xref: /openbmc/linux/drivers/hwmon/nct7904.c (revision f3539c12)
1 /*
2  * nct7904.c - driver for Nuvoton NCT7904D.
3  *
4  * Copyright (c) 2015 Kontron
5  * Author: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/i2c.h>
22 #include <linux/mutex.h>
23 #include <linux/hwmon.h>
24 #include <linux/hwmon-sysfs.h>
25 
26 #define VENDOR_ID_REG		0x7A	/* Any bank */
27 #define NUVOTON_ID		0x50
28 #define CHIP_ID_REG		0x7B	/* Any bank */
29 #define NCT7904_ID		0xC5
30 #define DEVICE_ID_REG		0x7C	/* Any bank */
31 
32 #define BANK_SEL_REG		0xFF
33 #define BANK_0			0x00
34 #define BANK_1			0x01
35 #define BANK_2			0x02
36 #define BANK_3			0x03
37 #define BANK_4			0x04
38 #define BANK_MAX		0x04
39 
40 #define FANIN_MAX		12	/* Counted from 1 */
41 #define VSEN_MAX		21	/* VSEN1..14, 3VDD, VBAT, V3VSB,
42 					   LTD (not a voltage), VSEN17..19 */
43 #define FANCTL_MAX		4	/* Counted from 1 */
44 #define TCPU_MAX		8	/* Counted from 1 */
45 #define TEMP_MAX		4	/* Counted from 1 */
46 
47 #define VT_ADC_CTRL0_REG	0x20	/* Bank 0 */
48 #define VT_ADC_CTRL1_REG	0x21	/* Bank 0 */
49 #define VT_ADC_CTRL2_REG	0x22	/* Bank 0 */
50 #define FANIN_CTRL0_REG		0x24
51 #define FANIN_CTRL1_REG		0x25
52 #define DTS_T_CTRL0_REG		0x26
53 #define DTS_T_CTRL1_REG		0x27
54 #define VT_ADC_MD_REG		0x2E
55 
56 #define VSEN1_HV_REG		0x40	/* Bank 0; 2 regs (HV/LV) per sensor */
57 #define TEMP_CH1_HV_REG		0x42	/* Bank 0; same as VSEN2_HV */
58 #define LTD_HV_REG		0x62	/* Bank 0; 2 regs in VSEN range */
59 #define FANIN1_HV_REG		0x80	/* Bank 0; 2 regs (HV/LV) per sensor */
60 #define T_CPU1_HV_REG		0xA0	/* Bank 0; 2 regs (HV/LV) per sensor */
61 
62 #define PRTS_REG		0x03	/* Bank 2 */
63 #define FANCTL1_FMR_REG		0x00	/* Bank 3; 1 reg per channel */
64 #define FANCTL1_OUT_REG		0x10	/* Bank 3; 1 reg per channel */
65 
66 static const unsigned short normal_i2c[] = {
67 	0x2d, 0x2e, I2C_CLIENT_END
68 };
69 
70 struct nct7904_data {
71 	struct i2c_client *client;
72 	struct mutex bank_lock;
73 	int bank_sel;
74 	u32 fanin_mask;
75 	u32 vsen_mask;
76 	u32 tcpu_mask;
77 	u8 fan_mode[FANCTL_MAX];
78 };
79 
80 /* Access functions */
81 static int nct7904_bank_lock(struct nct7904_data *data, unsigned bank)
82 {
83 	int ret;
84 
85 	mutex_lock(&data->bank_lock);
86 	if (data->bank_sel == bank)
87 		return 0;
88 	ret = i2c_smbus_write_byte_data(data->client, BANK_SEL_REG, bank);
89 	if (ret == 0)
90 		data->bank_sel = bank;
91 	else
92 		data->bank_sel = -1;
93 	return ret;
94 }
95 
96 static inline void nct7904_bank_release(struct nct7904_data *data)
97 {
98 	mutex_unlock(&data->bank_lock);
99 }
100 
101 /* Read 1-byte register. Returns unsigned reg or -ERRNO on error. */
102 static int nct7904_read_reg(struct nct7904_data *data,
103 			    unsigned bank, unsigned reg)
104 {
105 	struct i2c_client *client = data->client;
106 	int ret;
107 
108 	ret = nct7904_bank_lock(data, bank);
109 	if (ret == 0)
110 		ret = i2c_smbus_read_byte_data(client, reg);
111 
112 	nct7904_bank_release(data);
113 	return ret;
114 }
115 
116 /*
117  * Read 2-byte register. Returns register in big-endian format or
118  * -ERRNO on error.
