[deliverable/linux.git] / drivers / staging / iio / dac / max517.c

/*
 *  max517.c - Support for Maxim MAX517, MAX518 and MAX519
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

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

#include "max517.h"

#define MAX517_DRV_NAME	"max517"

/* Commands */
#define COMMAND_CHANNEL0	0x00
#define COMMAND_CHANNEL1	0x01 /* for MAX518 and MAX519 */
#define COMMAND_PD		0x08 /* Power Down */

enum max517_device_ids {
	ID_MAX517,
	ID_MAX518,
	ID_MAX519,
};

struct max517_data {
	struct iio_dev		*indio_dev;
	struct i2c_client	*client;
	unsigned short		vref_mv[2];
};

/*
 * channel: bit 0: channel 1
 *          bit 1: channel 2
 * (this way, it's possible to set both channels at once)
 */
static ssize_t max517_set_value(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count, int channel)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct max517_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;
	u8 outbuf[4]; /* 1x or 2x command + value */
	int outbuf_size = 0;
	int res;
	long val;

	res = strict_strtol(buf, 10, &val);

	if (res)
		return res;

	if (val < 0 || val > 255)
		return -EINVAL;

	if (channel & 1) {
		outbuf[outbuf_size++] = COMMAND_CHANNEL0;
		outbuf[outbuf_size++] = val;
	}
	if (channel & 2) {
		outbuf[outbuf_size++] = COMMAND_CHANNEL1;
		outbuf[outbuf_size++] = val;
	}

	/*
	 * At this point, there are always 1 or 2 two-byte commands in
	 * outbuf. With 2 commands, the device can set two outputs
	 * simultaneously, latching the values upon the end of the I2C
	 * transfer.
	 */

	res = i2c_master_send(client, outbuf, outbuf_size);
	if (res < 0)
		return res;

	return count;
}

static ssize_t max517_set_value_1(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	return max517_set_value(dev, attr, buf, count, 1);
}
static IIO_DEV_ATTR_OUT_RAW(1, max517_set_value_1, 0);

static ssize_t max517_set_value_2(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	return max517_set_value(dev, attr, buf, count, 2);
}
static IIO_DEV_ATTR_OUT_RAW(2, max517_set_value_2, 1);

static ssize_t max517_set_value_both(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	return max517_set_value(dev, attr, buf, count, 3);
}
static IIO_DEVICE_ATTR_NAMED(out_voltage1and2_raw,
			     out_voltage1&2_raw, S_IWUSR, NULL,
			     max517_set_value_both, -1);

static ssize_t max517_show_scale(struct device *dev,
				struct device_attribute *attr,
				char *buf, int channel)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct max517_data *data = iio_priv(indio_dev);
	/* Corresponds to Vref / 2^(bits) */
	unsigned int scale_uv = (data->vref_mv[channel - 1] * 1000) >> 8;

	return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
}

static ssize_t max517_show_scale1(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	return max517_show_scale(dev, attr, buf, 1);
}
static IIO_DEVICE_ATTR(out_voltage1_scale, S_IRUGO,
		       max517_show_scale1, NULL, 0);

static ssize_t max517_show_scale2(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	return max517_show_scale(dev, attr, buf, 2);
}
static IIO_DEVICE_ATTR(out_voltage2_scale, S_IRUGO,
		       max517_show_scale2, NULL, 0);

/* On MAX517 variant, we have one output */
static struct attribute *max517_attributes[] = {
	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
	NULL
};

static struct attribute_group max517_attribute_group = {
	.attrs = max517_attributes,
};

/* On MAX518 and MAX519 variant, we have two outputs */
static struct attribute *max518_attributes[] = {
	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
	&iio_dev_attr_out_voltage2_raw.dev_attr.attr,
	&iio_dev_attr_out_voltage2_scale.dev_attr.attr,
	&iio_dev_attr_out_voltage1and2_raw.dev_attr.attr,
	NULL
};

static struct attribute_group max518_attribute_group = {
	.attrs = max518_attributes,
};

#ifdef CONFIG_PM_SLEEP
static int max517_suspend(struct device *dev)
{
	u8 outbuf = COMMAND_PD;

	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
}

static int max517_resume(struct device *dev)
{
	u8 outbuf = 0;

