xref: /openbmc/linux/drivers/hwmon/ltc2992.c (revision e65e175b)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /*
3  * LTC2992 - Dual Wide Range Power Monitor
4  *
5  * Copyright 2020 Analog Devices Inc.
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bitops.h>
10 #include <linux/err.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/hwmon.h>
13 #include <linux/i2c.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/property.h>
17 #include <linux/regmap.h>
18 
19 #define LTC2992_CTRLB			0x01
20 #define LTC2992_FAULT1			0x03
21 #define LTC2992_POWER1			0x05
22 #define LTC2992_POWER1_MAX		0x08
23 #define LTC2992_POWER1_MIN		0x0B
24 #define LTC2992_POWER1_MAX_THRESH	0x0E
25 #define LTC2992_POWER1_MIN_THRESH	0x11
26 #define LTC2992_DSENSE1			0x14
27 #define LTC2992_DSENSE1_MAX		0x16
28 #define LTC2992_DSENSE1_MIN		0x18
29 #define LTC2992_DSENSE1_MAX_THRESH	0x1A
30 #define LTC2992_DSENSE1_MIN_THRESH	0x1C
31 #define LTC2992_SENSE1			0x1E
32 #define LTC2992_SENSE1_MAX		0x20
33 #define LTC2992_SENSE1_MIN		0x22
34 #define LTC2992_SENSE1_MAX_THRESH	0x24
35 #define LTC2992_SENSE1_MIN_THRESH	0x26
36 #define LTC2992_G1			0x28
37 #define LTC2992_G1_MAX			0x2A
38 #define LTC2992_G1_MIN			0x2C
39 #define LTC2992_G1_MAX_THRESH		0x2E
40 #define LTC2992_G1_MIN_THRESH		0x30
41 #define LTC2992_FAULT2			0x35
42 #define LTC2992_G2			0x5A
43 #define LTC2992_G2_MAX			0x5C
44 #define LTC2992_G2_MIN			0x5E
45 #define LTC2992_G2_MAX_THRESH		0x60
46 #define LTC2992_G2_MIN_THRESH		0x62
47 #define LTC2992_G3			0x64
48 #define LTC2992_G3_MAX			0x66
49 #define LTC2992_G3_MIN			0x68
50 #define LTC2992_G3_MAX_THRESH		0x6A
51 #define LTC2992_G3_MIN_THRESH		0x6C
52 #define LTC2992_G4			0x6E
53 #define LTC2992_G4_MAX			0x70
54 #define LTC2992_G4_MIN			0x72
55 #define LTC2992_G4_MAX_THRESH		0x74
56 #define LTC2992_G4_MIN_THRESH		0x76
57 #define LTC2992_FAULT3			0x92
58 #define LTC2992_GPIO_STATUS		0x95
59 #define LTC2992_GPIO_IO_CTRL		0x96
60 #define LTC2992_GPIO_CTRL		0x97
61 
62 #define LTC2992_POWER(x)		(LTC2992_POWER1 + ((x) * 0x32))
63 #define LTC2992_POWER_MAX(x)		(LTC2992_POWER1_MAX + ((x) * 0x32))
64 #define LTC2992_POWER_MIN(x)		(LTC2992_POWER1_MIN + ((x) * 0x32))
65 #define LTC2992_POWER_MAX_THRESH(x)	(LTC2992_POWER1_MAX_THRESH + ((x) * 0x32))
66 #define LTC2992_POWER_MIN_THRESH(x)	(LTC2992_POWER1_MIN_THRESH + ((x) * 0x32))
67 #define LTC2992_DSENSE(x)		(LTC2992_DSENSE1 + ((x) * 0x32))
68 #define LTC2992_DSENSE_MAX(x)		(LTC2992_DSENSE1_MAX + ((x) * 0x32))
69 #define LTC2992_DSENSE_MIN(x)		(LTC2992_DSENSE1_MIN + ((x) * 0x32))
70 #define LTC2992_DSENSE_MAX_THRESH(x)	(LTC2992_DSENSE1_MAX_THRESH + ((x) * 0x32))
71 #define LTC2992_DSENSE_MIN_THRESH(x)	(LTC2992_DSENSE1_MIN_THRESH + ((x) * 0x32))
72 #define LTC2992_SENSE(x)		(LTC2992_SENSE1 + ((x) * 0x32))
73 #define LTC2992_SENSE_MAX(x)		(LTC2992_SENSE1_MAX + ((x) * 0x32))
74 #define LTC2992_SENSE_MIN(x)		(LTC2992_SENSE1_MIN + ((x) * 0x32))
75 #define LTC2992_SENSE_MAX_THRESH(x)	(LTC2992_SENSE1_MAX_THRESH + ((x) * 0x32))
76 #define LTC2992_SENSE_MIN_THRESH(x)	(LTC2992_SENSE1_MIN_THRESH + ((x) * 0x32))
77 #define LTC2992_POWER_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
78 #define LTC2992_SENSE_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
79 #define LTC2992_DSENSE_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
80 
81 /* CTRLB register bitfields */
82 #define LTC2992_RESET_HISTORY		BIT(3)
83 
84 /* FAULT1 FAULT2 registers common bitfields */
