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Release 4.10 drivers/hwmon/max6642.c

Directory: drivers/hwmon
/*
 * 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 <bug-track@fisher-privat.net>
 *                          Jean Delvare <jdelvare@suse.de>
 *
 * 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
 *
 * 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/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; }

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static int temp_from_reg(int val) { return val * 1000; }

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static int temp_to_reg(int val) { return val / 1000; }

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/* * 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); }

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/* 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; }

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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; }

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/* * Sysfs stuff */
static ssize_t show_temp_max10(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])); }

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static ssize_t show_temp_max(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])); }

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static ssize_t set_temp_max(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; }

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static ssize_t show_alarm(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); }

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static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_max10, NULL, 0); static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_max10, NULL, 1); static SENSOR_DEVICE_ATTR_2(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max, 0, MAX6642_REG_W_LOCAL_HIGH); static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max, 1, MAX6642_REG_W_REMOTE_HIGH); static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2); static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6); static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 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, const struct i2c_device_id *id) { 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); }

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/* * 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 = max6642_probe, .id_table = max6642_id, .detect = max6642_detect, .address_list = normal_i2c, }; module_i2c_driver(max6642_driver); MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>"); MODULE_DESCRIPTION("MAX6642 sensor driver"); MODULE_LICENSE("GPL");

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Directory: drivers/hwmon
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