xref: /linux/drivers/hwmon/ltc4282.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Analog Devices LTC4282 I2C High Current Hot Swap Controller over I2C
4  *
5  * Copyright 2023 Analog Devices Inc.
6  */
7 #include <linux/bitfield.h>
8 #include <linux/cleanup.h>
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/debugfs.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/hwmon.h>
15 #include <linux/hwmon-sysfs.h>
16 #include <linux/i2c.h>
17 #include <linux/math.h>
18 #include <linux/minmax.h>
19 #include <linux/module.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/mutex.h>
22 #include <linux/regmap.h>
23 #include <linux/property.h>
24 #include <linux/string.h>
25 #include <linux/units.h>
26 #include <linux/util_macros.h>
27 
28 #define LTC4282_CTRL_LSB			0x00
29   #define LTC4282_CTRL_OV_RETRY_MASK		BIT(0)
30   #define LTC4282_CTRL_UV_RETRY_MASK		BIT(1)
31   #define LTC4282_CTRL_OC_RETRY_MASK		BIT(2)
32   #define LTC4282_CTRL_ON_ACTIVE_LOW_MASK	BIT(5)
33   #define LTC4282_CTRL_ON_DELAY_MASK		BIT(6)
34 #define LTC4282_CTRL_MSB			0x01
35   #define LTC4282_CTRL_VIN_MODE_MASK		GENMASK(1, 0)
36   #define LTC4282_CTRL_OV_MODE_MASK		GENMASK(3, 2)
37   #define LTC4282_CTRL_UV_MODE_MASK		GENMASK(5, 4)
38 #define LTC4282_FAULT_LOG			0x04
39   #define LTC4282_OV_FAULT_MASK			BIT(0)
40   #define LTC4282_UV_FAULT_MASK			BIT(1)
41   #define LTC4282_VDD_FAULT_MASK \
42 		(LTC4282_OV_FAULT_MASK | LTC4282_UV_FAULT_MASK)
43   #define LTC4282_OC_FAULT_MASK			BIT(2)
44   #define LTC4282_POWER_BAD_FAULT_MASK		BIT(3)
45   #define LTC4282_FET_SHORT_FAULT_MASK		BIT(5)
46   #define LTC4282_FET_BAD_FAULT_MASK		BIT(6)
47   #define LTC4282_FET_FAILURE_FAULT_MASK \
48 		(LTC4282_FET_SHORT_FAULT_MASK | LTC4282_FET_BAD_FAULT_MASK)
49 #define LTC4282_ADC_ALERT_LOG			0x05
50   #define LTC4282_GPIO_ALARM_L_MASK		BIT(0)
51   #define LTC4282_GPIO_ALARM_H_MASK		BIT(1)
52   #define LTC4282_VSOURCE_ALARM_L_MASK		BIT(2)
53   #define LTC4282_VSOURCE_ALARM_H_MASK		BIT(3)
54   #define LTC4282_VSENSE_ALARM_L_MASK		BIT(4)
55   #define LTC4282_VSENSE_ALARM_H_MASK		BIT(5)
56   #define LTC4282_POWER_ALARM_L_MASK		BIT(6)
57   #define LTC4282_POWER_ALARM_H_MASK		BIT(7)
58 #define LTC4282_FET_BAD_FAULT_TIMEOUT		0x06
59   #define LTC4282_FET_BAD_MAX_TIMEOUT		255
60 #define LTC4282_GPIO_CONFIG			0x07
61   #define LTC4282_GPIO_2_FET_STRESS_MASK	BIT(1)
62   #define LTC4282_GPIO_1_CONFIG_MASK		GENMASK(5, 4)
63 #define LTC4282_VGPIO_MIN			0x08
64 #define LTC4282_VGPIO_MAX			0x09
65 #define LTC4282_VSOURCE_MIN			0x0a
66 #define LTC4282_VSOURCE_MAX			0x0b
67 #define LTC4282_VSENSE_MIN			0x0c
68 #define LTC4282_VSENSE_MAX			0x0d
69 #define LTC4282_POWER_MIN			0x0e
70 #define LTC4282_POWER_MAX			0x0f
71 #define LTC4282_CLK_DIV				0x10
72   #define LTC4282_CLK_DIV_MASK			GENMASK(4, 0)
73   #define LTC4282_CLKOUT_MASK			GENMASK(6, 5)
74 #define LTC4282_ILIM_ADJUST			0x11
75   #define LTC4282_GPIO_MODE_MASK		BIT(1)
76   #define LTC4282_VDD_MONITOR_MASK		BIT(2)
77   #define LTC4282_FOLDBACK_MODE_MASK		GENMASK(4, 3)
78   #define LTC4282_ILIM_ADJUST_MASK		GENMASK(7, 5)
79 #define LTC4282_ENERGY				0x12
80 #define LTC4282_TIME_COUNTER			0x18
81 #define LTC4282_ALERT_CTRL			0x1c
82   #define LTC4282_ALERT_OUT_MASK		BIT(6)
83 #define LTC4282_ADC_CTRL			0x1d
84   #define LTC4282_FAULT_LOG_EN_MASK		BIT(2)
85   #define LTC4282_METER_HALT_MASK		BIT(5)
86   #define LTC4282_METER_RESET_MASK		BIT(6)
87   #define LTC4282_RESET_MASK			BIT(7)
88 #define LTC4282_STATUS_LSB			0x1e
89   #define LTC4282_OV_STATUS_MASK		BIT(0)
90   #define LTC4282_UV_STATUS_MASK		BIT(1)
91   #define LTC4282_VDD_STATUS_MASK \
92 		(LTC4282_OV_STATUS_MASK | LTC4282_UV_STATUS_MASK)
93   #define LTC4282_OC_STATUS_MASK		BIT(2)
94   #define LTC4282_POWER_GOOD_MASK		BIT(3)
95   #define LTC4282_FET_FAILURE_MASK		GENMASK(6, 5)
96 #define LTC4282_STATUS_MSB			0x1f