85 #define LTC2992_POWER_FAULT_MSK(x)	(BIT(6) << (x))
86 #define LTC2992_DSENSE_FAULT_MSK(x)	(BIT(4) << (x))
87 #define LTC2992_SENSE_FAULT_MSK(x)	(BIT(2) << (x))
88 
89 /* FAULT1 bitfields */
90 #define LTC2992_GPIO1_FAULT_MSK(x)	(BIT(0) << (x))
91 
92 /* FAULT2 bitfields */
93 #define LTC2992_GPIO2_FAULT_MSK(x)	(BIT(0) << (x))
94 
95 /* FAULT3 bitfields */
96 #define LTC2992_GPIO3_FAULT_MSK(x)	(BIT(6) << (x))
97 #define LTC2992_GPIO4_FAULT_MSK(x)	(BIT(4) << (x))
98 
99 #define LTC2992_IADC_NANOV_LSB		12500
100 #define LTC2992_VADC_UV_LSB		25000
101 #define LTC2992_VADC_GPIO_UV_LSB	500
102 
103 #define LTC2992_GPIO_NR		4
104 #define LTC2992_GPIO1_BIT	7
105 #define LTC2992_GPIO2_BIT	6
106 #define LTC2992_GPIO3_BIT	0
107 #define LTC2992_GPIO4_BIT	6
108 #define LTC2992_GPIO_BIT(x)	(LTC2992_GPIO_NR - (x) - 1)
109 
110 struct ltc2992_state {
111 	struct i2c_client		*client;
112 	struct gpio_chip		gc;
113 	struct mutex			gpio_mutex; /* lock for gpio access */
114 	const char			*gpio_names[LTC2992_GPIO_NR];
115 	struct regmap			*regmap;
116 	u32				r_sense_uohm[2];
117 };
118 
119 struct ltc2992_gpio_regs {
120 	u8	data;
121 	u8	max;
122 	u8	min;
123 	u8	max_thresh;
124 	u8	min_thresh;
125 	u8	alarm;
126 	u8	min_alarm_msk;
127 	u8	max_alarm_msk;
128 	u8	ctrl;
129 	u8	ctrl_bit;
130 };
131 
132 static const struct ltc2992_gpio_regs ltc2992_gpio_addr_map[] = {
133 	{
134 		.data = LTC2992_G1,
135 		.max = LTC2992_G1_MAX,
136 		.min = LTC2992_G1_MIN,
137 		.max_thresh = LTC2992_G1_MAX_THRESH,
138 		.min_thresh = LTC2992_G1_MIN_THRESH,
139 		.alarm = LTC2992_FAULT1,
140 		.min_alarm_msk = LTC2992_GPIO1_FAULT_MSK(0),
141 		.max_alarm_msk = LTC2992_GPIO1_FAULT_MSK(1),
142 		.ctrl = LTC2992_GPIO_IO_CTRL,
143 		.ctrl_bit = LTC2992_GPIO1_BIT,
144 	},
145 	{
146 		.data = LTC2992_G2,
147 		.max = LTC2992_G2_MAX,
148 		.min = LTC2992_G2_MIN,
149 		.max_thresh = LTC2992_G2_MAX_THRESH,
150 		.min_thresh = LTC2992_G2_MIN_THRESH,
151 		.alarm = LTC2992_FAULT2,
152 		.min_alarm_msk = LTC2992_GPIO2_FAULT_MSK(0),
153 		.max_alarm_msk = LTC2992_GPIO2_FAULT_MSK(1),
154 		.ctrl = LTC2992_GPIO_IO_CTRL,
155 		.ctrl_bit = LTC2992_GPIO2_BIT,
156 	},
157 	{
158 		.data = LTC2992_G3,
159 		.max = LTC2992_G3_MAX,
160 		.min = LTC2992_G3_MIN,
161 		.max_thresh = LTC2992_G3_MAX_THRESH,
162 		.min_thresh = LTC2992_G3_MIN_THRESH,
163 		.alarm = LTC2992_FAULT3,
164 		.min_alarm_msk = LTC2992_GPIO3_FAULT_MSK(0),
165 		.max_alarm_msk = LTC2992_GPIO3_FAULT_MSK(1),
166 		.ctrl = LTC2992_GPIO_IO_CTRL,
167 		.ctrl_bit = LTC2992_GPIO3_BIT,
168 	},
169 	{
170 		.data = LTC2992_G4,
171 		.max = LTC2992_G4_MAX,
172 		.min = LTC2992_G4_MIN,
173 		.max_thresh = LTC2992_G4_MAX_THRESH,
174 		.min_thresh = LTC2992_G4_MIN_THRESH,
175 		.alarm = LTC2992_FAULT3,
176 		.min_alarm_msk = LTC2992_GPIO4_FAULT_MSK(0),
177 		.max_alarm_msk = LTC2992_GPIO4_FAULT_MSK(1),
178 		.ctrl = LTC2992_GPIO_CTRL,
179 		.ctrl_bit = LTC2992_GPIO4_BIT,
180 	},
181 };
182 
183 static const char *ltc2992_gpio_names[LTC2992_GPIO_NR] = {
184 	"GPIO1", "GPIO2", "GPIO3", "GPIO4",
185 };
186 
187 static int ltc2992_read_reg(struct ltc2992_state *st, u8 addr, const u8 reg_len)
188 {
189 	u8 regvals[4];
190 	int val;
191 	int ret;
192 	int i;
193 
194 	ret = regmap_bulk_read(st->regmap, addr, regvals, reg_len);
195 	if (ret < 0)
196 		return ret;
197 
198 	val = 0;
199 	for (i = 0; i < reg_len; i++)
200 		val |= regvals[reg_len - i - 1] << (i * 8);
