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linux-next/drivers/hwmon/adt7410.c
Dan Carpenter 37f9648b27 hwmon: (adt7410) handle errors from adt7410_update_device()
Smatch complains that adt7410_update_device() can return error pointers.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2012-09-23 21:08:33 -07:00

465 lines
12 KiB
C

/*
* adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
* This driver handles the ADT7410 and compatible digital temperature sensors.
* Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
* based on lm75.c by Frodo Looijaard <frodol@dds.nl>
* and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
*
* 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
/*
* ADT7410 registers definition
*/
#define ADT7410_TEMPERATURE 0
#define ADT7410_STATUS 2
#define ADT7410_CONFIG 3
#define ADT7410_T_ALARM_HIGH 4
#define ADT7410_T_ALARM_LOW 6
#define ADT7410_T_CRIT 8
#define ADT7410_T_HYST 0xA
/*
* ADT7410 status
*/
#define ADT7410_STAT_T_LOW (1 << 4)
#define ADT7410_STAT_T_HIGH (1 << 5)
#define ADT7410_STAT_T_CRIT (1 << 6)
#define ADT7410_STAT_NOT_RDY (1 << 7)
/*
* ADT7410 config
*/
#define ADT7410_FAULT_QUEUE_MASK (1 << 0 | 1 << 1)
#define ADT7410_CT_POLARITY (1 << 2)
#define ADT7410_INT_POLARITY (1 << 3)
#define ADT7410_EVENT_MODE (1 << 4)
#define ADT7410_MODE_MASK (1 << 5 | 1 << 6)
#define ADT7410_FULL (0 << 5 | 0 << 6)
#define ADT7410_PD (1 << 5 | 1 << 6)
#define ADT7410_RESOLUTION (1 << 7)
/*
* ADT7410 masks
*/
#define ADT7410_T13_VALUE_MASK 0xFFF8
#define ADT7410_T_HYST_MASK 0xF
/* straight from the datasheet */
#define ADT7410_TEMP_MIN (-55000)
#define ADT7410_TEMP_MAX 150000
enum adt7410_type { /* keep sorted in alphabetical order */
adt7410,
};
/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
I2C_CLIENT_END };
static const u8 ADT7410_REG_TEMP[4] = {
ADT7410_TEMPERATURE, /* input */
ADT7410_T_ALARM_HIGH, /* high */
ADT7410_T_ALARM_LOW, /* low */
ADT7410_T_CRIT, /* critical */
};
/* Each client has this additional data */
struct adt7410_data {
struct device *hwmon_dev;
struct mutex update_lock;
u8 config;
u8 oldconfig;
bool valid; /* true if registers valid */
unsigned long last_updated; /* In jiffies */
s16 temp[4]; /* Register values,
0 = input
1 = high
2 = low
3 = critical */
u8 hyst; /* hysteresis offset */
};
/*
* adt7410 register access by I2C
*/
static int adt7410_temp_ready(struct i2c_client *client)
{
int i, status;
for (i = 0; i < 6; i++) {
status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
if (status < 0)
return status;
if (!(status & ADT7410_STAT_NOT_RDY))
return 0;
msleep(60);
}
return -ETIMEDOUT;
}
static struct adt7410_data *adt7410_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
struct adt7410_data *ret = data;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|| !data->valid) {
int i, status;
dev_dbg(&client->dev, "Starting update\n");
status = adt7410_temp_ready(client); /* check for new value */
if (unlikely(status)) {
ret = ERR_PTR(status);
goto abort;
}
for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
status = i2c_smbus_read_word_swapped(client,
ADT7410_REG_TEMP[i]);
if (unlikely(status < 0)) {
dev_dbg(dev,
"Failed to read value: reg %d, error %d\n",
ADT7410_REG_TEMP[i], status);
ret = ERR_PTR(status);
goto abort;
}
data->temp[i] = status;
}
status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
if (unlikely(status < 0)) {
dev_dbg(dev,
"Failed to read value: reg %d, error %d\n",
ADT7410_T_HYST, status);
ret = ERR_PTR(status);
goto abort;
}
data->hyst = status;
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
static s16 ADT7410_TEMP_TO_REG(long temp)
{
return DIV_ROUND_CLOSEST(SENSORS_LIMIT(temp, ADT7410_TEMP_MIN,
ADT7410_TEMP_MAX) * 128, 1000);
}
static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
{
/* in 13 bit mode, bits 0-2 are status flags - mask them out */
if (!(data->config & ADT7410_RESOLUTION))
reg &= ADT7410_T13_VALUE_MASK;
/*
* temperature is stored in twos complement format, in steps of
* 1/128°C
*/
return DIV_ROUND_CLOSEST(reg * 1000, 128);
}
/*-----------------------------------------------------------------------*/
/* sysfs attributes for hwmon */
static ssize_t adt7410_show_temp(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct adt7410_data *data = adt7410_update_device(dev);
if (IS_ERR(data))
return PTR_ERR(data);
return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
data->temp[attr->index]));
}
static ssize_t adt7410_set_temp(struct device *dev,
struct device_attribute *da,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
int nr = attr->index;
long temp;
int ret;
ret = kstrtol(buf, 10, &temp);
if (ret)
return ret;
mutex_lock(&data->update_lock);
data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
data->temp[nr]);
if (ret)
count = ret;
