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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * An hwmon driver for the Analog Devices AD74144 *5 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering6 *7 * Copyright (c) 2008 PIKA Technologies8 * Sean MacLennan <smaclennan@pikatech.com>9 *10 * Copyright (c) 2008 Spansion Inc.11 * Frank Edelhaeuser <frank.edelhaeuser at spansion.com>12 * (converted to "new style" I2C driver model, removed checkpatch.pl warnings)13 *14 * Based on ad7418.c15 * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>16 */17 18#include <linux/module.h>19#include <linux/jiffies.h>20#include <linux/i2c.h>21#include <linux/hwmon.h>22#include <linux/hwmon-sysfs.h>23#include <linux/err.h>24#include <linux/mutex.h>25#include <linux/sysfs.h>26#include <linux/slab.h>27 28 29/* AD7414 registers */30#define AD7414_REG_TEMP 0x0031#define AD7414_REG_CONF 0x0132#define AD7414_REG_T_HIGH 0x0233#define AD7414_REG_T_LOW 0x0334 35static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };36 37struct ad7414_data {38 struct i2c_client *client;39 struct mutex lock; /* atomic read data updates */40 bool valid; /* true if following fields are valid */41 unsigned long next_update; /* In jiffies */42 s16 temp_input; /* Register values */43 s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)];44};45 46/* REG: (0.25C/bit, two's complement) << 6 */47static inline int ad7414_temp_from_reg(s16 reg)48{49 /*50 * use integer division instead of equivalent right shift to51 * guarantee arithmetic shift and preserve the sign52 */53 return ((int)reg / 64) * 250;54}55 56static inline int ad7414_read(struct i2c_client *client, u8 reg)57{58 if (reg == AD7414_REG_TEMP)59 return i2c_smbus_read_word_swapped(client, reg);60 else61 return i2c_smbus_read_byte_data(client, reg);62}63 64static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)65{66 return i2c_smbus_write_byte_data(client, reg, value);67}68 69static struct ad7414_data *ad7414_update_device(struct device *dev)70{71 struct ad7414_data *data = dev_get_drvdata(dev);72 struct i2c_client *client = data->client;73 74 mutex_lock(&data->lock);75 76 if (time_after(jiffies, data->next_update) || !data->valid) {77 int value, i;78 79 dev_dbg(&client->dev, "starting ad7414 update\n");80 81 value = ad7414_read(client, AD7414_REG_TEMP);82 if (value < 0)83 dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",84 value);85 else86 data->temp_input = value;87 88 for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {89 value = ad7414_read(client, AD7414_REG_LIMIT[i]);90 if (value < 0)91 dev_dbg(&client->dev, "AD7414 reg %d err %d\n",92 AD7414_REG_LIMIT[i], value);93 else94 data->temps[i] = value;95 }96 97 data->next_update = jiffies + HZ + HZ / 2;98 data->valid = true;99 }100 101 mutex_unlock(&data->lock);102 103 return data;104}105 106static ssize_t temp_input_show(struct device *dev,107 struct device_attribute *attr, char *buf)108{109 struct ad7414_data *data = ad7414_update_device(dev);110 return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));111}112static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);113 114static ssize_t max_min_show(struct device *dev, struct device_attribute *attr,115 char *buf)116{117 int index = to_sensor_dev_attr(attr)->index;118 struct ad7414_data *data = ad7414_update_device(dev);119 return sprintf(buf, "%d\n", data->temps[index] * 1000);120}121 122static ssize_t max_min_store(struct device *dev,123 struct device_attribute *attr, const char *buf,124 size_t count)125{126 struct ad7414_data *data = dev_get_drvdata(dev);127 struct i2c_client *client = data->client;128 int index = to_sensor_dev_attr(attr)->index;129 u8 reg = AD7414_REG_LIMIT[index];130 long temp;131 int ret = kstrtol(buf, 10, &temp);132 133 if (ret < 0)134 return ret;135 136 temp = clamp_val(temp, -40000, 85000);137 temp = (temp + (temp < 0 ? -500 : 500)) / 1000;138 139 mutex_lock(&data->lock);140 data->temps[index] = temp;141 ad7414_write(client, reg, temp);142 mutex_unlock(&data->lock);143 return count;144}145 146static SENSOR_DEVICE_ATTR_RW(temp1_max, max_min, 0);147static SENSOR_DEVICE_ATTR_RW(temp1_min, max_min, 1);148 149static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,150 char *buf)151{152 int bitnr = to_sensor_dev_attr(attr)->index;153 struct ad7414_data *data = ad7414_update_device(dev);154 int value = (data->temp_input >> bitnr) & 1;155 return sprintf(buf, "%d\n", value);156}157 158static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 3);159static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 4);160 161static struct attribute *ad7414_attrs[] = {162 &sensor_dev_attr_temp1_input.dev_attr.attr,163 &sensor_dev_attr_temp1_max.dev_attr.attr,164 &sensor_dev_attr_temp1_min.dev_attr.attr,165 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,166 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,167 NULL168};169 170ATTRIBUTE_GROUPS(ad7414);171 172static int ad7414_probe(struct i2c_client *client)173{174 struct device *dev = &client->dev;175 struct ad7414_data *data;176 struct device *hwmon_dev;177 int conf;178 179 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |180 I2C_FUNC_SMBUS_READ_WORD_DATA))181 return -EOPNOTSUPP;182 183 data = devm_kzalloc(dev, sizeof(struct ad7414_data), GFP_KERNEL);184 if (!data)185 return -ENOMEM;186 187 data->client = client;188 mutex_init(&data->lock);189 190 dev_info(&client->dev, "chip found\n");191 192 /* Make sure the chip is powered up. */193 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);194 if (conf < 0)195 dev_warn(dev, "ad7414_probe unable to read config register.\n");196 else {197 conf &= ~(1 << 7);198 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);199 }200 201 hwmon_dev = devm_hwmon_device_register_with_groups(dev,202 client->name,203 data, ad7414_groups);204 return PTR_ERR_OR_ZERO(hwmon_dev);205}206 207static const struct i2c_device_id ad7414_id[] = {208 { "ad7414" },209 {}210};211MODULE_DEVICE_TABLE(i2c, ad7414_id);212 213static const struct of_device_id __maybe_unused ad7414_of_match[] = {214 { .compatible = "ad,ad7414" },215 { },216};217MODULE_DEVICE_TABLE(of, ad7414_of_match);218 219static struct i2c_driver ad7414_driver = {220 .driver = {221 .name = "ad7414",222 .of_match_table = of_match_ptr(ad7414_of_match),223 },224 .probe = ad7414_probe,225 .id_table = ad7414_id,226};227 228module_i2c_driver(ad7414_driver);229 230MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "231 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");232 233MODULE_DESCRIPTION("AD7414 driver");234MODULE_LICENSE("GPL");235