119  */
120 static int nct7904_read_reg16(struct nct7904_data *data,
121 			      unsigned bank, unsigned reg)
122 {
123 	struct i2c_client *client = data->client;
124 	int ret, hi;
125 
126 	ret = nct7904_bank_lock(data, bank);
127 	if (ret == 0) {
128 		ret = i2c_smbus_read_byte_data(client, reg);
129 		if (ret >= 0) {
130 			hi = ret;
131 			ret = i2c_smbus_read_byte_data(client, reg + 1);
132 			if (ret >= 0)
133 				ret |= hi << 8;
134 		}
135 	}
136 
137 	nct7904_bank_release(data);
138 	return ret;
139 }
140 
141 /* Write 1-byte register. Returns 0 or -ERRNO on error. */
142 static int nct7904_write_reg(struct nct7904_data *data,
143 			     unsigned bank, unsigned reg, u8 val)
144 {
145 	struct i2c_client *client = data->client;
146 	int ret;
147 
148 	ret = nct7904_bank_lock(data, bank);
149 	if (ret == 0)
150 		ret = i2c_smbus_write_byte_data(client, reg, val);
151 
152 	nct7904_bank_release(data);
153 	return ret;
154 }
155 
156 /* FANIN ATTR */
157 static ssize_t show_fan(struct device *dev,
158 			struct device_attribute *devattr, char *buf)
159 {
160 	int index = to_sensor_dev_attr(devattr)->index;
161 	struct nct7904_data *data = dev_get_drvdata(dev);
162 	int ret;
163 	unsigned cnt, rpm;
164 
165 	ret = nct7904_read_reg16(data, BANK_0, FANIN1_HV_REG + index * 2);
166 	if (ret < 0)
167 		return ret;
168 	cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f);
169 	if (cnt == 0x1fff)
170 		rpm = 0;
171 	else
172 		rpm = 1350000 / cnt;
173 	return sprintf(buf, "%u\n", rpm);
174 }
175 
176 static umode_t nct7904_fanin_is_visible(struct kobject *kobj,
177 					struct attribute *a, int n)
178 {
179 	struct device *dev = container_of(kobj, struct device, kobj);
180 	struct nct7904_data *data = dev_get_drvdata(dev);
181 
182 	if (data->fanin_mask & (1 << n))
183 		return a->mode;
184 	return 0;
185 }
186 
187 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0);
188 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1);
189 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, show_fan, NULL, 2);
190 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, show_fan, NULL, 3);
191 static SENSOR_DEVICE_ATTR(fan5_input, S_IRUGO, show_fan, NULL, 4);
192 static SENSOR_DEVICE_ATTR(fan6_input, S_IRUGO, show_fan, NULL, 5);
193 static SENSOR_DEVICE_ATTR(fan7_input, S_IRUGO, show_fan, NULL, 6);
194 static SENSOR_DEVICE_ATTR(fan8_input, S_IRUGO, show_fan, NULL, 7);
195 static SENSOR_DEVICE_ATTR(fan9_input, S_IRUGO, show_fan, NULL, 8);
196 static SENSOR_DEVICE_ATTR(fan10_input, S_IRUGO, show_fan, NULL, 9);
197 static SENSOR_DEVICE_ATTR(fan11_input, S_IRUGO, show_fan, NULL, 10);
198 static SENSOR_DEVICE_ATTR(fan12_input, S_IRUGO, show_fan, NULL, 11);
199 
200 static struct attribute *nct7904_fanin_attrs[] = {
201 	&sensor_dev_attr_fan1_input.dev_attr.attr,
202 	&sensor_dev_attr_fan2_input.dev_attr.attr,
203 	&sensor_dev_attr_fan3_input.dev_attr.attr,
204 	&sensor_dev_attr_fan4_input.dev_attr.attr,
205 	&sensor_dev_attr_fan5_input.dev_attr.attr,
206 	&sensor_dev_attr_fan6_input.dev_attr.attr,
207 	&sensor_dev_attr_fan7_input.dev_attr.attr,