97 #define LTC4282_RESERVED_1			0x32
98 #define LTC4282_RESERVED_2			0x33
99 #define LTC4282_VGPIO				0x34
100 #define LTC4282_VGPIO_LOWEST			0x36
101 #define LTC4282_VGPIO_HIGHEST			0x38
102 #define LTC4282_VSOURCE				0x3a
103 #define LTC4282_VSOURCE_LOWEST			0x3c
104 #define LTC4282_VSOURCE_HIGHEST			0x3e
105 #define LTC4282_VSENSE				0x40
106 #define LTC4282_VSENSE_LOWEST			0x42
107 #define LTC4282_VSENSE_HIGHEST			0x44
108 #define LTC4282_POWER				0x46
109 #define LTC4282_POWER_LOWEST			0x48
110 #define LTC4282_POWER_HIGHEST			0x4a
111 #define LTC4282_RESERVED_3			0x50
112 
113 #define LTC4282_CLKIN_MIN	(250 * KILO)
114 #define LTC4282_CLKIN_MAX	(15500 * KILO)
115 #define LTC4282_CLKIN_RANGE	(LTC4282_CLKIN_MAX - LTC4282_CLKIN_MIN + 1)
116 #define LTC4282_CLKOUT_SYSTEM	(250 * KILO)
117 #define LTC4282_CLKOUT_CNV	15
118 
119 enum {
120 	LTC4282_CHAN_VSOURCE,
121 	LTC4282_CHAN_VDD,
122 	LTC4282_CHAN_VGPIO,
123 };
124 
125 struct ltc4282_cache {
126 	u32 in_max_raw;
127 	u32 in_min_raw;
128 	long in_highest;
129 	long in_lowest;
130 	bool en;
131 };
132 
133 struct ltc4282_state {
134 	struct regmap *map;
135 	/* Protect against multiple accesses to the device registers */
136 	struct mutex lock;
137 	struct clk_hw clk_hw;
138 	/*
139 	 * Used to cache values for VDD/VSOURCE depending which will be used
140 	 * when hwmon is not enabled for that channel. Needed because they share
141 	 * the same registers.
142 	 */
143 	struct ltc4282_cache in0_1_cache[LTC4282_CHAN_VGPIO];
144 	u32 vsense_max;
145 	long power_max;
146 	u32 rsense;
147 	u16 vdd;
148 	u16 vfs_out;
149 	bool energy_en;
150 };
151 
152 enum {
153 	LTC4282_CLKOUT_NONE,
154 	LTC4282_CLKOUT_INT,
155 	LTC4282_CLKOUT_TICK,
156 };
157 
158 static int ltc4282_set_rate(struct clk_hw *hw,
159 			    unsigned long rate, unsigned long parent_rate)
160 {
161 	struct ltc4282_state *st = container_of(hw, struct ltc4282_state,
162 						clk_hw);
163 	u32 val = LTC4282_CLKOUT_INT;
164 
165 	if (rate == LTC4282_CLKOUT_CNV)
166 		val = LTC4282_CLKOUT_TICK;
167 
168 	return regmap_update_bits(st->map, LTC4282_CLK_DIV, LTC4282_CLKOUT_MASK,
169 				  FIELD_PREP(LTC4282_CLKOUT_MASK, val));
170 }
171 
172 /*
173  * Note the 15HZ conversion rate assumes 12bit ADC which is what we are
174  * supporting for now.
175  */
176 static const unsigned int ltc4282_out_rates[] = {
177 	LTC4282_CLKOUT_CNV, LTC4282_CLKOUT_SYSTEM
178 };
179 
180 static long ltc4282_round_rate(struct clk_hw *hw, unsigned long rate,
181 			       unsigned long *parent_rate)
182 {
183 	int idx = find_closest(rate, ltc4282_out_rates,
184 			       ARRAY_SIZE(ltc4282_out_rates));
185 
186 	return ltc4282_out_rates[idx];
187 }
188 
189 static unsigned long ltc4282_recalc_rate(struct clk_hw *hw,
190 					 unsigned long parent)
191 {
192 	struct ltc4282_state *st = container_of(hw, struct ltc4282_state,
193 						clk_hw);
194 	u32 clkdiv;
195 	int ret;
196 
197 	ret = regmap_read(st->map, LTC4282_CLK_DIV, &clkdiv);
198 	if (ret)
199 		return 0;
200 
201 	clkdiv = FIELD_GET(LTC4282_CLKOUT_MASK, clkdiv);
202 	if (!clkdiv)
203 		return 0;
204 	if (clkdiv == LTC4282_CLKOUT_INT)
205 		return LTC4282_CLKOUT_SYSTEM;
206 
207 	return LTC4282_CLKOUT_CNV;
208 }
209 
210 static void ltc4282_disable(struct clk_hw *clk_hw)
211 {
212 	struct ltc4282_state *st = container_of(clk_hw, struct ltc4282_state,
213 						clk_hw);
214 
215 	regmap_clear_bits(st->map, LTC4282_CLK_DIV, LTC4282_CLKOUT_MASK);
216 }
217 
218 static int ltc4282_read_voltage_word(const struct ltc4282_state *st, u32 reg,
219 				     u32 fs, long *val)
220 {
221 	__be16 in;
222 	int ret;
223 
224 	ret = regmap_bulk_read(st->map, reg, &in, sizeof(in));
225 	if (ret)
226 		return ret;
227 
228 	/*
229 	 * This is also used to calculate current in which case fs comes in
230 	 * 10 * uV. Hence the ULL usage.
