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iio: adc: ad7091r5: Add scale and external VREF support

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The scale can now be obtained with the "in_voltage_scale" file.
By default, the scale returned corresponds to the internal VREF of 2.5V.

It is possible to use an external VREF (through the REFIN/REFOUT pin of
the chip), by passing a regulator to the driver. The scale will then be
calculated according to the voltage reported by the regulator.

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Co-developed-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Paul Cercueil 2019-11-15 15:57:21 +02:00 committed by Jonathan Cameron
parent ca69300173
commit 260442cc5b
3 changed files with 44 additions and 0 deletions
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38
drivers/iio/adc/ad7091r-base.c
View file

@ -11,6 +11,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include "ad7091r-base.h"
@ -42,6 +43,7 @@ enum ad7091r_mode {
struct ad7091r_state {
struct device *dev;
struct regmap *map;
struct regulator *vref;
const struct ad7091r_chip_info *chip_info;
enum ad7091r_mode mode;
struct mutex lock; /*lock to prevent concurent reads */
@ -141,6 +143,21 @@ static int ad7091r_read_raw(struct iio_dev *iio_dev,
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
if (st->vref) {
ret = regulator_get_voltage(st->vref);
if (ret < 0)
goto unlock;
*val = ret / 1000;
} else {
*val = st->chip_info->vref_mV;
}
*val2 = chan->scan_type.realbits;
ret = IIO_VAL_FRACTIONAL_LOG2;
break;
default:
ret = -EINVAL;
break;
@ -183,6 +200,13 @@ static irqreturn_t ad7091r_event_handler(int irq, void *private)
return IRQ_HANDLED;
}
static void ad7091r_remove(void *data)
{
struct ad7091r_state *st = data;
regulator_disable(st->vref);
}
int ad7091r_probe(struct device *dev, const char *name,
const struct ad7091r_chip_info *chip_info,
struct regmap *map, int irq)
@ -216,6 +240,20 @@ int ad7091r_probe(struct device *dev, const char *name,
return ret;
}
st->vref = devm_regulator_get_optional(dev, "vref");
if (IS_ERR(st->vref)) {
if (PTR_ERR(st->vref) == -EPROBE_DEFER)
return -EPROBE_DEFER;
st->vref = NULL;
} else {
ret = regulator_enable(st->vref);
if (ret)
return ret;
ret = devm_add_action_or_reset(dev, ad7091r_remove, st);
if (ret)
return ret;
}
/* Use command mode by default to convert only desired channels*/
ret = ad7091r_set_mode(st, AD7091R_MODE_COMMAND);
if (ret)

1
drivers/iio/adc/ad7091r-base.h
View file

@ -14,6 +14,7 @@ struct ad7091r_state;
struct ad7091r_chip_info {
unsigned int num_channels;
const struct iio_chan_spec *channels;
unsigned int vref_mV;
};
extern const struct regmap_config ad7091r_regmap_config;

5
drivers/iio/adc/ad7091r5.c
View file

@ -35,10 +35,13 @@ static const struct iio_event_spec ad7091r5_events[] = {
#define AD7091R_CHANNEL(idx, bits, ev, num_ev) { \
.type = IIO_VOLTAGE, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.indexed = 1, \
.channel = idx, \
.event_spec = ev, \
.num_event_specs = num_ev, \
.scan_type.storagebits = 16, \
.scan_type.realbits = bits, \
}
static const struct iio_chan_spec ad7091r5_channels_irq[] = {
AD7091R_CHANNEL(0, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
@ -57,11 +60,13 @@ static const struct iio_chan_spec ad7091r5_channels_noirq[] = {
static const struct ad7091r_chip_info ad7091r5_chip_info_irq = {
.channels = ad7091r5_channels_irq,
.num_channels = ARRAY_SIZE(ad7091r5_channels_irq),
.vref_mV = 2500,
};
static const struct ad7091r_chip_info ad7091r5_chip_info_noirq = {
.channels = ad7091r5_channels_noirq,
.num_channels = ARRAY_SIZE(ad7091r5_channels_noirq),
.vref_mV = 2500,
};
static int ad7091r5_i2c_probe(struct i2c_client *i2c,