[v6,1/2] iio: dac: ds4422/ds4424 dac driver
diff mbox

Message ID 20170922201226.23721-1-Ismail.Kose@maximintegrated.com
State New
Headers show

Commit Message

Ismail Kose Sept. 22, 2017, 8:12 p.m. UTC
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: Ismail H. Kose <Ismail.Kose@maximintegrated.com>
Signed-off-by: Ismail H. Kose <ihkose@gmail.com>
---
v6:
	* Removed reference resistor parsing
v5:
	* Removed unused variable
v4:
	* Removed unnecessary code and space optimization
	* Alphabetic order in Kconfig and Makefile
v3:
	* Removed iio-map and platform file support
	* Removed ds4424.h file
	* Fixed ADC value read bug
	* Removed confused comments
	* Added device tree binding file
	* Fixed bugs in probe and read function
v2:
	* Fixed coding style and removed unncessary code
	* Removed min/max rfs, ifs-scale, etc values from device tree
	* Removed unused code, definitions and some comments
	* Removed regulator control and made standard structure
	* Removed data processing and channel scale
	* Removed device tree binding file

 drivers/iio/dac/Kconfig  |   9 ++
 drivers/iio/dac/Makefile |   1 +
 drivers/iio/dac/ds4424.c | 340 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 350 insertions(+)
 create mode 100644 drivers/iio/dac/ds4424.c

Comments

Jonathan Cameron Sept. 24, 2017, 2:45 p.m. UTC | #1
On Fri, 22 Sep 2017 13:12:08 -0700
"Ismail H. Kose" <Ismail.Kose@maximintegrated.com> wrote:

> 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: Ismail H. Kose <Ismail.Kose@maximintegrated.com>
> Signed-off-by: Ismail H. Kose <ihkose@gmail.com>

A few minor comments inline.  This is coming together nicely.

Jonathan

> ---
> v6:
> 	* Removed reference resistor parsing
> v5:
> 	* Removed unused variable
> v4:
> 	* Removed unnecessary code and space optimization
> 	* Alphabetic order in Kconfig and Makefile
> v3:
> 	* Removed iio-map and platform file support
> 	* Removed ds4424.h file
> 	* Fixed ADC value read bug
> 	* Removed confused comments
> 	* Added device tree binding file
> 	* Fixed bugs in probe and read function
> v2:
> 	* Fixed coding style and removed unncessary code
> 	* Removed min/max rfs, ifs-scale, etc values from device tree
> 	* Removed unused code, definitions and some comments
> 	* Removed regulator control and made standard structure
> 	* Removed data processing and channel scale
> 	* Removed device tree binding file
> 
>  drivers/iio/dac/Kconfig  |   9 ++
>  drivers/iio/dac/Makefile |   1 +
>  drivers/iio/dac/ds4424.c | 340 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 350 insertions(+)
>  create mode 100644 drivers/iio/dac/ds4424.c
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index 25bed2d7d2b9..57c179830981 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -211,6 +211,15 @@ config AD8801
>  	  To compile this driver as a module choose M here: the module will be called
>  	  ad8801.
>  
> +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 DPOT_DAC
>  	tristate "DAC emulation using a DPOT"
>  	depends on OF
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 603587cc2f07..abf5c3094454 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_AD5686) += ad5686.o
>  obj-$(CONFIG_AD7303) += ad7303.o
>  obj-$(CONFIG_AD8801) += ad8801.o
>  obj-$(CONFIG_CIO_DAC) += cio-dac.o
> +obj-$(CONFIG_DS4424) += ds4424.o
>  obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
>  obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
>  obj-$(CONFIG_LTC2632) += ltc2632.o
> diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
> new file mode 100644
> index 000000000000..aea0cd12f9b8
> --- /dev/null
> +++ b/drivers/iio/dac/ds4424.c
> @@ -0,0 +1,340 @@
> +/*
> + * 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;
> +	__maybe_unused 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;
> +	mutex_unlock(&data->lock);
> +	return 0;

Lose previous two lines and use the logic in the error path.

> +
> +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) {
> +		mutex_unlock(&data->lock);

A goto unlock: would be slightly cleaner.

> +		return ret;
> +	}
> +
> +	data->raw[chan->channel] = val;
> +	mutex_unlock(&data->lock);
> +
> +	return 0;
> +}
> +
> +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 -EPERM;

Slightly odd error.  -ENODEV probably makes more sense...

> +	}
> +
> +	data->vcc_reg = devm_regulator_get(&client->dev, "vcc");
> +	if (IS_ERR(data->vcc_reg)) {
> +		ret = PTR_ERR(data->vcc_reg);
> +		dev_err(&client->dev,
> +			"Failed to get vcc-supply regulator: %d\n", ret);
> +		return ret;

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)

regulator disable?  Easier if you do a goto block at the end
for any error handling which is not a valid direct return
(see below).

> +		return -ENXIO;
> +
> +	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");
> +		regulator_disable(data->vcc_reg);

Given you have multiple error paths where regulator_disable is needed,
I would prefer this done as a goto with the error handling laid
out at the end of this function rather than mutiple copies inline.

> +		return -ENXIO;
> +	}
> +
> +	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);
> +		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");

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Patch
diff mbox

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 25bed2d7d2b9..57c179830981 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -211,6 +211,15 @@  config AD8801
 	  To compile this driver as a module choose M here: the module will be called
 	  ad8801.
 
+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 DPOT_DAC
 	tristate "DAC emulation using a DPOT"
 	depends on OF
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 603587cc2f07..abf5c3094454 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -22,6 +22,7 @@  obj-$(CONFIG_AD5686) += ad5686.o
 obj-$(CONFIG_AD7303) += ad7303.o
 obj-$(CONFIG_AD8801) += ad8801.o
 obj-$(CONFIG_CIO_DAC) += cio-dac.o
+obj-$(CONFIG_DS4424) += ds4424.o
 obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
 obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
 obj-$(CONFIG_LTC2632) += ltc2632.o
diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
new file mode 100644
index 000000000000..aea0cd12f9b8
--- /dev/null
+++ b/drivers/iio/dac/ds4424.c
@@ -0,0 +1,340 @@ 
+/*
+ * 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;
+	__maybe_unused 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;
+	mutex_unlock(&data->lock);
+	return 0;
+
+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) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->raw[chan->channel] = val;
+	mutex_unlock(&data->lock);
+
+	return 0;
+}
+
+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 -EPERM;
+	}
+
+	data->vcc_reg = devm_regulator_get(&client->dev, "vcc");
+	if (IS_ERR(data->vcc_reg)) {
+		ret = PTR_ERR(data->vcc_reg);
+		dev_err(&client->dev,
+			"Failed to get vcc-supply regulator: %d\n", ret);
+		return ret;
+	}
+
+	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)
+		return -ENXIO;
+
+	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");
+		regulator_disable(data->vcc_reg);
+		return -ENXIO;
+	}
+
+	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);
+		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");