xref: /openbmc/linux/drivers/hwmon/nct7904.c (revision ebd09753)
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 
25 #define VENDOR_ID_REG		0x7A	/* Any bank */
26 #define NUVOTON_ID		0x50
27 #define CHIP_ID_REG		0x7B	/* Any bank */
28 #define NCT7904_ID		0xC5
29 #define DEVICE_ID_REG		0x7C	/* Any bank */
30 
31 #define BANK_SEL_REG		0xFF
32 #define BANK_0			0x00
33 #define BANK_1			0x01
34 #define BANK_2			0x02
35 #define BANK_3			0x03
36 #define BANK_4			0x04
37 #define BANK_MAX		0x04
38 
39 #define FANIN_MAX		12	/* Counted from 1 */
40 #define VSEN_MAX		21	/* VSEN1..14, 3VDD, VBAT, V3VSB,
41 					   LTD (not a voltage), VSEN17..19 */
42 #define FANCTL_MAX		4	/* Counted from 1 */
43 #define TCPU_MAX		8	/* Counted from 1 */
44 #define TEMP_MAX		4	/* Counted from 1 */
45 
46 #define VT_ADC_CTRL0_REG	0x20	/* Bank 0 */
47 #define VT_ADC_CTRL1_REG	0x21	/* Bank 0 */
48 #define VT_ADC_CTRL2_REG	0x22	/* Bank 0 */
49 #define FANIN_CTRL0_REG		0x24
50 #define FANIN_CTRL1_REG		0x25
51 #define DTS_T_CTRL0_REG		0x26
52 #define DTS_T_CTRL1_REG		0x27
53 #define VT_ADC_MD_REG		0x2E
54 
55 #define VSEN1_HV_REG		0x40	/* Bank 0; 2 regs (HV/LV) per sensor */
56 #define TEMP_CH1_HV_REG		0x42	/* Bank 0; same as VSEN2_HV */
57 #define LTD_HV_REG		0x62	/* Bank 0; 2 regs in VSEN range */
58 #define FANIN1_HV_REG		0x80	/* Bank 0; 2 regs (HV/LV) per sensor */
59 #define T_CPU1_HV_REG		0xA0	/* Bank 0; 2 regs (HV/LV) per sensor */
60 
61 #define PRTS_REG		0x03	/* Bank 2 */
62 #define FANCTL1_FMR_REG		0x00	/* Bank 3; 1 reg per channel */
63 #define FANCTL1_OUT_REG		0x10	/* Bank 3; 1 reg per channel */
64 
65 static const unsigned short normal_i2c[] = {
66 	0x2d, 0x2e, I2C_CLIENT_END
67 };
68 
69 struct nct7904_data {
70 	struct i2c_client *client;
71 	struct mutex bank_lock;
72 	int bank_sel;
73 	u32 fanin_mask;
74 	u32 vsen_mask;
75 	u32 tcpu_mask;
76 	u8 fan_mode[FANCTL_MAX];
77 };
78 
79 /* Access functions */
80 static int nct7904_bank_lock(struct nct7904_data *data, unsigned int bank)
81 {
82 	int ret;
83 
84 	mutex_lock(&data->bank_lock);
85 	if (data->bank_sel == bank)
86 		return 0;
87 	ret = i2c_smbus_write_byte_data(data->client, BANK_SEL_REG, bank);
88 	if (ret == 0)
89 		data->bank_sel = bank;
90 	else
91 		data->bank_sel = -1;
92 	return ret;
93 }
94 
95 static inline void nct7904_bank_release(struct nct7904_data *data)
96 {
97 	mutex_unlock(&data->bank_lock);
98 }
99 
100 /* Read 1-byte register. Returns unsigned reg or -ERRNO on error. */
101 static int nct7904_read_reg(struct nct7904_data *data,
102 			    unsigned int bank, unsigned int reg)
103 {
104 	struct i2c_client *client = data->client;
105 	int ret;
106 
107 	ret = nct7904_bank_lock(data, bank);
108 	if (ret == 0)
109 		ret = i2c_smbus_read_byte_data(client, reg);
110 
111 	nct7904_bank_release(data);
112 	return ret;
113 }
114 
115 /*
116  * Read 2-byte register. Returns register in big-endian format or
117  * -ERRNO on error.
