576 lines
14 KiB
C
576 lines
14 KiB
C
/*
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* lm75.c - Part of lm_sensors, Linux kernel modules for hardware
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* monitoring
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* Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
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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/of.h>
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#include <linux/regmap.h>
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#include "lm75.h"
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/*
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* This driver handles the LM75 and compatible digital temperature sensors.
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*/
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enum lm75_type { /* keep sorted in alphabetical order */
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adt75,
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ds1775,
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ds75,
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ds7505,
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g751,
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lm75,
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lm75a,
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lm75b,
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max6625,
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max6626,
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mcp980x,
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stds75,
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tcn75,
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tmp100,
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tmp101,
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tmp105,
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tmp112,
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tmp175,
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tmp275,
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tmp75,
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tmp75c,
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};
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/* Addresses scanned */
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static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
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0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
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/* The LM75 registers */
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#define LM75_REG_TEMP 0x00
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#define LM75_REG_CONF 0x01
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#define LM75_REG_HYST 0x02
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#define LM75_REG_MAX 0x03
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/* Each client has this additional data */
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struct lm75_data {
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struct i2c_client *client;
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struct regmap *regmap;
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u8 orig_conf;
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u8 resolution; /* In bits, between 9 and 12 */
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u8 resolution_limits;
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unsigned int sample_time; /* In ms */
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};
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/*-----------------------------------------------------------------------*/
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static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
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{
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return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
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}
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static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long *val)
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{
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struct lm75_data *data = dev_get_drvdata(dev);
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unsigned int regval;
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int err, reg;
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switch (type) {
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case hwmon_chip:
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switch (attr) {
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case hwmon_chip_update_interval:
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*val = data->sample_time;
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break;;
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default:
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return -EINVAL;
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}
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break;
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case hwmon_temp:
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switch (attr) {
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case hwmon_temp_input:
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reg = LM75_REG_TEMP;
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break;
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case hwmon_temp_max:
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reg = LM75_REG_MAX;
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break;
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case hwmon_temp_max_hyst:
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reg = LM75_REG_HYST;
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break;
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default:
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return -EINVAL;
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}
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err = regmap_read(data->regmap, reg, ®val);
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if (err < 0)
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return err;
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*val = lm75_reg_to_mc(regval, data->resolution);
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long temp)
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{
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struct lm75_data *data = dev_get_drvdata(dev);
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u8 resolution;
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int reg;
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if (type != hwmon_temp)
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return -EINVAL;
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switch (attr) {
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case hwmon_temp_max:
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reg = LM75_REG_MAX;
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break;
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case hwmon_temp_max_hyst:
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reg = LM75_REG_HYST;
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break;
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default:
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return -EINVAL;
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}
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/*
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* Resolution of limit registers is assumed to be the same as the
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* temperature input register resolution unless given explicitly.
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*/
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if (data->resolution_limits)
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resolution = data->resolution_limits;
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else
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resolution = data->resolution;
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temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
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temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
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1000) << (16 - resolution);
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return regmap_write(data->regmap, reg, temp);
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}
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static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
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u32 attr, int channel)
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{
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switch (type) {
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case hwmon_chip:
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switch (attr) {
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case hwmon_chip_update_interval:
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return S_IRUGO;
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}
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break;
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case hwmon_temp:
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switch (attr) {
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case hwmon_temp_input:
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return S_IRUGO;
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case hwmon_temp_max:
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case hwmon_temp_max_hyst:
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return S_IRUGO | S_IWUSR;
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}
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break;
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default:
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break;
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}
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return 0;
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}
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/*-----------------------------------------------------------------------*/
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/* device probe and removal */
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/* chip configuration */
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static const u32 lm75_chip_config[] = {
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HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
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0
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};
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static const struct hwmon_channel_info lm75_chip = {
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.type = hwmon_chip,
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.config = lm75_chip_config,
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};
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static const u32 lm75_temp_config[] = {
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HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST,
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0
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};
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static const struct hwmon_channel_info lm75_temp = {
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.type = hwmon_temp,
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.config = lm75_temp_config,
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};
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static const struct hwmon_channel_info *lm75_info[] = {
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&lm75_chip,
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&lm75_temp,
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NULL
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};
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static const struct hwmon_ops lm75_hwmon_ops = {
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.is_visible = lm75_is_visible,
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.read = lm75_read,
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.write = lm75_write,
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};
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static const struct hwmon_chip_info lm75_chip_info = {
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.ops = &lm75_hwmon_ops,
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.info = lm75_info,
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};
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static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
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{
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return reg != LM75_REG_TEMP;
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}
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static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
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{
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return reg == LM75_REG_TEMP;
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}
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static const struct regmap_config lm75_regmap_config = {
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.reg_bits = 8,
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.val_bits = 16,
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.max_register = LM75_REG_MAX,
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.writeable_reg = lm75_is_writeable_reg,
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.volatile_reg = lm75_is_volatile_reg,
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.val_format_endian = REGMAP_ENDIAN_BIG,
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.cache_type = REGCACHE_RBTREE,
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.use_single_rw = true,
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};
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static void lm75_remove(void *data)
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{
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struct lm75_data *lm75 = data;
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struct i2c_client *client = lm75->client;
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i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
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}
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static int
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lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct device *hwmon_dev;
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struct lm75_data *data;
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int status, err;
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u8 set_mask, clr_mask;
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int new;
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enum lm75_type kind = id->driver_data;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
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return -EIO;
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data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->client = client;
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data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
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if (IS_ERR(data->regmap))
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return PTR_ERR(data->regmap);
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/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
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* Then tweak to be more precise when appropriate.
