[net-next-2.6.git] / drivers / misc / ds1682.c

/*
 * Dallas Semiconductor DS1682 Elapsed Time Recorder device driver
 *
 * Written by: Grant Likely <grant.likely@secretlab.ca>
 *
 * Copyright (C) 2007 Secret Lab Technologies Ltd.
 *
 * 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.
 */

/*
 * The DS1682 elapsed timer recorder is a simple device that implements
 * one elapsed time counter, one event counter, an alarm signal and 10
 * bytes of general purpose EEPROM.
 *
 * This driver provides access to the DS1682 counters and user data via
 * the sysfs.  The following attributes are added to the device node:
 *     elapsed_time (u32): Total elapsed event time in ms resolution
 *     alarm_time (u32): When elapsed time exceeds the value in alarm_time,
 *                       then the alarm pin is asserted.
 *     event_count (u16): number of times the event pin has gone low.
 *     eeprom (u8[10]): general purpose EEPROM
 *
 * Counter registers and user data are both read/write unless the device
 * has been write protected.  This driver does not support turning off write
 * protection.  Once write protection is turned on, it is impossible to
 * turn it off again, so I have left the feature out of this driver to avoid
 * accidental enabling, but it is trivial to add write protect support.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/sysfs.h>
#include <linux/ctype.h>
#include <linux/hwmon-sysfs.h>

/* Device registers */
#define DS1682_REG_CONFIG		0x00
#define DS1682_REG_ALARM		0x01
#define DS1682_REG_ELAPSED		0x05
#define DS1682_REG_EVT_CNTR		0x09
#define DS1682_REG_EEPROM		0x0b
#define DS1682_REG_RESET		0x1d
#define DS1682_REG_WRITE_DISABLE	0x1e
#define DS1682_REG_WRITE_MEM_DISABLE	0x1f

#define DS1682_EEPROM_SIZE		10

/*
 * Generic counter attributes
 */
static ssize_t ds1682_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	struct i2c_client *client = to_i2c_client(dev);
	__le32 val = 0;
	int rc;

	dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);

	/* Read the register */
	rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
					   (u8 *) & val);
	if (rc < 0)
		return -EIO;

	/* Special case: the 32 bit regs are time values with 1/4s
	 * resolution, scale them up to milliseconds */
	if (sattr->nr == 4)
		return sprintf(buf, "%llu\n",
			((unsigned long long)le32_to_cpu(val)) * 250);

	/* Format the output string and return # of bytes */
	return sprintf(buf, "%li\n", (long)le32_to_cpu(val));
}

static ssize_t ds1682_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	struct i2c_client *client = to_i2c_client(dev);
	char *endp;
	u64 val;
	__le32 val_le;
	int rc;

	dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name);

	/* Decode input */
	val = simple_strtoull(buf, &endp, 0);
	if (buf == endp) {
		dev_dbg(dev, "input string not a number\n");
		return -EINVAL;
	}

	/* Special case: the 32 bit regs are time values with 1/4s
	 * resolution, scale input down to quarter-seconds */
	if (sattr->nr == 4)
		do_div(val, 250);

	/* write out the value */
	val_le = cpu_to_le32(val);
	rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr,
					    (u8 *) & val_le);
	if (rc < 0) {
		dev_err(dev, "register write failed; reg=0x%x, size=%i\n",
			sattr->index, sattr->nr);
		return -EIO;
	}

	return count;
}

/*
 * Simple register attributes
 */
static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO | S_IWUSR, ds1682_show,
			    ds1682_store, 4, DS1682_REG_ELAPSED);
static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO | S_IWUSR, ds1682_show,
			    ds1682_store, 4, DS1682_REG_ALARM);
static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO | S_IWUSR, ds1682_show,
			    ds1682_store, 2, DS1682_REG_EVT_CNTR);

static const struct attribute_group ds1682_group = {
	.attrs = (struct attribute *[]) {
		&sensor_dev_attr_elapsed_time.dev_attr.attr,
		&sensor_dev_attr_alarm_time.dev_attr.attr,
		&sensor_dev_attr_event_count.dev_attr.attr,
		NULL,
	},
};

