xref: /openbmc/linux/drivers/hwmon/adt7411.c (revision b34e08d5)
1 /*
2  *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
3  *
4  *  Copyright (C) 2008, 2010 Pengutronix
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License version 2 as
8  *  published by the Free Software Foundation.
9  *
10  *  TODO: SPI, support for external temperature sensor
11  *	  use power-down mode for suspend?, interrupt handling?
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/err.h>
18 #include <linux/mutex.h>
19 #include <linux/jiffies.h>
20 #include <linux/i2c.h>
21 #include <linux/hwmon.h>
22 #include <linux/hwmon-sysfs.h>
23 #include <linux/slab.h>
24 
25 #define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
26 #define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
27 #define ADT7411_REG_VDD_MSB			0x06
28 #define ADT7411_REG_INT_TEMP_MSB		0x07
29 #define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08
30 
31 #define ADT7411_REG_CFG1			0x18
32 #define ADT7411_CFG1_START_MONITOR		(1 << 0)
33 
34 #define ADT7411_REG_CFG2			0x19
35 #define ADT7411_CFG2_DISABLE_AVG		(1 << 5)
36 
37 #define ADT7411_REG_CFG3			0x1a
38 #define ADT7411_CFG3_ADC_CLK_225		(1 << 0)
39 #define ADT7411_CFG3_REF_VDD			(1 << 4)
40 
41 #define ADT7411_REG_DEVICE_ID			0x4d
42 #define ADT7411_REG_MANUFACTURER_ID		0x4e
43 
44 #define ADT7411_DEVICE_ID			0x2
45 #define ADT7411_MANUFACTURER_ID			0x41
46 
47 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
48 
49 struct adt7411_data {
50 	struct mutex device_lock;	/* for "atomic" device accesses */
51 	struct mutex update_lock;
52 	unsigned long next_update;
53 	int vref_cached;
54 	struct device *hwmon_dev;
55 };
56 
57 /*
58  * When reading a register containing (up to 4) lsb, all associated
59  * msb-registers get locked by the hardware. After _one_ of those msb is read,
60  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
61  * is protected here with a mutex, too.
62  */
63 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
64 				u8 msb_reg, u8 lsb_shift)
65 {
66 	struct adt7411_data *data = i2c_get_clientdata(client);
67 	int val, tmp;
68 
69 	mutex_lock(&data->device_lock);
70 
71 	val = i2c_smbus_read_byte_data(client, lsb_reg);
72 	if (val < 0)
73 		goto exit_unlock;
74 
75 	tmp = (val >> lsb_shift) & 3;
76 	val = i2c_smbus_read_byte_data(client, msb_reg);
77 
78 	if (val >= 0)
79 		val = (val << 2) | tmp;
80 
81  exit_unlock:
82 	mutex_unlock(&data->device_lock);
83 
84 	return val;
85 }
86 
87 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
88 				bool flag)
89 {
90 	struct adt7411_data *data = i2c_get_clientdata(client);
91 	int ret, val;
92 
93 	mutex_lock(&data->device_lock);
94 
95 	ret = i2c_smbus_read_byte_data(client, reg);
96 	if (ret < 0)
97 		goto exit_unlock;
98 
99 	if (flag)
100 		val = ret | bit;
101 	else
102 		val = ret & ~bit;
103 
104 	ret = i2c_smbus_write_byte_data(client, reg, val);
105 
106  exit_unlock:
107 	mutex_unlock(&data->device_lock);
108 	return ret;
109 }
110 
111 static ssize_t adt7411_show_vdd(struct device *dev,
112 				struct device_attribute *attr, char *buf)
113 {
114 	struct i2c_client *client = to_i2c_client(dev);
115 	int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
116 			ADT7411_REG_VDD_MSB, 2);
117 
118 	return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
119 }
120 
121 static ssize_t adt7411_show_temp(struct device *dev,
122 			struct device_attribute *attr, char *buf)
123 {
124 	struct i2c_client *client = to_i2c_client(dev);
125 	int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
126 			ADT7411_REG_INT_TEMP_MSB, 0);
127 
128 	if (val < 0)
129 		return val;
130 
131 	val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
132 
133 	return sprintf(buf, "%d\n", val * 250);
134 }
135 
136 static ssize_t adt7411_show_input(struct device *dev,
137 				  struct device_attribute *attr, char *buf)
138 {
139 	int nr = to_sensor_dev_attr(attr)->index;
140 	struct i2c_client *client = to_i2c_client(dev);
141 	struct adt7411_data *data = i2c_get_clientdata(client);
142 	int val;
143 	u8 lsb_reg, lsb_shift;
144 
145 	mutex_lock(&data->update_lock);
146 	if (time_after_eq(jiffies, data->next_update)) {
147 		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
148 		if (val < 0)
149 			goto exit_unlock;
150 
151 		if (val & ADT7411_CFG3_REF_VDD) {
152 			val = adt7411_read_10_bit(client,
153 					ADT7411_REG_INT_TEMP_VDD_LSB,
154 					ADT7411_REG_VDD_MSB, 2);
155 			if (val < 0)
156 				goto exit_unlock;
157 
158 			data->vref_cached = val * 7000 / 1024;
159 		} else {
160 			data->vref_cached = 2250;
161 		}
162 
163 		data->next_update = jiffies + HZ;
164 	}
165 
166 	lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
167 	lsb_shift = 2 * (nr & 0x03);
168 	val = adt7411_read_10_bit(client, lsb_reg,
169 			ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
170 	if (val < 0)
171 		goto exit_unlock;
172 
173 	val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
174  exit_unlock:
175 	mutex_unlock(&data->update_lock);
176 	return val;
177 }
178 
179 static ssize_t adt7411_show_bit(struct device *dev,
180 				struct device_attribute *attr, char *buf)
181 {
182 	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
183 	struct i2c_client *client = to_i2c_client(dev);
