linux/drivers/hwmon/ltc4261.c
Jean Delvare dcd8f39230 hwmon: Add missing inclusions of <linux/jiffies.h>
Many hwmon drivers use jiffies but omit the inclusion of the header
file. Fix that, and also fix one driver which was including the header
file but didn't need it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Luca Tettamanti <kronos.it@gmail.com>
Cc: Marc Hulsman <m.hulsman@tudelft.nl>
Cc: Rudolf Marek <r.marek@assembler.cz>
2012-10-10 15:25:56 +02:00

299 lines
7.7 KiB
C

/*
* Driver for Linear Technology LTC4261 I2C Negative Voltage Hot Swap Controller
*
* Copyright (C) 2010 Ericsson AB.
*
* Derived from:
*
* Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller
* Copyright (C) 2008 Ira W. Snyder <iws@ovro.caltech.edu>
*
* Datasheet: http://cds.linear.com/docs/Datasheet/42612fb.pdf
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
/* chip registers */
#define LTC4261_STATUS 0x00 /* readonly */
#define LTC4261_FAULT 0x01
#define LTC4261_ALERT 0x02
#define LTC4261_CONTROL 0x03
#define LTC4261_SENSE_H 0x04
#define LTC4261_SENSE_L 0x05
#define LTC4261_ADIN2_H 0x06
#define LTC4261_ADIN2_L 0x07
#define LTC4261_ADIN_H 0x08
#define LTC4261_ADIN_L 0x09
/*
* Fault register bits
*/
#define FAULT_OV (1<<0)
#define FAULT_UV (1<<1)
#define FAULT_OC (1<<2)
struct ltc4261_data {
struct device *hwmon_dev;
struct mutex update_lock;
bool valid;
unsigned long last_updated; /* in jiffies */
/* Registers */
u8 regs[10];
};
static struct ltc4261_data *ltc4261_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ltc4261_data *data = i2c_get_clientdata(client);
struct ltc4261_data *ret = data;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ / 4) || !data->valid) {
int i;
/* Read registers -- 0x00 to 0x09 */
for (i = 0; i < ARRAY_SIZE(data->regs); i++) {
int val;
val = i2c_smbus_read_byte_data(client, i);
if (unlikely(val < 0)) {
dev_dbg(dev,
"Failed to read ADC value: error %d\n",
val);
ret = ERR_PTR(val);
data->valid = 0;
goto abort;
}
data->regs[i] = val;
}
data->last_updated = jiffies;
data->valid = 1;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
/* Return the voltage from the given register in mV or mA */
static int ltc4261_get_value(struct ltc4261_data *data, u8 reg)
{
u32 val;
val = (data->regs[reg] << 2) + (data->regs[reg + 1] >> 6);
switch (reg) {
case LTC4261_ADIN_H:
case LTC4261_ADIN2_H:
/* 2.5mV resolution. Convert to mV. */
val = val * 25 / 10;
break;
case LTC4261_SENSE_H:
/*
* 62.5uV resolution. Convert to current as measured with
* an 1 mOhm sense resistor, in mA. If a different sense
* resistor is installed, calculate the actual current by
* dividing the reported current by the sense resistor value
* in mOhm.
*/
val = val * 625 / 10;
break;
default:
/* If we get here, the developer messed up */
WARN_ON_ONCE(1);
val = 0;
break;
}
return val;
}
static ssize_t ltc4261_show_value(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ltc4261_data *data = ltc4261_update_device(dev);
int value;
if (IS_ERR(data))
return PTR_ERR(data);
value = ltc4261_get_value(data, attr->index);
return snprintf(buf, PAGE_SIZE, "%d\n", value);
}
static ssize_t ltc4261_show_bool(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
struct ltc4261_data *data = ltc4261_update_device(dev);
u8 fault;
if (IS_ERR(data))
return PTR_ERR(data);
fault = data->regs[LTC4261_FAULT] & attr->index;
if (fault) /* Clear reported faults in chip register */
i2c_smbus_write_byte_data(client, LTC4261_FAULT, ~fault);
return snprintf(buf, PAGE_SIZE, "%d\n", fault ? 1 : 0);
}
/*
* These macros are used below in constructing device attribute objects
* for use with sysfs_create_group() to make a sysfs device file
* for each register.
*/
#define LTC4261_VALUE(name, ltc4261_cmd_idx) \
static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
ltc4261_show_value, NULL, ltc4261_cmd_idx)
#define LTC4261_BOOL(name, mask) \
static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
ltc4261_show_bool, NULL, (mask))
/*
* Input voltages.
*/
LTC4261_VALUE(in1_input, LTC4261_ADIN_H);
LTC4261_VALUE(in2_input, LTC4261_ADIN2_H);
/*
* Voltage alarms. The chip has only one set of voltage alarm status bits,
* triggered by input voltage alarms. In many designs, those alarms are
* associated with the ADIN2 sensor, due to the proximity of the ADIN2 pin
* to the OV pin. ADIN2 is, however, not available on all chip variants.
* To ensure that the alarm condition is reported to the user, report it
* with both voltage sensors.
*/
LTC4261_BOOL(in1_min_alarm, FAULT_UV);
LTC4261_BOOL(in1_max_alarm, FAULT_OV);
LTC4261_BOOL(in2_min_alarm, FAULT_UV);
LTC4261_BOOL(in2_max_alarm, FAULT_OV);
/* Currents (via sense resistor) */
LTC4261_VALUE(curr1_input, LTC4261_SENSE_H);
/* Overcurrent alarm */
LTC4261_BOOL(curr1_max_alarm, FAULT_OC);
static struct attribute *ltc4261_attributes[] = {
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in2_min_alarm.dev_attr.attr,
&sensor_dev_attr_in2_max_alarm.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
NULL,
};
static const struct attribute_group ltc4261_group = {
.attrs = ltc4261_attributes,
};
static int ltc4261_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = client->adapter;
struct ltc4261_data *data;
int ret;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
if (i2c_smbus_read_byte_data(client, LTC4261_STATUS) < 0) {
dev_err(&client->dev, "Failed to read status register\n");
return -ENODEV;
}
data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* Clear faults */
i2c_smbus_write_byte_data(client, LTC4261_FAULT, 0x00);
/* Register sysfs hooks */
ret = sysfs_create_group(&client->dev.kobj, &ltc4261_group);
if (ret)
return ret;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
ret = PTR_ERR(data->hwmon_dev);
goto out_hwmon_device_register;
}
return 0;
out_hwmon_device_register:
sysfs_remove_group(&client->dev.kobj, &ltc4261_group);
return ret;
}
static int ltc4261_remove(struct i2c_client *client)
{
struct ltc4261_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &ltc4261_group);
return 0;
}
static const struct i2c_device_id ltc4261_id[] = {
{"ltc4261", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, ltc4261_id);
/* This is the driver that will be inserted */
static struct i2c_driver ltc4261_driver = {
.driver = {
.name = "ltc4261",
},
.probe = ltc4261_probe,
.remove = ltc4261_remove,
.id_table = ltc4261_id,
};
module_i2c_driver(ltc4261_driver);
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("LTC4261 driver");
MODULE_LICENSE("GPL");