summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/ad7414.c
blob: a529f2efc79017e9db5d4747620e6b08b42e50e6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * An hwmon driver for the Analog Devices AD7414
 *
 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
 *
 * Copyright (c) 2008 PIKA Technologies
 *   Sean MacLennan <smaclennan@pikatech.com>
 *
 * Copyright (c) 2008 Spansion Inc.
 *   Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
 *   (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
 *
 * Based on ad7418.c
 * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
 */

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>


/* AD7414 registers */
#define AD7414_REG_TEMP		0x00
#define AD7414_REG_CONF		0x01
#define AD7414_REG_T_HIGH	0x02
#define AD7414_REG_T_LOW	0x03

static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };

struct ad7414_data {
	struct i2c_client	*client;
	struct mutex		lock;	/* atomic read data updates */
	char			valid;	/* !=0 if following fields are valid */
	unsigned long		next_update;	/* In jiffies */
	s16			temp_input;	/* Register values */
	s8			temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
};

/* REG: (0.25C/bit, two's complement) << 6 */
static inline int ad7414_temp_from_reg(s16 reg)
{
	/*
	 * use integer division instead of equivalent right shift to
	 * guarantee arithmetic shift and preserve the sign
	 */
	return ((int)reg / 64) * 250;
}

static inline int ad7414_read(struct i2c_client *client, u8 reg)
{
	if (reg == AD7414_REG_TEMP)
		return i2c_smbus_read_word_swapped(client, reg);
	else
		return i2c_smbus_read_byte_data(client, reg);
}

static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
{
	return i2c_smbus_write_byte_data(client, reg, value);
}

static struct ad7414_data *ad7414_update_device(struct device *dev)
{
	struct ad7414_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	mutex_lock(&data->lock);

	if (time_after(jiffies, data->next_update) || !data->valid) {
		int value, i;

		dev_dbg(&client->dev, "starting ad7414 update\n");

		value = ad7414_read(client, AD7414_REG_TEMP);
		if (value < 0)
			dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
				value);
		else
			data->temp_input = value;

		for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
			value = ad7414_read(client, AD7414_REG_LIMIT[i]);
			if (value < 0)
				dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
					AD7414_REG_LIMIT[i], value);
			else
				data->temps[i] = value;
		}

		data->next_update = jiffies + HZ + HZ / 2;
		data->valid = 1;
	}

	mutex_unlock(&data->lock);

	return data;
}

static ssize_t temp_input_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct ad7414_data *data = ad7414_update_device(dev);
	return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
}
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);

static ssize_t max_min_show(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	int index = to_sensor_dev_attr(attr)->index;
	struct ad7414_data *data = ad7414_update_device(dev);
	return sprintf(buf, "%d\n", data->temps[index] * 1000);
}

static ssize_t max_min_store(struct device *dev,
			     struct device_attribute *attr, const char *buf,
			     size_t count)
{
	struct ad7414_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int index = to_sensor_dev_attr(attr)->index;
	u8 reg = AD7414_REG_LIMIT[index];
	long temp;
	int ret = kstrtol(buf, 10, &temp);

	if (ret < 0)
		return ret;

	temp = clamp_val(temp, -40000, 85000);
	temp = (temp + (temp < 0 ? -500 : 500)) / 1000;

	mutex_lock(&data->lock);
	data->temps[index] = temp;
	ad7414_write(client, reg, temp);
	mutex_unlock(&data->lock);
	return count;
}

static SENSOR_DEVICE_ATTR_RW(temp1_max, max_min, 0);
static SENSOR_DEVICE_ATTR_RW(temp1_min, max_min, 1);

static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	int bitnr = to_sensor_dev_attr(attr)->index;
	struct ad7414_data *data = ad7414_update_device(dev);
	int value = (data->temp_input >> bitnr) & 1;
	return sprintf(buf, "%d\n", value);
}

static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 3);
static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 4);

static struct attribute *ad7414_attrs[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(ad7414);

static int ad7414_probe(struct i2c_client *client,
			const struct i2c_device_id *dev_id)
{
	struct device *dev = &client->dev;
	struct ad7414_data *data;
	struct device *hwmon_dev;
	int conf;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -EOPNOTSUPP;

	data = devm_kzalloc(dev, sizeof(struct ad7414_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->client = client;
	mutex_init(&data->lock);

	dev_info(&client->dev, "chip found\n");

	/* Make sure the chip is powered up. */
	conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
	if (conf < 0)
		dev_warn(dev, "ad7414_probe unable to read config register.\n");
	else {
		conf &= ~(1 << 7);
		i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
	}

	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
							   client->name,
							   data, ad7414_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id ad7414_id[] = {
	{ "ad7414", 0 },
	{}
};
MODULE_DEVICE_TABLE(i2c, ad7414_id);

static const struct of_device_id __maybe_unused ad7414_of_match[] = {
	{ .compatible = "ad,ad7414" },
	{ },
};
MODULE_DEVICE_TABLE(of, ad7414_of_match);

static struct i2c_driver ad7414_driver = {
	.driver = {
		.name	= "ad7414",
		.of_match_table = of_match_ptr(ad7414_of_match),
	},
	.probe	= ad7414_probe,
	.id_table = ad7414_id,
};

module_i2c_driver(ad7414_driver);

MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
	      "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");

MODULE_DESCRIPTION("AD7414 driver");
MODULE_LICENSE("GPL");