208 	&sensor_dev_attr_fan8_input.dev_attr.attr,
209 	&sensor_dev_attr_fan9_input.dev_attr.attr,
210 	&sensor_dev_attr_fan10_input.dev_attr.attr,
211 	&sensor_dev_attr_fan11_input.dev_attr.attr,
212 	&sensor_dev_attr_fan12_input.dev_attr.attr,
213 	NULL
214 };
215 
216 static const struct attribute_group nct7904_fanin_group = {
217 	.attrs = nct7904_fanin_attrs,
218 	.is_visible = nct7904_fanin_is_visible,
219 };
220 
221 /* VSEN ATTR */
222 static ssize_t show_voltage(struct device *dev,
223 			    struct device_attribute *devattr, char *buf)
224 {
225 	int index = to_sensor_dev_attr(devattr)->index;
226 	struct nct7904_data *data = dev_get_drvdata(dev);
227 	int ret;
228 	int volt;
229 
230 	ret = nct7904_read_reg16(data, BANK_0, VSEN1_HV_REG + index * 2);
231 	if (ret < 0)
232 		return ret;
233 	volt = ((ret & 0xff00) >> 5) | (ret & 0x7);
234 	if (index < 14)
235 		volt *= 2; /* 0.002V scale */
236 	else
237 		volt *= 6; /* 0.006V scale */
238 
239 	return sprintf(buf, "%d\n", volt);
240 }
241 
242 static ssize_t show_ltemp(struct device *dev,
243 			  struct device_attribute *devattr, char *buf)
244 {
245 	struct nct7904_data *data = dev_get_drvdata(dev);
246 	int ret;
247 	int temp;
248 
249 	ret = nct7904_read_reg16(data, BANK_0, LTD_HV_REG);
250 	if (ret < 0)
251 		return ret;
252 	temp = ((ret & 0xff00) >> 5) | (ret & 0x7);
253 	temp = sign_extend32(temp, 10) * 125;
254 
255 	return sprintf(buf, "%d\n", temp);
256 }
257 
258 static umode_t nct7904_vsen_is_visible(struct kobject *kobj,
259 				       struct attribute *a, int n)
260 {
261 	struct device *dev = container_of(kobj, struct device, kobj);
262 	struct nct7904_data *data = dev_get_drvdata(dev);
263 
264 	if (data->vsen_mask & (1 << n))
265 		return a->mode;
266 	return 0;
267 }
268 
269 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_voltage, NULL, 0);
270 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_voltage, NULL, 1);
271 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_voltage, NULL, 2);
272 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_voltage, NULL, 3);
273 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, show_voltage, NULL, 4);
274 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, show_voltage, NULL, 5);
275 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, show_voltage, NULL, 6);
276 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, show_voltage, NULL, 7);
277 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, show_voltage, NULL, 8);
278 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, show_voltage, NULL, 9);
279 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, show_voltage, NULL, 10);
280 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, show_voltage, NULL, 11);
281 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, show_voltage, NULL, 12);
282 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, show_voltage, NULL, 13);
283 /*
284  * Next 3 voltage sensors have specific names in the Nuvoton doc
285  * (3VDD, VBAT, 3VSB) but we use vacant numbers for them.
