1/*
2 * An hwmon driver for the Analog Devices AD7416/17/18
3 * Copyright (C) 2006-07 Tower Technologies
4 *
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * Based on lm75.c
8 * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License,
12 * as published by the Free Software Foundation - version 2.
13 */
14
15#include <linux/module.h>
16#include <linux/jiffies.h>
17#include <linux/i2c.h>
18#include <linux/hwmon.h>
19#include <linux/hwmon-sysfs.h>
20#include <linux/err.h>
21#include <linux/mutex.h>
22#include <linux/delay.h>
23#include <linux/slab.h>
24
25#include "lm75.h"
26
27#define DRV_VERSION "0.4"
28
29enum chips { ad7416, ad7417, ad7418 };
30
31/* AD7418 registers */
32#define AD7418_REG_TEMP_IN	0x00
33#define AD7418_REG_CONF		0x01
34#define AD7418_REG_TEMP_HYST	0x02
35#define AD7418_REG_TEMP_OS	0x03
36#define AD7418_REG_ADC		0x04
37#define AD7418_REG_CONF2	0x05
38
39#define AD7418_REG_ADC_CH(x)	((x) << 5)
40#define AD7418_CH_TEMP		AD7418_REG_ADC_CH(0)
41
42static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
43					AD7418_REG_TEMP_HYST,
44					AD7418_REG_TEMP_OS };
45
46struct ad7418_data {
47	struct i2c_client	*client;
48	enum chips		type;
49	struct mutex		lock;
50	int			adc_max;	/* number of ADC channels */
51	char			valid;
52	unsigned long		last_updated;	/* In jiffies */
53	s16			temp[3];	/* Register values */
54	u16			in[4];
55};
56
57static struct ad7418_data *ad7418_update_device(struct device *dev)
58{
59	struct ad7418_data *data = dev_get_drvdata(dev);
60	struct i2c_client *client = data->client;
61
62	mutex_lock(&data->lock);
63
64	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
65		|| !data->valid) {
66		u8 cfg;
67		int i, ch;
68
69		/* read config register and clear channel bits */
70		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
71		cfg &= 0x1F;
72
73		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
74						cfg | AD7418_CH_TEMP);
75		udelay(30);
76
77		for (i = 0; i < 3; i++) {
78			data->temp[i] =
79				i2c_smbus_read_word_swapped(client,
80						AD7418_REG_TEMP[i]);
81		}
82
83		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
84			i2c_smbus_write_byte_data(client,
85					AD7418_REG_CONF,
86					cfg | AD7418_REG_ADC_CH(ch));
87
88			udelay(15);
89			data->in[data->adc_max - 1 - i] =
90				i2c_smbus_read_word_swapped(client,
91						AD7418_REG_ADC);
92		}
93
94		/* restore old configuration value */
95		i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);
96
97		data->last_updated = jiffies;
98		data->valid = 1;
99	}
100
101	mutex_unlock(&data->lock);
102
103	return data;
104}
105
106static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
107			char *buf)
108{
109	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
110	struct ad7418_data *data = ad7418_update_device(dev);
111	return sprintf(buf, "%d\n",
112		LM75_TEMP_FROM_REG(data->temp[attr->index]));
113}
114
115static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
116			char *buf)
117{
118	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
119	struct ad7418_data *data = ad7418_update_device(dev);
120
121	return sprintf(buf, "%d\n",
122		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
123}
124
125static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
126			const char *buf, size_t count)
127{
128	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
129	struct ad7418_data *data = dev_get_drvdata(dev);
130	struct i2c_client *client = data->client;
131	long temp;
132	int ret = kstrtol(buf, 10, &temp);
133
134	if (ret < 0)
135		return ret;
136
137	mutex_lock(&data->lock);
138	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
139	i2c_smbus_write_word_swapped(client,
140				     AD7418_REG_TEMP[attr->index],
141				     data->temp[attr->index]);
142	mutex_unlock(&data->lock);
143	return count;
144}
145
