xref: /openbmc/linux/drivers/hwmon/nct7904.c (revision a20eefae)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * nct7904.c - driver for Nuvoton NCT7904D.
4  *
5  * Copyright (c) 2015 Kontron
6  * Author: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>
7  *
8  * Copyright (c) 2019 Advantech
9  * Author: Amy.Shih <amy.shih@advantech.com.tw>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/init.h>
15 #include <linux/i2c.h>
16 #include <linux/mutex.h>
17 #include <linux/hwmon.h>
18 
19 #define VENDOR_ID_REG		0x7A	/* Any bank */
20 #define NUVOTON_ID		0x50
21 #define CHIP_ID_REG		0x7B	/* Any bank */
22 #define NCT7904_ID		0xC5
23 #define DEVICE_ID_REG		0x7C	/* Any bank */
24 
25 #define BANK_SEL_REG		0xFF
26 #define BANK_0			0x00
27 #define BANK_1			0x01
28 #define BANK_2			0x02
29 #define BANK_3			0x03
30 #define BANK_4			0x04
31 #define BANK_MAX		0x04
32 
33 #define FANIN_MAX		12	/* Counted from 1 */
34 #define VSEN_MAX		21	/* VSEN1..14, 3VDD, VBAT, V3VSB,
35 					   LTD (not a voltage), VSEN17..19 */
36 #define FANCTL_MAX		4	/* Counted from 1 */
37 #define TCPU_MAX		8	/* Counted from 1 */
38 #define TEMP_MAX		4	/* Counted from 1 */
39 
40 #define VT_ADC_CTRL0_REG	0x20	/* Bank 0 */
41 #define VT_ADC_CTRL1_REG	0x21	/* Bank 0 */
42 #define VT_ADC_CTRL2_REG	0x22	/* Bank 0 */
43 #define FANIN_CTRL0_REG		0x24
44 #define FANIN_CTRL1_REG		0x25
45 #define DTS_T_CTRL0_REG		0x26
46 #define DTS_T_CTRL1_REG		0x27
47 #define VT_ADC_MD_REG		0x2E
48 
49 #define VSEN1_HV_REG		0x40	/* Bank 0; 2 regs (HV/LV) per sensor */
50 #define TEMP_CH1_HV_REG		0x42	/* Bank 0; same as VSEN2_HV */
51 #define LTD_HV_REG		0x62	/* Bank 0; 2 regs in VSEN range */
52 #define FANIN1_HV_REG		0x80	/* Bank 0; 2 regs (HV/LV) per sensor */
53 #define T_CPU1_HV_REG		0xA0	/* Bank 0; 2 regs (HV/LV) per sensor */
54 
55 #define PRTS_REG		0x03	/* Bank 2 */
56 #define PFE_REG			0x00	/* Bank 2; PECI Function Enable */
57 #define TSI_CTRL_REG		0x50	/* Bank 2; TSI Control Register */
58 #define FANCTL1_FMR_REG		0x00	/* Bank 3; 1 reg per channel */
59 #define FANCTL1_OUT_REG		0x10	/* Bank 3; 1 reg per channel */
60 
61 static const unsigned short normal_i2c[] = {
62 	0x2d, 0x2e, I2C_CLIENT_END
63 };
64 
65 struct nct7904_data {
66 	struct i2c_client *client;
67 	struct mutex bank_lock;
68 	int bank_sel;
69 	u32 fanin_mask;
70 	u32 vsen_mask;
71 	u32 tcpu_mask;
72 	u8 fan_mode[FANCTL_MAX];
73 	u8 enable_dts;
74 	u8 has_dts;
75 };
76 
77 /* Access functions */
78 static int nct7904_bank_lock(struct nct7904_data *data, unsigned int bank)
79 {
80 	int ret;
81 
82 	mutex_lock(&data->bank_lock);
83 	if (data->bank_sel == bank)
84 		return 0;
85 	ret = i2c_smbus_write_byte_data(data->client, BANK_SEL_REG, bank);
86 	if (ret == 0)
87 		data->bank_sel = bank;
88 	else
89 		data->bank_sel = -1;
90 	return ret;
91 }
92 
93 static inline void nct7904_bank_release(struct nct7904_data *data)
94 {
95 	mutex_unlock(&data->bank_lock);
96 }
97 
98 /* Read 1-byte register. Returns unsigned reg or -ERRNO on error. */
99 static int nct7904_read_reg(struct nct7904_data *data,
100 			    unsigned int bank, unsigned int reg)
101 {
102 	struct i2c_client *client = data->client;
103 	int ret;
104 
105 	ret = nct7904_bank_lock(data, bank);
106 	if (ret == 0)
107 		ret = i2c_smbus_read_byte_data(client, reg);
108 
109 	nct7904_bank_release(data);
110 	return ret;
111 }
112 
113 /*
114  * Read 2-byte register. Returns register in big-endian format or
115  * -ERRNO on error.