118  */
119 static int nct7904_read_reg16(struct nct7904_data *data,
120 			      unsigned int bank, unsigned int reg)
121 {
122 	struct i2c_client *client = data->client;
123 	int ret, hi;
124 
125 	ret = nct7904_bank_lock(data, bank);
126 	if (ret == 0) {
127 		ret = i2c_smbus_read_byte_data(client, reg);
128 		if (ret >= 0) {
129 			hi = ret;
130 			ret = i2c_smbus_read_byte_data(client, reg + 1);
131 			if (ret >= 0)
132 				ret |= hi << 8;
133 		}
134 	}
135 
136 	nct7904_bank_release(data);
137 	return ret;
138 }
139 
140 /* Write 1-byte register. Returns 0 or -ERRNO on error. */
141 static int nct7904_write_reg(struct nct7904_data *data,
142 			     unsigned int bank, unsigned int reg, u8 val)
143 {
144 	struct i2c_client *client = data->client;
145 	int ret;
146 
147 	ret = nct7904_bank_lock(data, bank);
148 	if (ret == 0)
149 		ret = i2c_smbus_write_byte_data(client, reg, val);
150 
151 	nct7904_bank_release(data);
152 	return ret;
153 }
154 
155 static int nct7904_read_fan(struct device *dev, u32 attr, int channel,
156 			    long *val)
157 {
158 	struct nct7904_data *data = dev_get_drvdata(dev);
159 	unsigned int cnt, rpm;
160 	int ret;
161 
162 	switch (attr) {
163 	case hwmon_fan_input:
164 		ret = nct7904_read_reg16(data, BANK_0,
165 					 FANIN1_HV_REG + channel * 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 		*val = rpm;
174 		return 0;
175 	default:
176 		return -EOPNOTSUPP;
177 	}
178 }
179 
180 static umode_t nct7904_fan_is_visible(const void *_data, u32 attr, int channel)
181 {
182 	const struct nct7904_data *data = _data;
183 
184 	if (attr == hwmon_fan_input && data->fanin_mask & (1 << channel))
185 		return S_IRUGO;
186 	return 0;
187 }
188 
189 static u8 nct7904_chan_to_index[] = {
190 	0,	/* Not used */
191 	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
192 	18, 19, 20, 16
193 };
194 
195 static int nct7904_read_in(struct device *dev, u32 attr, int channel,
196 			   long *val)
197 {
198 	struct nct7904_data *data = dev_get_drvdata(dev);
199 	int ret, volt, index;
200 
201 	index = nct7904_chan_to_index[channel];
202 
203 	switch (attr) {
204 	case hwmon_in_input:
205 		ret = nct7904_read_reg16(data, BANK_0,
206 					 VSEN1_HV_REG + index * 2);
207 		if (ret < 0)
208 			return ret;
209 		volt = ((ret & 0xff00) >> 5) | (ret & 0x7);
210 		if (index < 14)
211 			volt *= 2; /* 0.002V scale */
212 		else
213 			volt *= 6; /* 0.006V scale */
214 		*val = volt;
215 		return 0;
216 	default:
217 		return -EOPNOTSUPP;
218 	}
219 }
220 
221 static umode_t nct7904_in_is_visible(const void *_data, u32 attr, int channel)
222 {
223 	const struct nct7904_data *data = _data;
224 	int index = nct7904_chan_to_index[channel];
225 
226 	if (channel > 0 && attr == hwmon_in_input &&
227 	    (data->vsen_mask & BIT(index)))
228 		return S_IRUGO;
229 
230 	return 0;
231 }
232 
233 static int nct7904_read_temp(struct device *dev, u32 attr, int channel,
234 			     long *val)
235 {
236 	struct nct7904_data *data = dev_get_drvdata(dev);
237 	int ret, temp;
238 
239 	switch (attr) {
