Commit d632a2bd authored by Ismail H. Kose's avatar Ismail H. Kose Committed by Jonathan Cameron
Browse files

iio: dac: ds4422/ds4424 dac driver 



This patch provides an iio device driver for DS4422/DS4424 chips that support
two/four channel 7-bit Sink/Source Current DAC.

Signed-off-by: default avatarIsmail H. Kose <Ismail.Kose@maximintegrated.com>
Signed-off-by: default avatarIsmail H. Kose <ihkose@gmail.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent b091b9ed

drivers/iio/dac/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -222,6 +222,15 @@ config DPOT_DAC 
	  To compile this driver as a module, choose M here: the module will be

	  called dpot-dac.



config DS4424

	tristate "Maxim Integrated DS4422/DS4424 DAC driver"

	depends on I2C

	help

	  If you say yes here you get support for Maxim chips DS4422, DS4424.



	  This driver can also be built as a module.  If so, the module

	  will be called ds4424.



config LPC18XX_DAC

	tristate "NXP LPC18xx DAC driver"

	depends on ARCH_LPC18XX || COMPILE_TEST

drivers/iio/dac/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ obj-$(CONFIG_AD7303) += ad7303.o 
obj-$(CONFIG_AD8801) += ad8801.o

obj-$(CONFIG_CIO_DAC) += cio-dac.o

obj-$(CONFIG_DPOT_DAC) += dpot-dac.o

obj-$(CONFIG_DS4424) += ds4424.o

obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o

obj-$(CONFIG_LTC2632) += ltc2632.o

obj-$(CONFIG_M62332) += m62332.o

drivers/iio/dac/ds4424.c

0 → 100644
+341 −0
Original line number Diff line number Diff line 
/*

 * Maxim Integrated

 * 7-bit, Multi-Channel Sink/Source Current DAC Driver

 * Copyright (C) 2017 Maxim Integrated

 *

 * 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/regulator/consumer.h>

#include <linux/err.h>

#include <linux/delay.h>

#include <linux/iio/iio.h>

#include <linux/iio/driver.h>

#include <linux/iio/machine.h>

#include <linux/iio/consumer.h>



#define DS4422_MAX_DAC_CHANNELS		2

#define DS4424_MAX_DAC_CHANNELS		4



#define DS4424_DAC_ADDR(chan)   ((chan) + 0xf8)

#define DS4424_SOURCE_I		1

#define DS4424_SINK_I		0



#define DS4424_CHANNEL(chan) { \

	.type = IIO_CURRENT, \

	.indexed = 1, \

	.output = 1, \

	.channel = chan, \

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \

}



/*

 * DS4424 DAC control register 8 bits

 * [7]		0: to sink; 1: to source

 * [6:0]	steps to sink/source

 * bit[7] looks like a sign bit, but the value of the register is

 * not a two's complement code considering the bit[6:0] is a absolute

 * distance from the zero point.

 */

union ds4424_raw_data {

	struct {

		u8 dx:7;

		u8 source_bit:1;

	};

	u8 bits;

};



enum ds4424_device_ids {

	ID_DS4422,

	ID_DS4424,

};



struct ds4424_data {

	struct i2c_client *client;

	struct mutex lock;

	uint8_t save[DS4424_MAX_DAC_CHANNELS];

	struct regulator *vcc_reg;

	uint8_t raw[DS4424_MAX_DAC_CHANNELS];

};



static const struct iio_chan_spec ds4424_channels[] = {

	DS4424_CHANNEL(0),

	DS4424_CHANNEL(1),

	DS4424_CHANNEL(2),

	DS4424_CHANNEL(3),

};



static int ds4424_get_value(struct iio_dev *indio_dev,

			     int *val, int channel)

{

	struct ds4424_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->lock);

	ret = i2c_smbus_read_byte_data(data->client, DS4424_DAC_ADDR(channel));

	if (ret < 0)

		goto fail;



	*val = ret;



fail:

	mutex_unlock(&data->lock);

	return ret;

}



static int ds4424_set_value(struct iio_dev *indio_dev,

			     int val, struct iio_chan_spec const *chan)

{

	struct ds4424_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->lock);

	ret = i2c_smbus_write_byte_data(data->client,

			DS4424_DAC_ADDR(chan->channel), val);

	if (ret < 0)

		goto fail;



	data->raw[chan->channel] = val;



fail:

	mutex_unlock(&data->lock);

	return ret;

}



static int ds4424_read_raw(struct iio_dev *indio_dev,

			   struct iio_chan_spec const *chan,

			   int *val, int *val2, long mask)

{

	union ds4424_raw_data raw;

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		ret = ds4424_get_value(indio_dev, val, chan->channel);

		if (ret < 0) {

			pr_err("%s : ds4424_get_value returned %d\n",

							__func__, ret);

			return ret;

		}

		raw.bits = *val;

		*val = raw.dx;

		if (raw.source_bit == DS4424_SINK_I)

			*val = -*val;

		return IIO_VAL_INT;



	default:

		return -EINVAL;

	}

}



static int ds4424_write_raw(struct iio_dev *indio_dev,

			     struct iio_chan_spec const *chan,

			     int val, int val2, long mask)

