iio: add support of the max5821

Signed-off-by: Philippe Reynes <tremyfr@yahoo.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Philippe Reynes 2014-07-25 22:43:00 +01:00 committed by Jonathan Cameron
parent 03d795589d
commit 4729889727
4 changed files with 428 additions and 0 deletions

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@ -0,0 +1,14 @@
Maxim max5821 DAC device driver
Required properties:
- compatible: Must be "maxim,max5821"
- reg: Should contain the DAC I2C address
- vref-supply: Phandle to the vref power supply
Example:
max5821@38 {
compatible = "maxim,max5821";
reg = <0x38>;
vref-supply = <&reg_max5821>;
};

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@ -152,6 +152,14 @@ config MAX517
This driver can also be built as a module. If so, the module
will be called max517.
config MAX5821
tristate "Maxim MAX5821 DAC driver"
depends on I2C
depends on OF
help
Say yes here to build support for Maxim MAX5821
10 bits DAC.
config MCP4725
tristate "MCP4725 DAC driver"
depends on I2C

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@ -17,5 +17,6 @@ obj-$(CONFIG_AD5791) += ad5791.o
obj-$(CONFIG_AD5686) += ad5686.o
obj-$(CONFIG_AD7303) += ad7303.o
obj-$(CONFIG_MAX517) += max517.o
obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
obj-$(CONFIG_MCP4922) += mcp4922.o

405
drivers/iio/dac/max5821.c Normal file
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@ -0,0 +1,405 @@
/*
* iio/dac/max5821.c
* Copyright (C) 2014 Philippe Reynes
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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 sprintf(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", &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;
}
}
#ifdef CONFIG_PM_SLEEP
static int 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 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);
#define MAX5821_PM_OPS (&max5821_pm_ops)
#else
#define MAX5821_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
static const struct iio_info max5821_info = {
.read_raw = max5821_read_raw,
.write_raw = max5821_write_raw,
.driver_module = THIS_MODULE,
};
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);
i2c_set_clientdata(client, 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)) {
ret = PTR_ERR(data->vref_reg);
dev_err(&client->dev,
"Failed to get vref regulator: %d\n", ret);
goto error_free_reg;
}
ret = regulator_enable(data->vref_reg);
if (ret) {
dev_err(&client->dev,
"Failed to enable vref regulator: %d\n", ret);
goto error_free_reg;
}
ret = regulator_get_voltage(data->vref_reg);
if (ret < 0) {
dev_err(&client->dev,
"Failed to get voltage on regulator: %d\n", ret);
goto error_disable_reg;
}
data->vref_mv = ret / 1000;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
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 iio_device_register(indio_dev);
error_disable_reg:
regulator_disable(data->vref_reg);
error_free_reg:
return ret;
}
static int max5821_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct max5821_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
regulator_disable(data->vref_reg);
return 0;
}
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" },
{ }
};
static struct i2c_driver max5821_driver = {
.driver = {
.name = "max5821",
.pm = MAX5821_PM_OPS,
.owner = THIS_MODULE,
},
.probe = max5821_probe,
.remove = max5821_remove,
.id_table = max5821_id,
};
module_i2c_driver(max5821_driver);
MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
MODULE_DESCRIPTION("MAX5821 DAC");
MODULE_LICENSE("GPL v2");