201 
202 	return val;
203 }
204 
205 static int ltc2992_write_reg(struct ltc2992_state *st, u8 addr, const u8 reg_len, u32 val)
206 {
207 	u8 regvals[4];
208 	int i;
209 
210 	for (i = 0; i < reg_len; i++)
211 		regvals[reg_len - i - 1] = (val >> (i * 8)) & 0xFF;
212 
213 	return regmap_bulk_write(st->regmap, addr, regvals, reg_len);
214 }
215 
216 static int ltc2992_gpio_get(struct gpio_chip *chip, unsigned int offset)
217 {
218 	struct ltc2992_state *st = gpiochip_get_data(chip);
219 	unsigned long gpio_status;
220 	int reg;
221 
222 	mutex_lock(&st->gpio_mutex);
223 	reg = ltc2992_read_reg(st, LTC2992_GPIO_STATUS, 1);
224 	mutex_unlock(&st->gpio_mutex);
225 
226 	if (reg < 0)
227 		return reg;
228 
229 	gpio_status = reg;
230 
231 	return !test_bit(LTC2992_GPIO_BIT(offset), &gpio_status);
232 }
233 
234 static int ltc2992_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
235 				     unsigned long *bits)
236 {
237 	struct ltc2992_state *st = gpiochip_get_data(chip);
238 	unsigned long gpio_status;
239 	unsigned int gpio_nr;
240 	int reg;
241 
242 	mutex_lock(&st->gpio_mutex);
243 	reg = ltc2992_read_reg(st, LTC2992_GPIO_STATUS, 1);
244 	mutex_unlock(&st->gpio_mutex);
245 
246 	if (reg < 0)
247 		return reg;
248 
249 	gpio_status = reg;
250 
251 	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
252 		if (test_bit(LTC2992_GPIO_BIT(gpio_nr), &gpio_status))
253 			set_bit(gpio_nr, bits);
254 	}
255 
256 	return 0;
257 }
258 
259 static void ltc2992_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
260 {
261 	struct ltc2992_state *st = gpiochip_get_data(chip);
262 	unsigned long gpio_ctrl;
263 	int reg;
264 
265 	mutex_lock(&st->gpio_mutex);
266 	reg = ltc2992_read_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1);
267 	if (reg < 0) {
268 		mutex_unlock(&st->gpio_mutex);
269 		return;
270 	}
271 
272 	gpio_ctrl = reg;
273 	assign_bit(ltc2992_gpio_addr_map[offset].ctrl_bit, &gpio_ctrl, value);
274 
275 	ltc2992_write_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1, gpio_ctrl);
276 	mutex_unlock(&st->gpio_mutex);
277 }
278 
279 static void ltc2992_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
280 				      unsigned long *bits)
281 {
282 	struct ltc2992_state *st = gpiochip_get_data(chip);
283 	unsigned long gpio_ctrl_io = 0;
284 	unsigned long gpio_ctrl = 0;
285 	unsigned int gpio_nr;
286 
287 	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
288 		if (gpio_nr < 3)
289 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl_io, true);
290 
291 		if (gpio_nr == 3)
292 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl, true);
293 	}
294 
295 	mutex_lock(&st->gpio_mutex);
296 	ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, gpio_ctrl_io);
297 	ltc2992_write_reg(st, LTC2992_GPIO_CTRL, 1, gpio_ctrl);
298 	mutex_unlock(&st->gpio_mutex);
299 }
300 
301 static int ltc2992_config_gpio(struct ltc2992_state *st)
302 {
303 	const char *name = dev_name(&st->client->dev);
304 	char *gpio_name;
305 	int ret;
306 	int i;
307 
308 	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, 0);
309 	if (ret < 0)
310 		return ret;
311 
312 	mutex_init(&st->gpio_mutex);
313 
314 	for (i = 0; i < ARRAY_SIZE(st->gpio_names); i++) {
315 		gpio_name = devm_kasprintf(&st->client->dev, GFP_KERNEL, "ltc2992-%x-%s",
316 					   st->client->addr, ltc2992_gpio_names[i]);
317 		if (!gpio_name)
318 			return -ENOMEM;
319 
320 		st->gpio_names[i] = gpio_name;
