forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
314 lines
8.2 KiB
314 lines
8.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Driver for +/-1 degree C, SMBus-Compatible Remote/Local Temperature Sensor |
|
* with Overtemperature Alarm |
|
* |
|
* Copyright (C) 2011 AppearTV AS |
|
* |
|
* Derived from: |
|
* |
|
* Based on the max1619 driver. |
|
* Copyright (C) 2003-2004 Oleksij Rempel <[email protected]> |
|
* Jean Delvare <[email protected]> |
|
* |
|
* The MAX6642 is a sensor chip made by Maxim. |
|
* It reports up to two temperatures (its own plus up to |
|
* one external one). Complete datasheet can be |
|
* obtained from Maxim's website at: |
|
* http://datasheets.maxim-ic.com/en/ds/MAX6642.pdf |
|
*/ |
|
|
|
|
|
#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/sysfs.h> |
|
|
|
static const unsigned short normal_i2c[] = { |
|
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
|
|
|
/* |
|
* The MAX6642 registers |
|
*/ |
|
|
|
#define MAX6642_REG_R_MAN_ID 0xFE |
|
#define MAX6642_REG_R_CONFIG 0x03 |
|
#define MAX6642_REG_W_CONFIG 0x09 |
|
#define MAX6642_REG_R_STATUS 0x02 |
|
#define MAX6642_REG_R_LOCAL_TEMP 0x00 |
|
#define MAX6642_REG_R_LOCAL_TEMPL 0x11 |
|
#define MAX6642_REG_R_LOCAL_HIGH 0x05 |
|
#define MAX6642_REG_W_LOCAL_HIGH 0x0B |
|
#define MAX6642_REG_R_REMOTE_TEMP 0x01 |
|
#define MAX6642_REG_R_REMOTE_TEMPL 0x10 |
|
#define MAX6642_REG_R_REMOTE_HIGH 0x07 |
|
#define MAX6642_REG_W_REMOTE_HIGH 0x0D |
|
|
|
/* |
|
* Conversions |
|
*/ |
|
|
|
static int temp_from_reg10(int val) |
|
{ |
|
return val * 250; |
|
} |
|
|
|
static int temp_from_reg(int val) |
|
{ |
|
return val * 1000; |
|
} |
|
|
|
static int temp_to_reg(int val) |
|
{ |
|
return val / 1000; |
|
} |
|
|
|
/* |
|
* Client data (each client gets its own) |
|
*/ |
|
|
|
struct max6642_data { |
|
struct i2c_client *client; |
|
struct mutex update_lock; |
|
bool valid; /* zero until following fields are valid */ |
|
unsigned long last_updated; /* in jiffies */ |
|
|
|
/* registers values */ |
|
u16 temp_input[2]; /* local/remote */ |
|
u16 temp_high[2]; /* local/remote */ |
|
u8 alarms; |
|
}; |
|
|
|
/* |
|
* Real code |
|
*/ |
|
|
|
static void max6642_init_client(struct max6642_data *data, |
|
struct i2c_client *client) |
|
{ |
|
u8 config; |
|
|
|
/* |
|
* Start the conversions. |
|
*/ |
|
config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); |
|
if (config & 0x40) |
|
i2c_smbus_write_byte_data(client, MAX6642_REG_W_CONFIG, |
|
config & 0xBF); /* run */ |
|
|
|
data->temp_high[0] = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_LOCAL_HIGH); |
|
data->temp_high[1] = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_REMOTE_HIGH); |
|
} |
|
|
|
/* Return 0 if detection is successful, -ENODEV otherwise */ |
|
static int max6642_detect(struct i2c_client *client, |
|
struct i2c_board_info *info) |
|
{ |
|
struct i2c_adapter *adapter = client->adapter; |
|
u8 reg_config, reg_status, man_id; |
|
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
|
return -ENODEV; |
|
|
|
/* identification */ |
|
man_id = i2c_smbus_read_byte_data(client, MAX6642_REG_R_MAN_ID); |
|
if (man_id != 0x4D) |
|
return -ENODEV; |
|
|
|
/* sanity check */ |
|
if (i2c_smbus_read_byte_data(client, 0x04) != 0x4D |
|
|| i2c_smbus_read_byte_data(client, 0x06) != 0x4D |
|
|| i2c_smbus_read_byte_data(client, 0xff) != 0x4D) |
|
return -ENODEV; |
|
|
|
/* |
|
* We read the config and status register, the 4 lower bits in the |
|
* config register should be zero and bit 5, 3, 1 and 0 should be |
|
* zero in the status register. |
|
*/ |
|
reg_config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); |
|
if ((reg_config & 0x0f) != 0x00) |
|
return -ENODEV; |
|
|
|
/* in between, another round of sanity checks */ |
|
if (i2c_smbus_read_byte_data(client, 0x04) != reg_config |
|
|| i2c_smbus_read_byte_data(client, 0x06) != reg_config |
|
|| i2c_smbus_read_byte_data(client, 0xff) != reg_config) |
|
return -ENODEV; |
|
|
|
reg_status = i2c_smbus_read_byte_data(client, MAX6642_REG_R_STATUS); |
|
if ((reg_status & 0x2b) != 0x00) |
|
return -ENODEV; |
|
|
|
strlcpy(info->type, "max6642", I2C_NAME_SIZE); |
|
|
|
return 0; |
|
} |
|
|
|
static struct max6642_data *max6642_update_device(struct device *dev) |
|
{ |
|
struct max6642_data *data = dev_get_drvdata(dev); |
|
struct i2c_client *client = data->client; |
|
u16 val, tmp; |
|
|
|
mutex_lock(&data->update_lock); |
|
|
|