116  */
117 static int nct7904_read_reg16(struct nct7904_data *data,
118 			      unsigned int bank, unsigned int reg)
119 {
120 	struct i2c_client *client = data->client;
121 	int ret, hi;
122 
123 	ret = nct7904_bank_lock(data, bank);
124 	if (ret == 0) {
125 		ret = i2c_smbus_read_byte_data(client, reg);
126 		if (ret >= 0) {
127 			hi = ret;
128 			ret = i2c_smbus_read_byte_data(client, reg + 1);
129 			if (ret >= 0)
130 				ret |= hi << 8;
131 		}
132 	}
133 
134 	nct7904_bank_release(data);
135 	return ret;
136 }
137 
138 /* Write 1-byte register. Returns 0 or -ERRNO on error. */
139 static int nct7904_write_reg(struct nct7904_data *data,
140 			     unsigned int bank, unsigned int reg, u8 val)
141 {
142 	struct i2c_client *client = data->client;
143 	int ret;
144 
145 	ret = nct7904_bank_lock(data, bank);
146 	if (ret == 0)
147 		ret = i2c_smbus_write_byte_data(client, reg, val);
148 
149 	nct7904_bank_release(data);
150 	return ret;
151 }
152 
153 static int nct7904_read_fan(struct device *dev, u32 attr, int channel,
154 			    long *val)
155 {
156 	struct nct7904_data *data = dev_get_drvdata(dev);
157 	unsigned int cnt, rpm;
158 	int ret;
159 
160 	switch (attr) {
161 	case hwmon_fan_input:
162 		ret = nct7904_read_reg16(data, BANK_0,
163 					 FANIN1_HV_REG + channel * 2);
164 		if (ret < 0)
165 			return ret;
166 		cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f);
167 		if (cnt == 0x1fff)
168 			rpm = 0;
169 		else
170 			rpm = 1350000 / cnt;
171 		*val = rpm;
172 		return 0;
173 	default:
174 		return -EOPNOTSUPP;
175 	}
176 }
177 
178 static umode_t nct7904_fan_is_visible(const void *_data, u32 attr, int channel)
179 {
180 	const struct nct7904_data *data = _data;
181 
182 	if (attr == hwmon_fan_input && data->fanin_mask & (1 << channel))
183 		return 0444;
184 	return 0;
185 }
186 
187 static u8 nct7904_chan_to_index[] = {
188 	0,	/* Not used */
189 	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
190 	18, 19, 20, 16
191 };
192 
193 static int nct7904_read_in(struct device *dev, u32 attr, int channel,
194 			   long *val)
195 {
196 	struct nct7904_data *data = dev_get_drvdata(dev);
197 	int ret, volt, index;
198 
199 	index = nct7904_chan_to_index[channel];
200 
201 	switch (attr) {
202 	case hwmon_in_input:
203 		ret = nct7904_read_reg16(data, BANK_0,
204 					 VSEN1_HV_REG + index * 2);
205 		if (ret < 0)
206 			return ret;
207 		volt = ((ret & 0xff00) >> 5) | (ret & 0x7);
208 		if (index < 14)
209 			volt *= 2; /* 0.002V scale */
210 		else
211 			volt *= 6; /* 0.006V scale */
212 		*val = volt;
213 		return 0;
214 	default:
215 		return -EOPNOTSUPP;
216 	}
217 }
218 
219 static umode_t nct7904_in_is_visible(const void *_data, u32 attr, int channel)
220 {
221 	const struct nct7904_data *data = _data;
222 	int index = nct7904_chan_to_index[channel];
223 
224 	if (channel > 0 && attr == hwmon_in_input &&
225 	    (data->vsen_mask & BIT(index)))
226 		return 0444;
227 
228 	return 0;
229 }
230 
231 static int nct7904_read_temp(struct device *dev, u32 attr, int channel,
232 			     long *val)
233 {
234 	struct nct7904_data *data = dev_get_drvdata(dev);
235 	int ret, temp;
236 
237 	switch (attr) {
238 	case hwmon_temp_input:
239 		if (channel == 4)
240 			ret = nct7904_read_reg16(data, BANK_0, LTD_HV_REG);
241 		else if (channel < 5)
242 			ret = nct7904_read_reg16(data, BANK_0,
