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 #define ADT7411_CFG1_RESERVED_BIT3 (1 << 3)
34
35 #define ADT7411_REG_CFG2 0x19
36 #define ADT7411_CFG2_DISABLE_AVG (1 << 5)
37
38 #define ADT7411_REG_CFG3 0x1a
39 #define ADT7411_CFG3_ADC_CLK_225 (1 << 0)
40 #define ADT7411_CFG3_REF_VDD (1 << 4)
41
42 #define ADT7411_REG_DEVICE_ID 0x4d
43 #define ADT7411_REG_MANUFACTURER_ID 0x4e
44
45 #define ADT7411_DEVICE_ID 0x2
46 #define ADT7411_MANUFACTURER_ID 0x41
47
48 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
49
50 struct adt7411_data {
51 struct mutex device_lock; /* for "atomic" device accesses */
52 struct mutex update_lock;
53 unsigned long next_update;
54 int vref_cached;
55 struct i2c_client *client;
56 };
57
58 /*
59 * When reading a register containing (up to 4) lsb, all associated
60 * msb-registers get locked by the hardware. After _one_ of those msb is read,
61 * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
62 * is protected here with a mutex, too.
63 */
adt7411_read_10_bit(struct i2c_client * client,u8 lsb_reg,u8 msb_reg,u8 lsb_shift)64 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
65 u8 msb_reg, u8 lsb_shift)
66 {
67 struct adt7411_data *data = i2c_get_clientdata(client);
68 int val, tmp;
69
70 mutex_lock(&data->device_lock);
71
72 val = i2c_smbus_read_byte_data(client, lsb_reg);
73 if (val < 0)
74 goto exit_unlock;
75
76 tmp = (val >> lsb_shift) & 3;
77 val = i2c_smbus_read_byte_data(client, msb_reg);
78
79 if (val >= 0)
80 val = (val << 2) | tmp;
81
82 exit_unlock:
83 mutex_unlock(&data->device_lock);
84
85 return val;
86 }
87
adt7411_modify_bit(struct i2c_client * client,u8 reg,u8 bit,bool flag)88 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
89 bool flag)
90 {
91 struct adt7411_data *data = i2c_get_clientdata(client);
92 int ret, val;
93
94 mutex_lock(&data->device_lock);
95
96 ret = i2c_smbus_read_byte_data(client, reg);
97 if (ret < 0)
98 goto exit_unlock;
99
100 if (flag)
101 val = ret | bit;
102 else
103 val = ret & ~bit;
104
105 ret = i2c_smbus_write_byte_data(client, reg, val);
106
107 exit_unlock:
108 mutex_unlock(&data->device_lock);
109 return ret;
110 }
111
adt7411_show_vdd(struct device * dev,struct device_attribute * attr,char * buf)112 static ssize_t adt7411_show_vdd(struct device *dev,
113 struct device_attribute *attr, char *buf)
114 {
115 struct adt7411_data *data = dev_get_drvdata(dev);
116 struct i2c_client *client = data->client;
117 int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
118 ADT7411_REG_VDD_MSB, 2);
119
120 return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
121 }
122
adt7411_show_temp(struct device * dev,struct device_attribute * attr,char * buf)123 static ssize_t adt7411_show_temp(struct device *dev,
124 struct device_attribute *attr, char *buf)
125 {
126 struct adt7411_data *data = dev_get_drvdata(dev);
127 struct i2c_client *client = data->client;
128 int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
129 ADT7411_REG_INT_TEMP_MSB, 0);
130
131 if (val < 0)
132 return val;
133
134 val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
135
136 return sprintf(buf, "%d\n", val * 250);
137 }
138
adt7411_show_input(struct device * dev,struct device_attribute * attr,char * buf)139 static ssize_t adt7411_show_input(struct device *dev,
140 struct device_attribute *attr, char *buf)
141 {
142 int nr = to_sensor_dev_attr(attr)->index;
143 struct adt7411_data *data = dev_get_drvdata(dev);
144 struct i2c_client *client = data->client;
145 int val;
146 u8 lsb_reg, lsb_shift;
147
148 mutex_lock(&data->update_lock);
149 if (time_after_eq(jiffies, data->next_update)) {
150 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
151 if (val < 0)
152 goto exit_unlock;
153
154 if (val & ADT7411_CFG3_REF_VDD) {
155 val = adt7411_read_10_bit(client,
156 ADT7411_REG_INT_TEMP_VDD_LSB,
157 ADT7411_REG_VDD_MSB, 2);
158 if (val < 0)
159 goto exit_unlock;
160
161 data->vref_cached = val * 7000 / 1024;
162 } else {
163 data->vref_cached = 2250;
164 }
165
166 data->next_update = jiffies + HZ;
167 }
168
169 lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
170 lsb_shift = 2 * (nr & 0x03);
171 val = adt7411_read_10_bit(client, lsb_reg,
172 ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
173 if (val < 0)
174 goto exit_unlock;
175
176 val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
177 exit_unlock:
178 mutex_unlock(&data->update_lock);
179 return val;
180 }
181
adt7411_show_bit(struct device * dev,struct device_attribute * attr,char * buf)182 static ssize_t adt7411_show_bit(struct device *dev,
183 struct device_attribute *attr, char *buf)
184 {
185 struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
186 struct adt7411_data *data = dev_get_drvdata(dev);
187 struct i2c_client *client = data->client;
188 int ret = i2c_smbus_read_byte_data(client, attr2->index);
189
