Contributors: 12
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Grant C. Likely |
848 |
83.30% |
1 |
7.14% |
| Thomas VanSelus |
46 |
4.52% |
1 |
7.14% |
| Jean Delvare |
33 |
3.24% |
2 |
14.29% |
| Aaron Sierra |
31 |
3.05% |
1 |
7.14% |
| Javier Martinez Canillas |
26 |
2.55% |
1 |
7.14% |
| Chris Wright |
10 |
0.98% |
1 |
7.14% |
| Al Viro |
10 |
0.98% |
1 |
7.14% |
| Sebastien Bourdelin |
8 |
0.79% |
1 |
7.14% |
| Thomas Gleixner |
2 |
0.20% |
1 |
7.14% |
| Uwe Kleine-König |
2 |
0.20% |
2 |
14.29% |
| Bhumika Goyal |
1 |
0.10% |
1 |
7.14% |
| Axel Lin |
1 |
0.10% |
1 |
7.14% |
| Total |
1018 |
|
14 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Dallas Semiconductor DS1682 Elapsed Time Recorder device driver
*
* Written by: Grant Likely <grant.likely@secretlab.ca>
*
* Copyright (C) 2007 Secret Lab Technologies Ltd.
*/
/*
* 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);
unsigned long long val, check;
__le32 val_le = 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_le);
if (rc < 0)
return -EIO;
val = le32_to_cpu(val_le);
if (sattr->index == DS1682_REG_ELAPSED) {
int retries = 5;
/* Detect and retry when a tick occurs mid-read */
do {
rc = i2c_smbus_read_i2c_block_data(client, sattr->index,
sattr->nr,
(u8 *)&val_le);
if (rc < 0 || retries <= 0)
return -EIO;
check = val;
val = le32_to_cpu(val_le);
retries--;
} while (val != check && val != (check + 1));
}
/* Format the output string and return # of bytes
* Special case: the 32 bit regs are time values with 1/4s
* resolution, scale them up to milliseconds
*/
return sprintf(buf, "%llu\n", (sattr->nr == 4) ? (val * 250) : 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)
{
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 void ds1682_remove(struct i2c_client *client)
{
sysfs_remove_bin_file(&client->dev.kobj, &ds1682_eeprom_attr);
sysfs_remove_group(&client->dev.kobj, &ds1682_group);
}
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_new = 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");