	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
}

static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
#define MAX517_PM_OPS (&max517_pm_ops)
#else
#define MAX517_PM_OPS NULL
#endif

static const struct iio_info max517_info = {
	.attrs = &max517_attribute_group,
	.driver_module = THIS_MODULE,
};

static const struct iio_info max518_info = {
	.attrs = &max518_attribute_group,
	.driver_module = THIS_MODULE,
};

static int max517_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct max517_data *data;
	struct iio_dev *indio_dev;
	struct max517_platform_data *platform_data = client->dev.platform_data;
	int err;

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

	/* establish that the iio_dev is a child of the i2c device */
	indio_dev->dev.parent = &client->dev;

	/* reduced attribute set for MAX517 */
	if (id->driver_data == ID_MAX517)
		indio_dev->info = &max517_info;
	else
		indio_dev->info = &max518_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	/*
	 * Reference voltage on MAX518 and default is 5V, else take vref_mv
	 * from platform_data
	 */
	if (id->driver_data == ID_MAX518 || !platform_data) {
		data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
	} else {
		data->vref_mv[0] = platform_data->vref_mv[0];
		data->vref_mv[1] = platform_data->vref_mv[1];
	}

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

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

	return 0;

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

static int max517_remove(struct i2c_client *client)
{
	iio_free_device(i2c_get_clientdata(client));

	return 0;
}

static const struct i2c_device_id max517_id[] = {
	{ "max517", ID_MAX517 },
	{ "max518", ID_MAX518 },
	{ "max519", ID_MAX519 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max517_id);

static struct i2c_driver max517_driver = {
	.driver = {
		.name	= MAX517_DRV_NAME,
		.pm		= MAX517_PM_OPS,
	},
	.probe		= max517_probe,
	.remove		= max517_remove,
	.id_table	= max517_id,
};
module_i2c_driver(max517_driver);

MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
MODULE_LICENSE("GPL");
Commit	Line	Data
6ddc5fb4 RS	1	/*
	2	* max517.c - Support for Maxim MAX517, MAX518 and MAX519
	3	*
	4	* Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/init.h>
	23	#include <linux/slab.h>
	24	#include <linux/jiffies.h>
	25	#include <linux/i2c.h>
	26	#include <linux/err.h>
	27
06458e27 JC	28	#include <linux/iio/iio.h>
06458e27 JC	29	#include <linux/iio/sysfs.h>
6ddc5fb4 RS	30	#include "dac.h"
	31
	32	#include "max517.h"
	33
	34	#define MAX517_DRV_NAME "max517"
	35
	36	/* Commands */
	37	#define COMMAND_CHANNEL0 0x00
	38	#define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */
	39	#define COMMAND_PD 0x08 /* Power Down */
	40
	41	enum max517_device_ids {
	42	ID_MAX517,
	43	ID_MAX518,
	44	ID_MAX519,
	45	};
	46
	47	struct max517_data {
	48	struct iio_dev *indio_dev;
826514b4	49	struct i2c_client *client;
6ddc5fb4 RS	50	unsigned short vref_mv[2];
	51	};
	52
	53	/*
	54	* channel: bit 0: channel 1
	55	* bit 1: channel 2
	56	* (this way, it's possible to set both channels at once)
	57	*/
	58	static ssize_t max517_set_value(struct device *dev,
	59	struct device_attribute *attr,
	60	const char *buf, size_t count, int channel)
	61	{
638e59fc JC	62	struct iio_dev *indio_dev = dev_get_drvdata(dev);
638e59fc JC	63	struct max517_data *data = iio_priv(indio_dev);
826514b4	64	struct i2c_client *client = data->client;
6ddc5fb4 RS	65	u8 outbuf[4]; /* 1x or 2x command + value */
	66	int outbuf_size = 0;
	67	int res;
	68	long val;
	69
	70	res = strict_strtol(buf, 10, &val);
	71
	72	if (res)
	73	return res;
	74
	75	if (val < 0 \|\| val > 255)
	76	return -EINVAL;
	77
	78	if (channel & 1) {
	79	outbuf[outbuf_size++] = COMMAND_CHANNEL0;
	80	outbuf[outbuf_size++] = val;
	81	}
	82	if (channel & 2) {
	83	outbuf[outbuf_size++] = COMMAND_CHANNEL1;
	84	outbuf[outbuf_size++] = val;
	85	}
	86
	87	/*
	88	* At this point, there are always 1 or 2 two-byte commands in
	89	* outbuf. With 2 commands, the device can set two outputs
	90	* simultaneously, latching the values upon the end of the I2C
	91	* transfer.
	92	*/
	93
	94	res = i2c_master_send(client, outbuf, outbuf_size);
	95	if (res < 0)
	96	return res;
	97
	98	return count;
	99	}
	100
	101	static ssize_t max517_set_value_1(struct device *dev,
	102	struct device_attribute *attr,
	103	const char *buf, size_t count)
	104	{
	105	return max517_set_value(dev, attr, buf, count, 1);
	106	}
	107	static IIO_DEV_ATTR_OUT_RAW(1, max517_set_value_1, 0);
	108
	109	static ssize_t max517_set_value_2(struct device *dev,
	110	struct device_attribute *attr,
	111	const char *buf, size_t count)
	112	{
	113	return max517_set_value(dev, attr, buf, count, 2);
	114	}
	115	static IIO_DEV_ATTR_OUT_RAW(2, max517_set_value_2, 1);
	116
	117	static ssize_t max517_set_value_both(struct device *dev,
	118	struct device_attribute *attr,
	119	const char *buf, size_t count)
	120	{
	121	return max517_set_value(dev, attr, buf, count, 3);
	122	}
322c9563 JC	123	static IIO_DEVICE_ATTR_NAMED(out_voltage1and2_raw,
	124	out_voltage1&2_raw, S_IWUSR, NULL,
	125	max517_set_value_both, -1);
6ddc5fb4 RS	126
	127	static ssize_t max517_show_scale(struct device *dev,
	128	struct device_attribute *attr,
	129	char *buf, int channel)
	130	{
638e59fc JC	131	struct iio_dev *indio_dev = dev_get_drvdata(dev);
638e59fc JC	132	struct max517_data *data = iio_priv(indio_dev);
6ddc5fb4 RS	133	/* Corresponds to Vref / 2^(bits) */
	134	unsigned int scale_uv = (data->vref_mv[channel - 1] * 1000) >> 8;
	135
	136	return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
	137	}
	138
	139	static ssize_t max517_show_scale1(struct device *dev,
	140	struct device_attribute *attr,
	141	char *buf)
	142	{
	143	return max517_show_scale(dev, attr, buf, 1);
	144	}
322c9563 JC	145	static IIO_DEVICE_ATTR(out_voltage1_scale, S_IRUGO,
322c9563 JC	146	max517_show_scale1, NULL, 0);
6ddc5fb4 RS	147
	148	static ssize_t max517_show_scale2(struct device *dev,
	149	struct device_attribute *attr,
	150	char *buf)
	151	{
	152	return max517_show_scale(dev, attr, buf, 2);
	153	}
322c9563 JC	154	static IIO_DEVICE_ATTR(out_voltage2_scale, S_IRUGO,
322c9563 JC	155	max517_show_scale2, NULL, 0);
6ddc5fb4	156
826514b4	157	/* On MAX517 variant, we have one output */
6ddc5fb4	158	static struct attribute *max517_attributes[] = {