190 return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
191 }
192
adt7411_set_bit(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)193 static ssize_t adt7411_set_bit(struct device *dev,
194 struct device_attribute *attr, const char *buf,
195 size_t count)
196 {
197 struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
198 struct adt7411_data *data = dev_get_drvdata(dev);
199 struct i2c_client *client = data->client;
200 int ret;
201 unsigned long flag;
202
203 ret = kstrtoul(buf, 0, &flag);
204 if (ret || flag > 1)
205 return -EINVAL;
206
207 ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
208
209 /* force update */
210 mutex_lock(&data->update_lock);
211 data->next_update = jiffies;
212 mutex_unlock(&data->update_lock);
213
214 return ret < 0 ? ret : count;
215 }
216
217 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
218 SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
219 adt7411_set_bit, __bit, __reg)
220
221 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
222 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
223 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
224 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
225 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
226 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
227 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
228 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
229 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
230 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
231 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
232 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
233 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
234
235 static struct attribute *adt7411_attrs[] = {
236 &dev_attr_temp1_input.attr,
237 &dev_attr_in0_input.attr,
238 &sensor_dev_attr_in1_input.dev_attr.attr,
239 &sensor_dev_attr_in2_input.dev_attr.attr,
240 &sensor_dev_attr_in3_input.dev_attr.attr,
241 &sensor_dev_attr_in4_input.dev_attr.attr,
242 &sensor_dev_attr_in5_input.dev_attr.attr,
243 &sensor_dev_attr_in6_input.dev_attr.attr,
244 &sensor_dev_attr_in7_input.dev_attr.attr,
245 &sensor_dev_attr_in8_input.dev_attr.attr,
246 &sensor_dev_attr_no_average.dev_attr.attr,
247 &sensor_dev_attr_fast_sampling.dev_attr.attr,
248 &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
249 NULL
250 };
251
252 ATTRIBUTE_GROUPS(adt7411);
253
adt7411_detect(struct i2c_client * client,struct i2c_board_info * info)254 static int adt7411_detect(struct i2c_client *client,
255 struct i2c_board_info *info)
256 {
257 int val;
258
259 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
260 return -ENODEV;
261
262 val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
263 if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
264 dev_dbg(&client->dev,
265 "Wrong manufacturer ID. Got %d, expected %d\n",
266 val, ADT7411_MANUFACTURER_ID);
267 return -ENODEV;
268 }
269
270 val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
271 if (val < 0 || val != ADT7411_DEVICE_ID) {
272 dev_dbg(&client->dev,
273 "Wrong device ID. Got %d, expected %d\n",
274 val, ADT7411_DEVICE_ID);
275 return -ENODEV;
276 }
277
278 strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
279
280 return 0;
281 }
282
adt7411_probe(struct i2c_client * client,const struct i2c_device_id * id)283 static int adt7411_probe(struct i2c_client *client,
284 const struct i2c_device_id *id)
285 {
286 struct device *dev = &client->dev;
287 struct adt7411_data *data;
288 struct device *hwmon_dev;
289 int ret;
290
291 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
292 if (!data)
293 return -ENOMEM;
294
295 i2c_set_clientdata(client, data);
296 data->client = client;
297 mutex_init(&data->device_lock);
298 mutex_init(&data->update_lock);
299
300 /* According to the datasheet, we must only write 1 to bit 3 */
301 ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
302 ADT7411_CFG1_RESERVED_BIT3
303 | ADT7411_CFG1_START_MONITOR, 1);
304 if (ret < 0)
305 return ret;
306
307 /* force update on first occasion */
308 data->next_update = jiffies;
309
310 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
311 data,
312 adt7411_groups);
313 return PTR_ERR_OR_ZERO(hwmon_dev);
314 }
315
316 static const struct i2c_device_id adt7411_id[] = {
317 { "adt7411", 0 },
318 { }
319 };
320 MODULE_DEVICE_TABLE(i2c, adt7411_id);
321
322 static struct i2c_driver adt7411_driver = {
323 .driver = {
324 .name = "adt7411",
325 },
326 .probe = adt7411_probe,
327 .id_table = adt7411_id,
328 .detect = adt7411_detect,
329 .address_list = normal_i2c,
330 .class = I2C_CLASS_HWMON,
331 };
332
333 module_i2c_driver(adt7411_driver);
334
335 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
336 "Wolfram Sang <w.sang@pengutronix.de>");
337 MODULE_DESCRIPTION("ADT7411 driver");
338 MODULE_LICENSE("GPL v2");
339