231 	 */
232 	*val = DIV_ROUND_CLOSEST_ULL(be16_to_cpu(in) * (u64)fs, U16_MAX);
233 	return 0;
234 }
235 
236 static int ltc4282_read_voltage_byte_cached(const struct ltc4282_state *st,
237 					    u32 reg, u32 fs, long *val,
238 					    u32 *cached_raw)
239 {
240 	int ret;
241 	u32 in;
242 
243 	if (cached_raw) {
244 		in = *cached_raw;
245 	} else {
246 		ret = regmap_read(st->map, reg, &in);
247 		if (ret)
248 			return ret;
249 	}
250 
251 	*val = DIV_ROUND_CLOSEST(in * fs, U8_MAX);
252 	return 0;
253 }
254 
255 static int ltc4282_read_voltage_byte(const struct ltc4282_state *st, u32 reg,
256 				     u32 fs, long *val)
257 {
258 	return ltc4282_read_voltage_byte_cached(st, reg, fs, val, NULL);
259 }
260 
261 static int __ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
262 				long *val)
263 {
264 	u32 alarm;
265 	int ret;
266 
267 	ret = regmap_read(st->map, reg, &alarm);
268 	if (ret)
269 		return ret;
270 
271 	*val = !!(alarm & mask);
272 
273 	/* if not status/fault logs, clear the alarm after reading it */
274 	if (reg != LTC4282_STATUS_LSB && reg != LTC4282_FAULT_LOG)
275 		return regmap_clear_bits(st->map, reg, mask);
276 
277 	return 0;
278 }
279 
280 static int ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
281 			      long *val)
282 {
283 	guard(mutex)(&st->lock);
284 	return __ltc4282_read_alarm(st, reg, mask, val);
285 }
286 
287 static int ltc4282_vdd_source_read_in(struct ltc4282_state *st, u32 channel,
288 				      long *val)
289 {
290 	guard(mutex)(&st->lock);
291 	if (!st->in0_1_cache[channel].en)
292 		return -ENODATA;
293 
294 	return ltc4282_read_voltage_word(st, LTC4282_VSOURCE, st->vfs_out, val);
295 }
296 
297 static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
298 					u32 channel, long *cached, long *val)
299 {
300 	int ret;
301 
302 	guard(mutex)(&st->lock);
303 	if (!st->in0_1_cache[channel].en) {
304 		*val = *cached;
305 		return 0;
306 	}
307 
308 	ret = ltc4282_read_voltage_word(st, reg, st->vfs_out, val);
309 	if (ret)
310 		return ret;
311 
312 	*cached = *val;
313 	return 0;
314 }
315 
316 static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
317 				       u32 channel, u32 *cached, long *val)
318 {
319 	guard(mutex)(&st->lock);
320 	if (!st->in0_1_cache[channel].en)
321 		return ltc4282_read_voltage_byte_cached(st, reg, st->vfs_out,
322 							val, cached);
323 
324 	return ltc4282_read_voltage_byte(st, reg, st->vfs_out, val);
325 }
326 
327 static int ltc4282_vdd_source_read_alm(struct ltc4282_state *st, u32 mask,
328 				       u32 channel, long *val)
329 {
330 	guard(mutex)(&st->lock);
331 	if (!st->in0_1_cache[channel].en) {
332 		/*
333 		 * Do this otherwise alarms can get confused because we clear
334 		 * them after reading them. So, if someone mistakenly reads
335 		 * VSOURCE right before VDD (or the other way around), we might
336 		 * get no alarm just because it was cleared when reading VSOURCE
337 		 * and had no time for a new conversion and thus having the
338 		 * alarm again.
