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
24#include "lm75.h"
25
26#define DRV_VERSION "0.3"
27
28/* Addresses to scan */
29static unsigned short normal_i2c[] = { 0x28, I2C_CLIENT_END };
30/* Insmod parameters */
31I2C_CLIENT_INSMOD_3(ad7416, ad7417, ad7418);
32
33/* AD7418 registers */
34#define AD7418_REG_TEMP_IN	0x00
35#define AD7418_REG_CONF		0x01
36#define AD7418_REG_TEMP_HYST	0x02
37#define AD7418_REG_TEMP_OS	0x03
38#define AD7418_REG_ADC		0x04
39#define AD7418_REG_CONF2	0x05
40
41#define AD7418_REG_ADC_CH(x)	((x) << 5)
42#define AD7418_CH_TEMP		AD7418_REG_ADC_CH(0)
43
44static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
45					AD7418_REG_TEMP_HYST,
46					AD7418_REG_TEMP_OS };
47
48struct ad7418_data {
49	struct i2c_client	client;
50	struct class_device	*class_dev;
51	struct attribute_group	attrs;
52	enum chips		type;
53	struct mutex		lock;
54	int			adc_max;	/* number of ADC channels */
55	char			valid;
56	unsigned long		last_updated;	/* In jiffies */
57	s16			temp[3];	/* Register values */
58	u16			in[4];
59};
60
61static int ad7418_attach_adapter(struct i2c_adapter *adapter);
62static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind);
63static int ad7418_detach_client(struct i2c_client *client);
64
65static struct i2c_driver ad7418_driver = {
66	.driver = {
67		.name	= "ad7418",
68	},
69	.attach_adapter	= ad7418_attach_adapter,
70	.detach_client	= ad7418_detach_client,
71};
72
73/* All registers are word-sized, except for the configuration registers.
74 * AD7418 uses a high-byte first convention. Do NOT use those functions to
75 * access the configuration registers CONF and CONF2, as they are byte-sized.
76 */
77static inline int ad7418_read(struct i2c_client *client, u8 reg)
78{
79	return swab16(i2c_smbus_read_word_data(client, reg));
80}
81
82static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
83{
84	return i2c_smbus_write_word_data(client, reg, swab16(value));
85}
86
87static void ad7418_init_client(struct i2c_client *client)
88{
89	struct ad7418_data *data = i2c_get_clientdata(client);
90
91	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
92	if (reg < 0) {
93		dev_err(&client->dev, "cannot read configuration register\n");
94	} else {
95		dev_info(&client->dev, "configuring for mode 1\n");
96		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
97
98		if (data->type == ad7417 || data->type == ad7418)
99			i2c_smbus_write_byte_data(client,
100						AD7418_REG_CONF2, 0x00);
101	}
102}
103
104static struct ad7418_data *ad7418_update_device(struct device *dev)
105{
106	struct i2c_client *client = to_i2c_client(dev);
107	struct ad7418_data *data = i2c_get_clientdata(client);
108
109	mutex_lock(&data->lock);
110
111	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
112		|| !data->valid) {
113		u8 cfg;
114		int i, ch;
115
116		/* read config register and clear channel bits */
117		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
118		cfg &= 0x1F;
119
120		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
121						cfg | AD7418_CH_TEMP);
122		udelay(30);
123
124		for (i = 0; i < 3; i++) {
125			data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
126		}
127
128		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
129			i2c_smbus_write_byte_data(client,
130					AD7418_REG_CONF,
131					cfg | AD7418_REG_ADC_CH(ch));
132
133			udelay(15);
134			data->in[data->adc_max - 1 - i] =
135				ad7418_read(client, AD7418_REG_ADC);
136		}
137
138		/* restore old configuration value */
139		ad7418_write(client, AD7418_REG_CONF, cfg);
140
141		data->last_updated = jiffies;
142		data->valid = 1;
143	}
144
145	mutex_unlock(&data->lock);
146
147	return data;
148}
149
150static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
151			char *buf)
152{
153	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
154	struct ad7418_data *data = ad7418_update_device(dev);
155	return sprintf(buf, "%d\n",
156		LM75_TEMP_FROM_REG(data->temp[attr->index]));
157}
158
159static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
160			char *buf)
161{
162	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
163	struct ad7418_data *data = ad7418_update_device(dev);
164
165	return sprintf(buf, "%d\n",
166		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
167}
168
169static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
170			const char *buf, size_t count)
171{
172	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
173	struct i2c_client *client = to_i2c_client(dev);
174	struct ad7418_data *data = i2c_get_clientdata(client);
175	int temp = simple_strtol(buf, NULL, 10);
176
177	mutex_lock(&data->lock);
178	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
179	ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
180	mutex_unlock(&data->lock);
181	return count;
182}
183
184static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
185static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
186				show_temp, set_temp, 1);
187static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
188				show_temp, set_temp, 2);