321 	}
322 
323 	st->gc.label = name;
324 	st->gc.parent = &st->client->dev;
325 	st->gc.owner = THIS_MODULE;
326 	st->gc.base = -1;
327 	st->gc.names = st->gpio_names;
328 	st->gc.ngpio = ARRAY_SIZE(st->gpio_names);
329 	st->gc.get = ltc2992_gpio_get;
330 	st->gc.get_multiple = ltc2992_gpio_get_multiple;
331 	st->gc.set = ltc2992_gpio_set;
332 	st->gc.set_multiple = ltc2992_gpio_set_multiple;
333 
334 	ret = devm_gpiochip_add_data(&st->client->dev, &st->gc, st);
335 	if (ret)
336 		dev_err(&st->client->dev, "GPIO registering failed (%d)\n", ret);
337 
338 	return ret;
339 }
340 
341 static umode_t ltc2992_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
342 				  int channel)
343 {
344 	const struct ltc2992_state *st = data;
345 
346 	switch (type) {
347 	case hwmon_chip:
348 		switch (attr) {
349 		case hwmon_chip_in_reset_history:
350 			return 0200;
351 		}
352 		break;
353 	case hwmon_in:
354 		switch (attr) {
355 		case hwmon_in_input:
356 		case hwmon_in_lowest:
357 		case hwmon_in_highest:
358 		case hwmon_in_min_alarm:
359 		case hwmon_in_max_alarm:
360 			return 0444;
361 		case hwmon_in_min:
362 		case hwmon_in_max:
363 			return 0644;
364 		}
365 		break;
366 	case hwmon_curr:
367 		switch (attr) {
368 		case hwmon_curr_input:
369 		case hwmon_curr_lowest:
370 		case hwmon_curr_highest:
371 		case hwmon_curr_min_alarm:
372 		case hwmon_curr_max_alarm:
373 			if (st->r_sense_uohm[channel])
374 				return 0444;
375 			break;
376 		case hwmon_curr_min:
377 		case hwmon_curr_max:
378 			if (st->r_sense_uohm[channel])
379 				return 0644;
380 			break;
381 		}
382 		break;
383 	case hwmon_power:
384 		switch (attr) {
385 		case hwmon_power_input:
386 		case hwmon_power_input_lowest:
387 		case hwmon_power_input_highest:
388 		case hwmon_power_min_alarm:
389 		case hwmon_power_max_alarm:
390 			if (st->r_sense_uohm[channel])
391 				return 0444;
392 			break;
393 		case hwmon_power_min:
394 		case hwmon_power_max:
395 			if (st->r_sense_uohm[channel])
396 				return 0644;
397 			break;
398 		}
399 		break;
400 	default:
401 		break;
402 	}
403 
404 	return 0;
405 }
406 
407 static int ltc2992_get_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long *val)
408 {
409 	int reg_val;
410 
411 	reg_val = ltc2992_read_reg(st, reg, 2);
412 	if (reg_val < 0)
413 		return reg_val;
414 
415 	reg_val = reg_val >> 4;
416 	*val = DIV_ROUND_CLOSEST(reg_val * scale, 1000);
417 
418 	return 0;
419 }
420 
421 static int ltc2992_set_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long val)
422 {
423 	val = DIV_ROUND_CLOSEST(val * 1000, scale);
424 	val = val << 4;
425 
426 	return ltc2992_write_reg(st, reg, 2, val);
427 }
428 
429 static int ltc2992_read_gpio_alarm(struct ltc2992_state *st, int nr_gpio, u32 attr, long *val)
430 {
431 	int reg_val;
432 	u32 mask;
433 
434 	if (attr == hwmon_in_max_alarm)
435 		mask = ltc2992_gpio_addr_map[nr_gpio].max_alarm_msk;
436 	else
437 		mask = ltc2992_gpio_addr_map[nr_gpio].min_alarm_msk;
438 
439 	reg_val = ltc2992_read_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1);
440 	if (reg_val < 0)
441 		return reg_val;
442 
443 	*val = !!(reg_val & mask);
444 	reg_val &= ~mask;
445 
446 	return ltc2992_write_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1, reg_val);
447 }
448 
449 static int ltc2992_read_gpios_in(struct device *dev, u32 attr, int nr_gpio, long *val)
450 {
451 	struct ltc2992_state *st = dev_get_drvdata(dev);
