387 lines
8.9 KiB
C
387 lines
8.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* iio/dac/max5821.c
|
|
* Copyright (C) 2014 Philippe Reynes
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/regulator/consumer.h>
|
|
|
|
#define MAX5821_MAX_DAC_CHANNELS 2
|
|
|
|
/* command bytes */
|
|
#define MAX5821_LOAD_DAC_A_IN_REG_B 0x00
|
|
#define MAX5821_LOAD_DAC_B_IN_REG_A 0x10
|
|
#define MAX5821_EXTENDED_COMMAND_MODE 0xf0
|
|
#define MAX5821_READ_DAC_A_COMMAND 0xf1
|
|
#define MAX5821_READ_DAC_B_COMMAND 0xf2
|
|
|
|
#define MAX5821_EXTENDED_POWER_UP 0x00
|
|
#define MAX5821_EXTENDED_POWER_DOWN_MODE0 0x01
|
|
#define MAX5821_EXTENDED_POWER_DOWN_MODE1 0x02
|
|
#define MAX5821_EXTENDED_POWER_DOWN_MODE2 0x03
|
|
#define MAX5821_EXTENDED_DAC_A 0x04
|
|
#define MAX5821_EXTENDED_DAC_B 0x08
|
|
|
|
enum max5821_device_ids {
|
|
ID_MAX5821,
|
|
};
|
|
|
|
struct max5821_data {
|
|
struct i2c_client *client;
|
|
struct regulator *vref_reg;
|
|
unsigned short vref_mv;
|
|
bool powerdown[MAX5821_MAX_DAC_CHANNELS];
|
|
u8 powerdown_mode[MAX5821_MAX_DAC_CHANNELS];
|
|
struct mutex lock;
|
|
};
|
|
|
|
static const char * const max5821_powerdown_modes[] = {
|
|
"three_state",
|
|
"1kohm_to_gnd",
|
|
"100kohm_to_gnd",
|
|
};
|
|
|
|
enum {
|
|
MAX5821_THREE_STATE,
|
|
MAX5821_1KOHM_TO_GND,
|
|
MAX5821_100KOHM_TO_GND
|
|
};
|
|
|
|
static int max5821_get_powerdown_mode(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan)
|
|
{
|
|
struct max5821_data *st = iio_priv(indio_dev);
|
|
|
|
return st->powerdown_mode[chan->channel];
|
|
}
|
|
|
|
static int max5821_set_powerdown_mode(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan,
|
|
unsigned int mode)
|
|
{
|
|
struct max5821_data *st = iio_priv(indio_dev);
|
|
|
|
st->powerdown_mode[chan->channel] = mode;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct iio_enum max5821_powerdown_mode_enum = {
|
|
.items = max5821_powerdown_modes,
|
|
.num_items = ARRAY_SIZE(max5821_powerdown_modes),
|
|
.get = max5821_get_powerdown_mode,
|
|
.set = max5821_set_powerdown_mode,
|
|
};
|
|
|
|
static ssize_t max5821_read_dac_powerdown(struct iio_dev *indio_dev,
|
|
uintptr_t private,
|
|
const struct iio_chan_spec *chan,
|
|
char *buf)
|
|
{
|
|
struct max5821_data *st = iio_priv(indio_dev);
|
|
|
|
return sysfs_emit(buf, "%d\n", st->powerdown[chan->channel]);
|
|
}
|
|
|
|
static int max5821_sync_powerdown_mode(struct max5821_data *data,
|
|
const struct iio_chan_spec *chan)
|
|
{
|
|
u8 outbuf[2];
|
|
|
|
outbuf[0] = MAX5821_EXTENDED_COMMAND_MODE;
|
|
|
|
if (chan->channel == 0)
|
|
outbuf[1] = MAX5821_EXTENDED_DAC_A;
|
|
else
|
|
outbuf[1] = MAX5821_EXTENDED_DAC_B;
|
|
|
|
if (data->powerdown[chan->channel])
|
|
outbuf[1] |= data->powerdown_mode[chan->channel] + 1;
|
|
else
|
|
outbuf[1] |= MAX5821_EXTENDED_POWER_UP;
|
|
|
|
return i2c_master_send(data->client, outbuf, 2);
|
|
}
|
|
|
|
static ssize_t max5821_write_dac_powerdown(struct iio_dev *indio_dev,
|
|
uintptr_t private,
|
|
const struct iio_chan_spec *chan,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct max5821_data *data = iio_priv(indio_dev);
|
|
bool powerdown;
|
|
int ret;
|
|
|
|
ret = strtobool(buf, &powerdown);
|
|
if (ret)
|
|
return ret;
|
|
|
|
data->powerdown[chan->channel] = powerdown;
|
|
|
|
ret = max5821_sync_powerdown_mode(data, chan);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return len;