189
190static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
191static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
192static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
193static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
194
195static int ad7418_attach_adapter(struct i2c_adapter *adapter)
196{
197	if (!(adapter->class & I2C_CLASS_HWMON))
198		return 0;
199	return i2c_probe(adapter, &addr_data, ad7418_detect);
200}
201
202static struct attribute *ad7416_attributes[] = {
203	&sensor_dev_attr_temp1_max.dev_attr.attr,
204	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
205	&sensor_dev_attr_temp1_input.dev_attr.attr,
206	NULL
207};
208
209static struct attribute *ad7417_attributes[] = {
210	&sensor_dev_attr_temp1_max.dev_attr.attr,
211	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
212	&sensor_dev_attr_temp1_input.dev_attr.attr,
213	&sensor_dev_attr_in1_input.dev_attr.attr,
214	&sensor_dev_attr_in2_input.dev_attr.attr,
215	&sensor_dev_attr_in3_input.dev_attr.attr,
216	&sensor_dev_attr_in4_input.dev_attr.attr,
217	NULL
218};
219
220static struct attribute *ad7418_attributes[] = {
221	&sensor_dev_attr_temp1_max.dev_attr.attr,
222	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
223	&sensor_dev_attr_temp1_input.dev_attr.attr,
224	&sensor_dev_attr_in1_input.dev_attr.attr,
225	NULL
226};
227
228static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind)
229{
230	struct i2c_client *client;
231	struct ad7418_data *data;
232	int err = 0;
233
234	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
235					I2C_FUNC_SMBUS_WORD_DATA))
236		goto exit;
237
238	if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
239		err = -ENOMEM;
240		goto exit;
241	}
242
243	client = &data->client;
244	client->addr = address;
245	client->adapter = adapter;
246	client->driver = &ad7418_driver;
247
248	i2c_set_clientdata(client, data);
249
250	mutex_init(&data->lock);
251
252	/* AD7418 has a curious behaviour on registers 6 and 7. They
253	 * both always read 0xC071 and are not documented on the datasheet.
254	 * We use them to detect the chip.
255	 */
256	if (kind <= 0) {
257		int reg, reg6, reg7;
258
259		/* the AD7416 lies within this address range, but I have
260		 * no means to check.
261		 */
262		if (address >= 0x48 && address <= 0x4f) {
263			/* data->type = ad7416; */
264		}
265		/* here we might have AD7417 or AD7418 */
266		else if (address >= 0x28 && address <= 0x2f) {
267			reg6 = i2c_smbus_read_word_data(client, 0x06);
268			reg7 = i2c_smbus_read_word_data(client, 0x07);
269
270			if (address == 0x28 && reg6 == 0xC071 && reg7 == 0xC071)
271				data->type = ad7418;
272
273
274
275			/* both AD7417 and AD7418 have bits 0-5 of
276			 * the CONF2 register at 0
277			 */
278			reg = i2c_smbus_read_byte_data(client,
279							AD7418_REG_CONF2);
280			if (reg & 0x3F)
281				data->type = any_chip; /* detection failed */
282		}
283	} else {
284		dev_dbg(&adapter->dev, "detection forced\n");
285	}
286
287	if (kind > 0)
288		data->type = kind;
289	else if (kind < 0 && data->type == any_chip) {
290		err = -ENODEV;
291		goto exit_free;
292	}
293
294	switch (data->type) {
295	case any_chip:
296	case ad7416:
297		data->adc_max = 0;
298		data->attrs.attrs = ad7416_attributes;
299		strlcpy(client->name, "ad7416", I2C_NAME_SIZE);
300		break;
301
302	case ad7417:
303		data->adc_max = 4;
304		data->attrs.attrs = ad7417_attributes;
305		strlcpy(client->name, "ad7417", I2C_NAME_SIZE);
306		break;
307
308	case ad7418:
309		data->adc_max = 1;
310		data->attrs.attrs = ad7418_attributes;
311		strlcpy(client->name, "ad7418", I2C_NAME_SIZE);
312		break;
313	}
314
315	if ((err = i2c_attach_client(client)))
316		goto exit_free;
317
318	dev_info(&client->dev, "%s chip found\n", client->name);
319
320	/* Initialize the AD7418 chip */
321	ad7418_init_client(client);
322
323	/* Register sysfs hooks */
324	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
325		goto exit_detach;
326
327	data->class_dev = hwmon_device_register(&client->dev);
328	if (IS_ERR(data->class_dev)) {
329		err = PTR_ERR(data->class_dev);
330		goto exit_remove;
331	}
332
333	return 0;
334
335exit_remove:
336	sysfs_remove_group(&client->dev.kobj, &data->attrs);
337exit_detach:
338	i2c_detach_client(client);
339exit_free:
340	kfree(data);
341exit:
342	return err;
343}
344
345static int ad7418_detach_client(struct i2c_client *client)
346{
347	struct ad7418_data *data = i2c_get_clientdata(client);
348	hwmon_device_unregister(data->class_dev);
349	sysfs_remove_group(&client->dev.kobj, &data->attrs);
350	i2c_detach_client(client);
351	kfree(data);
352	return 0;
353}
354
355static int __init ad7418_init(void)
356{
357	return i2c_add_driver(&ad7418_driver);
358}
359
360static void __exit ad7418_exit(void)
361{
362	i2c_del_driver(&ad7418_driver);
363}
364
365MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
366MODULE_DESCRIPTION("AD7416/17/18 driver");
367MODULE_LICENSE("GPL");
368MODULE_VERSION(DRV_VERSION);
369
370module_init(ad7418_init);
371module_exit(ad7418_exit);
372