[mirror_ubuntu-bionic-kernel.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/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);
	u64 val;
	__le32 val_le;
	int rc;

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

	/* Decode input */
	rc = kstrtoull(buf, 0, &val);
	if (rc < 0) {
		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 file *filp, 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);

	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 file *filp, 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);

	/* 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 const 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 const struct of_device_id ds1682_of_match[] = {
	{ .compatible = "dallas,ds1682", },
	{}
};
MODULE_DEVICE_TABLE(of, ds1682_of_match);

static struct i2c_driver ds1682_driver = {
	.driver = {
		.name = "ds1682",
		.of_match_table = ds1682_of_match,
	},
	.probe = ds1682_probe,
	.remove = ds1682_remove,
	.id_table = ds1682_id,
};

module_i2c_driver(ds1682_driver);

MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
MODULE_LICENSE("GPL");
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>
5162b75b GL	35	#include <linux/i2c.h>
	36	#include <linux/string.h>
	37	#include <linux/list.h>
	38	#include <linux/sysfs.h>
	39	#include <linux/ctype.h>
	40	#include <linux/hwmon-sysfs.h>
	41
	42	/* Device registers */
	43	#define DS1682_REG_CONFIG 0x00
	44	#define DS1682_REG_ALARM 0x01
	45	#define DS1682_REG_ELAPSED 0x05
	46	#define DS1682_REG_EVT_CNTR 0x09
	47	#define DS1682_REG_EEPROM 0x0b
	48	#define DS1682_REG_RESET 0x1d
	49	#define DS1682_REG_WRITE_DISABLE 0x1e
	50	#define DS1682_REG_WRITE_MEM_DISABLE 0x1f
	51
	52	#define DS1682_EEPROM_SIZE 10
	53
	54	/*
	55	* Generic counter attributes
	56	*/
	57	static ssize_t ds1682_show(struct device dev, struct device_attribute attr,
	58	char *buf)
	59	{
	60	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	61	struct i2c_client *client = to_i2c_client(dev);
	62	__le32 val = 0;
	63	int rc;
	64
	65	dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);
	66
	67	/* Read the register */
	68	rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
	69	(u8 *) & val);
	70	if (rc < 0)
	71	return -EIO;
	72
	73	/* Special case: the 32 bit regs are time values with 1/4s
	74	* resolution, scale them up to milliseconds */
	75	if (sattr->nr == 4)
f52e0ef4 AM	76	return sprintf(buf, "%llu\n",
f52e0ef4 AM	77	((unsigned long long)le32_to_cpu(val)) * 250);
5162b75b GL	78
	79	/* Format the output string and return # of bytes */
	80	return sprintf(buf, "%li\n", (long)le32_to_cpu(val));
	81	}
	82
	83	static ssize_t ds1682_store(struct device dev, struct device_attribute attr,
	84	const char *buf, size_t count)
	85	{
	86	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
	87	struct i2c_client *client = to_i2c_client(dev);
5162b75b GL	88	u64 val;
	89	__le32 val_le;
	90	int rc;
	91
	92	dev_dbg(dev, "ds1682_store() called on %s\n", attr->attr.name);
	93
	94	/* Decode input */
40300745 SB	95	rc = kstrtoull(buf, 0, &val);
40300745 SB	96	if (rc < 0) {
5162b75b GL	97	dev_dbg(dev, "input string not a number\n");
	98	return -EINVAL;
	99	}
	100
	101	/* Special case: the 32 bit regs are time values with 1/4s
	102	* resolution, scale input down to quarter-seconds */
	103	if (sattr->nr == 4)
	104	do_div(val, 250);
	105
	106	/* write out the value */
	107	val_le = cpu_to_le32(val);
	108	rc = i2c_smbus_write_i2c_block_data(client, sattr->index, sattr->nr,
	109	(u8 *) & val_le);
	110	if (rc < 0) {
	111	dev_err(dev, "register write failed; reg=0x%x, size=%i\n",
	112	sattr->index, sattr->nr);
	113	return -EIO;
	114	}
	115
	116	return count;
	117	}
	118
	119	/*
	120	* Simple register attributes
	121	*/
	122	static SENSOR_DEVICE_ATTR_2(elapsed_time, S_IRUGO \| S_IWUSR, ds1682_show,
	123	ds1682_store, 4, DS1682_REG_ELAPSED);