452 	u32 reg;
453 
454 	switch (attr) {
455 	case hwmon_in_input:
456 		reg = ltc2992_gpio_addr_map[nr_gpio].data;
457 		break;
458 	case hwmon_in_lowest:
459 		reg = ltc2992_gpio_addr_map[nr_gpio].min;
460 		break;
461 	case hwmon_in_highest:
462 		reg = ltc2992_gpio_addr_map[nr_gpio].max;
463 		break;
464 	case hwmon_in_min:
465 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
466 		break;
467 	case hwmon_in_max:
468 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
469 		break;
470 	case hwmon_in_min_alarm:
471 	case hwmon_in_max_alarm:
472 		return ltc2992_read_gpio_alarm(st, nr_gpio, attr, val);
473 	default:
474 		return -EOPNOTSUPP;
475 	}
476 
477 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
478 }
479 
480 static int ltc2992_read_in_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
481 {
482 	int reg_val;
483 	u32 mask;
484 
485 	if (attr == hwmon_in_max_alarm)
486 		mask = LTC2992_SENSE_FAULT_MSK(1);
487 	else
488 		mask = LTC2992_SENSE_FAULT_MSK(0);
489 
490 	reg_val = ltc2992_read_reg(st, LTC2992_SENSE_FAULT(channel), 1);
491 	if (reg_val < 0)
492 		return reg_val;
493 
494 	*val = !!(reg_val & mask);
495 	reg_val &= ~mask;
496 
497 	return ltc2992_write_reg(st, LTC2992_SENSE_FAULT(channel), 1, reg_val);
498 }
499 
500 static int ltc2992_read_in(struct device *dev, u32 attr, int channel, long *val)
501 {
502 	struct ltc2992_state *st = dev_get_drvdata(dev);
503 	u32 reg;
504 
505 	if (channel > 1)
506 		return ltc2992_read_gpios_in(dev, attr, channel - 2, val);
507 
508 	switch (attr) {
509 	case hwmon_in_input:
510 		reg = LTC2992_SENSE(channel);
511 		break;
512 	case hwmon_in_lowest:
513 		reg = LTC2992_SENSE_MIN(channel);
514 		break;
515 	case hwmon_in_highest:
516 		reg = LTC2992_SENSE_MAX(channel);
517 		break;
518 	case hwmon_in_min:
519 		reg = LTC2992_SENSE_MIN_THRESH(channel);
520 		break;
521 	case hwmon_in_max:
522 		reg = LTC2992_SENSE_MAX_THRESH(channel);
523 		break;
524 	case hwmon_in_min_alarm:
525 	case hwmon_in_max_alarm:
526 		return ltc2992_read_in_alarm(st, channel, val, attr);
527 	default:
528 		return -EOPNOTSUPP;
529 	}
530 
531 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
532 }
533 
534 static int ltc2992_get_current(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
535 {
536 	int reg_val;
537 
538 	reg_val = ltc2992_read_reg(st, reg, 2);
539 	if (reg_val < 0)
540 		return reg_val;
541 
542 	reg_val = reg_val >> 4;
543 	*val = DIV_ROUND_CLOSEST(reg_val * LTC2992_IADC_NANOV_LSB, st->r_sense_uohm[channel]);
544 
545 	return 0;
546 }
547 
548 static int ltc2992_set_current(struct ltc2992_state *st, u32 reg, u32 channel, long val)
549 {
550 	u32 reg_val;
551 
552 	reg_val = DIV_ROUND_CLOSEST(val * st->r_sense_uohm[channel], LTC2992_IADC_NANOV_LSB);
553 	reg_val = reg_val << 4;
554 
555 	return ltc2992_write_reg(st, reg, 2, reg_val);
556 }
557 
558 static int ltc2992_read_curr_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
559 {
560 	int reg_val;
561 	u32 mask;
562 
563 	if (attr == hwmon_curr_max_alarm)
564 		mask = LTC2992_DSENSE_FAULT_MSK(1);
565 	else
566 		mask = LTC2992_DSENSE_FAULT_MSK(0);
567 
568 	reg_val = ltc2992_read_reg(st, LTC2992_DSENSE_FAULT(channel), 1);
569 	if (reg_val < 0)
570 		return reg_val;
571 
572 	*val = !!(reg_val & mask);
573 
574 	reg_val &= ~mask;
575 	return ltc2992_write_reg(st, LTC2992_DSENSE_FAULT(channel), 1, reg_val);
576 }
577 
