return ret;
return (be16_to_cpu(st->d16) >> shift);
}
static int ad7292_single_conversion(struct ad7292_state *st,
unsigned int chan_addr)
{
int ret;
struct spi_transfer t[] = {
{
.tx_buf = &st->d8,
.len = 4,
.delay_usecs = 6,
}, {
.rx_buf = &st->d16,
.len = 2,
},
};
st->d8[0] = chan_addr;
st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);
ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
if (ret < 0)
return ret;
return be16_to_cpu(st->d16);
}
static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
{
int samp_mode, range0, range1, factor = 1;
/*
* Every AD7292 ADC channel may have its input range adjusted according
* to the settings at the ADC sampling mode and VIN range subregisters.
* For a given channel, the minimum input range is equal to Vref, and it
* may be increased by a multiplier factor of 2 or 4 according to the
* following rule:
* If channel is being sampled with respect to AGND:
* factor = 4 if VIN range0 and VIN range1 equal 0
* factor = 2 if only one of VIN ranges equal 1
* factor = 1 if both VIN range0 and VIN range1 equal 1
* If channel is being sampled with respect to AVDD:
* factor = 4 if VIN range0 and VIN range1 equal 0
* Behavior is undefined if any of VIN range doesn't equal 0
*/
samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
AD7292_BANK_REG_SAMP_MODE, 2);
if (samp_mode < 0)
return samp_mode;
range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
AD7292_BANK_REG_VIN_RNG0, 2);
if (range0 < 0)
return range0;
range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
AD7292_BANK_REG_VIN_RNG1, 2);
if (range1 < 0)
return range1;
if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {
/* Sampling with respect to AGND */
if (!AD7292_CH_VIN_RANGE(range0, channel))
factor *= 2;
if (!AD7292_CH_VIN_RANGE(range1, channel))
factor *= 2;
} else {
/* Sampling with respect to AVDD */
if (AD7292_CH_VIN_RANGE(range0, channel) ||
AD7292_CH_VIN_RANGE(range1, channel))
return -EPERM;
factor = 4;
}
return factor;
}
static int ad7292_read_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
int *val, int *val2, long info)
{
struct ad7292_state *st = iio_priv(indio_dev);
unsigned int ch_addr;
int ret;
switch (info) {
case IIO_CHAN_INFO_RAW:
ch_addr = AD7292_REG_ADC_CH(chan->channel);
ret = ad7292_single_conversion(st, ch_addr);
if (ret < 0)
return ret;
*val = AD7292_ADC_DATA(ret);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
/*
* To convert a raw value to standard units, the IIO defines
* this formula: Scaled value = (raw + offset) * scale.
* For the scale to be a correct multiplier for (raw + offset),
* it must be calculated as the input range divided by the
* number of possible distinct input values. Given the ADC data
* is 10 bit long, it may assume 2^10 distinct values.
* Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2
* return type indicates to the IIO API to divide *val by 2 to
* the power of *val2 when returning from read_raw.
*/
ret = ad7292_vin_range_multiplier(st, chan->channel);
if (ret < 0)
return ret;
*val = st->vref_mv * ret;
*val2 = 10;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static const struct iio_info ad7292_info = {
.read_raw = ad7292_read_raw,
};
static void ad7292_regulator_disable(void *data)
{
struct ad7292_state *st = data;
regulator_disable(st->reg);
}
static int ad7292_probe(struct spi_device *spi)
{
struct ad7292_state *st;
struct iio_dev *indio_dev;
struct device_node *child;
bool diff_channels = 0;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->spi = spi;
ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);
if (ret != ADI_VENDOR_ID) {
dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);
return -EINVAL;
}
spi_set_drvdata(spi, indio_dev);
st->reg = devm_regulator_get_optional(&spi->dev, "vref");
if (!IS_ERR(st->reg)) {
ret = regulator_enable(st->reg);
if (ret) {
dev_err(&spi->dev,
"Failed to enable external vref supply\n");
return ret;
}
ret = devm_add_action_or_reset(&spi->dev,
ad7292_regulator_disable, st);
if (ret) {
regulator_disable(st->reg);
return ret;
}
ret = regulator_get_voltage(st->reg);
if (ret < 0)
return ret;
st->vref_mv = ret / 1000;
} else {
/* Use the internal voltage reference. */
st->vref_mv = 1250;
}
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &ad7292_info;
for_each_available_child_of_node(spi->dev.of_node, child) {
diff_channels = of_property_read_bool(child, "diff-channels");
if (diff_channels)
break;
}
if (diff_channels) {
indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);
indio_dev->channels = ad7292_channels_diff;
} else {
indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);
indio_dev->channels = ad7292_channels;
}
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct spi_device_id ad7292_id_table[] = {
{ "ad7292", 0 },
{}
};
MODULE_DEVICE_TABLE(spi, ad7292_id_table);
static const struct of_device_id ad7292_of_match[] = {
{ .compatible = "adi,ad7292" },
{ },
};
MODULE_DEVICE_TABLE(of, ad7292_of_match);
static struct spi_driver ad7292_driver = {
.driver = {
.name = "ad7292",
.of_match_table = ad7292_of_match,
},
.probe = ad7292_probe,
.id_table = ad7292_id_table,
};
module_spi_driver(ad7292_driver);
MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt1@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");
MODULE_LICENSE("GPL v2");
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