|
|
}
|
|
|
|
static const struct iio_chan_spec_ext_info max5821_ext_info[] = {
|
|
{
|
|
.name = "powerdown",
|
|
.read = max5821_read_dac_powerdown,
|
|
.write = max5821_write_dac_powerdown,
|
|
.shared = IIO_SEPARATE,
|
|
},
|
|
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &max5821_powerdown_mode_enum),
|
|
IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &max5821_powerdown_mode_enum),
|
|
{ },
|
|
};
|
|
|
|
#define MAX5821_CHANNEL(chan) { \
|
|
.type = IIO_VOLTAGE, \
|
|
.indexed = 1, \
|
|
.output = 1, \
|
|
.channel = (chan), \
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
|
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE), \
|
|
.ext_info = max5821_ext_info, \
|
|
}
|
|
|
|
static const struct iio_chan_spec max5821_channels[] = {
|
|
MAX5821_CHANNEL(0),
|
|
MAX5821_CHANNEL(1)
|
|
};
|
|
|
|
static const u8 max5821_read_dac_command[] = {
|
|
MAX5821_READ_DAC_A_COMMAND,
|
|
MAX5821_READ_DAC_B_COMMAND
|
|
};
|
|
|
|
static const u8 max5821_load_dac_command[] = {
|
|
MAX5821_LOAD_DAC_A_IN_REG_B,
|
|
MAX5821_LOAD_DAC_B_IN_REG_A
|
|
};
|
|
|
|
static int max5821_get_value(struct iio_dev *indio_dev,
|
|
int *val, int channel)
|
|
{
|
|
struct max5821_data *data = iio_priv(indio_dev);
|
|
struct i2c_client *client = data->client;
|
|
u8 outbuf[1];
|
|
u8 inbuf[2];
|
|
int ret;
|
|
|
|
if ((channel != 0) && (channel != 1))
|
|
return -EINVAL;
|
|
|
|
outbuf[0] = max5821_read_dac_command[channel];
|
|
|
|
mutex_lock(&data->lock);
|
|
|
|
ret = i2c_master_send(client, outbuf, 1);
|
|
if (ret < 0) {
|
|
mutex_unlock(&data->lock);
|
|
return ret;
|
|
} else if (ret != 1) {
|
|
mutex_unlock(&data->lock);
|
|
return -EIO;
|
|
}
|
|
|
|
ret = i2c_master_recv(client, inbuf, 2);
|
|
if (ret < 0) {
|
|
mutex_unlock(&data->lock);
|
|
return ret;
|
|
} else if (ret != 2) {
|
|
mutex_unlock(&data->lock);
|
|
return -EIO;
|
|
}
|
|
|
|
mutex_unlock(&data->lock);
|
|
|
|
*val = ((inbuf[0] & 0x0f) << 6) | (inbuf[1] >> 2);
|
|
|
|
return IIO_VAL_INT;
|
|
}
|
|
|
|
static int max5821_set_value(struct iio_dev *indio_dev,
|
|
int val, int channel)
|
|
{
|
|
struct max5821_data *data = iio_priv(indio_dev);
|
|
struct i2c_client *client = data->client;
|
|
u8 outbuf[2];
|
|
int ret;
|
|
|
|
if ((val < 0) || (val > 1023))
|
|
return -EINVAL;
|
|
|
|
if ((channel != 0) && (channel != 1))
|
|
return -EINVAL;
|
|
|
|
outbuf[0] = max5821_load_dac_command[channel];
|
|
outbuf[0] |= val >> 6;
|
|
outbuf[1] = (val & 0x3f) << 2;
|
|
|
|
ret = i2c_master_send(client, outbuf, 2);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret != 2)
|
|
return -EIO;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static int max5821_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int *val, int *val2, long mask)
|
|
{
|
|
struct max5821_data *data = iio_priv(indio_dev);
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
return max5821_get_value(indio_dev, val, chan->channel);
|
|
case IIO_CHAN_INFO_SCALE:
|
|
*val = data->vref_mv;
|
|
*val2 = 10;
|
|
return IIO_VAL_FRACTIONAL_LOG2;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int max5821_write_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int val, int val2, long mask)
|
|
{
|
|
if (val2 != 0)
|
|
return -EINVAL;
|
|
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