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*/
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set_mask = 0;
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clr_mask = LM75_SHUTDOWN; /* continuous conversions */
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switch (kind) {
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case adt75:
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clr_mask |= 1 << 5; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 8;
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break;
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case ds1775:
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case ds75:
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case stds75:
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clr_mask |= 3 << 5;
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set_mask |= 2 << 5; /* 11-bit mode */
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data->resolution = 11;
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data->sample_time = MSEC_PER_SEC;
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break;
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case ds7505:
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set_mask |= 3 << 5; /* 12-bit mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case g751:
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case lm75:
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case lm75a:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 2;
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break;
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case lm75b:
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data->resolution = 11;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case max6625:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case max6626:
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data->resolution = 12;
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data->resolution_limits = 9;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case tcn75:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 8;
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break;
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case mcp980x:
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data->resolution_limits = 9;
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/* fall through */
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case tmp100:
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case tmp101:
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set_mask |= 3 << 5; /* 12-bit mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC;
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clr_mask |= 1 << 7; /* not one-shot mode */
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break;
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case tmp112:
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set_mask |= 3 << 5; /* 12-bit mode */
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clr_mask |= 1 << 7; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case tmp105:
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case tmp175:
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case tmp275:
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case tmp75:
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set_mask |= 3 << 5; /* 12-bit mode */
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clr_mask |= 1 << 7; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 2;
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break;
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case tmp75c:
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clr_mask |= 1 << 5; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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}
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/* configure as specified */
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status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
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if (status < 0) {
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dev_dbg(dev, "Can't read config? %d\n", status);
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return status;
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}
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data->orig_conf = status;
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new = status & ~clr_mask;
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new |= set_mask;
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if (status != new)
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i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
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err = devm_add_action_or_reset(dev, lm75_remove, data);
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if (err)
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return err;
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dev_dbg(dev, "Config %02x\n", new);
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hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
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data, &lm75_chip_info,
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NULL);
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if (IS_ERR(hwmon_dev))
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return PTR_ERR(hwmon_dev);
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dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
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return 0;
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}
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static const struct i2c_device_id lm75_ids[] = {
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{ "adt75", adt75, },
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{ "ds1775", ds1775, },
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{ "ds75", ds75, },
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{ "ds7505", ds7505, },
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{ "g751", g751, },
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{ "lm75", lm75, },
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{ "lm75a", lm75a, },
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{ "lm75b", lm75b, },
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{ "max6625", max6625, },
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{ "max6626", max6626, },
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{ "mcp980x", mcp980x, },
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{ "stds75", stds75, },
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{ "tcn75", tcn75, },
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{ "tmp100", tmp100, },
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{ "tmp101", tmp101, },
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{ "tmp105", tmp105, },
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{ "tmp112", tmp112, },
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{ "tmp175", tmp175, },
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{ "tmp275", tmp275, },
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{ "tmp75", tmp75, },
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{ "tmp75c", tmp75c, },
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{ /* LIST END */ }
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};
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MODULE_DEVICE_TABLE(i2c, lm75_ids);
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#define LM75A_ID 0xA1
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/* Return 0 if detection is successful, -ENODEV otherwise */
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static int lm75_detect(struct i2c_client *new_client,
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struct i2c_board_info *info)
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{
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struct i2c_adapter *adapter = new_client->adapter;
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int i;
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int conf, hyst, os;
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bool is_lm75a = 0;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_WORD_DATA))
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return -ENODEV;
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/*
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* Now, we do the remaining detection. There is no identification-
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* dedicated register so we have to rely on several tricks:
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* unused bits, registers cycling over 8-address boundaries,
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* addresses 0x04-0x07 returning the last read value.