243 						 TEMP_CH1_HV_REG + channel * 4);
244 		else
245 			ret = nct7904_read_reg16(data, BANK_0,
246 						 T_CPU1_HV_REG + (channel - 5)
247 						 * 2);
248 		if (ret < 0)
249 			return ret;
250 		temp = ((ret & 0xff00) >> 5) | (ret & 0x7);
251 		*val = sign_extend32(temp, 10) * 125;
252 		return 0;
253 	default:
254 		return -EOPNOTSUPP;
255 	}
256 }
257 
258 static umode_t nct7904_temp_is_visible(const void *_data, u32 attr, int channel)
259 {
260 	const struct nct7904_data *data = _data;
261 
262 	if (attr == hwmon_temp_input) {
263 		if (channel < 5) {
264 			if (data->tcpu_mask & BIT(channel))
265 				return 0444;
266 		} else {
267 			if (data->has_dts & BIT(channel - 5))
268 				return 0444;
269 		}
270 	}
271 
272 	return 0;
273 }
274 
275 static int nct7904_read_pwm(struct device *dev, u32 attr, int channel,
276 			    long *val)
277 {
278 	struct nct7904_data *data = dev_get_drvdata(dev);
279 	int ret;
280 
281 	switch (attr) {
282 	case hwmon_pwm_input:
283 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_OUT_REG + channel);
284 		if (ret < 0)
285 			return ret;
286 		*val = ret;
287 		return 0;
288 	case hwmon_pwm_enable:
289 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + channel);
290 		if (ret < 0)
291 			return ret;
292 
293 		*val = ret ? 2 : 1;
294 		return 0;
295 	default:
296 		return -EOPNOTSUPP;
297 	}
298 }
299 
300 static int nct7904_write_pwm(struct device *dev, u32 attr, int channel,
301 			     long val)
302 {
303 	struct nct7904_data *data = dev_get_drvdata(dev);
304 	int ret;
305 
306 	switch (attr) {
307 	case hwmon_pwm_input:
308 		if (val < 0 || val > 255)
309 			return -EINVAL;
310 		ret = nct7904_write_reg(data, BANK_3, FANCTL1_OUT_REG + channel,
311 					val);
312 		return ret;
313 	case hwmon_pwm_enable:
314 		if (val < 1 || val > 2 ||
315 		    (val == 2 && !data->fan_mode[channel]))
316 			return -EINVAL;
317 		ret = nct7904_write_reg(data, BANK_3, FANCTL1_FMR_REG + channel,
318 					val == 2 ? data->fan_mode[channel] : 0);
319 		return ret;
320 	default:
321 		return -EOPNOTSUPP;
322 	}
323 }
324 
325 static umode_t nct7904_pwm_is_visible(const void *_data, u32 attr, int channel)
326 {
327 	switch (attr) {
328 	case hwmon_pwm_input:
329 	case hwmon_pwm_enable:
330 		return 0644;
331 	default:
332 		return 0;
333 	}
334 }
335 
336 static int nct7904_read(struct device *dev, enum hwmon_sensor_types type,
337 			u32 attr, int channel, long *val)
338 {
339 	switch (type) {
340 	case hwmon_in:
341 		return nct7904_read_in(dev, attr, channel, val);
342 	case hwmon_fan:
343 		return nct7904_read_fan(dev, attr, channel, val);
344 	case hwmon_pwm:
345 		return nct7904_read_pwm(dev, attr, channel, val);
346 	case hwmon_temp:
347 		return nct7904_read_temp(dev, attr, channel, val);
348 	default:
349 		return -EOPNOTSUPP;
350 	}
351 }
352 
353 static int nct7904_write(struct device *dev, enum hwmon_sensor_types type,
354 			 u32 attr, int channel, long val)
355 {
356 	switch (type) {
357 	case hwmon_pwm:
358 		return nct7904_write_pwm(dev, attr, channel, val);
359 	default:
360 		return -EOPNOTSUPP;
361 	}
362 }
363 
364 static umode_t nct7904_is_visible(const void *data,
365 				  enum hwmon_sensor_types type,
366 				  u32 attr, int channel)
367 {
368 	switch (type) {
369 	case hwmon_in:
370 		return nct7904_in_is_visible(data, attr, channel);
371 	case hwmon_fan:
372 		return nct7904_fan_is_visible(data, attr, channel);
373 	case hwmon_pwm:
374 		return nct7904_pwm_is_visible(data, attr, channel);
375 	case hwmon_temp:
376 		return nct7904_temp_is_visible(data, attr, channel);
377 	default:
378 		return 0;
379 	}
380 }
381 
382 /* Return 0 if detection is successful, -ENODEV otherwise */
383 static int nct7904_detect(struct i2c_client *client,
384 			  struct i2c_board_info *info)
385 {
386 	struct i2c_adapter *adapter = client->adapter;
387 
388 	if (!i2c_check_functionality(adapter,
389 				     I2C_FUNC_SMBUS_READ_BYTE |
390 				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
391 		return -ENODEV;
392 
393 	/* Determine the chip type. */
394 	if (i2c_smbus_read_byte_data(client, VENDOR_ID_REG) != NUVOTON_ID ||
395 	    i2c_smbus_read_byte_data(client, CHIP_ID_REG) != NCT7904_ID ||
396 	    (i2c_smbus_read_byte_data(client, DEVICE_ID_REG) & 0xf0) != 0x50 ||
397 	    (i2c_smbus_read_byte_data(client, BANK_SEL_REG) & 0xf8) != 0x00)
398 		return -ENODEV;
399 
400 	strlcpy(info->type, "nct7904", I2C_NAME_SIZE);
401 
402 	return 0;
403 }
404 
405 static const struct hwmon_channel_info *nct7904_info[] = {
406 	HWMON_CHANNEL_INFO(in,
407 			   HWMON_I_INPUT, /* dummy, skipped in is_visible */
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 			   HWMON_I_INPUT,
426 			   HWMON_I_INPUT,
427 			   HWMON_I_INPUT),
428 	HWMON_CHANNEL_INFO(fan,
429 			   HWMON_F_INPUT,
430 			   HWMON_F_INPUT,
431 			   HWMON_F_INPUT,
432 			   HWMON_F_INPUT,
433 			   HWMON_F_INPUT,
434 			   HWMON_F_INPUT,
435 			   HWMON_F_INPUT,
436 			   HWMON_F_INPUT),
437 	HWMON_CHANNEL_INFO(pwm,
438 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
439 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
440 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
441 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
442 	HWMON_CHANNEL_INFO(temp,
443 			   HWMON_T_INPUT,
444 			   HWMON_T_INPUT,
445 			   HWMON_T_INPUT,
446 			   HWMON_T_INPUT,
447 			   HWMON_T_INPUT,
448 			   HWMON_T_INPUT,
449 			   HWMON_T_INPUT,
450 			   HWMON_T_INPUT,
451 			   HWMON_T_INPUT),
452 	NULL
453 };
454 
455 static const struct hwmon_ops nct7904_hwmon_ops = {
456 	.is_visible = nct7904_is_visible,
457 	.read = nct7904_read,
458 	.write = nct7904_write,
459 };
460 
461 static const struct hwmon_chip_info nct7904_chip_info = {
462 	.ops = &nct7904_hwmon_ops,
463 	.info = nct7904_info,
464 };
465 
466 static int nct7904_probe(struct i2c_client *client,
467 			 const struct i2c_device_id *id)
468 {
469 	struct nct7904_data *data;
470 	struct device *hwmon_dev;
471 	struct device *dev = &client->dev;
472 	int ret, i;
473 	u32 mask;
474 	u8 val, bit;
475 
476 	data = devm_kzalloc(dev, sizeof(struct nct7904_data), GFP_KERNEL);
477 	if (!data)
478 		return -ENOMEM;
479 
480 	data->client = client;
481 	mutex_init(&data->bank_lock);
482 	data->bank_sel = -1;
483 
484 	/* Setup sensor groups. */
485 	/* FANIN attributes */
486 	ret = nct7904_read_reg16(data, BANK_0, FANIN_CTRL0_REG);
487 	if (ret < 0)
488 		return ret;
489 	data->fanin_mask = (ret >> 8) | ((ret & 0xff) << 8);
490 
491 	/*
492 	 * VSEN attributes
493 	 *
494 	 * Note: voltage sensors overlap with external temperature
495 	 * sensors. So, if we ever decide to support the latter
496 	 * we will have to adjust 'vsen_mask' accordingly.