240 	case hwmon_temp_input:
241 		if (channel == 0)
242 			ret = nct7904_read_reg16(data, BANK_0, LTD_HV_REG);
243 		else
244 			ret = nct7904_read_reg16(data, BANK_0,
245 					T_CPU1_HV_REG + (channel - 1) * 2);
246 		if (ret < 0)
247 			return ret;
248 		temp = ((ret & 0xff00) >> 5) | (ret & 0x7);
249 		*val = sign_extend32(temp, 10) * 125;
250 		return 0;
251 	default:
252 		return -EOPNOTSUPP;
253 	}
254 }
255 
256 static umode_t nct7904_temp_is_visible(const void *_data, u32 attr, int channel)
257 {
258 	const struct nct7904_data *data = _data;
259 
260 	if (attr == hwmon_temp_input) {
261 		if (channel == 0) {
262 			if (data->vsen_mask & BIT(17))
263 				return S_IRUGO;
264 		} else {
265 			if (data->tcpu_mask & BIT(channel - 1))
266 				return S_IRUGO;
267 		}
268 	}
269 
270 	return 0;
271 }
272 
273 static int nct7904_read_pwm(struct device *dev, u32 attr, int channel,
274 			    long *val)
275 {
276 	struct nct7904_data *data = dev_get_drvdata(dev);
277 	int ret;
278 
279 	switch (attr) {
280 	case hwmon_pwm_input:
281 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_OUT_REG + channel);
282 		if (ret < 0)
283 			return ret;
284 		*val = ret;
285 		return 0;
286 	case hwmon_pwm_enable:
287 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + channel);
288 		if (ret < 0)
289 			return ret;
290 
291 		*val = ret ? 2 : 1;
292 		return 0;
293 	default:
294 		return -EOPNOTSUPP;
295 	}
296 }
297 
298 static int nct7904_write_pwm(struct device *dev, u32 attr, int channel,
299 			     long val)
300 {
301 	struct nct7904_data *data = dev_get_drvdata(dev);
302 	int ret;
303 
304 	switch (attr) {
305 	case hwmon_pwm_input:
306 		if (val < 0 || val > 255)
307 			return -EINVAL;
308 		ret = nct7904_write_reg(data, BANK_3, FANCTL1_OUT_REG + channel,
309 					val);
310 		return ret;
311 	case hwmon_pwm_enable:
312 		if (val < 1 || val > 2 ||
313 		    (val == 2 && !data->fan_mode[channel]))
314 			return -EINVAL;
315 		ret = nct7904_write_reg(data, BANK_3, FANCTL1_FMR_REG + channel,
316 					val == 2 ? data->fan_mode[channel] : 0);
317 		return ret;
318 	default:
319 		return -EOPNOTSUPP;
320 	}
321 }
322 
323 static umode_t nct7904_pwm_is_visible(const void *_data, u32 attr, int channel)
324 {
325 	switch (attr) {
326 	case hwmon_pwm_input:
327 	case hwmon_pwm_enable:
328 		return S_IRUGO | S_IWUSR;
329 	default:
330 		return 0;
331 	}
332 }
333 
334 static int nct7904_read(struct device *dev, enum hwmon_sensor_types type,
335 			u32 attr, int channel, long *val)
336 {
337 	switch (type) {
338 	case hwmon_in:
339 		return nct7904_read_in(dev, attr, channel, val);
340 	case hwmon_fan:
341 		return nct7904_read_fan(dev, attr, channel, val);
342 	case hwmon_pwm:
343 		return nct7904_read_pwm(dev, attr, channel, val);
344 	case hwmon_temp:
345 		return nct7904_read_temp(dev, attr, channel, val);
346 	default:
347 		return -EOPNOTSUPP;
348 	}
349 }
350 
351 static int nct7904_write(struct device *dev, enum hwmon_sensor_types type,
352 			 u32 attr, int channel, long val)
353 {
354 	switch (type) {
355 	case hwmon_pwm:
