drivers/misc/ds1682.c - arm/linux - Git at Google

 /*
  * 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");
	/*
	* 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");