[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / iio / dac / mcp4725.c

/*
 * mcp4725.c - Support for Microchip MCP4725
 *
 * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * Based on max517 by Roland Stigge <stigge@antcom.de>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
 * (7-bit I2C slave address 0x60, the three LSBs can be configured in
 * hardware)
 *
 * writing the DAC value to EEPROM is not supported
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/err.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#include <linux/iio/dac/mcp4725.h>

#define MCP4725_DRV_NAME "mcp4725"

struct mcp4725_data {
	struct i2c_client *client;
	u16 vref_mv;
	u16 dac_value;
};

#ifdef CONFIG_PM_SLEEP
static int mcp4725_suspend(struct device *dev)
{
	u8 outbuf[2];

	outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
	outbuf[1] = 0;

	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
}

static int mcp4725_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct mcp4725_data *data = iio_priv(indio_dev);
	u8 outbuf[2];

	/* restore previous DAC value */
	outbuf[0] = (data->dac_value >> 8) & 0xf;
	outbuf[1] = data->dac_value & 0xff;

	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
}

static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
#define MCP4725_PM_OPS (&mcp4725_pm_ops)
#else
#define MCP4725_PM_OPS NULL
#endif

static const struct iio_chan_spec mcp4725_channel = {
	.type		= IIO_VOLTAGE,
	.indexed	= 1,
	.output		= 1,
	.channel	= 0,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
	.scan_type	= IIO_ST('u', 12, 16, 0),
};

static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
{
	struct mcp4725_data *data = iio_priv(indio_dev);
	u8 outbuf[2];
	int ret;

	if (val >= (1 << 12) || val < 0)
		return -EINVAL;

	outbuf[0] = (val >> 8) & 0xf;
	outbuf[1] = val & 0xff;

	ret = i2c_master_send(data->client, outbuf, 2);
	if (ret < 0)
		return ret;
	else if (ret != 2)
		return -EIO;
	else
		return 0;
}

static int mcp4725_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val, int *val2, long mask)
{
	struct mcp4725_data *data = iio_priv(indio_dev);
	unsigned long scale_uv;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		*val = data->dac_value;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		scale_uv = (data->vref_mv * 1000) >> 12;
		*val =  scale_uv / 1000000;
		*val2 = scale_uv % 1000000;
		return IIO_VAL_INT_PLUS_MICRO;
	}
	return -EINVAL;
}

static int mcp4725_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan,
			       int val, int val2, long mask)
{
	struct mcp4725_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = mcp4725_set_value(indio_dev, val);
		data->dac_value = val;
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static const struct iio_info mcp4725_info = {
	.read_raw = mcp4725_read_raw,
	.write_raw = mcp4725_write_raw,
	.driver_module = THIS_MODULE,
};

static int mcp4725_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct mcp4725_data *data;
	struct iio_dev *indio_dev;
	struct mcp4725_platform_data *platform_data = client->dev.platform_data;
	u8 inbuf[3];
	int err;

	if (!platform_data || !platform_data->vref_mv) {
		dev_err(&client->dev, "invalid platform data");
		err = -EINVAL;
		goto exit;
	}

	indio_dev = iio_device_alloc(sizeof(*data));
	if (indio_dev == NULL) {
		err = -ENOMEM;
		goto exit;
	}
	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = id->name;
	indio_dev->info = &mcp4725_info;
	indio_dev->channels = &mcp4725_channel;
	indio_dev->num_channels = 1;
	indio_dev->modes = INDIO_DIRECT_MODE;

	data->vref_mv = platform_data->vref_mv;

