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alistair23-linux/drivers/hwmon/max6642.c
Thomas Gleixner 74ba9207e1 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 441 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:36:45 +02:00

316 lines
8.2 KiB
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// 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 <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
*/
#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,
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);
}
/*
* 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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