356 		return nct7904_write_pwm(dev, attr, channel, val);
357 	default:
358 		return -EOPNOTSUPP;
359 	}
360 }
361 
362 static umode_t nct7904_is_visible(const void *data,
363 				  enum hwmon_sensor_types type,
364 				  u32 attr, int channel)
365 {
366 	switch (type) {
367 	case hwmon_in:
368 		return nct7904_in_is_visible(data, attr, channel);
369 	case hwmon_fan:
370 		return nct7904_fan_is_visible(data, attr, channel);
371 	case hwmon_pwm:
372 		return nct7904_pwm_is_visible(data, attr, channel);
373 	case hwmon_temp:
374 		return nct7904_temp_is_visible(data, attr, channel);
375 	default:
376 		return 0;
377 	}
378 }
379 
380 /* Return 0 if detection is successful, -ENODEV otherwise */
381 static int nct7904_detect(struct i2c_client *client,
382 			  struct i2c_board_info *info)
383 {
384 	struct i2c_adapter *adapter = client->adapter;
385 
386 	if (!i2c_check_functionality(adapter,
387 				     I2C_FUNC_SMBUS_READ_BYTE |
388 				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
389 		return -ENODEV;
390 
391 	/* Determine the chip type. */
392 	if (i2c_smbus_read_byte_data(client, VENDOR_ID_REG) != NUVOTON_ID ||
393 	    i2c_smbus_read_byte_data(client, CHIP_ID_REG) != NCT7904_ID ||
394 	    (i2c_smbus_read_byte_data(client, DEVICE_ID_REG) & 0xf0) != 0x50 ||
395 	    (i2c_smbus_read_byte_data(client, BANK_SEL_REG) & 0xf8) != 0x00)
396 		return -ENODEV;
397 
398 	strlcpy(info->type, "nct7904", I2C_NAME_SIZE);
399 
400 	return 0;
401 }
402 
403 static const u32 nct7904_in_config[] = {
404 	HWMON_I_INPUT,                  /* dummy, skipped in is_visible */
405 	HWMON_I_INPUT,
406 	HWMON_I_INPUT,
407 	HWMON_I_INPUT,
408 	HWMON_I_INPUT,
409 	HWMON_I_INPUT,
410 	HWMON_I_INPUT,
411 	HWMON_I_INPUT,
412 	HWMON_I_INPUT,
413 	HWMON_I_INPUT,
414 	HWMON_I_INPUT,
415 	HWMON_I_INPUT,
416 	HWMON_I_INPUT,
417 	HWMON_I_INPUT,
418 	HWMON_I_INPUT,
419 	HWMON_I_INPUT,
420 	HWMON_I_INPUT,
421 	HWMON_I_INPUT,
422 	HWMON_I_INPUT,
423 	HWMON_I_INPUT,
424 	HWMON_I_INPUT,
425 	0
426 };
427 
428 static const struct hwmon_channel_info nct7904_in = {
429 	.type = hwmon_in,
430 	.config = nct7904_in_config,
431 };
432 
433 static const u32 nct7904_fan_config[] = {
434 	HWMON_F_INPUT,
435 	HWMON_F_INPUT,
436 	HWMON_F_INPUT,
437 	HWMON_F_INPUT,
438 	HWMON_F_INPUT,
439 	HWMON_F_INPUT,
440 	HWMON_F_INPUT,
441 	HWMON_F_INPUT,
442 	0
443 };
444 
445 static const struct hwmon_channel_info nct7904_fan = {
446 	.type = hwmon_fan,
447 	.config = nct7904_fan_config,
448 };
449 
450 static const u32 nct7904_pwm_config[] = {
451 	HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
452 	HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
453 	HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
454 	HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
455 	0
456 };
457 
458 static const struct hwmon_channel_info nct7904_pwm = {
459 	.type = hwmon_pwm,
460 	.config = nct7904_pwm_config,
461 };
462 
463 static const u32 nct7904_temp_config[] = {
464 	HWMON_T_INPUT,
465 	HWMON_T_INPUT,
466 	HWMON_T_INPUT,
467 	HWMON_T_INPUT,
468 	HWMON_T_INPUT,