286  */
287 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, show_voltage, NULL, 14);
288 static SENSOR_DEVICE_ATTR(in16_input, S_IRUGO, show_voltage, NULL, 15);
289 static SENSOR_DEVICE_ATTR(in20_input, S_IRUGO, show_voltage, NULL, 16);
290 /* This is not a voltage, but a local temperature sensor. */
291 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_ltemp, NULL, 0);
292 static SENSOR_DEVICE_ATTR(in17_input, S_IRUGO, show_voltage, NULL, 18);
293 static SENSOR_DEVICE_ATTR(in18_input, S_IRUGO, show_voltage, NULL, 19);
294 static SENSOR_DEVICE_ATTR(in19_input, S_IRUGO, show_voltage, NULL, 20);
295 
296 static struct attribute *nct7904_vsen_attrs[] = {
297 	&sensor_dev_attr_in1_input.dev_attr.attr,
298 	&sensor_dev_attr_in2_input.dev_attr.attr,
299 	&sensor_dev_attr_in3_input.dev_attr.attr,
300 	&sensor_dev_attr_in4_input.dev_attr.attr,
301 	&sensor_dev_attr_in5_input.dev_attr.attr,
302 	&sensor_dev_attr_in6_input.dev_attr.attr,
303 	&sensor_dev_attr_in7_input.dev_attr.attr,
304 	&sensor_dev_attr_in8_input.dev_attr.attr,
305 	&sensor_dev_attr_in9_input.dev_attr.attr,
306 	&sensor_dev_attr_in10_input.dev_attr.attr,
307 	&sensor_dev_attr_in11_input.dev_attr.attr,
308 	&sensor_dev_attr_in12_input.dev_attr.attr,
309 	&sensor_dev_attr_in13_input.dev_attr.attr,
310 	&sensor_dev_attr_in14_input.dev_attr.attr,
311 	&sensor_dev_attr_in15_input.dev_attr.attr,
312 	&sensor_dev_attr_in16_input.dev_attr.attr,
313 	&sensor_dev_attr_in20_input.dev_attr.attr,
314 	&sensor_dev_attr_temp1_input.dev_attr.attr,
315 	&sensor_dev_attr_in17_input.dev_attr.attr,
316 	&sensor_dev_attr_in18_input.dev_attr.attr,
317 	&sensor_dev_attr_in19_input.dev_attr.attr,
318 	NULL
319 };
320 
321 static const struct attribute_group nct7904_vsen_group = {
322 	.attrs = nct7904_vsen_attrs,
323 	.is_visible = nct7904_vsen_is_visible,
324 };
325 
326 /* CPU_TEMP ATTR */
327 static ssize_t show_tcpu(struct device *dev,
328 			 struct device_attribute *devattr, char *buf)
329 {
330 	int index = to_sensor_dev_attr(devattr)->index;
331 	struct nct7904_data *data = dev_get_drvdata(dev);
332 	int ret;
333 	int temp;
334 
335 	ret = nct7904_read_reg16(data, BANK_0, T_CPU1_HV_REG + index * 2);
336 	if (ret < 0)
337 		return ret;
338 
339 	temp = ((ret & 0xff00) >> 5) | (ret & 0x7);
340 	temp = sign_extend32(temp, 10) * 125;
341 	return sprintf(buf, "%d\n", temp);
342 }
343 
344 static umode_t nct7904_tcpu_is_visible(struct kobject *kobj,
345 				       struct attribute *a, int n)
346 {
347 	struct device *dev = container_of(kobj, struct device, kobj);
348 	struct nct7904_data *data = dev_get_drvdata(dev);
349 
350 	if (data->tcpu_mask & (1 << n))
351 		return a->mode;
352 	return 0;
353 }
354 
355 /* "temp1_input" reserved for local temp */
356 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_tcpu, NULL, 0);
357 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_tcpu, NULL, 1);
358 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_tcpu, NULL, 2);
359 static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_tcpu, NULL, 3);
360 static SENSOR_DEVICE_ATTR(temp6_input, S_IRUGO, show_tcpu, NULL, 4);
361 static SENSOR_DEVICE_ATTR(temp7_input, S_IRUGO, show_tcpu, NULL, 5);
362 static SENSOR_DEVICE_ATTR(temp8_input, S_IRUGO, show_tcpu, NULL, 6);
363 static SENSOR_DEVICE_ATTR(temp9_input, S_IRUGO, show_tcpu, NULL, 7);
364 
365 static struct attribute *nct7904_tcpu_attrs[] = {
366 	&sensor_dev_attr_temp2_input.dev_attr.attr,
367 	&sensor_dev_attr_temp3_input.dev_attr.attr,
368 	&sensor_dev_attr_temp4_input.dev_attr.attr,
369 	&sensor_dev_attr_temp5_input.dev_attr.attr,
