Commit b87b0c0f authored by Dmitry Eremin-Solenikov's avatar Dmitry Eremin-Solenikov Committed by Jonathan Cameron
Browse files

iio: add m62332 DAC driver 



m62332 is a simple 2-channel DAC used on several Sharp Zaurus boards to
control LCD voltage, backlight and sound. The driver use regulators to
control the reference voltage and enabling/disabling the DAC.

Signed-off-by: default avatarDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent c06cee8d

drivers/iio/dac/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -142,6 +142,16 @@ config AD7303 
	  To compile this driver as module choose M here: the module will be called

	  ad7303.



config M62332

	tristate "Mitsubishi M62332 DAC driver"

	depends on I2C

	help

	  If you say yes here you get support for the Mitsubishi M62332

	  (I2C 8-Bit DACs with rail-to-rail outputs).



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

	  will be called m62332.



config MAX517

	tristate "Maxim MAX517/518/519/520/521 DAC driver"

	depends on I2C

drivers/iio/dac/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD5764) += ad5764.o 
obj-$(CONFIG_AD5791) += ad5791.o

obj-$(CONFIG_AD5686) += ad5686.o

obj-$(CONFIG_AD7303) += ad7303.o

obj-$(CONFIG_M62332) += m62332.o

obj-$(CONFIG_MAX517) += max517.o

obj-$(CONFIG_MAX5821) += max5821.o

obj-$(CONFIG_MCP4725) += mcp4725.o

drivers/iio/dac/m62332.c

0 → 100644
+269 −0
Original line number Diff line number Diff line 
/*

 *  m62332.c - Support for Mitsubishi m62332 DAC

 *

 *  Copyright (c) 2014 Dmitry Eremin-Solenikov

 *

 *  Based on max517 driver:

 *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 */



#include <linux/module.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/err.h>



#include <linux/iio/iio.h>

#include <linux/iio/driver.h>



#include <linux/regulator/consumer.h>



#define M62332_CHANNELS 2



struct m62332_data {

	struct i2c_client	*client;

	u16			vref_mv;

	struct regulator	*vcc;

	struct mutex		mutex;

	u8			raw[M62332_CHANNELS];

#ifdef CONFIG_PM_SLEEP

	u8			save[M62332_CHANNELS];

#endif

};



static int m62332_set_value(struct iio_dev *indio_dev,

	u8 val, int channel)

{

	struct m62332_data *data = iio_priv(indio_dev);

	struct i2c_client *client = data->client;

	u8 outbuf[2];

	int res;



	if (val == data->raw[channel])

		return 0;



	outbuf[0] = channel;

	outbuf[1] = val;



	mutex_lock(&data->mutex);



	if (val) {

		res = regulator_enable(data->vcc);

		if (res)

			goto out;

	}



	res = i2c_master_send(client, outbuf, 2);

	if (res >= 0 && res != 2)

		res = -EIO;

	if (res < 0)

		goto out;



	data->raw[channel] = val;



	if (!val)

		regulator_disable(data->vcc);



	mutex_unlock(&data->mutex);



	return 0;



out:

	mutex_unlock(&data->mutex);



	return res;

}



static int m62332_read_raw(struct iio_dev *indio_dev,

			   struct iio_chan_spec const *chan,

			   int *val,

			   int *val2,

			   long m)

{

	struct m62332_data *data = iio_priv(indio_dev);



	switch (m) {

	case IIO_CHAN_INFO_SCALE:

		/* Corresponds to Vref / 2^(bits) */

		*val = data->vref_mv;

		*val2 = 8;

		return IIO_VAL_FRACTIONAL_LOG2;

	case IIO_CHAN_INFO_RAW:

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

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_OFFSET:

		*val = 1;

		return IIO_VAL_INT;

	default:

		break;

	}

	return -EINVAL;

}



static int m62332_write_raw(struct iio_dev *indio_dev,

	struct iio_chan_spec const *chan, int val, int val2, long mask)

{

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (val < 0 || val > 255)

			return -EINVAL;



		ret = m62332_set_value(indio_dev, val, chan->channel);

		break;

	default:

		ret = -EINVAL;

		break;

	}



	return ret;

}



#ifdef CONFIG_PM_SLEEP

static int m62332_suspend(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct m62332_data *data = iio_priv(indio_dev);

	int ret;



	data->save[0] = data->raw[0];

	data->save[1] = data->raw[1];



	ret = m62332_set_value(indio_dev, 0, 0);

	if (ret < 0)

		return ret;



	return m62332_set_value(indio_dev, 0, 1);

}



static int m62332_resume(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct m62332_data *data = iio_priv(indio_dev);

	int ret;



	ret = m62332_set_value(indio_dev, data->save[0], 0);

	if (ret < 0)

		return ret;



	return m62332_set_value(indio_dev, data->save[1], 1);

}



static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);

#define M62332_PM_OPS (&m62332_pm_ops)

#else

#define M62332_PM_OPS NULL

#endif



static const struct iio_info m62332_info = {

	.read_raw = m62332_read_raw,

	.write_raw = m62332_write_raw,

	.driver_module = THIS_MODULE,

};



#define M62332_CHANNEL(chan) {				\

	.type = IIO_VOLTAGE,				\

	.indexed = 1,					\

	.output = 1,					\

	.channel = (chan),				\

	.datasheet_name = "CH" #chan,			\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\

		BIT(IIO_CHAN_INFO_SCALE) |		\

		BIT(IIO_CHAN_INFO_OFFSET),		\

}



static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = {

	M62332_CHANNEL(0),

	M62332_CHANNEL(1)

};



static int m62332_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct m62332_data *data;

	struct iio_dev *indio_dev;

	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->mutex);



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

	if (IS_ERR(data->vcc))

		return PTR_ERR(data->vcc);



	/* establish that the iio_dev is a child of the i2c device */

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



	indio_dev->num_channels = M62332_CHANNELS;

	indio_dev->channels = m62332_channels;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = &m62332_info;



	ret = regulator_get_voltage(data->vcc);

	if (ret < 0)

		return ret;

	data->vref_mv = ret / 1000; /* mV */



	ret = iio_map_array_register(indio_dev, client->dev.platform_data);

	if (ret < 0)

		return ret;



	ret = iio_device_register(indio_dev);

	if (ret < 0)

		goto err;



	return 0;



err:

	iio_map_array_unregister(indio_dev);

	return ret;

}



static int m62332_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	iio_device_unregister(indio_dev);

	iio_map_array_unregister(indio_dev);



	return 0;

}



static const struct i2c_device_id m62332_id[] = {

	{ "m62332", },

	{ }

};

MODULE_DEVICE_TABLE(i2c, m62332_id);



static struct i2c_driver m62332_driver = {

	.driver = {

		.name	= "m62332",

		.pm	= M62332_PM_OPS,

	},

	.probe		= m62332_probe,

	.remove		= m62332_remove,

	.id_table	= m62332_id,

};

module_i2c_driver(m62332_driver);



MODULE_AUTHOR("Dmitry Eremin-Solenikov");

MODULE_DESCRIPTION("M62332 8-bit DAC");

MODULE_LICENSE("GPL v2");

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