{

	union ds4424_raw_data raw;



	if (val2 != 0)

		return -EINVAL;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (val < S8_MIN || val > S8_MAX)

			return -EINVAL;



		if (val > 0) {

			raw.source_bit = DS4424_SOURCE_I;

			raw.dx = val;

		} else {

			raw.source_bit = DS4424_SINK_I;

			raw.dx = -val;

		}



		return ds4424_set_value(indio_dev, raw.bits, chan);



	default:

		return -EINVAL;

	}

}



static int ds4424_verify_chip(struct iio_dev *indio_dev)

{

	int ret, val;



	ret = ds4424_get_value(indio_dev, &val, DS4424_DAC_ADDR(0));

	if (ret < 0)

		dev_err(&indio_dev->dev,

				"%s failed. ret: %d\n", __func__, ret);



	return ret;

}



static int __maybe_unused ds4424_suspend(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct ds4424_data *data = iio_priv(indio_dev);

	int ret = 0;

	int i;



	for (i = 0; i < indio_dev->num_channels; i++) {

		data->save[i] = data->raw[i];

		ret = ds4424_set_value(indio_dev, 0,

				&indio_dev->channels[i]);

		if (ret < 0)

			return ret;

	}

	return ret;

}



static int __maybe_unused ds4424_resume(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct ds4424_data *data = iio_priv(indio_dev);

	int ret = 0;

	int i;



	for (i = 0; i < indio_dev->num_channels; i++) {

		ret = ds4424_set_value(indio_dev, data->save[i],

				&indio_dev->channels[i]);

		if (ret < 0)

			return ret;

	}

	return ret;

}



static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume);



static const struct iio_info ds4424_info = {

	.read_raw = ds4424_read_raw,

	.write_raw = ds4424_write_raw,

};



static int ds4424_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct ds4424_data *data;

	struct iio_dev *indio_dev;

	int ret;



	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));

	if (!indio_dev) {

		dev_err(&client->dev, "iio dev alloc failed.\n");

		return -ENOMEM;

	}



	data = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);

	data->client = client;

	indio_dev->name = id->name;

	indio_dev->dev.of_node = client->dev.of_node;

	indio_dev->dev.parent = &client->dev;



	if (!client->dev.of_node) {

		dev_err(&client->dev,

				"Not found DT.\n");

		return -ENODEV;

	}



	data->vcc_reg = devm_regulator_get(&client->dev, "vcc");

	if (IS_ERR(data->vcc_reg)) {

		dev_err(&client->dev,

			"Failed to get vcc-supply regulator. err: %ld\n",

				PTR_ERR(data->vcc_reg));

		return PTR_ERR(data->vcc_reg);

	}



	mutex_init(&data->lock);

	ret = regulator_enable(data->vcc_reg);

	if (ret < 0) {

		dev_err(&client->dev,

				"Unable to enable the regulator.\n");

		return ret;

	}



	usleep_range(1000, 1200);

	ret = ds4424_verify_chip(indio_dev);

	if (ret < 0)

		goto fail;



	switch (id->driver_data) {

	case ID_DS4422:

		indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS;

		break;

	case ID_DS4424:

		indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS;

		break;

	default:

		dev_err(&client->dev,

				"ds4424: Invalid chip id.\n");

		ret = -ENXIO;

		goto fail;

	}



	indio_dev->channels = ds4424_channels;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = &ds4424_info;



	ret = iio_device_register(indio_dev);

	if (ret < 0) {

		dev_err(&client->dev,

				"iio_device_register failed. ret: %d\n", ret);

		goto fail;

	}



	return ret;



fail:

	regulator_disable(data->vcc_reg);

	return ret;

}



static int ds4424_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct ds4424_data *data = iio_priv(indio_dev);



	iio_device_unregister(indio_dev);

	regulator_disable(data->vcc_reg);



	return 0;

}



static const struct i2c_device_id ds4424_id[] = {

	{ "ds4422", ID_DS4422 },

	{ "ds4424", ID_DS4424 },

	{ }

};



MODULE_DEVICE_TABLE(i2c, ds4424_id);



static const struct of_device_id ds4424_of_match[] = {

	{ .compatible = "maxim,ds4422" },

	{ .compatible = "maxim,ds4424" },

	{ },

};



MODULE_DEVICE_TABLE(of, ds4424_of_match);



static struct i2c_driver ds4424_driver = {

	.driver = {

		.name	= "ds4424",

		.of_match_table = ds4424_of_match,

		.pm     = &ds4424_pm_ops,

	},

	.probe		= ds4424_probe,

	.remove		= ds4424_remove,

	.id_table	= ds4424_id,

};

module_i2c_driver(ds4424_driver);



MODULE_DESCRIPTION("Maxim DS4424 DAC Driver");

MODULE_AUTHOR("Ismail H. Kose <ismail.kose@maximintegrated.com>");

MODULE_AUTHOR("Vishal Sood <vishal.sood@maximintegrated.com>");

MODULE_AUTHOR("David Jung <david.jung@maximintegrated.com>");

MODULE_LICENSE("GPL v2");