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 | 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 */ |
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, command: reg); |
60 | else |
61 | return i2c_smbus_read_byte_data(client, command: 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, command: 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, reg: 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(lock: &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, fmt: "%d\n" , ad7414_temp_from_reg(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, fmt: "%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(s: buf, base: 10, res: &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, value: temp); |
142 | mutex_unlock(lock: &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, fmt: "%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 | { |
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(adap: client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
180 | I2C_FUNC_SMBUS_READ_WORD_DATA)) |
181 | return -EOPNOTSUPP; |
182 | |
183 | data = devm_kzalloc(dev, size: 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, value: conf); |
199 | } |
200 | |
201 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, |
202 | name: client->name, |
203 | drvdata: data, groups: ad7414_groups); |
204 | return PTR_ERR_OR_ZERO(ptr: hwmon_dev); |
205 | } |
206 | |
207 | static const struct i2c_device_id ad7414_id[] = { |
208 | { "ad7414" , 0 }, |
209 | {} |
210 | }; |
211 | MODULE_DEVICE_TABLE(i2c, ad7414_id); |
212 | |
213 | static const struct of_device_id __maybe_unused ad7414_of_match[] = { |
214 | { .compatible = "ad,ad7414" }, |
215 | { }, |
216 | }; |
217 | MODULE_DEVICE_TABLE(of, ad7414_of_match); |
218 | |
219 | static 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 | |
228 | module_i2c_driver(ad7414_driver); |
229 | |
230 | MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " |
231 | "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>" ); |
232 | |
233 | MODULE_DESCRIPTION("AD7414 driver" ); |
234 | MODULE_LICENSE("GPL" ); |
235 | |