![Jean Delvare](/assets/img/avatar_default.png)
Make use of the new i2c_smbus_{read,write}_word_swapped functions. This makes the driver code more compact and readable. It also ensures proper error handling. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Acked-by: Guenter Roeck <guenter.roeck@ericsson.com> Cc: Dirk Eibach <eibach@gdsys.de> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Guillaume Ligneul <guillaume.ligneul@gmail.com>
316 lines
8.1 KiB
C
316 lines
8.1 KiB
C
/*
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* ds620.c - Support for temperature sensor and thermostat DS620
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*
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* Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
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*
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* based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/sysfs.h>
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#include <linux/i2c/ds620.h>
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/*
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* Many DS620 constants specified below
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* 15 14 13 12 11 10 09 08
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* |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT|
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*
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* 07 06 05 04 03 02 01 00
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* |PO2 |PO1 |A2 |A1 |A0 | | | |
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*/
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#define DS620_REG_CONFIG_DONE 0x8000
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#define DS620_REG_CONFIG_NVB 0x4000
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#define DS620_REG_CONFIG_THF 0x2000
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#define DS620_REG_CONFIG_TLF 0x1000
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#define DS620_REG_CONFIG_R1 0x0800
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#define DS620_REG_CONFIG_R0 0x0400
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#define DS620_REG_CONFIG_AUTOC 0x0200
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#define DS620_REG_CONFIG_1SHOT 0x0100
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#define DS620_REG_CONFIG_PO2 0x0080
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#define DS620_REG_CONFIG_PO1 0x0040
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#define DS620_REG_CONFIG_A2 0x0020
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#define DS620_REG_CONFIG_A1 0x0010
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#define DS620_REG_CONFIG_A0 0x0008
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/* The DS620 registers */
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static const u8 DS620_REG_TEMP[3] = {
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0xAA, /* input, word, RO */
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0xA2, /* min, word, RW */
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0xA0, /* max, word, RW */
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};
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#define DS620_REG_CONF 0xAC /* word, RW */
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#define DS620_COM_START 0x51 /* no data */
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#define DS620_COM_STOP 0x22 /* no data */
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/* Each client has this additional data */
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struct ds620_data {
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struct device *hwmon_dev;
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struct mutex update_lock;
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char valid; /* !=0 if following fields are valid */
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unsigned long last_updated; /* In jiffies */
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s16 temp[3]; /* Register values, word */
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};
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static void ds620_init_client(struct i2c_client *client)
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{
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struct ds620_platform_data *ds620_info = client->dev.platform_data;
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u16 conf, new_conf;
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new_conf = conf =
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i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
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/* switch to continuous conversion mode */
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new_conf &= ~DS620_REG_CONFIG_1SHOT;
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/* already high at power-on, but don't trust the BIOS! */
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new_conf |= DS620_REG_CONFIG_PO2;
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/* thermostat mode according to platform data */
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if (ds620_info && ds620_info->pomode == 1)
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new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */
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else if (ds620_info && ds620_info->pomode == 2)
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new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */
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else
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new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */
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/* with highest precision */
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new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0;
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if (conf != new_conf)
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i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);
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/* start conversion */
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i2c_smbus_write_byte(client, DS620_COM_START);
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}
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static struct ds620_data *ds620_update_client(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct ds620_data *data = i2c_get_clientdata(client);
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struct ds620_data *ret = data;
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mutex_lock(&data->update_lock);
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if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
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|| !data->valid) {
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int i;
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int res;
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dev_dbg(&client->dev, "Starting ds620 update\n");
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for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
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res = i2c_smbus_read_word_swapped(client,
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DS620_REG_TEMP[i]);
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if (res < 0) {
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ret = ERR_PTR(res);
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goto abort;
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}
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data->temp[i] = res;
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}
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data->last_updated = jiffies;
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data->valid = 1;
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}
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abort:
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mutex_unlock(&data->update_lock);
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return ret;
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}
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static ssize_t show_temp(struct device *dev, struct device_attribute *da,
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char *buf)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct ds620_data *data = ds620_update_client(dev);
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if (IS_ERR(data))
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return PTR_ERR(data);
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return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10);
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}
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static ssize_t set_temp(struct device *dev, struct device_attribute *da,
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const char *buf, size_t count)
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{
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int res;