146static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
147static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
148				show_temp, set_temp, 1);
149static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
150				show_temp, set_temp, 2);
151
152static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
153static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
154static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
155static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
156
157static struct attribute *ad7416_attrs[] = {
158	&sensor_dev_attr_temp1_max.dev_attr.attr,
159	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
160	&sensor_dev_attr_temp1_input.dev_attr.attr,
161	NULL
162};
163ATTRIBUTE_GROUPS(ad7416);
164
165static struct attribute *ad7417_attrs[] = {
166	&sensor_dev_attr_temp1_max.dev_attr.attr,
167	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
168	&sensor_dev_attr_temp1_input.dev_attr.attr,
169	&sensor_dev_attr_in1_input.dev_attr.attr,
170	&sensor_dev_attr_in2_input.dev_attr.attr,
171	&sensor_dev_attr_in3_input.dev_attr.attr,
172	&sensor_dev_attr_in4_input.dev_attr.attr,
173	NULL
174};
175ATTRIBUTE_GROUPS(ad7417);
176
177static struct attribute *ad7418_attrs[] = {
178	&sensor_dev_attr_temp1_max.dev_attr.attr,
179	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
180	&sensor_dev_attr_temp1_input.dev_attr.attr,
181	&sensor_dev_attr_in1_input.dev_attr.attr,
182	NULL
183};
184ATTRIBUTE_GROUPS(ad7418);
185
186static void ad7418_init_client(struct i2c_client *client)
187{
188	struct ad7418_data *data = i2c_get_clientdata(client);
189
190	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
191	if (reg < 0) {
192		dev_err(&client->dev, "cannot read configuration register\n");
193	} else {
194		dev_info(&client->dev, "configuring for mode 1\n");
195		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
196
197		if (data->type == ad7417 || data->type == ad7418)
198			i2c_smbus_write_byte_data(client,
199						AD7418_REG_CONF2, 0x00);
200	}
201}
202
203static int ad7418_probe(struct i2c_client *client,
204			 const struct i2c_device_id *id)
205{
206	struct device *dev = &client->dev;
207	struct i2c_adapter *adapter = client->adapter;
208	struct ad7418_data *data;
209	struct device *hwmon_dev;
210	const struct attribute_group **attr_groups = NULL;
211
212	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
213					I2C_FUNC_SMBUS_WORD_DATA))
214		return -EOPNOTSUPP;
215
216	data = devm_kzalloc(dev, sizeof(struct ad7418_data), GFP_KERNEL);
217	if (!data)
218		return -ENOMEM;
219
220	i2c_set_clientdata(client, data);
221
222	mutex_init(&data->lock);
223	data->client = client;
224	data->type = id->driver_data;
225
226	switch (data->type) {
227	case ad7416:
228		data->adc_max = 0;
229		attr_groups = ad7416_groups;
230		break;
231
232	case ad7417:
233		data->adc_max = 4;
234		attr_groups = ad7417_groups;
235		break;
236
237	case ad7418:
238		data->adc_max = 1;
239		attr_groups = ad7418_groups;
240		break;
241	}
242
243	dev_info(dev, "%s chip found\n", client->name);
244
245	/* Initialize the AD7418 chip */
246	ad7418_init_client(client);
247
248	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
249							   client->name,
250							   data, attr_groups);
251	return PTR_ERR_OR_ZERO(hwmon_dev);
252}
253
254static const struct i2c_device_id ad7418_id[] = {
255	{ "ad7416", ad7416 },
256	{ "ad7417", ad7417 },
257	{ "ad7418", ad7418 },
258	{ }
259};
260MODULE_DEVICE_TABLE(i2c, ad7418_id);
261
262static struct i2c_driver ad7418_driver = {
263	.driver = {
264		.name	= "ad7418",
265	},
266	.probe		= ad7418_probe,
267	.id_table	= ad7418_id,
268};
269
270module_i2c_driver(ad7418_driver);
271
272MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
273MODULE_DESCRIPTION("AD7416/17/18 driver");
274MODULE_LICENSE("GPL");
275MODULE_VERSION(DRV_VERSION);
276