370 	&sensor_dev_attr_temp6_input.dev_attr.attr,
371 	&sensor_dev_attr_temp7_input.dev_attr.attr,
372 	&sensor_dev_attr_temp8_input.dev_attr.attr,
373 	&sensor_dev_attr_temp9_input.dev_attr.attr,
374 	NULL
375 };
376 
377 static const struct attribute_group nct7904_tcpu_group = {
378 	.attrs = nct7904_tcpu_attrs,
379 	.is_visible = nct7904_tcpu_is_visible,
380 };
381 
382 /* PWM ATTR */
383 static ssize_t store_pwm(struct device *dev, struct device_attribute *devattr,
384 			 const char *buf, size_t count)
385 {
386 	int index = to_sensor_dev_attr(devattr)->index;
387 	struct nct7904_data *data = dev_get_drvdata(dev);
388 	unsigned long val;
389 	int ret;
390 
391 	if (kstrtoul(buf, 10, &val) < 0)
392 		return -EINVAL;
393 	if (val > 255)
394 		return -EINVAL;
395 
396 	ret = nct7904_write_reg(data, BANK_3, FANCTL1_OUT_REG + index, val);
397 
398 	return ret ? ret : count;
399 }
400 
401 static ssize_t show_pwm(struct device *dev,
402 			struct device_attribute *devattr, char *buf)
403 {
404 	int index = to_sensor_dev_attr(devattr)->index;
405 	struct nct7904_data *data = dev_get_drvdata(dev);
406 	int val;
407 
408 	val = nct7904_read_reg(data, BANK_3, FANCTL1_OUT_REG + index);
409 	if (val < 0)
410 		return val;
411 
412 	return sprintf(buf, "%d\n", val);
413 }
414 
415 static ssize_t store_enable(struct device *dev,
416 			    struct device_attribute *devattr,
417 			    const char *buf, size_t count)
418 {
419 	int index = to_sensor_dev_attr(devattr)->index;
420 	struct nct7904_data *data = dev_get_drvdata(dev);
421 	unsigned long val;
422 	int ret;
423 
424 	if (kstrtoul(buf, 10, &val) < 0)
425 		return -EINVAL;
426 	if (val < 1 || val > 2 || (val == 2 && !data->fan_mode[index]))
427 		return -EINVAL;
428 
429 	ret = nct7904_write_reg(data, BANK_3, FANCTL1_FMR_REG + index,
430 				val == 2 ? data->fan_mode[index] : 0);
431 
432 	return ret ? ret : count;
433 }
434 
435 /* Return 1 for manual mode or 2 for SmartFan mode */
436 static ssize_t show_enable(struct device *dev,
437 			   struct device_attribute *devattr, char *buf)
438 {
439 	int index = to_sensor_dev_attr(devattr)->index;
440 	struct nct7904_data *data = dev_get_drvdata(dev);
441 	int val;
442 
443 	val = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + index);
444 	if (val < 0)
445 		return val;
446 
447 	return sprintf(buf, "%d\n", val ? 2 : 1);
448 }
449 
450 /* 2 attributes per channel: pwm and mode */
451 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR,
452 			show_pwm, store_pwm, 0);
453 static SENSOR_DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
454 			show_enable, store_enable, 0);
455 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR,
456 			show_pwm, store_pwm, 1);
457 static SENSOR_DEVICE_ATTR(pwm2_enable, S_IRUGO | S_IWUSR,
458 			show_enable, store_enable, 1);
459 static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO | S_IWUSR,
460 			show_pwm, store_pwm, 2);
461 static SENSOR_DEVICE_ATTR(pwm3_enable, S_IRUGO | S_IWUSR,
462 			show_enable, store_enable, 2);
463 static SENSOR_DEVICE_ATTR(pwm4, S_IRUGO | S_IWUSR,
464 			show_pwm, store_pwm, 3);
465 static SENSOR_DEVICE_ATTR(pwm4_enable, S_IRUGO | S_IWUSR,
466 			show_enable, store_enable, 3);
467 
468 static struct attribute *nct7904_fanctl_attrs[] = {
469 	&sensor_dev_attr_pwm1.dev_attr.attr,
470 	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
471 	&sensor_dev_attr_pwm2.dev_attr.attr,
472 	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
473 	&sensor_dev_attr_pwm3.dev_attr.attr,
474 	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