/*
 * User data attribute
 */
static ssize_t ds1682_eeprom_read(struct kobject *kobj, struct bin_attribute *attr,
				  char *buf, loff_t off, size_t count)
{
	struct i2c_client *client = kobj_to_i2c_client(kobj);
	int rc;

	dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n",
		buf, off, count);

	if (off >= DS1682_EEPROM_SIZE)
		return 0;

	if (off + count > DS1682_EEPROM_SIZE)
		count = DS1682_EEPROM_SIZE - off;

	rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off,
					   count, buf);
	if (rc < 0)
		return -EIO;

	return count;
}

static ssize_t ds1682_eeprom_write(struct kobject *kobj, struct bin_attribute *attr,
				   char *buf, loff_t off, size_t count)
{
	struct i2c_client *client = kobj_to_i2c_client(kobj);

	dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n",
		buf, off, count);

	if (off >= DS1682_EEPROM_SIZE)
		return -ENOSPC;

	if (off + count > DS1682_EEPROM_SIZE)
		count = DS1682_EEPROM_SIZE - off;

	/* Write out to the device */
	if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off,
					   count, buf) < 0)
		return -EIO;

	return count;
}

static struct bin_attribute ds1682_eeprom_attr = {
	.attr = {
		.name = "eeprom",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = DS1682_EEPROM_SIZE,
	.read = ds1682_eeprom_read,
	.write = ds1682_eeprom_write,
};

/*
 * Called when a ds1682 device is matched with this driver
 */
static int ds1682_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	int rc;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_I2C_BLOCK)) {
		dev_err(&client->dev, "i2c bus does not support the ds1682\n");
		rc = -ENODEV;
		goto exit;
	}

	rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
	if (rc)
		goto exit;

	rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	if (rc)
		goto exit_bin_attr;

	return 0;

 exit_bin_attr:
	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
 exit:
	return rc;
}

static int ds1682_remove(struct i2c_client *client)
{
	sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
	return 0;
}

static const struct i2c_device_id ds1682_id[] = {
	{ "ds1682", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ds1682_id);

static struct i2c_driver ds1682_driver = {
	.driver = {
		.name = "ds1682",
	},
	.probe = ds1682_probe,
	.remove = ds1682_remove,
	.id_table = ds1682_id,
};

static int __init ds1682_init(void)
{
	return i2c_add_driver(&ds1682_driver);
}

static void __exit ds1682_exit(void)
{
	i2c_del_driver(&ds1682_driver);
}

MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
MODULE_LICENSE("GPL");