	124	static SENSOR_DEVICE_ATTR_2(alarm_time, S_IRUGO \| S_IWUSR, ds1682_show,
	125	ds1682_store, 4, DS1682_REG_ALARM);
	126	static SENSOR_DEVICE_ATTR_2(event_count, S_IRUGO \| S_IWUSR, ds1682_show,
	127	ds1682_store, 2, DS1682_REG_EVT_CNTR);
	128
	129	static const struct attribute_group ds1682_group = {
	130	.attrs = (struct attribute *[]) {
	131	&sensor_dev_attr_elapsed_time.dev_attr.attr,
	132	&sensor_dev_attr_alarm_time.dev_attr.attr,
	133	&sensor_dev_attr_event_count.dev_attr.attr,
	134	NULL,
	135	},
	136	};
	137
	138	/*
	139	* User data attribute
	140	*/
2c3c8bea CW	141	static ssize_t ds1682_eeprom_read(struct file filp, struct kobject kobj,
2c3c8bea CW	142	struct bin_attribute *attr,
05bd711e	143	char *buf, loff_t off, size_t count)
5162b75b GL	144	{
	145	struct i2c_client *client = kobj_to_i2c_client(kobj);
	146	int rc;
	147
	148	dev_dbg(&client->dev, "ds1682_eeprom_read(p=%p, off=%lli, c=%zi)\n",
	149	buf, off, count);
	150
5162b75b GL	151	rc = i2c_smbus_read_i2c_block_data(client, DS1682_REG_EEPROM + off,
	152	count, buf);
	153	if (rc < 0)
	154	return -EIO;
	155
	156	return count;
	157	}
	158
2c3c8bea CW	159	static ssize_t ds1682_eeprom_write(struct file filp, struct kobject kobj,
2c3c8bea CW	160	struct bin_attribute *attr,
05bd711e	161	char *buf, loff_t off, size_t count)
5162b75b GL	162	{
	163	struct i2c_client *client = kobj_to_i2c_client(kobj);
	164
	165	dev_dbg(&client->dev, "ds1682_eeprom_write(p=%p, off=%lli, c=%zi)\n",
	166	buf, off, count);
	167
5162b75b GL	168	/* Write out to the device */
	169	if (i2c_smbus_write_i2c_block_data(client, DS1682_REG_EEPROM + off,
	170	count, buf) < 0)
	171	return -EIO;
	172
	173	return count;
	174	}
	175
57daedf8	176	static const struct bin_attribute ds1682_eeprom_attr = {
5162b75b GL	177	.attr = {
	178	.name = "eeprom",
	179	.mode = S_IRUGO \| S_IWUSR,
5162b75b GL	180	},
	181	.size = DS1682_EEPROM_SIZE,
	182	.read = ds1682_eeprom_read,
	183	.write = ds1682_eeprom_write,
	184	};
	185
	186	/*
	187	* Called when a ds1682 device is matched with this driver
	188	*/
d2653e92 JD	189	static int ds1682_probe(struct i2c_client *client,
d2653e92 JD	190	const struct i2c_device_id *id)
5162b75b GL	191	{
	192	int rc;
	193
	194	if (!i2c_check_functionality(client->adapter,
	195	I2C_FUNC_SMBUS_I2C_BLOCK)) {
	196	dev_err(&client->dev, "i2c bus does not support the ds1682\n");
	197	rc = -ENODEV;
	198	goto exit;
	199	}
	200
	201	rc = sysfs_create_group(&client->dev.kobj, &ds1682_group);
	202	if (rc)
	203	goto exit;
	204
	205	rc = sysfs_create_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	206	if (rc)
	207	goto exit_bin_attr;
	208
	209	return 0;
	210
	211	exit_bin_attr:
	212	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
	213	exit:
	214	return rc;
	215	}
	216
	217	static int ds1682_remove(struct i2c_client *client)
	218	{
	219	sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
	220	sysfs_remove_group(&client->dev.kobj, &ds1682_group);
	221	return 0;
	222	}
	223
3760f736 JD	224	static const struct i2c_device_id ds1682_id[] = {
	225	{ "ds1682", 0 },
	226	{ }
	227	};
	228	MODULE_DEVICE_TABLE(i2c, ds1682_id);
	229
5ef16854 JMC	230	static const struct of_device_id ds1682_of_match[] = {
	231	{ .compatible = "dallas,ds1682", },
	232	{}
	233	};
	234	MODULE_DEVICE_TABLE(of, ds1682_of_match);
	235
5162b75b GL	236	static struct i2c_driver ds1682_driver = {
	237	.driver = {
	238	.name = "ds1682",
5ef16854	239	.of_match_table = ds1682_of_match,
5162b75b GL	240	},
	241	.probe = ds1682_probe,
	242	.remove = ds1682_remove,
3760f736	243	.id_table = ds1682_id,
5162b75b GL	244	};
5162b75b GL	245
a64fe2ed	246	module_i2c_driver(ds1682_driver);
5162b75b GL	247
	248	MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
	249	MODULE_DESCRIPTION("DS1682 Elapsed Time Indicator driver");
	250	MODULE_LICENSE("GPL");