469 	HWMON_T_INPUT,
470 	HWMON_T_INPUT,
471 	HWMON_T_INPUT,
472 	HWMON_T_INPUT,
473 	0
474 };
475 
476 static const struct hwmon_channel_info nct7904_temp = {
477 	.type = hwmon_temp,
478 	.config = nct7904_temp_config,
479 };
480 
481 static const struct hwmon_channel_info *nct7904_info[] = {
482 	&nct7904_in,
483 	&nct7904_fan,
484 	&nct7904_pwm,
485 	&nct7904_temp,
486 	NULL
487 };
488 
489 static const struct hwmon_ops nct7904_hwmon_ops = {
490 	.is_visible = nct7904_is_visible,
491 	.read = nct7904_read,
492 	.write = nct7904_write,
493 };
494 
495 static const struct hwmon_chip_info nct7904_chip_info = {
496 	.ops = &nct7904_hwmon_ops,
497 	.info = nct7904_info,
498 };
499 
500 static int nct7904_probe(struct i2c_client *client,
501 			 const struct i2c_device_id *id)
502 {
503 	struct nct7904_data *data;
504 	struct device *hwmon_dev;
505 	struct device *dev = &client->dev;
506 	int ret, i;
507 	u32 mask;
508 
509 	data = devm_kzalloc(dev, sizeof(struct nct7904_data), GFP_KERNEL);
510 	if (!data)
511 		return -ENOMEM;
512 
513 	data->client = client;
514 	mutex_init(&data->bank_lock);
515 	data->bank_sel = -1;
516 
517 	/* Setup sensor groups. */
518 	/* FANIN attributes */
519 	ret = nct7904_read_reg16(data, BANK_0, FANIN_CTRL0_REG);
520 	if (ret < 0)
521 		return ret;
522 	data->fanin_mask = (ret >> 8) | ((ret & 0xff) << 8);
523 
524 	/*
525 	 * VSEN attributes
526 	 *
527 	 * Note: voltage sensors overlap with external temperature
528 	 * sensors. So, if we ever decide to support the latter
529 	 * we will have to adjust 'vsen_mask' accordingly.
530 	 */
531 	mask = 0;
532 	ret = nct7904_read_reg16(data, BANK_0, VT_ADC_CTRL0_REG);
533 	if (ret >= 0)
534 		mask = (ret >> 8) | ((ret & 0xff) << 8);
535 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_CTRL2_REG);
536 	if (ret >= 0)
537 		mask |= (ret << 16);
538 	data->vsen_mask = mask;
539 
540 	/* CPU_TEMP attributes */
541 	ret = nct7904_read_reg16(data, BANK_0, DTS_T_CTRL0_REG);
542 	if (ret < 0)
543 		return ret;
544 	data->tcpu_mask = ((ret >> 8) & 0xf) | ((ret & 0xf) << 4);
545 
546 	for (i = 0; i < FANCTL_MAX; i++) {
547 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + i);
548 		if (ret < 0)
549 			return ret;
550 		data->fan_mode[i] = ret;
551 	}
552 
553 	hwmon_dev =
554 		devm_hwmon_device_register_with_info(dev, client->name, data,
555 						     &nct7904_chip_info, NULL);
556 	return PTR_ERR_OR_ZERO(hwmon_dev);
557 }
558 
559 static const struct i2c_device_id nct7904_id[] = {
560 	{"nct7904", 0},
561 	{}
562 };
563 MODULE_DEVICE_TABLE(i2c, nct7904_id);
564 
565 static struct i2c_driver nct7904_driver = {
566 	.class = I2C_CLASS_HWMON,
567 	.driver = {
568 		.name = "nct7904",
569 	},
570 	.probe = nct7904_probe,
571 	.id_table = nct7904_id,
572 	.detect = nct7904_detect,
573 	.address_list = normal_i2c,
574 };
575 
576 module_i2c_driver(nct7904_driver);
577 
578 MODULE_AUTHOR("Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>");
579 MODULE_DESCRIPTION("Hwmon driver for NUVOTON NCT7904");
580 MODULE_LICENSE("GPL");
581