1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * An hwmon driver for the Analog Devices AD7414 4 * 5 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering 6 * 7 * Copyright (c) 2008 PIKA Technologies 8 * 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.c 15 * 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 0x00 31 #define AD7414_REG_CONF 0x01 32 #define AD7414_REG_T_HIGH 0x02 33 #define AD7414_REG_T_LOW 0x03 34 35 static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW }; 36 37 struct ad7414_data { 38 struct i2c_client *client; 39 struct mutex lock; /* atomic read data updates */ 40 char valid; /* !=0 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 */ 47 static inline int ad7414_temp_from_reg(s16 reg) 48 { 49 /* 50 * use integer division instead of equivalent right shift to 51 * guarantee arithmetic shift and preserve the sign 52 */ 53 return ((int)reg / 64) * 250; 54 } 55 56 static 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 else 61 return i2c_smbus_read_byte_data(client, reg); 62 } 63 64 static 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 69 static 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 else 86 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 else 94 data->temps[i] = value; 95 } 96 97 data->next_update = jiffies + HZ + HZ / 2; 98 data->valid = 1; 99 } 100 101 mutex_unlock(&data->lock); 102 103 return data; 104 } 105 106 static 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 } 112 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0); 113 114 static 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 } 121 122 static 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 } 145 146 static SENSOR_DEVICE_ATTR_RW(temp1_max, max_min, 0); 147 static SENSOR_DEVICE_ATTR_RW(temp1_min, max_min, 1); 148 149 static 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 } 157 158 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 3); 159 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 4); 160 161 static 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 NULL 168 }; 169 170 ATTRIBUTE_GROUPS(ad7414); 171 172 static int ad7414_probe(struct i2c_client *client, 173 const struct i2c_device_id *dev_id) 174 { 175 struct device *dev = &client->dev; 176 struct ad7414_data *data; 177 struct device *hwmon_dev; 178 int conf; 179 180 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | 181 I2C_FUNC_SMBUS_READ_WORD_DATA)) 182 return -EOPNOTSUPP; 183 184 data = devm_kzalloc(dev, sizeof(struct ad7414_data), GFP_KERNEL); 185 if (!data) 186 return -ENOMEM; 187 188 data->client = client; 189 mutex_init(&data->lock); 190 191 dev_info(&client->dev, "chip found\n"); 192 193 /* Make sure the chip is powered up. */ 194 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF); 195 if (conf < 0) 196 dev_warn(dev, "ad7414_probe unable to read config register.\n"); 197 else { 198 conf &= ~(1 << 7); 199 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf); 200 } 201 202 hwmon_dev = devm_hwmon_device_register_with_groups(dev, 203 client->name, 204 data, ad7414_groups); 205 return PTR_ERR_OR_ZERO(hwmon_dev); 206 } 207 208 static const struct i2c_device_id ad7414_id[] = { 209 { "ad7414", 0 }, 210 {} 211 }; 212 MODULE_DEVICE_TABLE(i2c, ad7414_id); 213 214 static const struct of_device_id __maybe_unused ad7414_of_match[] = { 215 { .compatible = "ad,ad7414" }, 216 { }, 217 }; 218 MODULE_DEVICE_TABLE(of, ad7414_of_match); 219 220 static struct i2c_driver ad7414_driver = { 221 .driver = { 222 .name = "ad7414", 223 .of_match_table = of_match_ptr(ad7414_of_match), 224 }, 225 .probe = ad7414_probe, 226 .id_table = ad7414_id, 227 }; 228 229 module_i2c_driver(ad7414_driver); 230 231 MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " 232 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>"); 233 234 MODULE_DESCRIPTION("AD7414 driver"); 235 MODULE_LICENSE("GPL"); 236