	/* read current DAC value */
	err = i2c_master_recv(client, inbuf, 3);
	if (err < 0) {
		dev_err(&client->dev, "failed to read DAC value");
		goto exit_free_device;
	}
	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);

	err = iio_device_register(indio_dev);
	if (err)
		goto exit_free_device;

	dev_info(&client->dev, "MCP4725 DAC registered\n");

	return 0;

exit_free_device:
	iio_device_free(indio_dev);
exit:
	return err;
}

static int mcp4725_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);
	iio_device_free(indio_dev);

	return 0;
}

static const struct i2c_device_id mcp4725_id[] = {
	{ "mcp4725", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mcp4725_id);

static struct i2c_driver mcp4725_driver = {
	.driver = {
		.name	= MCP4725_DRV_NAME,
		.pm	= MCP4725_PM_OPS,
	},
	.probe		= mcp4725_probe,
	.remove		= mcp4725_remove,
	.id_table	= mcp4725_id,
};
module_i2c_driver(mcp4725_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("MCP4725 12-bit DAC");
MODULE_LICENSE("GPL");
Commit	Line	Data
cf35ad61 PM	1	/*
	2	* mcp4725.c - Support for Microchip MCP4725
	3	*
	4	* Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
	5	*
	6	* Based on max517 by Roland Stigge <stigge@antcom.de>
	7	*
	8	* This file is subject to the terms and conditions of version 2 of
	9	* the GNU General Public License. See the file COPYING in the main
	10	* directory of this archive for more details.
	11	*
	12	* driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
	13	* (7-bit I2C slave address 0x60, the three LSBs can be configured in
	14	* hardware)
	15	*
	16	* writing the DAC value to EEPROM is not supported
	17	*/
	18
	19	#include <linux/module.h>
	20	#include <linux/init.h>
	21	#include <linux/i2c.h>
	22	#include <linux/err.h>
	23
	24	#include <linux/iio/iio.h>
	25	#include <linux/iio/sysfs.h>
	26
	27	#include <linux/iio/dac/mcp4725.h>
	28
	29	#define MCP4725_DRV_NAME "mcp4725"
	30
	31	struct mcp4725_data {
	32	struct i2c_client *client;
	33	u16 vref_mv;
	34	u16 dac_value;
	35	};
	36
	37	#ifdef CONFIG_PM_SLEEP
	38	static int mcp4725_suspend(struct device *dev)
	39	{
	40	u8 outbuf[2];
	41
	42	outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
	43	outbuf[1] = 0;
	44
	45	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
	46	}
	47
	48	static int mcp4725_resume(struct device *dev)
	49	{
	50	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	51	struct mcp4725_data *data = iio_priv(indio_dev);
	52	u8 outbuf[2];
	53
	54	/* restore previous DAC value */
	55	outbuf[0] = (data->dac_value >> 8) & 0xf;
	56	outbuf[1] = data->dac_value & 0xff;
	57
	58	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
	59	}
	60
	61	static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
	62	#define MCP4725_PM_OPS (&mcp4725_pm_ops)
	63	#else
	64	#define MCP4725_PM_OPS NULL
65	#endif
66
67	static const struct iio_chan_spec mcp4725_channel = {
68	.type = IIO_VOLTAGE,
69	.indexed = 1,
70	.output = 1,
71	.channel = 0,
90b46374 JC	72	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
90b46374 JC	73	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
cf35ad61 PM	74	.scan_type = IIO_ST('u', 12, 16, 0),
	75	};
	76
	77	static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
	78	{
	79	struct mcp4725_data *data = iio_priv(indio_dev);
	80	u8 outbuf[2];
	81	int ret;
	82
	83	if (val >= (1 << 12) \|\| val < 0)
	84	return -EINVAL;
	85
	86	outbuf[0] = (val >> 8) & 0xf;
	87	outbuf[1] = val & 0xff;
	88
	89	ret = i2c_master_send(data->client, outbuf, 2);
	90	if (ret < 0)
	91	return ret;
	92	else if (ret != 2)
