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 device		*hwmon_dev;
48	struct attribute_group	attrs;
49	enum chips		type;
50	struct mutex		lock;
51	int			adc_max;	/* number of ADC channels */
52	char			valid;
53	unsigned long		last_updated;	/* In jiffies */
54	s16			temp[3];	/* Register values */
55	u16			in[4];
56};
57
58static int ad7418_probe(struct i2c_client *client,
59			const struct i2c_device_id *id);
60static int ad7418_remove(struct i2c_client *client);
61
62static const struct i2c_device_id ad7418_id[] = {
63	{ "ad7416", ad7416 },
64	{ "ad7417", ad7417 },
65	{ "ad7418", ad7418 },
66	{ }
67};
68MODULE_DEVICE_TABLE(i2c, ad7418_id);
69
70static struct i2c_driver ad7418_driver = {
71	.driver = {
72		.name	= "ad7418",
73	},
74	.probe		= ad7418_probe,
75	.remove		= ad7418_remove,
76	.id_table	= ad7418_id,
77};
78
79static void ad7418_init_client(struct i2c_client *client)
80{
81	struct ad7418_data *data = i2c_get_clientdata(client);
82
83	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
84	if (reg < 0) {
85		dev_err(&client->dev, "cannot read configuration register\n");
86	} else {
87		dev_info(&client->dev, "configuring for mode 1\n");
88		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
89
90		if (data->type == ad7417 || data->type == ad7418)
91			i2c_smbus_write_byte_data(client,
92						AD7418_REG_CONF2, 0x00);
93	}
94}
95
96static struct ad7418_data *ad7418_update_device(struct device *dev)
97{
98	struct i2c_client *client = to_i2c_client(dev);
99	struct ad7418_data *data = i2c_get_clientdata(client);
100
101	mutex_lock(&data->lock);
102
103	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
104		|| !data->valid) {
105		u8 cfg;
106		int i, ch;
107
108		/* read config register and clear channel bits */
109		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
110		cfg &= 0x1F;
111
112		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
113						cfg | AD7418_CH_TEMP);
114		udelay(30);
115
116		for (i = 0; i < 3; i++) {
117			data->temp[i] =
118				i2c_smbus_read_word_swapped(client,
119						AD7418_REG_TEMP[i]);
120		}
121
122		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
123			i2c_smbus_write_byte_data(client,
124					AD7418_REG_CONF,
125					cfg | AD7418_REG_ADC_CH(ch));
126
127			udelay(15);
128			data->in[data->adc_max - 1 - i] =
129				i2c_smbus_read_word_swapped(client,
130						AD7418_REG_ADC);
131		}
132
133		/* restore old configuration value */
134		i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);
135
136		data->last_updated = jiffies;
137		data->valid = 1;
138	}
139
140	mutex_unlock(&data->lock);
141
142	return data;
143}
144
145static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
146			char *buf)
147{
148	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
149	struct ad7418_data *data = ad7418_update_device(dev);
150	return sprintf(buf, "%d\n",
151		LM75_TEMP_FROM_REG(data->temp[attr->index]));
152}
153
154static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
155			char *buf)
156{
157	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
158	struct ad7418_data *data = ad7418_update_device(dev);
159
160	return sprintf(buf, "%d\n",
161		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
162}
163
164static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
165			const char *buf, size_t count)
166{
167	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
168	struct i2c_client *client = to_i2c_client(dev);
169	struct ad7418_data *data = i2c_get_clientdata(client);
170	long temp = simple_strtol(buf, NULL, 10);
171
172	mutex_lock(&data->lock);
173	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
174	i2c_smbus_write_word_swapped(client,
175				     AD7418_REG_TEMP[attr->index],
176				     data->temp[attr->index]);
177	mutex_unlock(&data->lock);
178	return count;
179}
180
181static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
182static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
183				show_temp, set_temp, 1);
184static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
185				show_temp, set_temp, 2);
186
187static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
188static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
189static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
190static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
191
192static struct attribute *ad7416_attributes[] = {
193	&sensor_dev_attr_temp1_max.dev_attr.attr,
194	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
195	&sensor_dev_attr_temp1_input.dev_attr.attr,
196	NULL
197};
198
199static struct attribute *ad7417_attributes[] = {
200	&sensor_dev_attr_temp1_max.dev_attr.attr,
201	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
202	&sensor_dev_attr_temp1_input.dev_attr.attr,
203	&sensor_dev_attr_in1_input.dev_attr.attr,
204	&sensor_dev_attr_in2_input.dev_attr.attr,
205	&sensor_dev_attr_in3_input.dev_attr.attr,
206	&sensor_dev_attr_in4_input.dev_attr.attr,
207	NULL
208};
209
210static struct attribute *ad7418_attributes[] = {
211	&sensor_dev_attr_temp1_max.dev_attr.attr,
212	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
213	&sensor_dev_attr_temp1_input.dev_attr.attr,
214	&sensor_dev_attr_in1_input.dev_attr.attr,
215	NULL
216};
217
218static int ad7418_probe(struct i2c_client *client,
219			 const struct i2c_device_id *id)
220{
221	struct i2c_adapter *adapter = client->adapter;
222	struct ad7418_data *data;
223	int err;
224
225	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
226					I2C_FUNC_SMBUS_WORD_DATA)) {
227		err = -EOPNOTSUPP;
228		goto exit;
229	}
230
231	if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
232		err = -ENOMEM;
233		goto exit;
234	}
235
236	i2c_set_clientdata(client, data);
237
238	mutex_init(&data->lock);
239	data->type = id->driver_data;
240
241	switch (data->type) {
242	case ad7416:
243		data->adc_max = 0;
244		data->attrs.attrs = ad7416_attributes;
245		break;
246
247	case ad7417:
248		data->adc_max = 4;
249		data->attrs.attrs = ad7417_attributes;
250		break;
251
252	case ad7418:
253		data->adc_max = 1;
254		data->attrs.attrs = ad7418_attributes;
255		break;
256	}
257
258	dev_info(&client->dev, "%s chip found\n", client->name);
259
260	/* Initialize the AD7418 chip */
261	ad7418_init_client(client);
262
263	/* Register sysfs hooks */
264	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
265		goto exit_free;
266
267	data->hwmon_dev = hwmon_device_register(&client->dev);
268	if (IS_ERR(data->hwmon_dev)) {
269		err = PTR_ERR(data->hwmon_dev);
270		goto exit_remove;
271	}
272
273	return 0;
274
275exit_remove:
276	sysfs_remove_group(&client->dev.kobj, &data->attrs);
277exit_free:
278	kfree(data);
279exit:
280	return err;
281}
282
283static int ad7418_remove(struct i2c_client *client)
284{
285	struct ad7418_data *data = i2c_get_clientdata(client);
286	hwmon_device_unregister(data->hwmon_dev);
287	sysfs_remove_group(&client->dev.kobj, &data->attrs);
288	kfree(data);
289	return 0;
290}
291
292static int __init ad7418_init(void)
293{
294	return i2c_add_driver(&ad7418_driver);
295}
296
297static void __exit ad7418_exit(void)
298{
299	i2c_del_driver(&ad7418_driver);
300}
301
302MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
303MODULE_DESCRIPTION("AD7416/17/18 driver");
304MODULE_LICENSE("GPL");
305MODULE_VERSION(DRV_VERSION);
306
307module_init(ad7418_init);
308module_exit(ad7418_exit);
309