module_init(ds1682_init);
module_exit(ds1682_exit);
Commit	Line	Data
5162b75b GL	1	/*
	2	* Dallas Semiconductor DS1682 Elapsed Time Recorder device driver
	3	*
	4	* Written by: Grant Likely <grant.likely@secretlab.ca>
	5	*
	6	* Copyright (C) 2007 Secret Lab Technologies Ltd.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	/*
	14	* The DS1682 elapsed timer recorder is a simple device that implements
	15	* one elapsed time counter, one event counter, an alarm signal and 10
	16	* bytes of general purpose EEPROM.
	17	*
	18	* This driver provides access to the DS1682 counters and user data via
	19	* the sysfs. The following attributes are added to the device node:
	20	* elapsed_time (u32): Total elapsed event time in ms resolution
	21	* alarm_time (u32): When elapsed time exceeds the value in alarm_time,
	22	* then the alarm pin is asserted.
	23	* event_count (u16): number of times the event pin has gone low.
	24	* eeprom (u8[10]): general purpose EEPROM
	25	*
	26	* Counter registers and user data are both read/write unless the device
	27	* has been write protected. This driver does not support turning off write
	28	* protection. Once write protection is turned on, it is impossible to
	29	* turn it off again, so I have left the feature out of this driver to avoid
	30	* accidental enabling, but it is trivial to add write protect support.
	31	*
	32	*/
	33
	34	#include <linux/module.h>
	35	#include <linux/init.h>
	36	#include <linux/slab.h>
	37	#include <linux/i2c.h>
	38	#include <linux/string.h>
	39	#include <linux/list.h>
	40	#include <linux/sysfs.h>
	41	#include <linux/ctype.h>
	42	#include <linux/hwmon-sysfs.h>
	43
	44	/* Device registers */
	45	#define DS1682_REG_CONFIG 0x00
	46	#define DS1682_REG_ALARM 0x01
	47	#define DS1682_REG_ELAPSED 0x05
	48	#define DS1682_REG_EVT_CNTR 0x09
	49	#define DS1682_REG_EEPROM 0x0b
	50	#define DS1682_REG_RESET 0x1d
	51	#define DS1682_REG_WRITE_DISABLE 0x1e
	52	#define DS1682_REG_WRITE_MEM_DISABLE 0x1f
	53
	54	#define DS1682_EEPROM_SIZE 10
	55
	56	/*
	57	* Generic counter attributes
	58	*/
	59	static ssize_t ds1682_show(struct device dev, struct device_attribute attr,
	60	char *buf)
	61	{
	62	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	63	struct i2c_client *client = to_i2c_client(dev);
	64	__le32 val = 0;
65	int rc;
66
67	dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);
68
69	/* Read the register */
70	rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
71	(u8 *) & val);
72	if (rc < 0)
73	return -EIO;
74
75	/* Special case: the 32 bit regs are time values with 1/4s
76	* resolution, scale them up to milliseconds */
77	if (sattr->nr == 4)
f52e0ef4 AM	78	return sprintf(buf, "%llu\n",
f52e0ef4 AM	79	((unsigned long long)le32_to_cpu(val)) * 250);
5162b75b GL	80
	81	/* Format the output string and return # of bytes */
	82	return sprintf(buf, "%li\n", (long)le32_to_cpu(val));
	83	}
	84
	85	static ssize_t ds1682_store(struct device dev, struct device_attribute attr,
	86	const char *buf, size_t count)
	87	{
	88	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	89	struct i2c_client *client = to_i2c_client(dev);
	90	char *endp;
	91	u64 val;
	92	__le32 val_le;
	93	int rc;
	94
	95	dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name);
	96
	97	/* Decode input */
	98	val = simple_strtoull(buf, &endp, 0);
	99	if (buf == endp) {
	100	dev_dbg(dev, "input string not a number\n");
	101	return -EINVAL;
	102	}
	103
	104	/* Special case: the 32 bit regs are time values with 1/4s
	105	* resolution, scale input down to quarter-seconds */
	106	if (sattr->nr == 4)
	107	do_div(val, 250);
	108
	109	/* write out the value */
	110	val_le = cpu_to_le32(val);
	111	rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr,
	112	(u8 *) & val_le);
	113	if (rc < 0) {
	114	dev_err(dev, "register write failed; reg=0x%x, size=%i\n",
	115	sattr->index, sattr->nr);
	116	return -EIO;
	117	}
	118
	119	return count;
	120	}
	121
	122	/*
	123	* Simple register attributes
	124	*/