578 static int ltc2992_read_curr(struct device *dev, u32 attr, int channel, long *val)
579 {
580 	struct ltc2992_state *st = dev_get_drvdata(dev);
581 	u32 reg;
582 
583 	switch (attr) {
584 	case hwmon_curr_input:
585 		reg = LTC2992_DSENSE(channel);
586 		break;
587 	case hwmon_curr_lowest:
588 		reg = LTC2992_DSENSE_MIN(channel);
589 		break;
590 	case hwmon_curr_highest:
591 		reg = LTC2992_DSENSE_MAX(channel);
592 		break;
593 	case hwmon_curr_min:
594 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
595 		break;
596 	case hwmon_curr_max:
597 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
598 		break;
599 	case hwmon_curr_min_alarm:
600 	case hwmon_curr_max_alarm:
601 		return ltc2992_read_curr_alarm(st, channel, val, attr);
602 	default:
603 		return -EOPNOTSUPP;
604 	}
605 
606 	return ltc2992_get_current(st, reg, channel, val);
607 }
608 
609 static int ltc2992_get_power(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
610 {
611 	int reg_val;
612 
613 	reg_val = ltc2992_read_reg(st, reg, 3);
614 	if (reg_val < 0)
615 		return reg_val;
616 
617 	*val = mul_u64_u32_div(reg_val, LTC2992_VADC_UV_LSB * LTC2992_IADC_NANOV_LSB,
618 			       st->r_sense_uohm[channel] * 1000);
619 
620 	return 0;
621 }
622 
623 static int ltc2992_set_power(struct ltc2992_state *st, u32 reg, u32 channel, long val)
624 {
625 	u32 reg_val;
626 
627 	reg_val = mul_u64_u32_div(val, st->r_sense_uohm[channel] * 1000,
628 				  LTC2992_VADC_UV_LSB * LTC2992_IADC_NANOV_LSB);
629 
630 	return ltc2992_write_reg(st, reg, 3, reg_val);
631 }
632 
633 static int ltc2992_read_power_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
634 {
635 	int reg_val;
636 	u32 mask;
637 
638 	if (attr == hwmon_power_max_alarm)
639 		mask = LTC2992_POWER_FAULT_MSK(1);
640 	else
641 		mask = LTC2992_POWER_FAULT_MSK(0);
642 
643 	reg_val = ltc2992_read_reg(st, LTC2992_POWER_FAULT(channel), 1);
644 	if (reg_val < 0)
645 		return reg_val;
646 
647 	*val = !!(reg_val & mask);
648 	reg_val &= ~mask;
649 
650 	return ltc2992_write_reg(st, LTC2992_POWER_FAULT(channel), 1, reg_val);
651 }
652 
653 static int ltc2992_read_power(struct device *dev, u32 attr, int channel, long *val)
654 {
655 	struct ltc2992_state *st = dev_get_drvdata(dev);
656 	u32 reg;
657 
658 	switch (attr) {
659 	case hwmon_power_input:
660 		reg = LTC2992_POWER(channel);
661 		break;
662 	case hwmon_power_input_lowest:
663 		reg = LTC2992_POWER_MIN(channel);
664 		break;
665 	case hwmon_power_input_highest:
666 		reg = LTC2992_POWER_MAX(channel);
667 		break;
668 	case hwmon_power_min:
669 		reg = LTC2992_POWER_MIN_THRESH(channel);
670 		break;
671 	case hwmon_power_max:
672 		reg = LTC2992_POWER_MAX_THRESH(channel);
673 		break;
674 	case hwmon_power_min_alarm:
675 	case hwmon_power_max_alarm:
676 		return ltc2992_read_power_alarm(st, channel, val, attr);
677 	default:
678 		return -EOPNOTSUPP;
679 	}
680 
681 	return ltc2992_get_power(st, reg, channel, val);
682 }
683 
684 static int ltc2992_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
685 			long *val)
686 {
687 	switch (type) {
688 	case hwmon_in:
689 		return ltc2992_read_in(dev, attr, channel, val);
690 	case hwmon_curr:
691 		return ltc2992_read_curr(dev, attr, channel, val);
692 	case hwmon_power:
693 		return ltc2992_read_power(dev, attr, channel, val);
694 	default:
695 		return -EOPNOTSUPP;
696 	}
697 }
698 
699 static int ltc2992_write_curr(struct device *dev, u32 attr, int channel, long val)
700 {
