// SPDX-License-Identifier: GPL-2.0-only
/*
* ltc2497-core.c - Common code for Analog Devices/Linear Technology
* LTC2496 and LTC2497 ADCs
*
* Copyright (C) 2017 Analog Devices Inc.
*/
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regulator/consumer.h>
#include "ltc2497.h"
#define LTC2497_SGL BIT(4)
#define LTC2497_DIFF 0
#define LTC2497_SIGN BIT(3)
static int ltc2497core_wait_conv(struct ltc2497core_driverdata *ddata)
{
s64 time_elapsed;
time_elapsed = ktime_ms_delta(ktime_get(), ddata->time_prev);
if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
/* delay if conversion time not passed
* since last read or write
*/
if (msleep_interruptible(
LTC2497_CONVERSION_TIME_MS - time_elapsed))
return -ERESTARTSYS;
return 0;
}
if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
/* We're in automatic mode -
* so the last reading is still not outdated
*/
return 0;
}
return 1;
}
static int ltc2497core_read(struct ltc2497core_driverdata *ddata, u8 address, int *val)
{
int ret;
ret = ltc2497core_wait_conv(ddata);
if (ret < 0)
return ret;
if (ret || ddata->addr_prev != address) {
ret = ddata->result_and_measure(ddata, address, NULL);
if (ret < 0)
return ret;
ddata->addr_prev = address;
if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
return -ERESTARTSYS;
}
ret = ddata->result_and_measure(ddata, address, val);
if (ret < 0)
return ret;
ddata->time_prev = ktime_get();
return ret;
}
static int ltc2497core_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&ddata->lock);
ret = ltc2497core_read(ddata, chan->address, val);
mutex_unlock(&ddata->lock);
if (ret < 0)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(ddata->ref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = ddata->chip_info->resolution + 1;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (_chan), \
.address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = (_ds_name), \
}
#define LTC2497_CHAN_DIFF(_chan, _addr) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
.channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
.address = (_addr | _chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.differential = 1, \
}
static const struct iio_chan_spec ltc2497core_channel[] = {
LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
};
static const struct iio_info ltc2497core_info = {
.read_raw = ltc2497core_read_raw,
};
int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
int ret;
/*
* Keep using dev_name() for the iio_dev's name on some of the parts,
* since updating it would result in a ABI breakage.
*/
if (ddata->chip_info->name)
indio_dev->name = ddata->chip_info->name;
else
indio_dev->name = dev_name(dev);
indio_dev->info = <c2497core_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ltc2497core_channel;
indio_dev->num_channels = ARRAY_SIZE(ltc2497core_channel);
ret = ddata->result_and_measure(ddata, LTC2497_CONFIG_DEFAULT, NULL);
if (ret < 0)
return ret;
ddata->ref = devm_regulator_get(dev, "vref");
if (IS_ERR(ddata->ref))
return dev_err_probe(dev, PTR_ERR(ddata->ref),
"Failed to get vref regulator\n");
ret = regulator_enable(ddata->ref);
if (ret < 0) {
dev_err(dev, "Failed to enable vref regulator: %pe\n",
ERR_PTR(ret));
return ret;
}
if (dev->platform_data) {
struct iio_map *plat_data;
plat_data = (struct iio_map *)dev->platform_data;
ret = iio_map_array_register(indio_dev, plat_data);
if (ret) {
dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
goto err_regulator_disable;
}
}
ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
ddata->time_prev = ktime_get();
mutex_init(&ddata->lock);
ret = iio_device_register(indio_dev);
if (ret < 0)
goto err_array_unregister;
return 0;
err_array_unregister:
iio_map_array_unregister(indio_dev);
err_regulator_disable:
regulator_disable(ddata->ref);
return ret;
}
EXPORT_SYMBOL_NS(ltc2497core_probe, LTC2497);
void ltc2497core_remove(struct iio_dev *indio_dev)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_map_array_unregister(indio_dev);
regulator_disable(ddata->ref);
}
EXPORT_SYMBOL_NS(ltc2497core_remove, LTC2497);
MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers");
MODULE_LICENSE("GPL v2");
Codebase Browser
linux