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { |
|
dev_dbg(dev, "Updating max6642 data.\n"); |
|
val = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_LOCAL_TEMPL); |
|
tmp = (val >> 6) & 3; |
|
val = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_LOCAL_TEMP); |
|
val = (val << 2) | tmp; |
|
data->temp_input[0] = val; |
|
val = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_REMOTE_TEMPL); |
|
tmp = (val >> 6) & 3; |
|
val = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_REMOTE_TEMP); |
|
val = (val << 2) | tmp; |
|
data->temp_input[1] = val; |
|
data->alarms = i2c_smbus_read_byte_data(client, |
|
MAX6642_REG_R_STATUS); |
|
|
|
data->last_updated = jiffies; |
|
data->valid = 1; |
|
} |
|
|
|
mutex_unlock(&data->update_lock); |
|
|
|
return data; |
|
} |
|
|
|
/* |
|
* Sysfs stuff |
|
*/ |
|
|
|
static ssize_t temp_max10_show(struct device *dev, |
|
struct device_attribute *dev_attr, char *buf) |
|
{ |
|
struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr); |
|
struct max6642_data *data = max6642_update_device(dev); |
|
|
|
return sprintf(buf, "%d\n", |
|
temp_from_reg10(data->temp_input[attr->index])); |
|
} |
|
|
|
static ssize_t temp_max_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); |
|
struct max6642_data *data = max6642_update_device(dev); |
|
|
|
return sprintf(buf, "%d\n", temp_from_reg(data->temp_high[attr2->nr])); |
|
} |
|
|
|
static ssize_t temp_max_store(struct device *dev, |
|
struct device_attribute *attr, const char *buf, |
|
size_t count) |
|
{ |
|
struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); |
|
struct max6642_data *data = dev_get_drvdata(dev); |
|
unsigned long val; |
|
int err; |
|
|
|
err = kstrtoul(buf, 10, &val); |
|
if (err < 0) |
|
return err; |
|
|
|
mutex_lock(&data->update_lock); |
|
data->temp_high[attr2->nr] = clamp_val(temp_to_reg(val), 0, 255); |
|
i2c_smbus_write_byte_data(data->client, attr2->index, |
|
data->temp_high[attr2->nr]); |
|
mutex_unlock(&data->update_lock); |
|
return count; |
|
} |
|
|
|
static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
int bitnr = to_sensor_dev_attr(attr)->index; |
|
struct max6642_data *data = max6642_update_device(dev); |
|
return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1); |
|
} |
|
|
|
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_max10, 0); |
|
static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_max10, 1); |
|
static SENSOR_DEVICE_ATTR_2_RW(temp1_max, temp_max, 0, |
|
MAX6642_REG_W_LOCAL_HIGH); |
|
static SENSOR_DEVICE_ATTR_2_RW(temp2_max, temp_max, 1, |
|
MAX6642_REG_W_REMOTE_HIGH); |
|
static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2); |
|
static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6); |
|
static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4); |
|
|
|
static struct attribute *max6642_attrs[] = { |
|
&sensor_dev_attr_temp1_input.dev_attr.attr, |
|
&sensor_dev_attr_temp2_input.dev_attr.attr, |
|
&sensor_dev_attr_temp1_max.dev_attr.attr, |
|
&sensor_dev_attr_temp2_max.dev_attr.attr, |
|
|
|
&sensor_dev_attr_temp2_fault.dev_attr.attr, |
|
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr, |
|
&sensor_dev_attr_temp2_max_alarm.dev_attr.attr, |
|
NULL |
|
}; |
|
ATTRIBUTE_GROUPS(max6642); |
|
|
|
static int max6642_probe(struct i2c_client *client) |
|
{ |
|
struct device *dev = &client->dev; |
|
struct max6642_data *data; |
|
struct device *hwmon_dev; |
|
|
|
data = devm_kzalloc(dev, sizeof(struct max6642_data), GFP_KERNEL); |
|
if (!data) |
|
return -ENOMEM; |
|
|
|
data->client = client; |
|
mutex_init(&data->update_lock); |
|
|
|
/* Initialize the MAX6642 chip */ |
|
max6642_init_client(data, client); |
|
|
|
hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev, |
|
client->name, data, |
|
max6642_groups); |
|
return PTR_ERR_OR_ZERO(hwmon_dev); |
|
} |
|
|
|
/* |
|
* Driver data (common to all clients) |
|
*/ |
|
|
|
static const struct i2c_device_id max6642_id[] = { |
|
{ "max6642", 0 }, |
|
{ } |
|
}; |
|
MODULE_DEVICE_TABLE(i2c, max6642_id); |
|
|
|
static struct i2c_driver max6642_driver = { |
|
.class = I2C_CLASS_HWMON, |
|
.driver = { |
|
.name = "max6642", |
|
}, |
|
.probe_new = max6642_probe, |
|
.id_table = max6642_id, |
|
.detect = max6642_detect, |
|
.address_list = normal_i2c, |
|
}; |
|
|
|
module_i2c_driver(max6642_driver); |
|
|
|
MODULE_AUTHOR("Per Dalen <[email protected]>"); |
|
MODULE_DESCRIPTION("MAX6642 sensor driver"); |
|
MODULE_LICENSE("GPL");
|
|
|