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
66static const unsigned short normal_i2c[] = {
67	0x2d, 0x2e, I2C_CLIENT_END
68};
69
70struct 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 */
81static 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
96static 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. */
102static 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 */
120static 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. */
142static 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 */
157static 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
176static 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
187static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0);
188static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1);
189static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, show_fan, NULL, 2);
190static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, show_fan, NULL, 3);
191static SENSOR_DEVICE_ATTR(fan5_input, S_IRUGO, show_fan, NULL, 4);
192static SENSOR_DEVICE_ATTR(fan6_input, S_IRUGO, show_fan, NULL, 5);
193static SENSOR_DEVICE_ATTR(fan7_input, S_IRUGO, show_fan, NULL, 6);
194static SENSOR_DEVICE_ATTR(fan8_input, S_IRUGO, show_fan, NULL, 7);
195static SENSOR_DEVICE_ATTR(fan9_input, S_IRUGO, show_fan, NULL, 8);
196static SENSOR_DEVICE_ATTR(fan10_input, S_IRUGO, show_fan, NULL, 9);
197static SENSOR_DEVICE_ATTR(fan11_input, S_IRUGO, show_fan, NULL, 10);
198static SENSOR_DEVICE_ATTR(fan12_input, S_IRUGO, show_fan, NULL, 11);
199
200static 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
216static const struct attribute_group nct7904_fanin_group = {
217	.attrs = nct7904_fanin_attrs,
218	.is_visible = nct7904_fanin_is_visible,
219};
220
221/* VSEN ATTR */
222static 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
242static 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
258static 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
269static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_voltage, NULL, 0);
270static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_voltage, NULL, 1);
271static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_voltage, NULL, 2);
272static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_voltage, NULL, 3);
273static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, show_voltage, NULL, 4);
274static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, show_voltage, NULL, 5);
275static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, show_voltage, NULL, 6);
276static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, show_voltage, NULL, 7);
277static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, show_voltage, NULL, 8);
278static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, show_voltage, NULL, 9);
279static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, show_voltage, NULL, 10);
280static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, show_voltage, NULL, 11);
281static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, show_voltage, NULL, 12);
282static 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 */
287static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, show_voltage, NULL, 14);
288static SENSOR_DEVICE_ATTR(in16_input, S_IRUGO, show_voltage, NULL, 15);
289static SENSOR_DEVICE_ATTR(in20_input, S_IRUGO, show_voltage, NULL, 16);
290/* This is not a voltage, but a local temperature sensor. */
291static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_ltemp, NULL, 0);
292static SENSOR_DEVICE_ATTR(in17_input, S_IRUGO, show_voltage, NULL, 18);
293static SENSOR_DEVICE_ATTR(in18_input, S_IRUGO, show_voltage, NULL, 19);
294static SENSOR_DEVICE_ATTR(in19_input, S_IRUGO, show_voltage, NULL, 20);
295
296static 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
321static 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 */
327static 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
344static 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 */
356static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_tcpu, NULL, 0);
357static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_tcpu, NULL, 1);
358static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_tcpu, NULL, 2);
359static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_tcpu, NULL, 3);
360static SENSOR_DEVICE_ATTR(temp6_input, S_IRUGO, show_tcpu, NULL, 4);
361static SENSOR_DEVICE_ATTR(temp7_input, S_IRUGO, show_tcpu, NULL, 5);
362static SENSOR_DEVICE_ATTR(temp8_input, S_IRUGO, show_tcpu, NULL, 6);
363static SENSOR_DEVICE_ATTR(temp9_input, S_IRUGO, show_tcpu, NULL, 7);
364
365static 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
377static const struct attribute_group nct7904_tcpu_group = {
378	.attrs = nct7904_tcpu_attrs,
379	.is_visible = nct7904_tcpu_is_visible,
380};
381
382/* PWM ATTR */
383static 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
401static 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
415static 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 */
436static 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 */
451static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR,
452			show_pwm, store_pwm, 0);
453static SENSOR_DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
454			show_enable, store_enable, 0);
455static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR,
456			show_pwm, store_pwm, 1);
457static SENSOR_DEVICE_ATTR(pwm2_enable, S_IRUGO | S_IWUSR,
458			show_enable, store_enable, 1);
459static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO | S_IWUSR,
460			show_pwm, store_pwm, 2);
461static SENSOR_DEVICE_ATTR(pwm3_enable, S_IRUGO | S_IWUSR,
462			show_enable, store_enable, 2);
463static SENSOR_DEVICE_ATTR(pwm4, S_IRUGO | S_IWUSR,
464			show_pwm, store_pwm, 3);
465static SENSOR_DEVICE_ATTR(pwm4_enable, S_IRUGO | S_IWUSR,
466			show_enable, store_enable, 3);
467
468static 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
480static const struct attribute_group nct7904_fanctl_group = {
481	.attrs = nct7904_fanctl_attrs,
482};
483
484static 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 */
493static 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
515static 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
574static const struct i2c_device_id nct7904_id[] = {
575	{"nct7904", 0},
576	{}
577};
578MODULE_DEVICE_TABLE(i2c, nct7904_id);
579
580static 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
591module_i2c_driver(nct7904_driver);
592
593MODULE_AUTHOR("Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>");
594MODULE_DESCRIPTION("Hwmon driver for NUVOTON NCT7904");
595MODULE_LICENSE("GPL");
596