android_kernel_motorola_sm6225/drivers/hwmon/adt7410.c
Lars-Peter Clausen c55dc91e92 hwmon: (adt7410) Don't re-read non-volatile registers
Currently each time the temperature register is read the driver also reads the
threshold and hysteresis registers. This increases the amount of I2C traffic and
time needed to read the temperature by a factor of ~5. Neither the threshold nor
the hysteresis change on their own, so once we have read them, we should be able
to just use the cached value of the registers. This patch modifies the code
accordingly and only reads the threshold and hysteresis registers once during
probe.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-07 21:16:38 -07:00

485 lines
13 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,
};
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 int adt7410_update_temp(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
int ret = 0;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|| !data->valid) {
int temp;
dev_dbg(&client->dev, "Starting update\n");
ret = adt7410_temp_ready(client); /* check for new value */
if (ret)
goto abort;
temp = i2c_smbus_read_word_swapped(client, ADT7410_REG_TEMP[0]);
if (temp < 0) {
ret = temp;
dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
ADT7410_REG_TEMP[0], ret);
goto abort;
}
data->temp[0] = temp;
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
static int adt7410_fill_cache(struct i2c_client *client)
{
struct adt7410_data *data = i2c_get_clientdata(client);
int ret;
int i;
for (i = 1; i < ARRAY_SIZE(ADT7410_REG_TEMP); i++) {
ret = i2c_smbus_read_word_swapped(client, ADT7410_REG_TEMP[i]);
if (ret < 0) {
dev_dbg(&client->dev,
"Failed to read value: reg %d, error %d\n",
ADT7410_REG_TEMP[i], ret);
return ret;
}
data->temp[i] = ret;
}
ret = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
if (ret < 0) {
dev_dbg(&client->dev,
"Failed to read value: hyst reg, error %d\n",
ret);
return ret;
}
data->hyst = ret;
return 0;
}
static s16 ADT7410_TEMP_TO_REG(long temp)
{
return DIV_ROUND_CLOSEST(clamp_val(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 i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
if (attr->index == 0) {
int ret;
ret = adt7410_update_temp(dev);
if (ret)
return ret;
}
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 i2c_client *client = to_i2c_client(dev);
struct adt7410_data *data = i2c_get_clientdata(client);
int nr = attr->index;
int hyst;
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 = clamp_val(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
data->hyst = clamp_val(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.
*/
ret &= ~ADT7410_MODE_MASK;
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);
ret = adt7410_fill_cache(client);
if (ret)
goto exit_restore;
/* 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, },
{ "adt7420", adt7410, },
{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, adt7410_ids);
#ifdef CONFIG_PM_SLEEP
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 SIMPLE_DEV_PM_OPS(adt7410_dev_pm_ops, adt7410_suspend, 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 = I2C_ADDRS(0x48, 0x49, 0x4a, 0x4b),
};
module_i2c_driver(adt7410_driver);
MODULE_AUTHOR("Hartmut Knaack");
MODULE_DESCRIPTION("ADT7410/ADT7420 driver");
MODULE_LICENSE("GPL");