184 	int ret = i2c_smbus_read_byte_data(client, attr2->index);
185 
186 	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
187 }
188 
189 static ssize_t adt7411_set_bit(struct device *dev,
190 			       struct device_attribute *attr, const char *buf,
191 			       size_t count)
192 {
193 	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
194 	struct i2c_client *client = to_i2c_client(dev);
195 	struct adt7411_data *data = i2c_get_clientdata(client);
196 	int ret;
197 	unsigned long flag;
198 
199 	ret = kstrtoul(buf, 0, &flag);
200 	if (ret || flag > 1)
201 		return -EINVAL;
202 
203 	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
204 
205 	/* force update */
206 	mutex_lock(&data->update_lock);
207 	data->next_update = jiffies;
208 	mutex_unlock(&data->update_lock);
209 
210 	return ret < 0 ? ret : count;
211 }
212 
213 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
214 	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
215 	adt7411_set_bit, __bit, __reg)
216 
217 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
218 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
219 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
220 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
221 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
222 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
223 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
224 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
225 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
226 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
227 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
228 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
229 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
230 
231 static struct attribute *adt7411_attrs[] = {
232 	&dev_attr_temp1_input.attr,
233 	&dev_attr_in0_input.attr,
234 	&sensor_dev_attr_in1_input.dev_attr.attr,
235 	&sensor_dev_attr_in2_input.dev_attr.attr,
236 	&sensor_dev_attr_in3_input.dev_attr.attr,
237 	&sensor_dev_attr_in4_input.dev_attr.attr,
238 	&sensor_dev_attr_in5_input.dev_attr.attr,
239 	&sensor_dev_attr_in6_input.dev_attr.attr,
240 	&sensor_dev_attr_in7_input.dev_attr.attr,
241 	&sensor_dev_attr_in8_input.dev_attr.attr,
242 	&sensor_dev_attr_no_average.dev_attr.attr,
243 	&sensor_dev_attr_fast_sampling.dev_attr.attr,
244 	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
245 	NULL
246 };
247 
248 static const struct attribute_group adt7411_attr_grp = {
249 	.attrs = adt7411_attrs,
250 };
251 
252 static int adt7411_detect(struct i2c_client *client,
253 			  struct i2c_board_info *info)
254 {
255 	int val;
256 
257 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
258 		return -ENODEV;
259 
260 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
261 	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
262 		dev_dbg(&client->dev,
263 			"Wrong manufacturer ID. Got %d, expected %d\n",
264 			val, ADT7411_MANUFACTURER_ID);
265 		return -ENODEV;
266 	}
267 
268 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
269 	if (val < 0 || val != ADT7411_DEVICE_ID) {
270 		dev_dbg(&client->dev,
271 			"Wrong device ID. Got %d, expected %d\n",
272 			val, ADT7411_DEVICE_ID);
273 		return -ENODEV;
274 	}
275 
276 	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
277 
278 	return 0;
279 }
280 
281 static int adt7411_probe(struct i2c_client *client,
282 				   const struct i2c_device_id *id)
283 {
284 	struct adt7411_data *data;
285 	int ret;
286 
287 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
288 	if (!data)
289 		return -ENOMEM;
290 
291 	i2c_set_clientdata(client, data);
292 	mutex_init(&data->device_lock);
293 	mutex_init(&data->update_lock);
294 
295 	ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
296 				 ADT7411_CFG1_START_MONITOR, 1);
297 	if (ret < 0)
298 		return ret;
299 
300 	/* force update on first occasion */
301 	data->next_update = jiffies;
302 
303 	ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
304 	if (ret)
305 		return ret;
306 
307 	data->hwmon_dev = hwmon_device_register(&client->dev);
308 	if (IS_ERR(data->hwmon_dev)) {
309 		ret = PTR_ERR(data->hwmon_dev);
310 		goto exit_remove;
311 	}
312 
313 	dev_info(&client->dev, "successfully registered\n");
314 
315 	return 0;
316 
317  exit_remove:
318 	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
319 	return ret;
320 }
321 
322 static int adt7411_remove(struct i2c_client *client)
323 {
324 	struct adt7411_data *data = i2c_get_clientdata(client);
325 
326 	hwmon_device_unregister(data->hwmon_dev);
327 	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
328 	return 0;
329 }
330 
331 static const struct i2c_device_id adt7411_id[] = {
332 	{ "adt7411", 0 },
333 	{ }
334 };
335 MODULE_DEVICE_TABLE(i2c, adt7411_id);
336 
337 static struct i2c_driver adt7411_driver = {
338 	.driver		= {
339 		.name		= "adt7411",
340 	},
341 	.probe  = adt7411_probe,
342 	.remove	= adt7411_remove,
343 	.id_table = adt7411_id,
344 	.detect = adt7411_detect,
345 	.address_list = normal_i2c,
346 	.class = I2C_CLASS_HWMON,
347 };
348 
349 module_i2c_driver(adt7411_driver);
350 
351 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
352 	"Wolfram Sang <w.sang@pengutronix.de>");
353 MODULE_DESCRIPTION("ADT7411 driver");
354 MODULE_LICENSE("GPL v2");
355