xref: /openbmc/linux/drivers/hwmon/ad7418.c (revision 95e9fd10)
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 
29 enum 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 
42 static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
43 					AD7418_REG_TEMP_HYST,
44 					AD7418_REG_TEMP_OS };
45 
46 struct 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 
58 static int ad7418_probe(struct i2c_client *client,
59 			const struct i2c_device_id *id);
60 static int ad7418_remove(struct i2c_client *client);
61 
62 static const struct i2c_device_id ad7418_id[] = {
63 	{ "ad7416", ad7416 },
64 	{ "ad7417", ad7417 },
65 	{ "ad7418", ad7418 },
66 	{ }
67 };
68 MODULE_DEVICE_TABLE(i2c, ad7418_id);
69 
70 static 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 
79 static 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 
96 static 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 
145 static 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 
154 static 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 
164 static 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;
171 	int ret = kstrtol(buf, 10, &temp);
172 
173 	if (ret < 0)
174 		return ret;
175 
176 	mutex_lock(&data->lock);
177 	data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
178 	i2c_smbus_write_word_swapped(client,
179 				     AD7418_REG_TEMP[attr->index],
180 				     data->temp[attr->index]);
181 	mutex_unlock(&data->lock);
182 	return count;
183 }
184 
185 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
186 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
187 				show_temp, set_temp, 1);
188 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
189 				show_temp, set_temp, 2);
190 
191 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
192 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
193 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
194 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
195 
196 static struct attribute *ad7416_attributes[] = {
197 	&sensor_dev_attr_temp1_max.dev_attr.attr,
198 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
199 	&sensor_dev_attr_temp1_input.dev_attr.attr,
200 	NULL
201 };
202 
203 static struct attribute *ad7417_attributes[] = {
204 	&sensor_dev_attr_temp1_max.dev_attr.attr,
205 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
206 	&sensor_dev_attr_temp1_input.dev_attr.attr,
207 	&sensor_dev_attr_in1_input.dev_attr.attr,
208 	&sensor_dev_attr_in2_input.dev_attr.attr,
209 	&sensor_dev_attr_in3_input.dev_attr.attr,
210 	&sensor_dev_attr_in4_input.dev_attr.attr,
211 	NULL
212 };
213 
214 static struct attribute *ad7418_attributes[] = {
215 	&sensor_dev_attr_temp1_max.dev_attr.attr,
216 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
217 	&sensor_dev_attr_temp1_input.dev_attr.attr,
218 	&sensor_dev_attr_in1_input.dev_attr.attr,
219 	NULL
220 };
221 
222 static int ad7418_probe(struct i2c_client *client,
223 			 const struct i2c_device_id *id)
224 {
225 	struct i2c_adapter *adapter = client->adapter;
226 	struct ad7418_data *data;
227 	int err;
228 
229 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
230 					I2C_FUNC_SMBUS_WORD_DATA)) {
231 		err = -EOPNOTSUPP;
232 		goto exit;
233 	}
234 
235 	data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL);
236 	if (!data) {
237 		err = -ENOMEM;
238 		goto exit;
239 	}
240 
241 	i2c_set_clientdata(client, data);
242 
243 	mutex_init(&data->lock);
244 	data->type = id->driver_data;
245 
246 	switch (data->type) {
247 	case ad7416:
248 		data->adc_max = 0;
249 		data->attrs.attrs = ad7416_attributes;
250 		break;
251 
252 	case ad7417:
253 		data->adc_max = 4;
254 		data->attrs.attrs = ad7417_attributes;
255 		break;
256 
257 	case ad7418:
258 		data->adc_max = 1;
259 		data->attrs.attrs = ad7418_attributes;
260 		break;
261 	}
262 
263 	dev_info(&client->dev, "%s chip found\n", client->name);
264 
265 	/* Initialize the AD7418 chip */
266 	ad7418_init_client(client);
267 
268 	/* Register sysfs hooks */
269 	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
270 	if (err)
271 		goto exit_free;
272 
273 	data->hwmon_dev = hwmon_device_register(&client->dev);
274 	if (IS_ERR(data->hwmon_dev)) {
275 		err = PTR_ERR(data->hwmon_dev);
276 		goto exit_remove;
277 	}
278 
279 	return 0;
280 
281 exit_remove:
282 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
283 exit_free:
284 	kfree(data);
285 exit:
286 	return err;
287 }
288 
289 static int ad7418_remove(struct i2c_client *client)
290 {
291 	struct ad7418_data *data = i2c_get_clientdata(client);
292 	hwmon_device_unregister(data->hwmon_dev);
293 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
294 	kfree(data);
295 	return 0;
296 }
297 
298 module_i2c_driver(ad7418_driver);
299 
300 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
301 MODULE_DESCRIPTION("AD7416/17/18 driver");
302 MODULE_LICENSE("GPL");
303 MODULE_VERSION(DRV_VERSION);
304