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long val;
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct i2c_client *client = to_i2c_client(dev);
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struct ds620_data *data = i2c_get_clientdata(client);
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res = strict_strtol(buf, 10, &val);
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if (res)
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return res;
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val = (val * 10 / 625) * 8;
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mutex_lock(&data->update_lock);
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data->temp[attr->index] = val;
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i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
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data->temp[attr->index]);
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mutex_unlock(&data->update_lock);
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return count;
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}
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static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
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char *buf)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct ds620_data *data = ds620_update_client(dev);
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struct i2c_client *client = to_i2c_client(dev);
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u16 conf, new_conf;
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int res;
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if (IS_ERR(data))
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return PTR_ERR(data);
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/* reset alarms if necessary */
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res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
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if (res < 0)
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return res;
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new_conf = conf = res;
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new_conf &= ~attr->index;
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if (conf != new_conf) {
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res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
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new_conf);
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if (res < 0)
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return res;
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}
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return sprintf(buf, "%d\n", !!(conf & attr->index));
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}
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static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
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static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
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static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
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static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
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DS620_REG_CONFIG_TLF);
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static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
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DS620_REG_CONFIG_THF);
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static struct attribute *ds620_attributes[] = {
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&sensor_dev_attr_temp1_input.dev_attr.attr,
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&sensor_dev_attr_temp1_min.dev_attr.attr,
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&sensor_dev_attr_temp1_max.dev_attr.attr,
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&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
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&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
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NULL
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};
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static const struct attribute_group ds620_group = {
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.attrs = ds620_attributes,
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};
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static int ds620_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ds620_data *data;
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int err;
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data = kzalloc(sizeof(struct ds620_data), GFP_KERNEL);
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if (!data) {
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err = -ENOMEM;
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goto exit;
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}
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i2c_set_clientdata(client, data);
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mutex_init(&data->update_lock);
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/* Initialize the DS620 chip */
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ds620_init_client(client);
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/* Register sysfs hooks */
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err = sysfs_create_group(&client->dev.kobj, &ds620_group);
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if (err)
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goto exit_free;
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data->hwmon_dev = hwmon_device_register(&client->dev);
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if (IS_ERR(data->hwmon_dev)) {
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err = PTR_ERR(data->hwmon_dev);
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goto exit_remove_files;
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}
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dev_info(&client->dev, "temperature sensor found\n");
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return 0;
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exit_remove_files:
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sysfs_remove_group(&client->dev.kobj, &ds620_group);
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exit_free:
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kfree(data);
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exit:
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return err;
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}
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static int ds620_remove(struct i2c_client *client)
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{
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struct ds620_data *data = i2c_get_clientdata(client);
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hwmon_device_unregister(data->hwmon_dev);
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sysfs_remove_group(&client->dev.kobj, &ds620_group);
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kfree(data);
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return 0;
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}
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static const struct i2c_device_id ds620_id[] = {
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{"ds620", 0},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ds620_id);
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/* This is the driver that will be inserted */
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static struct i2c_driver ds620_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "ds620",
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},
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.probe = ds620_probe,
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.remove = ds620_remove,
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.id_table = ds620_id,
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};
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static int __init ds620_init(void)
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{
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return i2c_add_driver(&ds620_driver);
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}
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static void __exit ds620_exit(void)
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{
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i2c_del_driver(&ds620_driver);
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}
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MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
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MODULE_DESCRIPTION("DS620 driver");
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MODULE_LICENSE("GPL");
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module_init(ds620_init);
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module_exit(ds620_exit);
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