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* The cycling+unused addresses combination is not tested,
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* since it would significantly slow the detection down and would
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* hardly add any value.
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*
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* The National Semiconductor LM75A is different than earlier
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* LM75s. It has an ID byte of 0xaX (where X is the chip
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* revision, with 1 being the only revision in existence) in
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* register 7, and unused registers return 0xff rather than the
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* last read value.
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*
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* Note that this function only detects the original National
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* Semiconductor LM75 and the LM75A. Clones from other vendors
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* aren't detected, on purpose, because they are typically never
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* found on PC hardware. They are found on embedded designs where
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* they can be instantiated explicitly so detection is not needed.
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* The absence of identification registers on all these clones
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* would make their exhaustive detection very difficult and weak,
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* and odds are that the driver would bind to unsupported devices.
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*/
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/* Unused bits */
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conf = i2c_smbus_read_byte_data(new_client, 1);
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if (conf & 0xe0)
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return -ENODEV;
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/* First check for LM75A */
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if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
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/* LM75A returns 0xff on unused registers so
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just to be sure we check for that too. */
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if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
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|| i2c_smbus_read_byte_data(new_client, 5) != 0xff
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|| i2c_smbus_read_byte_data(new_client, 6) != 0xff)
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return -ENODEV;
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is_lm75a = 1;
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hyst = i2c_smbus_read_byte_data(new_client, 2);
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os = i2c_smbus_read_byte_data(new_client, 3);
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} else { /* Traditional style LM75 detection */
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/* Unused addresses */
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hyst = i2c_smbus_read_byte_data(new_client, 2);
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if (i2c_smbus_read_byte_data(new_client, 4) != hyst
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|| i2c_smbus_read_byte_data(new_client, 5) != hyst
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|| i2c_smbus_read_byte_data(new_client, 6) != hyst
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|| i2c_smbus_read_byte_data(new_client, 7) != hyst)
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return -ENODEV;
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os = i2c_smbus_read_byte_data(new_client, 3);
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if (i2c_smbus_read_byte_data(new_client, 4) != os
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|| i2c_smbus_read_byte_data(new_client, 5) != os
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|| i2c_smbus_read_byte_data(new_client, 6) != os
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|| i2c_smbus_read_byte_data(new_client, 7) != os)
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return -ENODEV;
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}
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/*
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* It is very unlikely that this is a LM75 if both
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* hysteresis and temperature limit registers are 0.
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*/
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if (hyst == 0 && os == 0)
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return -ENODEV;
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/* Addresses cycling */
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for (i = 8; i <= 248; i += 40) {
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if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
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|| i2c_smbus_read_byte_data(new_client, i + 2) != hyst
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|| i2c_smbus_read_byte_data(new_client, i + 3) != os)
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return -ENODEV;
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if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
|
|
!= LM75A_ID)
|
|
return -ENODEV;
|
|
}
|
|
|
|
strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int lm75_suspend(struct device *dev)
|
|
{
|
|
int status;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
|
|
if (status < 0) {
|
|
dev_dbg(&client->dev, "Can't read config? %d\n", status);
|
|
return status;
|
|
}
|
|
status = status | LM75_SHUTDOWN;
|
|
i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
|
|
return 0;
|
|
}
|
|
|
|
static int lm75_resume(struct device *dev)
|
|
{
|
|
int status;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
|
|
if (status < 0) {
|
|
dev_dbg(&client->dev, "Can't read config? %d\n", status);
|
|
return status;
|
|
}
|
|
status = status & ~LM75_SHUTDOWN;
|
|
i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops lm75_dev_pm_ops = {
|
|
.suspend = lm75_suspend,
|
|
.resume = lm75_resume,
|
|
};
|
|
#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
|
|
#else
|
|
#define LM75_DEV_PM_OPS NULL
|
|
#endif /* CONFIG_PM */
|
|
|
|
static struct i2c_driver lm75_driver = {
|
|
.class = I2C_CLASS_HWMON,
|
|
.driver = {
|
|
.name = "lm75",
|
|
.pm = LM75_DEV_PM_OPS,
|
|
},
|
|
.probe = lm75_probe,
|
|
.id_table = lm75_ids,
|
|
.detect = lm75_detect,
|
|
.address_list = normal_i2c,
|
|
};
|
|
|
|
module_i2c_driver(lm75_driver);
|
|
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
|
|
MODULE_DESCRIPTION("LM75 driver");
|
|
MODULE_LICENSE("GPL");
|