322c9563 JC	159	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
322c9563 JC	160	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
6ddc5fb4 RS	161	NULL
	162	};
	163
	164	static struct attribute_group max517_attribute_group = {
	165	.attrs = max517_attributes,
	166	};
	167
826514b4	168	/* On MAX518 and MAX519 variant, we have two outputs */
6ddc5fb4	169	static struct attribute *max518_attributes[] = {
322c9563 JC	170	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
	171	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
	172	&iio_dev_attr_out_voltage2_raw.dev_attr.attr,
	173	&iio_dev_attr_out_voltage2_scale.dev_attr.attr,
	174	&iio_dev_attr_out_voltage1and2_raw.dev_attr.attr,
6ddc5fb4 RS	175	NULL
	176	};
	177
	178	static struct attribute_group max518_attribute_group = {
	179	.attrs = max518_attributes,
	180	};
	181
01788c53 LPC	182	#ifdef CONFIG_PM_SLEEP
01788c53 LPC	183	static int max517_suspend(struct device *dev)
6ddc5fb4 RS	184	{
	185	u8 outbuf = COMMAND_PD;
	186
01788c53	187	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
6ddc5fb4 RS	188	}
6ddc5fb4 RS	189
01788c53	190	static int max517_resume(struct device *dev)
6ddc5fb4 RS	191	{
	192	u8 outbuf = 0;
	193
01788c53	194	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
6ddc5fb4 RS	195	}
6ddc5fb4 RS	196
01788c53 LPC	197	static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
	198	#define MAX517_PM_OPS (&max517_pm_ops)
	199	#else
	200	#define MAX517_PM_OPS NULL
	201	#endif
	202
6fe8135f JC	203	static const struct iio_info max517_info = {
	204	.attrs = &max517_attribute_group,
	205	.driver_module = THIS_MODULE,
	206	};
	207
	208	static const struct iio_info max518_info = {
8aa460e9	209	.attrs = &max518_attribute_group,
6fe8135f JC	210	.driver_module = THIS_MODULE,
	211	};
	212
6ddc5fb4 RS	213	static int max517_probe(struct i2c_client *client,
	214	const struct i2c_device_id *id)
	215	{
	216	struct max517_data *data;
cada11fa	217	struct iio_dev *indio_dev;
6ddc5fb4 RS	218	struct max517_platform_data *platform_data = client->dev.platform_data;
	219	int err;
	220
cada11fa JC	221	indio_dev = iio_allocate_device(sizeof(*data));
cada11fa JC	222	if (indio_dev == NULL) {
6ddc5fb4 RS	223	err = -ENOMEM;
	224	goto exit;
	225	}
cada11fa JC	226	data = iio_priv(indio_dev);
cada11fa JC	227	i2c_set_clientdata(client, indio_dev);
826514b4 RS	228	data->client = client;
826514b4 RS	229
6ddc5fb4	230	/* establish that the iio_dev is a child of the i2c device */
cada11fa	231	indio_dev->dev.parent = &client->dev;
6ddc5fb4 RS	232
	233	/* reduced attribute set for MAX517 */
	234	if (id->driver_data == ID_MAX517)
cada11fa	235	indio_dev->info = &max517_info;
6ddc5fb4	236	else
cada11fa JC	237	indio_dev->info = &max518_info;
cada11fa JC	238	indio_dev->modes = INDIO_DIRECT_MODE;
6ddc5fb4 RS	239
	240	/*
	241	* Reference voltage on MAX518 and default is 5V, else take vref_mv
	242	* from platform_data
	243	*/
	244	if (id->driver_data == ID_MAX518 \|\| !platform_data) {
	245	data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
	246	} else {
	247	data->vref_mv[0] = platform_data->vref_mv[0];
	248	data->vref_mv[1] = platform_data->vref_mv[1];
	249	}
	250
cada11fa	251	err = iio_device_register(indio_dev);
6ddc5fb4 RS	252	if (err)
	253	goto exit_free_device;
	254
	255	dev_info(&client->dev, "DAC registered\n");
	256
	257	return 0;
	258
	259	exit_free_device:
cada11fa	260	iio_free_device(indio_dev);
6ddc5fb4 RS	261	exit:
	262	return err;
	263	}
	264
	265	static int max517_remove(struct i2c_client *client)
	266	{
cada11fa	267	iio_free_device(i2c_get_clientdata(client));
6ddc5fb4 RS	268
	269	return 0;
	270	}
	271
	272	static const struct i2c_device_id max517_id[] = {
	273	{ "max517", ID_MAX517 },
	274	{ "max518", ID_MAX518 },
	275	{ "max519", ID_MAX519 },
	276	{ }
	277	};
	278	MODULE_DEVICE_TABLE(i2c, max517_id);
	279
	280	static struct i2c_driver max517_driver = {
	281	.driver = {
	282	.name = MAX517_DRV_NAME,
01788c53	283	.pm = MAX517_PM_OPS,
6ddc5fb4 RS	284	},
	285	.probe = max517_probe,
	286	.remove = max517_remove,
6ddc5fb4 RS	287	.id_table = max517_id,
6ddc5fb4 RS	288	};
6e5af184	289	module_i2c_driver(max517_driver);
6ddc5fb4 RS	290
	291	MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
	292	MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
	293	MODULE_LICENSE("GPL");