475 	&sensor_dev_attr_pwm4.dev_attr.attr,
476 	&sensor_dev_attr_pwm4_enable.dev_attr.attr,
477 	NULL
478 };
479 
480 static const struct attribute_group nct7904_fanctl_group = {
481 	.attrs = nct7904_fanctl_attrs,
482 };
483 
484 static const struct attribute_group *nct7904_groups[] = {
485 	&nct7904_fanin_group,
486 	&nct7904_vsen_group,
487 	&nct7904_tcpu_group,
488 	&nct7904_fanctl_group,
489 	NULL
490 };
491 
492 /* Return 0 if detection is successful, -ENODEV otherwise */
493 static int nct7904_detect(struct i2c_client *client,
494 			  struct i2c_board_info *info)
495 {
496 	struct i2c_adapter *adapter = client->adapter;
497 
498 	if (!i2c_check_functionality(adapter,
499 				     I2C_FUNC_SMBUS_READ_BYTE |
500 				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
501 		return -ENODEV;
502 
503 	/* Determine the chip type. */
504 	if (i2c_smbus_read_byte_data(client, VENDOR_ID_REG) != NUVOTON_ID ||
505 	    i2c_smbus_read_byte_data(client, CHIP_ID_REG) != NCT7904_ID ||
506 	    (i2c_smbus_read_byte_data(client, DEVICE_ID_REG) & 0xf0) != 0x50 ||
507 	    (i2c_smbus_read_byte_data(client, BANK_SEL_REG) & 0xf8) != 0x00)
508 		return -ENODEV;
509 
510 	strlcpy(info->type, "nct7904", I2C_NAME_SIZE);
511 
512 	return 0;
513 }
514 
515 static int nct7904_probe(struct i2c_client *client,
516 			 const struct i2c_device_id *id)
517 {
518 	struct nct7904_data *data;
519 	struct device *hwmon_dev;
520 	struct device *dev = &client->dev;
521 	int ret, i;
522 	u32 mask;
523 
524 	data = devm_kzalloc(dev, sizeof(struct nct7904_data), GFP_KERNEL);
525 	if (!data)
526 		return -ENOMEM;
527 
528 	data->client = client;
529 	mutex_init(&data->bank_lock);
530 	data->bank_sel = -1;
531 
532 	/* Setup sensor groups. */
533 	/* FANIN attributes */
534 	ret = nct7904_read_reg16(data, BANK_0, FANIN_CTRL0_REG);
535 	if (ret < 0)
536 		return ret;
537 	data->fanin_mask = (ret >> 8) | ((ret & 0xff) << 8);
538 
539 	/*
540 	 * VSEN attributes
541 	 *
542 	 * Note: voltage sensors overlap with external temperature
543 	 * sensors. So, if we ever decide to support the latter
544 	 * we will have to adjust 'vsen_mask' accordingly.
545 	 */
546 	mask = 0;
547 	ret = nct7904_read_reg16(data, BANK_0, VT_ADC_CTRL0_REG);
548 	if (ret >= 0)
549 		mask = (ret >> 8) | ((ret & 0xff) << 8);
550 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_CTRL2_REG);
551 	if (ret >= 0)
552 		mask |= (ret << 16);
553 	data->vsen_mask = mask;
554 
555 	/* CPU_TEMP attributes */
556 	ret = nct7904_read_reg16(data, BANK_0, DTS_T_CTRL0_REG);
557 	if (ret < 0)
558 		return ret;
559 	data->tcpu_mask = ((ret >> 8) & 0xf) | ((ret & 0xf) << 4);
560 
561 	for (i = 0; i < FANCTL_MAX; i++) {
562 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + i);
563 		if (ret < 0)
564 			return ret;
565 		data->fan_mode[i] = ret;
566 	}
567 
568 	hwmon_dev =
569 		devm_hwmon_device_register_with_groups(dev, client->name, data,
570 						       nct7904_groups);
571 	return PTR_ERR_OR_ZERO(hwmon_dev);
572 }
573 
574 static const struct i2c_device_id nct7904_id[] = {
575 	{"nct7904", 0},
576 	{}
577 };
578 MODULE_DEVICE_TABLE(i2c, nct7904_id);
579 
580 static struct i2c_driver nct7904_driver = {
581 	.class = I2C_CLASS_HWMON,
582 	.driver = {
583 		.name = "nct7904",
584 	},
585 	.probe = nct7904_probe,
586 	.id_table = nct7904_id,
587 	.detect = nct7904_detect,
588 	.address_list = normal_i2c,
589 };
590 
591 module_i2c_driver(nct7904_driver);
592 
593 MODULE_AUTHOR("Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>");
594 MODULE_DESCRIPTION("Hwmon driver for NUVOTON NCT7904");
595 MODULE_LICENSE("GPL");
596