339 		 */
340 		*val = 0;
341 		return 0;
342 	}
343 
344 	return __ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG, mask, val);
345 }
346 
347 static int ltc4282_read_in(struct ltc4282_state *st, u32 attr, long *val,
348 			   u32 channel)
349 {
350 	switch (attr) {
351 	case hwmon_in_input:
352 		if (channel == LTC4282_CHAN_VGPIO)
353 			return ltc4282_read_voltage_word(st, LTC4282_VGPIO,
354 							 1280, val);
355 
356 		return ltc4282_vdd_source_read_in(st, channel, val);
357 	case hwmon_in_highest:
358 		if (channel == LTC4282_CHAN_VGPIO)
359 			return ltc4282_read_voltage_word(st,
360 							 LTC4282_VGPIO_HIGHEST,
361 							 1280, val);
362 
363 		return ltc4282_vdd_source_read_hist(st, LTC4282_VSOURCE_HIGHEST,
364 						    channel,
365 						    &st->in0_1_cache[channel].in_highest, val);
366 	case hwmon_in_lowest:
367 		if (channel == LTC4282_CHAN_VGPIO)
368 			return ltc4282_read_voltage_word(st, LTC4282_VGPIO_LOWEST,
369 							 1280, val);
370 
371 		return ltc4282_vdd_source_read_hist(st, LTC4282_VSOURCE_LOWEST,
372 						    channel,
373 						    &st->in0_1_cache[channel].in_lowest, val);
374 	case hwmon_in_max_alarm:
375 		if (channel == LTC4282_CHAN_VGPIO)
376 			return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
377 						  LTC4282_GPIO_ALARM_H_MASK,
378 						  val);
379 
380 		return ltc4282_vdd_source_read_alm(st,
381 						   LTC4282_VSOURCE_ALARM_H_MASK,
382 						   channel, val);
383 	case hwmon_in_min_alarm:
384 		if (channel == LTC4282_CHAN_VGPIO)
385 			ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
386 					   LTC4282_GPIO_ALARM_L_MASK, val);
387 
388 		return ltc4282_vdd_source_read_alm(st,
389 						   LTC4282_VSOURCE_ALARM_L_MASK,
390 						   channel, val);
391 	case hwmon_in_crit_alarm:
392 		return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
393 					  LTC4282_OV_STATUS_MASK, val);
394 	case hwmon_in_lcrit_alarm:
395 		return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
396 					  LTC4282_UV_STATUS_MASK, val);
397 	case hwmon_in_max:
398 		if (channel == LTC4282_CHAN_VGPIO)
399 			return ltc4282_read_voltage_byte(st, LTC4282_VGPIO_MAX,
400 							 1280, val);
401 
402 		return ltc4282_vdd_source_read_lim(st, LTC4282_VSOURCE_MAX,
403 						   channel,
404 						   &st->in0_1_cache[channel].in_max_raw, val);
405 	case hwmon_in_min:
406 		if (channel == LTC4282_CHAN_VGPIO)
407 			return ltc4282_read_voltage_byte(st, LTC4282_VGPIO_MIN,
408 							 1280, val);
409 
410 		return ltc4282_vdd_source_read_lim(st, LTC4282_VSOURCE_MIN,
411 						   channel,
412 						   &st->in0_1_cache[channel].in_min_raw, val);
413 	case hwmon_in_enable:
414 		scoped_guard(mutex, &st->lock) {
415 			*val = st->in0_1_cache[channel].en;
416 		}
417 		return 0;
418 	case hwmon_in_fault:
419 		/*
420 		 * We report failure if we detect either a fer_bad or a
421 		 * fet_short in the status register.
422 		 */
423 		return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
424 					  LTC4282_FET_FAILURE_MASK, val);
425 	default:
426 		return -EOPNOTSUPP;
427 	}
428 }
429 
430 static int ltc4282_read_current_word(const struct ltc4282_state *st, u32 reg,
431 				     long *val)
432 {
433 	long in;
434 	int ret;
435 
436 	/*
437 	 * We pass in full scale in 10 * micro (note that 40 is already
438 	 * millivolt) so we have better approximations to calculate current.
439 	 */
440 	ret = ltc4282_read_voltage_word(st, reg, DECA * 40 * MILLI, &in);
441 	if (ret)
442 		return ret;
443 
444 	*val = DIV_ROUND_CLOSEST(in * MILLI, st->rsense);
445 
446 	return 0;
447 }
448 
449 static int ltc4282_read_current_byte(const struct ltc4282_state *st, u32 reg,
450 				     long *val)
451 {
452 	long in;
453 	int ret;
454 
455 	ret = ltc4282_read_voltage_byte(st, reg, DECA * 40 * MILLI, &in);
456 	if (ret)
457 		return ret;
458 
459 	*val = DIV_ROUND_CLOSEST(in * MILLI, st->rsense);
460 
461 	return 0;
462 }
463 
464 static int ltc4282_read_curr(struct ltc4282_state *st, const u32 attr,
465 			     long *val)
466 {
467 	switch (attr) {
468 	case hwmon_curr_input:
469 		return ltc4282_read_current_word(st, LTC4282_VSENSE, val);
470 	case hwmon_curr_highest:
471 		return ltc4282_read_current_word(st, LTC4282_VSENSE_HIGHEST,
