xref: /openbmc/linux/drivers/hwmon/ad7418.c (revision 9ac8d3fb)
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 "0.4"
27 
28 enum chips { ad7416, ad7417, ad7418 };
29 
30 /* AD7418 registers */
31 #define AD7418_REG_TEMP_IN	0x00
32 #define AD7418_REG_CONF		0x01
33 #define AD7418_REG_TEMP_HYST	0x02
34 #define AD7418_REG_TEMP_OS	0x03
35 #define AD7418_REG_ADC		0x04
36 #define AD7418_REG_CONF2	0x05
37 
38 #define AD7418_REG_ADC_CH(x)	((x) << 5)
39 #define AD7418_CH_TEMP		AD7418_REG_ADC_CH(0)
40 
41 static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
42 					AD7418_REG_TEMP_HYST,
43 					AD7418_REG_TEMP_OS };
44 
45 struct ad7418_data {
46 	struct device		*hwmon_dev;
47 	struct attribute_group	attrs;
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 
57 static int ad7418_probe(struct i2c_client *client,
58 			const struct i2c_device_id *id);
59 static int ad7418_remove(struct i2c_client *client);
60 
61 static const struct i2c_device_id ad7418_id[] = {
62 	{ "ad7416", ad7416 },
63 	{ "ad7417", ad7417 },
64 	{ "ad7418", ad7418 },
65 	{ }
66 };
67 MODULE_DEVICE_TABLE(i2c, ad7418_id);
68 
69 static struct i2c_driver ad7418_driver = {
70 	.driver = {
71 		.name	= "ad7418",
72 	},
73 	.probe		= ad7418_probe,
74 	.remove		= ad7418_remove,
75 	.id_table	= ad7418_id,
76 };
77 
78 /* All registers are word-sized, except for the configuration registers.
79  * AD7418 uses a high-byte first convention. Do NOT use those functions to
80  * access the configuration registers CONF and CONF2, as they are byte-sized.
81  */
82 static inline int ad7418_read(struct i2c_client *client, u8 reg)
83 {
84 	return swab16(i2c_smbus_read_word_data(client, reg));
85 }
86 
87 static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
88 {
89 	return i2c_smbus_write_word_data(client, reg, swab16(value));
90 }
91 
92 static void ad7418_init_client(struct i2c_client *client)
93 {
94 	struct ad7418_data *data = i2c_get_clientdata(client);
95 
96 	int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
97 	if (reg < 0) {
98 		dev_err(&client->dev, "cannot read configuration register\n");
99 	} else {
100 		dev_info(&client->dev, "configuring for mode 1\n");
101 		i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
102 
103 		if (data->type == ad7417 || data->type == ad7418)
104 			i2c_smbus_write_byte_data(client,
105 						AD7418_REG_CONF2, 0x00);
106 	}
107 }
108 
109 static struct ad7418_data *ad7418_update_device(struct device *dev)
110 {
111 	struct i2c_client *client = to_i2c_client(dev);
112 	struct ad7418_data *data = i2c_get_clientdata(client);
113 
114 	mutex_lock(&data->lock);
115 
116 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
117 		|| !data->valid) {
118 		u8 cfg;
119 		int i, ch;
120 
121 		/* read config register and clear channel bits */
122 		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
123 		cfg &= 0x1F;
124 
125 		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
126 						cfg | AD7418_CH_TEMP);
127 		udelay(30);
128 
129 		for (i = 0; i < 3; i++) {
130 			data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
131 		}
132 
133 		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
134 			i2c_smbus_write_byte_data(client,
135 					AD7418_REG_CONF,
136 					cfg | AD7418_REG_ADC_CH(ch));
137 
138 			udelay(15);
139 			data->in[data->adc_max - 1 - i] =
140 				ad7418_read(client, AD7418_REG_ADC);
141 		}
142 
143 		/* restore old configuration value */
144 		ad7418_write(client, AD7418_REG_CONF, cfg);
145 
146 		data->last_updated = jiffies;
147 		data->valid = 1;
148 	}
149 
150 	mutex_unlock(&data->lock);
151 
152 	return data;
153 }
154 
155 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
156 			char *buf)
157 {
158 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
159 	struct ad7418_data *data = ad7418_update_device(dev);
160 	return sprintf(buf, "%d\n",
161 		LM75_TEMP_FROM_REG(data->temp[attr->index]));
162 }
163 
164 static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
165 			char *buf)
166 {
167 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
168 	struct ad7418_data *data = ad7418_update_device(dev);
169 
170 	return sprintf(buf, "%d\n",
171 		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