	125	static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO \| S_IWUSR, ds1682_show,
	126	ds1682_store, 4, DS1682_REG_ELAPSED);
	127	static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO \| S_IWUSR, ds1682_show,
	128	ds1682_store, 4, DS1682_REG_ALARM);
	129	static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO \| S_IWUSR, ds1682_show,
	130	ds1682_store, 2, DS1682_REG_EVT_CNTR);
	131
	132	static const struct attribute_group ds1682_group = {
	133	.attrs = (struct attribute *[]) {
	134	&sensor_dev_attr_elapsed_time.dev_attr.attr,
	135	&sensor_dev_attr_alarm_time.dev_attr.attr,
	136	&sensor_dev_attr_event_count.dev_attr.attr,
	137	NULL,
	138	},
	139	};
	140
	141	/*
	142	* User data attribute
	143	*/
05bd711e AV	144	static ssize_t ds1682_eeprom_read(struct kobject kobj, struct bin_attribute attr,
05bd711e AV	145	char *buf, loff_t off, size_t count)
5162b75b GL	146	{
	147	struct i2c_client *client = kobj_to_i2c_client(kobj);
	148	int rc;
	149
	150	dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n",
	151	buf, off, count);
	152
	153	if (off >= DS1682_EEPROM_SIZE)
	154	return 0;
	155
	156	if (off + count > DS1682_EEPROM_SIZE)
	157	count = DS1682_EEPROM_SIZE - off;
	158
	159	rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off,
	160	count, buf);
	161	if (rc < 0)
	162	return -EIO;
	163
	164	return count;
	165	}
	166
05bd711e AV	167	static ssize_t ds1682_eeprom_write(struct kobject kobj, struct bin_attribute attr,
05bd711e AV	168	char *buf, loff_t off, size_t count)
5162b75b GL	169	{
	170	struct i2c_client *client = kobj_to_i2c_client(kobj);
	171
	172	dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n",
	173	buf, off, count);
	174
	175	if (off >= DS1682_EEPROM_SIZE)
	176	return -ENOSPC;
	177
	178	if (off + count > DS1682_EEPROM_SIZE)
	179	count = DS1682_EEPROM_SIZE - off;
	180
	181	/* Write out to the device */
	182	if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off,
	183	count, buf) < 0)
	184	return -EIO;
	185
	186	return count;
	187	}
	188
	189	static struct bin_attribute ds1682_eeprom_attr = {
	190	.attr = {
	191	.name = "eeprom",
	192	.mode = S_IRUGO \| S_IWUSR,
5162b75b GL	193	},
	194	.size = DS1682_EEPROM_SIZE,
	195	.read = ds1682_eeprom_read,
	196	.write = ds1682_eeprom_write,
	197	};
	198
	199	/*
	200	* Called when a ds1682 device is matched with this driver
	201	*/
d2653e92 JD	202	static int ds1682_probe(struct i2c_client *client,
d2653e92 JD	203	const struct i2c_device_id *id)
5162b75b GL	204	{
	205	int rc;
	206
	207	if (!i2c_check_functionality(client->adapter,
	208	I2C_FUNC_SMBUS_I2C_BLOCK)) {
	209	dev_err(&client->dev, "i2c bus does not support the ds1682\n");
	210	rc = -ENODEV;
	211	goto exit;
	212	}
	213
	214	rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
	215	if (rc)
	216	goto exit;
	217
	218	rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	219	if (rc)
	220	goto exit_bin_attr;
	221
	222	return 0;
	223
	224	exit_bin_attr:
	225	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
	226	exit:
	227	return rc;
	228	}
	229
	230	static int ds1682_remove(struct i2c_client *client)
	231	{
	232	sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	233	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
	234	return 0;
	235	}
	236
3760f736 JD	237	static const struct i2c_device_id ds1682_id[] = {
	238	{ "ds1682", 0 },
	239	{ }
	240	};
	241	MODULE_DEVICE_TABLE(i2c, ds1682_id);
	242
5162b75b GL	243	static struct i2c_driver ds1682_driver = {
	244	.driver = {
	245	.name = "ds1682",
	246	},
	247	.probe = ds1682_probe,
	248	.remove = ds1682_remove,
3760f736	249	.id_table = ds1682_id,
5162b75b GL	250	};
	251
	252	static int __init ds1682_init(void)
	253	{
	254	return i2c_add_driver(&ds1682_driver);
	255	}
	256
	257	static void __exit ds1682_exit(void)
	258	{
	259	i2c_del_driver(&ds1682_driver);
	260	}
	261
	262	MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
	263	MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
	264	MODULE_LICENSE("GPL");
	265
	266	module_init(ds1682_init);
	267	module_exit(ds1682_exit);