701 	struct ltc2992_state *st = dev_get_drvdata(dev);
702 	u32 reg;
703 
704 	switch (attr) {
705 	case hwmon_curr_min:
706 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
707 		break;
708 	case hwmon_curr_max:
709 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
710 		break;
711 	default:
712 		return -EOPNOTSUPP;
713 	}
714 
715 	return ltc2992_set_current(st, reg, channel, val);
716 }
717 
718 static int ltc2992_write_gpios_in(struct device *dev, u32 attr, int nr_gpio, long val)
719 {
720 	struct ltc2992_state *st = dev_get_drvdata(dev);
721 	u32 reg;
722 
723 	switch (attr) {
724 	case hwmon_in_min:
725 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
726 		break;
727 	case hwmon_in_max:
728 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
729 		break;
730 	default:
731 		return -EOPNOTSUPP;
732 	}
733 
734 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
735 }
736 
737 static int ltc2992_write_in(struct device *dev, u32 attr, int channel, long val)
738 {
739 	struct ltc2992_state *st = dev_get_drvdata(dev);
740 	u32 reg;
741 
742 	if (channel > 1)
743 		return ltc2992_write_gpios_in(dev, attr, channel - 2, val);
744 
745 	switch (attr) {
746 	case hwmon_in_min:
747 		reg = LTC2992_SENSE_MIN_THRESH(channel);
748 		break;
749 	case hwmon_in_max:
750 		reg = LTC2992_SENSE_MAX_THRESH(channel);
751 		break;
752 	default:
753 		return -EOPNOTSUPP;
754 	}
755 
756 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
757 }
758 
759 static int ltc2992_write_power(struct device *dev, u32 attr, int channel, long val)
760 {
761 	struct ltc2992_state *st = dev_get_drvdata(dev);
762 	u32 reg;
763 
764 	switch (attr) {
765 	case hwmon_power_min:
766 		reg = LTC2992_POWER_MIN_THRESH(channel);
767 		break;
768 	case hwmon_power_max:
769 		reg = LTC2992_POWER_MAX_THRESH(channel);
770 		break;
771 	default:
772 		return -EOPNOTSUPP;
773 	}
774 
775 	return ltc2992_set_power(st, reg, channel, val);
776 }
777 
778 static int ltc2992_write_chip(struct device *dev, u32 attr, int channel, long val)
779 {
780 	struct ltc2992_state *st = dev_get_drvdata(dev);
781 
782 	switch (attr) {
783 	case hwmon_chip_in_reset_history:
784 		return regmap_update_bits(st->regmap, LTC2992_CTRLB, LTC2992_RESET_HISTORY,
785 					  LTC2992_RESET_HISTORY);
786 	default:
787 		return -EOPNOTSUPP;
788 	}
789 }
790 
791 static int ltc2992_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
792 			 long val)
793 {
794 	switch (type) {
795 	case hwmon_chip:
796 		return ltc2992_write_chip(dev, attr, channel, val);
797 	case hwmon_in:
798 		return ltc2992_write_in(dev, attr, channel, val);
799 	case hwmon_curr:
800 		return ltc2992_write_curr(dev, attr, channel, val);
801 	case hwmon_power:
802 		return ltc2992_write_power(dev, attr, channel, val);
803 	default:
804 		return -EOPNOTSUPP;
805 	}
806 }
807 
808 static const struct hwmon_ops ltc2992_hwmon_ops = {
809 	.is_visible = ltc2992_is_visible,
810 	.read = ltc2992_read,
811 	.write = ltc2992_write,
812 };
813 
814 static const struct hwmon_channel_info *ltc2992_info[] = {
815 	HWMON_CHANNEL_INFO(chip,
816 			   HWMON_C_IN_RESET_HISTORY),
817 	HWMON_CHANNEL_INFO(in,
818 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
819 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
820 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
821 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
822 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