497 	 */
498 	mask = 0;
499 	ret = nct7904_read_reg16(data, BANK_0, VT_ADC_CTRL0_REG);
500 	if (ret >= 0)
501 		mask = (ret >> 8) | ((ret & 0xff) << 8);
502 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_CTRL2_REG);
503 	if (ret >= 0)
504 		mask |= (ret << 16);
505 	data->vsen_mask = mask;
506 
507 	/* CPU_TEMP attributes */
508 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_CTRL0_REG);
509 	if (ret < 0)
510 		return ret;
511 
512 	if ((ret & 0x6) == 0x6)
513 		data->tcpu_mask |= 1; /* TR1 */
514 	if ((ret & 0x18) == 0x18)
515 		data->tcpu_mask |= 2; /* TR2 */
516 	if ((ret & 0x20) == 0x20)
517 		data->tcpu_mask |= 4; /* TR3 */
518 	if ((ret & 0x80) == 0x80)
519 		data->tcpu_mask |= 8; /* TR4 */
520 
521 	/* LTD */
522 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_CTRL2_REG);
523 	if (ret < 0)
524 		return ret;
525 	if ((ret & 0x02) == 0x02)
526 		data->tcpu_mask |= 0x10;
527 
528 	/* Multi-Function detecting for Volt and TR/TD */
529 	ret = nct7904_read_reg(data, BANK_0, VT_ADC_MD_REG);
530 	if (ret < 0)
531 		return ret;
532 
533 	for (i = 0; i < 4; i++) {
534 		val = (ret & (0x03 << i)) >> (i * 2);
535 		bit = (1 << i);
536 		if (val == 0)
537 			data->tcpu_mask &= ~bit;
538 	}
539 
540 	/* PECI */
541 	ret = nct7904_read_reg(data, BANK_2, PFE_REG);
542 	if (ret < 0)
543 		return ret;
544 	if (ret & 0x80) {
545 		data->enable_dts = 1; /* Enable DTS & PECI */
546 	} else {
547 		ret = nct7904_read_reg(data, BANK_2, TSI_CTRL_REG);
548 		if (ret < 0)
549 			return ret;
550 		if (ret & 0x80)
551 			data->enable_dts = 0x3; /* Enable DTS & TSI */
552 	}
553 
554 	/* Check DTS enable status */
555 	if (data->enable_dts) {
556 		ret = nct7904_read_reg(data, BANK_0, DTS_T_CTRL0_REG);
557 		if (ret < 0)
558 			return ret;
559 		data->has_dts = ret & 0xF;
560 		if (data->enable_dts & 0x2) {
561 			ret = nct7904_read_reg(data, BANK_0, DTS_T_CTRL1_REG);
562 			if (ret < 0)
563 				return ret;
564 			data->has_dts |= (ret & 0xF) << 4;
565 		}
566 	}
567 
568 	for (i = 0; i < FANCTL_MAX; i++) {
569 		ret = nct7904_read_reg(data, BANK_3, FANCTL1_FMR_REG + i);
570 		if (ret < 0)
571 			return ret;
572 		data->fan_mode[i] = ret;
573 	}
574 
575 	hwmon_dev =
576 		devm_hwmon_device_register_with_info(dev, client->name, data,
577 						     &nct7904_chip_info, NULL);
578 	return PTR_ERR_OR_ZERO(hwmon_dev);
579 }
580 
581 static const struct i2c_device_id nct7904_id[] = {
582 	{"nct7904", 0},
583 	{}
584 };
585 MODULE_DEVICE_TABLE(i2c, nct7904_id);
586 
587 static struct i2c_driver nct7904_driver = {
588 	.class = I2C_CLASS_HWMON,
589 	.driver = {
590 		.name = "nct7904",
591 	},
592 	.probe = nct7904_probe,
593 	.id_table = nct7904_id,
594 	.detect = nct7904_detect,
595 	.address_list = normal_i2c,
596 };
597 
598 module_i2c_driver(nct7904_driver);
599 
600 MODULE_AUTHOR("Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>");
601 MODULE_DESCRIPTION("Hwmon driver for NUVOTON NCT7904");
602 MODULE_LICENSE("GPL");
603