472 						 val);
473 	case hwmon_curr_lowest:
474 		return ltc4282_read_current_word(st, LTC4282_VSENSE_LOWEST,
475 						 val);
476 	case hwmon_curr_max:
477 		return ltc4282_read_current_byte(st, LTC4282_VSENSE_MAX, val);
478 	case hwmon_curr_min:
479 		return ltc4282_read_current_byte(st, LTC4282_VSENSE_MIN, val);
480 	case hwmon_curr_max_alarm:
481 		return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
482 					  LTC4282_VSENSE_ALARM_H_MASK, val);
483 	case hwmon_curr_min_alarm:
484 		return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
485 					  LTC4282_VSENSE_ALARM_L_MASK, val);
486 	case hwmon_curr_crit_alarm:
487 		return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
488 					  LTC4282_OC_STATUS_MASK, val);
489 	default:
490 		return -EOPNOTSUPP;
491 	}
492 }
493 
494 static int ltc4282_read_power_word(const struct ltc4282_state *st, u32 reg,
495 				   long *val)
496 {
497 	u64 temp =  DECA * 40ULL * st->vfs_out * BIT(16), temp_2;
498 	__be16 raw;
499 	u16 power;
500 	int ret;
501 
502 	ret = regmap_bulk_read(st->map, reg, &raw, sizeof(raw));
503 	if (ret)
504 		return ret;
505 
506 	power = be16_to_cpu(raw);
507 	/*
508 	 * Power is given by:
509 	 *     P = CODE(16b) * 0.040 * Vfs(out) * 2^16 / ((2^16 - 1)^2 * Rsense)
510 	 */
511 	if (check_mul_overflow(power * temp, MICRO, &temp_2)) {
512 		temp = DIV_ROUND_CLOSEST_ULL(power * temp, U16_MAX);
513 		*val = DIV64_U64_ROUND_CLOSEST(temp * MICRO,
514 					       U16_MAX * (u64)st->rsense);
515 		return 0;
516 	}
517 
518 	*val = DIV64_U64_ROUND_CLOSEST(temp_2,
519 				       st->rsense * int_pow(U16_MAX, 2));
520 
521 	return 0;
522 }
523 
524 static int ltc4282_read_power_byte(const struct ltc4282_state *st, u32 reg,
525 				   long *val)
526 {
527 	u32 power;
528 	u64 temp;
529 	int ret;
530 
531 	ret = regmap_read(st->map, reg, &power);
532 	if (ret)
533 		return ret;
534 
535 	temp = power * 40 * DECA * st->vfs_out * BIT_ULL(8);
536 	*val = DIV64_U64_ROUND_CLOSEST(temp * MICRO,
537 				       int_pow(U8_MAX, 2) * st->rsense);
538 
539 	return 0;
540 }
541 
542 static int ltc4282_read_energy(const struct ltc4282_state *st, u64 *val)
543 {
544 	u64 temp, energy;
545 	__be64 raw;
546 	int ret;
547 
548 	ret = regmap_bulk_read(st->map, LTC4282_ENERGY, &raw, 6);
549 	if (ret)
550 		return ret;
551 
552 	energy =  be64_to_cpu(raw) >> 16;
553 	/*
554 	 * The formula for energy is given by:
555 	 *	E = CODE(48b) * 0.040 * Vfs(out) * Tconv * 256 /
556 	 *						((2^16 - 1)^2 * Rsense)
557 	 *
558 	 * Since we only support 12bit ADC, Tconv = 0.065535s. Passing Vfs(out)
559 	 * and 0.040 to mV and Tconv to us, we can simplify the formula to:
560 	 *	E = CODE(48b) * 40 * Vfs(out) * 256 / (U16_MAX * Rsense)
561 	 *
562 	 * As Rsense can have tenths of micro-ohm resolution, we need to
563 	 * multiply by DECA to get microujoule.
564 	 */
565 	if (check_mul_overflow(DECA * st->vfs_out * 40 * BIT(8), energy, &temp)) {
566 		temp = DIV_ROUND_CLOSEST(DECA * st->vfs_out * 40 * BIT(8), U16_MAX);
567 		*val = DIV_ROUND_CLOSEST_ULL(temp * energy, st->rsense);
568 		return 0;
569 	}
570 
571 	*val = DIV64_U64_ROUND_CLOSEST(temp, U16_MAX * (u64)st->rsense);
572 
573 	return 0;
574 }
575 
576 static int ltc4282_read_power(struct ltc4282_state *st, const u32 attr,
577 			      long *val)
578 {
579 	switch (attr) {
580 	case hwmon_power_input:
581 		return ltc4282_read_power_word(st, LTC4282_POWER, val);
582 	case hwmon_power_input_highest:
583 		return ltc4282_read_power_word(st, LTC4282_POWER_HIGHEST, val);
584 	case hwmon_power_input_lowest:
585 		return ltc4282_read_power_word(st, LTC4282_POWER_LOWEST, val);
586 	case hwmon_power_max_alarm:
587 		return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
588 					  LTC4282_POWER_ALARM_H_MASK, val);
589 	case hwmon_power_min_alarm:
590 		return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
591 					  LTC4282_POWER_ALARM_L_MASK, val);
592 	case hwmon_power_max:
593 		return ltc4282_read_power_byte(st, LTC4282_POWER_MAX, val);
594 	case hwmon_power_min:
595 		return ltc4282_read_power_byte(st, LTC4282_POWER_MIN, val);
596 	default:
597 		return -EOPNOTSUPP;
598 	}
599 }
600 