return max5821_set_value(indio_dev, val, chan->channel);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int __maybe_unused max5821_suspend(struct device *dev)
|
|
{
|
|
u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE,
|
|
MAX5821_EXTENDED_DAC_A |
|
|
MAX5821_EXTENDED_DAC_B |
|
|
MAX5821_EXTENDED_POWER_DOWN_MODE2 };
|
|
|
|
return i2c_master_send(to_i2c_client(dev), outbuf, 2);
|
|
}
|
|
|
|
static int __maybe_unused max5821_resume(struct device *dev)
|
|
{
|
|
u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE,
|
|
MAX5821_EXTENDED_DAC_A |
|
|
MAX5821_EXTENDED_DAC_B |
|
|
MAX5821_EXTENDED_POWER_UP };
|
|
|
|
return i2c_master_send(to_i2c_client(dev), outbuf, 2);
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(max5821_pm_ops, max5821_suspend, max5821_resume);
|
|
|
|
static const struct iio_info max5821_info = {
|
|
.read_raw = max5821_read_raw,
|
|
.write_raw = max5821_write_raw,
|
|
};
|
|
|
|
static void max5821_regulator_disable(void *reg)
|
|
{
|
|
regulator_disable(reg);
|
|
}
|
|
|
|
static int max5821_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct max5821_data *data;
|
|
struct iio_dev *indio_dev;
|
|
u32 tmp;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
data = iio_priv(indio_dev);
|
|
data->client = client;
|
|
mutex_init(&data->lock);
|
|
|
|
/* max5821 start in powerdown mode 100Kohm to ground */
|
|
for (tmp = 0; tmp < MAX5821_MAX_DAC_CHANNELS; tmp++) {
|
|
data->powerdown[tmp] = true;
|
|
data->powerdown_mode[tmp] = MAX5821_100KOHM_TO_GND;
|
|
}
|
|
|
|
data->vref_reg = devm_regulator_get(&client->dev, "vref");
|
|
if (IS_ERR(data->vref_reg))
|
|
return dev_err_probe(&client->dev, PTR_ERR(data->vref_reg),
|
|
"Failed to get vref regulator\n");
|
|
|
|
ret = regulator_enable(data->vref_reg);
|
|
if (ret) {
|
|
dev_err(&client->dev,
|
|
"Failed to enable vref regulator: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = devm_add_action_or_reset(&client->dev, max5821_regulator_disable,
|
|
data->vref_reg);
|
|
if (ret) {
|
|
dev_err(&client->dev,
|
|
"Failed to add action to managed regulator: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = regulator_get_voltage(data->vref_reg);
|
|
if (ret < 0) {
|
|
dev_err(&client->dev,
|
|
"Failed to get voltage on regulator: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
data->vref_mv = ret / 1000;
|
|
|
|
indio_dev->name = id->name;
|
|
indio_dev->num_channels = ARRAY_SIZE(max5821_channels);
|
|
indio_dev->channels = max5821_channels;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->info = &max5821_info;
|
|
|
|
return devm_iio_device_register(&client->dev, indio_dev);
|
|
}
|
|
|
|
static const struct i2c_device_id max5821_id[] = {
|
|
{ "max5821", ID_MAX5821 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, max5821_id);
|
|
|
|
static const struct of_device_id max5821_of_match[] = {
|
|
{ .compatible = "maxim,max5821" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, max5821_of_match);
|
|
|
|
static struct i2c_driver max5821_driver = {
|
|
.driver = {
|
|
.name = "max5821",
|
|
.of_match_table = max5821_of_match,
|
|
.pm = &max5821_pm_ops,
|
|
},
|
|
.probe = max5821_probe,
|
|
.id_table = max5821_id,
|
|
};
|
|
module_i2c_driver(max5821_driver);
|
|
|
|
MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
|
|
MODULE_DESCRIPTION("MAX5821 DAC");
|
|
MODULE_LICENSE("GPL v2");
|