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t adt7410_show_t_hyst(struct device *dev,
struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct adt7410_data *data;
int nr = attr->index;
int hyst;
data = adt7410_update_device(dev);
if (IS_ERR(data))
return PTR_ERR(data);
hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;
/*
* hysteresis is stored as a 4 bit offset in the device, convert it
* to an absolute value
*/
if (nr == 2) /* min has positive offset, others have negative */
hyst = -hyst;
return sprintf(buf, "%d\n",
ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
}
static ssize_t adt7410_set_t_hyst(struct device *dev,
struct device_attribute *da,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
int limit, ret;
long hyst;
ret = kstrtol(buf, 10, &hyst);
if (ret)
return ret;
/* convert absolute hysteresis value to a 4 bit delta value */
limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
hyst = SENSORS_LIMIT(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
data->hyst = SENSORS_LIMIT(DIV_ROUND_CLOSEST(limit - hyst, 1000),
0, ADT7410_T_HYST_MASK);
ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
if (ret)
return ret;
return count;
}
static ssize_t adt7410_show_alarm(struct device *dev,
struct device_attribute *da,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
int ret;
ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", !!(ret & attr->index));
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
adt7410_show_temp, adt7410_set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
adt7410_show_temp, adt7410_set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
adt7410_show_temp, adt7410_set_temp, 3);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
adt7410_show_t_hyst, NULL, 2);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
adt7410_show_t_hyst, NULL, 3);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
NULL, ADT7410_STAT_T_LOW);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
NULL, ADT7410_STAT_T_HIGH);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
NULL, ADT7410_STAT_T_CRIT);
static struct attribute *adt7410_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_crit.dev_attr.attr,
&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
NULL
};
static const struct attribute_group adt7410_group = {
.attrs = adt7410_attributes,
};
/*-----------------------------------------------------------------------*/
/* device probe and removal */
static int adt7410_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct adt7410_data *data;
int ret;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* configure as specified */
ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
if (ret < 0) {
dev_dbg(&client->dev, "Can't read config? %d\n", ret);
return ret;
}
data->oldconfig = ret;
/*
* Set to 16 bit resolution, continous conversion and comparator mode.
*/
data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |
ADT7410_EVENT_MODE;
if (data->config != data->oldconfig) {
ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
data->config);
if (ret)
return ret;
}
dev_dbg(&client->dev, "Config %02x\n", data->config);
/* Register sysfs hooks */
ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
if (ret)
goto exit_restore;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
ret = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
dev_info(&client->dev, "sensor '%s'\n", client->name);
return 0;
exit_remove:
sysfs_remove_group(&client->dev.kobj, &adt7410_group);
exit_restore:
i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
return ret;
}
static int adt7410_remove(struct i2c_client *client)
{
struct adt7410_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &adt7410_group);
if (data->oldconfig != data->config)
i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
data->oldconfig);
return 0;
}
static const struct i2c_device_id adt7410_ids[] = {
{ "adt7410", adt7410, },
{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, adt7410_ids);
#ifdef CONFIG_PM
static int adt7410_suspend(struct device *dev)
{
int ret;
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
data->config | ADT7410_PD);
return ret;
}
static int adt7410_resume(struct device *dev)
{
int ret;
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
return ret;
}
static const struct dev_pm_ops adt7410_dev_pm_ops = {
.suspend = adt7410_suspend,
.resume = adt7410_resume,
};
#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
#else
#define ADT7410_DEV_PM_OPS NULL
#endif /* CONFIG_PM */
static struct i2c_driver adt7410_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "adt7410",
.pm = ADT7410_DEV_PM_OPS,
},
.probe = adt7410_probe,
.remove = adt7410_remove,
.id_table = adt7410_ids,
.address_list = normal_i2c,
};
module_i2c_driver(adt7410_driver);
MODULE_AUTHOR("Hartmut Knaack");
MODULE_DESCRIPTION("ADT7410 driver");
MODULE_LICENSE("GPL");