601 static int ltc4282_read(struct device *dev, enum hwmon_sensor_types type,
602 			u32 attr, int channel, long *val)
603 {
604 	struct ltc4282_state *st = dev_get_drvdata(dev);
605 
606 	switch (type) {
607 	case hwmon_in:
608 		return ltc4282_read_in(st, attr, val, channel);
609 	case hwmon_curr:
610 		return ltc4282_read_curr(st, attr, val);
611 	case hwmon_power:
612 		return ltc4282_read_power(st, attr, val);
613 	case hwmon_energy:
614 		scoped_guard(mutex, &st->lock) {
615 			*val = st->energy_en;
616 		}
617 		return 0;
618 	default:
619 		return -EOPNOTSUPP;
620 	}
621 }
622 
623 static int ltc4282_write_power_byte(const struct ltc4282_state *st, u32 reg,
624 				    long val)
625 {
626 	u32 power;
627 	u64 temp;
628 
629 	if (val > st->power_max)
630 		val = st->power_max;
631 
632 	temp = val * int_pow(U8_MAX, 2) * st->rsense;
633 	power = DIV64_U64_ROUND_CLOSEST(temp,
634 					MICRO * DECA * 256ULL * st->vfs_out * 40);
635 
636 	return regmap_write(st->map, reg, power);
637 }
638 
639 static int ltc4282_write_power_word(const struct ltc4282_state *st, u32 reg,
640 				    long val)
641 {
642 	u64 temp = int_pow(U16_MAX, 2) * st->rsense, temp_2;
643 	__be16 __raw;
644 	u16 code;
645 
646 	if (check_mul_overflow(temp, val, &temp_2)) {
647 		temp = DIV_ROUND_CLOSEST_ULL(temp, DECA * MICRO);
648 		code = DIV64_U64_ROUND_CLOSEST(temp * val,
649 					       40ULL * BIT(16) * st->vfs_out);
650 	} else {
651 		temp =  DECA * MICRO * 40ULL * BIT(16) * st->vfs_out;
652 		code = DIV64_U64_ROUND_CLOSEST(temp_2, temp);
653 	}
654 
655 	__raw = cpu_to_be16(code);
656 	return regmap_bulk_write(st->map, reg, &__raw, sizeof(__raw));
657 }
658 
659 static int __ltc4282_in_write_history(const struct ltc4282_state *st, u32 reg,
660 				      long lowest, long highest, u32 fs)
661 {
662 	__be16 __raw;
663 	u16 tmp;
664 	int ret;
665 
666 	tmp = DIV_ROUND_CLOSEST(U16_MAX * lowest, fs);
667 
668 	__raw = cpu_to_be16(tmp);
669 
670 	ret = regmap_bulk_write(st->map, reg, &__raw, 2);
671 	if (ret)
672 		return ret;
673 
674 	tmp = DIV_ROUND_CLOSEST(U16_MAX * highest, fs);
675 
676 	__raw = cpu_to_be16(tmp);
677 
678 	return regmap_bulk_write(st->map, reg + 2, &__raw, 2);
679 }
680 
681 static int ltc4282_in_write_history(struct ltc4282_state *st, u32 reg,
682 				    long lowest, long highest, u32 fs)
683 {
684 	guard(mutex)(&st->lock);
685 	return __ltc4282_in_write_history(st, reg, lowest, highest, fs);
686 }
687 
688 static int ltc4282_power_reset_hist(struct ltc4282_state *st)
689 {
690 	int ret;
691 
692 	guard(mutex)(&st->lock);
693 
694 	ret = ltc4282_write_power_word(st, LTC4282_POWER_LOWEST,
695 				       st->power_max);
696 	if (ret)
697 		return ret;
698 
699 	ret = ltc4282_write_power_word(st, LTC4282_POWER_HIGHEST, 0);
700 	if (ret)
701 		return ret;
702 
703 	/* now, let's also clear possible power_bad fault logs */
704 	return regmap_clear_bits(st->map, LTC4282_FAULT_LOG,
705 				 LTC4282_POWER_BAD_FAULT_MASK);
706 }
707 
708 static int ltc4282_write_power(struct ltc4282_state *st, u32 attr,
709 			       long val)
710 {
711 	switch (attr) {
712 	case hwmon_power_max:
713 		return ltc4282_write_power_byte(st, LTC4282_POWER_MAX, val);
714 	case hwmon_power_min:
715 		return ltc4282_write_power_byte(st, LTC4282_POWER_MIN, val);
716 	case hwmon_power_reset_history:
717 		return ltc4282_power_reset_hist(st);
718 	default:
719 		return -EOPNOTSUPP;
720 	}
721 }
722 
723 static int ltc4282_write_voltage_byte_cached(const struct ltc4282_state *st,
724 					     u32 reg, u32 fs, long val,
725 					     u32 *cache_raw)
726 {
727 	u32 in;
728 
729 	val = clamp_val(val, 0, fs);
730 	in = DIV_ROUND_CLOSEST(val * U8_MAX, fs);
731 
732 	if (cache_raw) {
733 		*cache_raw = in;
734 		return 0;
735 	}
736 
737 	return regmap_write(st->map, reg, in);
738 }
739 
740 static int ltc4282_write_voltage_byte(const struct ltc4282_state *st, u32 reg,
741 				      u32 fs, long val)
742 {
743 	return ltc4282_write_voltage_byte_cached(st, reg, fs, val, NULL);
744 }
745 
746 static int ltc4282_cache_history(struct ltc4282_state *st, u32 channel)
747 {
748 	long val;
749 	int ret;
750 
751 	ret = ltc4282_read_voltage_word(st, LTC4282_VSOURCE_LOWEST, st->vfs_out,
752 					&val);