823 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
824 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
825 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
826 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
827 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
828 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
829 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM),
830 	HWMON_CHANNEL_INFO(curr,
831 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
832 			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM,
833 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
834 			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM),
835 	HWMON_CHANNEL_INFO(power,
836 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
837 			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM,
838 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
839 			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM),
840 	NULL
841 };
842 
843 static const struct hwmon_chip_info ltc2992_chip_info = {
844 	.ops = &ltc2992_hwmon_ops,
845 	.info = ltc2992_info,
846 };
847 
848 static const struct regmap_config ltc2992_regmap_config = {
849 	.reg_bits = 8,
850 	.val_bits = 8,
851 	.max_register = 0xE8,
852 };
853 
854 static int ltc2992_parse_dt(struct ltc2992_state *st)
855 {
856 	struct fwnode_handle *fwnode;
857 	struct fwnode_handle *child;
858 	u32 addr;
859 	u32 val;
860 	int ret;
861 
862 	fwnode = dev_fwnode(&st->client->dev);
863 
864 	fwnode_for_each_available_child_node(fwnode, child) {
865 		ret = fwnode_property_read_u32(child, "reg", &addr);
866 		if (ret < 0) {
867 			fwnode_handle_put(child);
868 			return ret;
869 		}
870 
871 		if (addr > 1) {
872 			fwnode_handle_put(child);
873 			return -EINVAL;
874 		}
875 
876 		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
877 		if (!ret)
878 			st->r_sense_uohm[addr] = val;
879 	}
880 
881 	return 0;
882 }
883 
884 static int ltc2992_i2c_probe(struct i2c_client *client)
885 {
886 	struct device *hwmon_dev;
887 	struct ltc2992_state *st;
888 	int ret;
889 
890 	st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
891 	if (!st)
892 		return -ENOMEM;
893 
894 	st->client = client;
895 	st->regmap = devm_regmap_init_i2c(client, &ltc2992_regmap_config);
896 	if (IS_ERR(st->regmap))
897 		return PTR_ERR(st->regmap);
898 
899 	ret = ltc2992_parse_dt(st);
900 	if (ret < 0)
901 		return ret;
902 
903 	ret = ltc2992_config_gpio(st);
904 	if (ret < 0)
905 		return ret;
906 
907 	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, client->name, st,
908 							 &ltc2992_chip_info, NULL);
909 
910 	return PTR_ERR_OR_ZERO(hwmon_dev);
911 }
912 
913 static const struct of_device_id ltc2992_of_match[] = {
914 	{ .compatible = "adi,ltc2992" },
915 	{ }
916 };
917 MODULE_DEVICE_TABLE(of, ltc2992_of_match);
918 
919 static const struct i2c_device_id ltc2992_i2c_id[] = {
920 	{"ltc2992", 0},
921 	{}
922 };
923 MODULE_DEVICE_TABLE(i2c, ltc2992_i2c_id);
924 
925 static struct i2c_driver ltc2992_i2c_driver = {
926 	.driver = {
927 		.name = "ltc2992",
928 		.of_match_table = ltc2992_of_match,
929 	},
930 	.probe_new = ltc2992_i2c_probe,
931 	.id_table = ltc2992_i2c_id,
932 };
933 
934 module_i2c_driver(ltc2992_i2c_driver);
935 
936 MODULE_AUTHOR("Alexandru Tachici <alexandru.tachici@analog.com>");
937 MODULE_DESCRIPTION("Hwmon driver for Linear Technology 2992");
938 MODULE_LICENSE("Dual BSD/GPL");
939