linux/drivers/iio/adc/ad7091r-base.c
Jonathan Cameron 8a0080af84 iio:adc:ad7091r: Move exports into IIO_AD7091R namespace.
In order to avoid unnecessary pollution of the global symbol namespace
move the core/library functions into a specific namespace and import
that into the various specific device drivers that use them.

For more information see https://lwn.net/Articles/760045/

An alternative here would be to conclude that we are unlikely to see
support for the other ad7091r parts in the near future and just merge
the two modules into one supporting just the i2c -5 variant.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220130205701.334592-3-jic23@kernel.org
2022-02-18 11:42:26 +00:00

298 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* AD7091RX Analog to Digital converter driver
*
* Copyright 2014-2019 Analog Devices Inc.
*/
#include <linux/bitops.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include "ad7091r-base.h"
#define AD7091R_REG_RESULT 0
#define AD7091R_REG_CHANNEL 1
#define AD7091R_REG_CONF 2
#define AD7091R_REG_ALERT 3
#define AD7091R_REG_CH_LOW_LIMIT(ch) ((ch) * 3 + 4)
#define AD7091R_REG_CH_HIGH_LIMIT(ch) ((ch) * 3 + 5)
#define AD7091R_REG_CH_HYSTERESIS(ch) ((ch) * 3 + 6)
/* AD7091R_REG_RESULT */
#define AD7091R_REG_RESULT_CH_ID(x) (((x) >> 13) & 0x3)
#define AD7091R_REG_RESULT_CONV_RESULT(x) ((x) & 0xfff)
/* AD7091R_REG_CONF */
#define AD7091R_REG_CONF_AUTO BIT(8)
#define AD7091R_REG_CONF_CMD BIT(10)
#define AD7091R_REG_CONF_MODE_MASK \
(AD7091R_REG_CONF_AUTO | AD7091R_REG_CONF_CMD)
enum ad7091r_mode {
AD7091R_MODE_SAMPLE,
AD7091R_MODE_COMMAND,
AD7091R_MODE_AUTOCYCLE,
};
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 */
};
static int ad7091r_set_mode(struct ad7091r_state *st, enum ad7091r_mode mode)
{
int ret, conf;
switch (mode) {
case AD7091R_MODE_SAMPLE:
conf = 0;
break;
case AD7091R_MODE_COMMAND:
conf = AD7091R_REG_CONF_CMD;
break;
case AD7091R_MODE_AUTOCYCLE:
conf = AD7091R_REG_CONF_AUTO;
break;
default:
return -EINVAL;
}
ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
AD7091R_REG_CONF_MODE_MASK, conf);
if (ret)
return ret;
st->mode = mode;
return 0;
}
static int ad7091r_set_channel(struct ad7091r_state *st, unsigned int channel)
{
unsigned int dummy;
int ret;
/* AD7091R_REG_CHANNEL specified which channels to be converted */
ret = regmap_write(st->map, AD7091R_REG_CHANNEL,
BIT(channel) | (BIT(channel) << 8));
if (ret)
return ret;
/*
* There is a latency of one conversion before the channel conversion
* sequence is updated
*/
return regmap_read(st->map, AD7091R_REG_RESULT, &dummy);
}
static int ad7091r_read_one(struct iio_dev *iio_dev,
unsigned int channel, unsigned int *read_val)
{
struct ad7091r_state *st = iio_priv(iio_dev);
unsigned int val;
int ret;
ret = ad7091r_set_channel(st, channel);
if (ret)
return ret;
ret = regmap_read(st->map, AD7091R_REG_RESULT, &val);
if (ret)
return ret;
if (AD7091R_REG_RESULT_CH_ID(val) != channel)
return -EIO;
*read_val = AD7091R_REG_RESULT_CONV_RESULT(val);
return 0;
}
static int ad7091r_read_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long m)
{
struct ad7091r_state *st = iio_priv(iio_dev);
unsigned int read_val;
int ret;
mutex_lock(&st->lock);
switch (m) {
case IIO_CHAN_INFO_RAW:
if (st->mode != AD7091R_MODE_COMMAND) {
ret = -EBUSY;
goto unlock;
}
ret = ad7091r_read_one(iio_dev, chan->channel, &read_val);
if (ret)
goto unlock;
*val = read_val;
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;
}
unlock:
mutex_unlock(&st->lock);
return ret;
}
static const struct iio_info ad7091r_info = {
.read_raw = ad7091r_read_raw,
};
static irqreturn_t ad7091r_event_handler(int irq, void *private)
{
struct ad7091r_state *st = (struct ad7091r_state *) private;
struct iio_dev *iio_dev = dev_get_drvdata(st->dev);
unsigned int i, read_val;
int ret;
s64 timestamp = iio_get_time_ns(iio_dev);
ret = regmap_read(st->map, AD7091R_REG_ALERT, &read_val);
if (ret)
return IRQ_HANDLED;
for (i = 0; i < st->chip_info->num_channels; i++) {
if (read_val & BIT(i * 2))
iio_push_event(iio_dev,
IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_RISING), timestamp);
if (read_val & BIT(i * 2 + 1))
iio_push_event(iio_dev,
IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_FALLING), timestamp);
}
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)
{
struct iio_dev *iio_dev;
struct ad7091r_state *st;
int ret;
iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!iio_dev)
return -ENOMEM;
st = iio_priv(iio_dev);
st->dev = dev;
st->chip_info = chip_info;
st->map = map;
iio_dev->name = name;
iio_dev->info = &ad7091r_info;
iio_dev->modes = INDIO_DIRECT_MODE;
iio_dev->num_channels = chip_info->num_channels;
iio_dev->channels = chip_info->channels;
if (irq) {
ret = devm_request_threaded_irq(dev, irq, NULL,
ad7091r_event_handler,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT, name, st);
if (ret)
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)
return ret;
return devm_iio_device_register(dev, iio_dev);
}
EXPORT_SYMBOL_NS_GPL(ad7091r_probe, IIO_AD7091R);
static bool ad7091r_writeable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case AD7091R_REG_RESULT:
case AD7091R_REG_ALERT:
return false;
default:
return true;
}
}
static bool ad7091r_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case AD7091R_REG_RESULT:
case AD7091R_REG_ALERT:
return true;
default:
return false;
}
}
const struct regmap_config ad7091r_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.writeable_reg = ad7091r_writeable_reg,
.volatile_reg = ad7091r_volatile_reg,
};
EXPORT_SYMBOL_NS_GPL(ad7091r_regmap_config, IIO_AD7091R);
MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7091Rx multi-channel converters");
MODULE_LICENSE("GPL v2");