753 	if (ret)
754 		return ret;
755 
756 	st->in0_1_cache[channel].in_lowest = val;
757 
758 	ret = ltc4282_read_voltage_word(st, LTC4282_VSOURCE_HIGHEST,
759 					st->vfs_out, &val);
760 	if (ret)
761 		return ret;
762 
763 	st->in0_1_cache[channel].in_highest = val;
764 
765 	ret = regmap_read(st->map, LTC4282_VSOURCE_MIN,
766 			  &st->in0_1_cache[channel].in_min_raw);
767 	if (ret)
768 		return ret;
769 
770 	return regmap_read(st->map, LTC4282_VSOURCE_MAX,
771 			  &st->in0_1_cache[channel].in_max_raw);
772 }
773 
774 static int ltc4282_cache_sync(struct ltc4282_state *st, u32 channel)
775 {
776 	int ret;
777 
778 	ret = __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
779 					 st->in0_1_cache[channel].in_lowest,
780 					 st->in0_1_cache[channel].in_highest,
781 					 st->vfs_out);
782 	if (ret)
783 		return ret;
784 
785 	ret = regmap_write(st->map, LTC4282_VSOURCE_MIN,
786 			   st->in0_1_cache[channel].in_min_raw);
787 	if (ret)
788 		return ret;
789 
790 	return regmap_write(st->map, LTC4282_VSOURCE_MAX,
791 			    st->in0_1_cache[channel].in_max_raw);
792 }
793 
794 static int ltc4282_vdd_source_write_lim(struct ltc4282_state *st, u32 reg,
795 					int channel, u32 *cache, long val)
796 {
797 	int ret;
798 
799 	guard(mutex)(&st->lock);
800 	if (st->in0_1_cache[channel].en)
801 		ret = ltc4282_write_voltage_byte(st, reg, st->vfs_out, val);
802 	else
803 		ret = ltc4282_write_voltage_byte_cached(st, reg, st->vfs_out,
804 							val, cache);
805 
806 	return ret;
807 }
808 
809 static int ltc4282_vdd_source_reset_hist(struct ltc4282_state *st, int channel)
810 {
811 	long lowest = st->vfs_out;
812 	int ret;
813 
814 	if (channel == LTC4282_CHAN_VDD)
815 		lowest = st->vdd;
816 
817 	guard(mutex)(&st->lock);
818 	if (st->in0_1_cache[channel].en) {
819 		ret = __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
820 						 lowest, 0, st->vfs_out);
821 		if (ret)
822 			return ret;
823 	}
824 
825 	st->in0_1_cache[channel].in_lowest = lowest;
826 	st->in0_1_cache[channel].in_highest = 0;
827 
828 	/*
829 	 * We are also clearing possible fault logs in reset_history. Clearing
830 	 * the logs might be important when the auto retry bits are not enabled
831 	 * as the chip only enables the output again after having these logs
832 	 * cleared. As some of these logs are related to limits, it makes sense
833 	 * to clear them in here. For VDD, we need to clear under/over voltage
834 	 * events. For VSOURCE, fet_short and fet_bad...
835 	 */
836 	if (channel == LTC4282_CHAN_VSOURCE)
837 		return regmap_clear_bits(st->map, LTC4282_FAULT_LOG,
838 					 LTC4282_FET_FAILURE_FAULT_MASK);
839 
840 	return regmap_clear_bits(st->map, LTC4282_FAULT_LOG,
841 				 LTC4282_VDD_FAULT_MASK);
842 }
843 
844 /*
845  * We need to mux between VSOURCE and VDD which means they are mutually
846  * exclusive. Moreover, we can't really disable both VDD and VSOURCE as the ADC
847  * is continuously running (we cannot independently halt it without also
848  * stopping VGPIO). Hence, the logic is that disabling or enabling VDD will
849  * automatically have the reverse effect on VSOURCE and vice-versa.
850  */
851 static int ltc4282_vdd_source_enable(struct ltc4282_state *st, int channel,
852 				     long val)
853 {
854 	int ret, other_chan = ~channel & 0x1;
855 	u8 __val = val;
856 
857 	guard(mutex)(&st->lock);
858 	if (st->in0_1_cache[channel].en == !!val)
859 		return 0;
860 
861 	/* clearing the bit makes the ADC to monitor VDD */
862 	if (channel == LTC4282_CHAN_VDD)
863 		__val = !__val;
864 
865 	ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
866 				 LTC4282_VDD_MONITOR_MASK,
867 				 FIELD_PREP(LTC4282_VDD_MONITOR_MASK, !!__val));
868 	if (ret)
869 		return ret;
870 
871 	st->in0_1_cache[channel].en = !!val;
872 	st->in0_1_cache[other_chan].en = !val;
873 
874 	if (st->in0_1_cache[channel].en) {
875 		/*
876 		 * Then, we are disabling @other_chan. Let's save it's current
877 		 * history.
878 		 */
879 		ret = ltc4282_cache_history(st, other_chan);
880 		if (ret)
881 			return ret;
882 
883 		return ltc4282_cache_sync(st, channel);
884 	}
885 	/*
886 	 * Then, we are enabling @other_chan. We need to do the opposite from
887 	 * above.
