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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 <[email protected]>
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
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 to
51 * guarantee arithmetic shift and preserve the sign
52 */
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 else
61 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 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 = 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 NULL
168};
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 { .name = "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");