172 }
173 
174 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
175 			const char *buf, size_t count)
176 {
177 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
178 	struct i2c_client *client = to_i2c_client(dev);
179 	struct ad7418_data *data = i2c_get_clientdata(client);
180 	long temp = simple_strtol(buf, NULL, 10);
181 
182 	mutex_lock(&data->lock);
183 	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
184 	ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
185 	mutex_unlock(&data->lock);
186 	return count;
187 }
188 
189 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
190 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
191 				show_temp, set_temp, 1);
192 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
193 				show_temp, set_temp, 2);
194 
195 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
196 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
197 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
198 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
199 
200 static struct attribute *ad7416_attributes[] = {
201 	&sensor_dev_attr_temp1_max.dev_attr.attr,
202 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
203 	&sensor_dev_attr_temp1_input.dev_attr.attr,
204 	NULL
205 };
206 
207 static struct attribute *ad7417_attributes[] = {
208 	&sensor_dev_attr_temp1_max.dev_attr.attr,
209 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
210 	&sensor_dev_attr_temp1_input.dev_attr.attr,
211 	&sensor_dev_attr_in1_input.dev_attr.attr,
212 	&sensor_dev_attr_in2_input.dev_attr.attr,
213 	&sensor_dev_attr_in3_input.dev_attr.attr,
214 	&sensor_dev_attr_in4_input.dev_attr.attr,
215 	NULL
216 };
217 
218 static struct attribute *ad7418_attributes[] = {
219 	&sensor_dev_attr_temp1_max.dev_attr.attr,
220 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
221 	&sensor_dev_attr_temp1_input.dev_attr.attr,
222 	&sensor_dev_attr_in1_input.dev_attr.attr,
223 	NULL
224 };
225 
226 static int ad7418_probe(struct i2c_client *client,
227 			 const struct i2c_device_id *id)
228 {
229 	struct i2c_adapter *adapter = client->adapter;
230 	struct ad7418_data *data;
231 	int err;
232 
233 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
234 					I2C_FUNC_SMBUS_WORD_DATA)) {
235 		err = -EOPNOTSUPP;
236 		goto exit;
237 	}
238 
239 	if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
240 		err = -ENOMEM;
241 		goto exit;
242 	}
243 
244 	i2c_set_clientdata(client, data);
245 
246 	mutex_init(&data->lock);
247 	data->type = id->driver_data;
248 
249 	switch (data->type) {
250 	case ad7416:
251 		data->adc_max = 0;
252 		data->attrs.attrs = ad7416_attributes;
253 		break;
254 
255 	case ad7417:
256 		data->adc_max = 4;
257 		data->attrs.attrs = ad7417_attributes;
258 		break;
259 
260 	case ad7418:
261 		data->adc_max = 1;
262 		data->attrs.attrs = ad7418_attributes;
263 		break;
264 	}
265 
266 	dev_info(&client->dev, "%s chip found\n", client->name);
267 
268 	/* Initialize the AD7418 chip */
269 	ad7418_init_client(client);
270 
271 	/* Register sysfs hooks */
272 	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
273 		goto exit_free;
274 
275 	data->hwmon_dev = hwmon_device_register(&client->dev);
276 	if (IS_ERR(data->hwmon_dev)) {
277 		err = PTR_ERR(data->hwmon_dev);
278 		goto exit_remove;
279 	}
280 
281 	return 0;
282 
283 exit_remove:
284 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
285 exit_free:
286 	kfree(data);
287 exit:
288 	return err;
289 }
290 
291 static int ad7418_remove(struct i2c_client *client)
292 {
293 	struct ad7418_data *data = i2c_get_clientdata(client);
294 	hwmon_device_unregister(data->hwmon_dev);
295 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
296 	kfree(data);
297 	return 0;
298 }
299 
300 static int __init ad7418_init(void)
301 {
302 	return i2c_add_driver(&ad7418_driver);
303 }
304 
305 static void __exit ad7418_exit(void)
306 {
307 	i2c_del_driver(&ad7418_driver);
308 }
309 
310 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
311 MODULE_DESCRIPTION("AD7416/17/18 driver");
312 MODULE_LICENSE("GPL");
313 MODULE_VERSION(DRV_VERSION);
314 
315 module_init(ad7418_init);
316 module_exit(ad7418_exit);
317