	93	return -EIO;
	94	else
	95	return 0;
	96	}
	97
	98	static int mcp4725_read_raw(struct iio_dev *indio_dev,
	99	struct iio_chan_spec const *chan,
	100	int val, int val2, long mask)
	101	{
	102	struct mcp4725_data *data = iio_priv(indio_dev);
	103	unsigned long scale_uv;
	104
	105	switch (mask) {
	106	case IIO_CHAN_INFO_RAW:
	107	*val = data->dac_value;
	108	return IIO_VAL_INT;
	109	case IIO_CHAN_INFO_SCALE:
	110	scale_uv = (data->vref_mv * 1000) >> 12;
	111	*val = scale_uv / 1000000;
	112	*val2 = scale_uv % 1000000;
	113	return IIO_VAL_INT_PLUS_MICRO;
	114	}
	115	return -EINVAL;
	116	}
	117
	118	static int mcp4725_write_raw(struct iio_dev *indio_dev,
	119	struct iio_chan_spec const *chan,
	120	int val, int val2, long mask)
	121	{
	122	struct mcp4725_data *data = iio_priv(indio_dev);
	123	int ret;
	124
	125	switch (mask) {
	126	case IIO_CHAN_INFO_RAW:
	127	ret = mcp4725_set_value(indio_dev, val);
	128	data->dac_value = val;
	129	break;
	130	default:
	131	ret = -EINVAL;
	132	break;
	133	}
	134
	135	return ret;
	136	}
	137
138	static const struct iio_info mcp4725_info = {
139	.read_raw = mcp4725_read_raw,
140	.write_raw = mcp4725_write_raw,
141	.driver_module = THIS_MODULE,
142	};
143
fc52692c GKH	144	static int mcp4725_probe(struct i2c_client *client,
fc52692c GKH	145	const struct i2c_device_id *id)
cf35ad61 PM	146	{
	147	struct mcp4725_data *data;
	148	struct iio_dev *indio_dev;
	149	struct mcp4725_platform_data *platform_data = client->dev.platform_data;
	150	u8 inbuf[3];
	151	int err;
	152
	153	if (!platform_data \|\| !platform_data->vref_mv) {
	154	dev_err(&client->dev, "invalid platform data");
	155	err = -EINVAL;
	156	goto exit;
	157	}
	158
	159	indio_dev = iio_device_alloc(sizeof(*data));
	160	if (indio_dev == NULL) {
	161	err = -ENOMEM;
	162	goto exit;
	163	}
	164	data = iio_priv(indio_dev);
	165	i2c_set_clientdata(client, indio_dev);
	166	data->client = client;
	167
	168	indio_dev->dev.parent = &client->dev;
2388eb1b	169	indio_dev->name = id->name;
cf35ad61 PM	170	indio_dev->info = &mcp4725_info;
	171	indio_dev->channels = &mcp4725_channel;
	172	indio_dev->num_channels = 1;
	173	indio_dev->modes = INDIO_DIRECT_MODE;
	174
	175	data->vref_mv = platform_data->vref_mv;
	176
	177	/* read current DAC value */
	178	err = i2c_master_recv(client, inbuf, 3);
	179	if (err < 0) {
	180	dev_err(&client->dev, "failed to read DAC value");
	181	goto exit_free_device;
	182	}
	183	data->dac_value = (inbuf[1] << 4) \| (inbuf[2] >> 4);
	184
	185	err = iio_device_register(indio_dev);
	186	if (err)
	187	goto exit_free_device;
	188
	189	dev_info(&client->dev, "MCP4725 DAC registered\n");
	190
	191	return 0;
	192
	193	exit_free_device:
	194	iio_device_free(indio_dev);
	195	exit:
	196	return err;
	197	}
	198
fc52692c	199	static int mcp4725_remove(struct i2c_client *client)
cf35ad61 PM	200	{
	201	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	202
	203	iio_device_unregister(indio_dev);
	204	iio_device_free(indio_dev);
	205
	206	return 0;
	207	}
	208
	209	static const struct i2c_device_id mcp4725_id[] = {
	210	{ "mcp4725", 0 },
	211	{ }
	212	};
	213	MODULE_DEVICE_TABLE(i2c, mcp4725_id);
	214
	215	static struct i2c_driver mcp4725_driver = {
	216	.driver = {
	217	.name = MCP4725_DRV_NAME,
	218	.pm = MCP4725_PM_OPS,
	219	},
	220	.probe = mcp4725_probe,
fc52692c	221	.remove = mcp4725_remove,
cf35ad61 PM	222	.id_table = mcp4725_id,
	223	};
	224	module_i2c_driver(mcp4725_driver);
	225
	226	MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
	227	MODULE_DESCRIPTION("MCP4725 12-bit DAC");
	228	MODULE_LICENSE("GPL");