888 	 */
889 	ret = ltc4282_cache_history(st, channel);
890 	if (ret)
891 		return ret;
892 
893 	return ltc4282_cache_sync(st, other_chan);
894 }
895 
896 static int ltc4282_write_in(struct ltc4282_state *st, u32 attr, long val,
897 			    int channel)
898 {
899 	switch (attr) {
900 	case hwmon_in_max:
901 		if (channel == LTC4282_CHAN_VGPIO)
902 			return ltc4282_write_voltage_byte(st, LTC4282_VGPIO_MAX,
903 							  1280, val);
904 
905 		return ltc4282_vdd_source_write_lim(st, LTC4282_VSOURCE_MAX,
906 						    channel,
907 						    &st->in0_1_cache[channel].in_max_raw, val);
908 	case hwmon_in_min:
909 		if (channel == LTC4282_CHAN_VGPIO)
910 			return ltc4282_write_voltage_byte(st, LTC4282_VGPIO_MIN,
911 							  1280, val);
912 
913 		return ltc4282_vdd_source_write_lim(st, LTC4282_VSOURCE_MIN,
914 						    channel,
915 						    &st->in0_1_cache[channel].in_min_raw, val);
916 	case hwmon_in_reset_history:
917 		if (channel == LTC4282_CHAN_VGPIO)
918 			return ltc4282_in_write_history(st,
919 							LTC4282_VGPIO_LOWEST,
920 							1280, 0, 1280);
921 
922 		return ltc4282_vdd_source_reset_hist(st, channel);
923 	case hwmon_in_enable:
924 		return ltc4282_vdd_source_enable(st, channel, val);
925 	default:
926 		return -EOPNOTSUPP;
927 	}
928 }
929 
930 static int ltc4282_curr_reset_hist(struct ltc4282_state *st)
931 {
932 	int ret;
933 
934 	guard(mutex)(&st->lock);
935 
936 	ret = __ltc4282_in_write_history(st, LTC4282_VSENSE_LOWEST,
937 					 st->vsense_max, 0, 40 * MILLI);
938 	if (ret)
939 		return ret;
940 
941 	/* now, let's also clear possible overcurrent fault logs */
942 	return regmap_clear_bits(st->map, LTC4282_FAULT_LOG,
943 				 LTC4282_OC_FAULT_MASK);
944 }
945 
946 static int ltc4282_write_curr(struct ltc4282_state *st, u32 attr,
947 			      long val)
948 {
949 	/* need to pass it in millivolt */
950 	u32 in = DIV_ROUND_CLOSEST_ULL((u64)val * st->rsense, DECA * MICRO);
951 
952 	switch (attr) {
953 	case hwmon_curr_max:
954 		return ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MAX, 40,
955 						  in);
956 	case hwmon_curr_min:
957 		return ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MIN, 40,
958 						  in);
959 	case hwmon_curr_reset_history:
960 		return ltc4282_curr_reset_hist(st);
961 	default:
962 		return -EOPNOTSUPP;
963 	}
964 }
965 
966 static int ltc4282_energy_enable_set(struct ltc4282_state *st, long val)
967 {
968 	int ret;
969 
970 	guard(mutex)(&st->lock);
971 	/* setting the bit halts the meter */
972 	ret = regmap_update_bits(st->map, LTC4282_ADC_CTRL,
973 				 LTC4282_METER_HALT_MASK,
974 				 FIELD_PREP(LTC4282_METER_HALT_MASK, !val));
975 	if (ret)
976 		return ret;
977 
978 	st->energy_en = !!val;
979 
980 	return 0;
981 }
982 
983 static int ltc4282_write(struct device *dev,
984 			 enum hwmon_sensor_types type,
985 			 u32 attr, int channel, long val)
986 {
987 	struct ltc4282_state *st = dev_get_drvdata(dev);
988 
989 	switch (type) {
990 	case hwmon_power:
991 		return ltc4282_write_power(st, attr, val);
992 	case hwmon_in:
993 		return ltc4282_write_in(st, attr, val, channel);
994 	case hwmon_curr:
995 		return ltc4282_write_curr(st, attr, val);
996 	case hwmon_energy:
997 		return ltc4282_energy_enable_set(st, val);
998 	default:
999 		return -EOPNOTSUPP;
1000 	}
1001 }
1002 
1003 static umode_t ltc4282_in_is_visible(const struct ltc4282_state *st, u32 attr)
1004 {
1005 	switch (attr) {
1006 	case hwmon_in_input:
1007 	case hwmon_in_highest:
1008 	case hwmon_in_lowest:
1009 	case hwmon_in_max_alarm:
1010 	case hwmon_in_min_alarm:
1011 	case hwmon_in_label:
1012 	case hwmon_in_lcrit_alarm:
1013 	case hwmon_in_crit_alarm:
1014 	case hwmon_in_fault:
1015 		return 0444;
1016 	case hwmon_in_max:
1017 	case hwmon_in_min:
1018 	case hwmon_in_enable:
1019 	case hwmon_in_reset_history:
1020 		return 0644;
1021 	default:
1022 		return 0;
1023 	}
1024 }
1025 
1026 static umode_t ltc4282_curr_is_visible(u32 attr)
1027 {
1028 	switch (attr) {
1029 	case hwmon_curr_input:
1030 	case hwmon_curr_highest:
1031 	case hwmon_curr_lowest:
1032 	case hwmon_curr_max_alarm:
1033 	case hwmon_curr_min_alarm:
1034 	case hwmon_curr_crit_alarm:
1035 	case hwmon_curr_label:
1036 		return 0444;
1037 	case hwmon_curr_max:
1038 	case hwmon_curr_min:
1039 	case hwmon_curr_reset_history:
1040 		return 0644;
1041 	default:
1042 		return 0;
1043 	}
1044 }
1045 
1046 static umode_t ltc4282_power_is_visible(u32 attr)
1047 {
1048 	switch (attr) {
1049 	case hwmon_power_input:
1050 	case hwmon_power_input_highest:
1051 	case hwmon_power_input_lowest:
1052 	case hwmon_power_label:
1053 	case hwmon_power_max_alarm:
1054 	case hwmon_power_min_alarm:
1055 		return 0444;
1056 	case hwmon_power_max:
1057 	case hwmon_power_min:
1058 	case hwmon_power_reset_history:
1059 		return 0644;
1060 	default:
1061 		return 0;
1062 	}
1063 }
1064 
1065 static umode_t ltc4282_is_visible(const void *data,
1066 				  enum hwmon_sensor_types type,
1067 				  u32 attr, int channel)
1068 {
1069 	switch (type) {
1070 	case hwmon_in:
1071 		return ltc4282_in_is_visible(data, attr);
1072 	case hwmon_curr:
1073 		return ltc4282_curr_is_visible(attr);
1074 	case hwmon_power:
1075 		return ltc4282_power_is_visible(attr);
1076 	case hwmon_energy:
1077 		/* hwmon_energy_enable */
1078 		return 0644;
1079 	default:
1080 		return 0;
1081 	}
1082 }
1083 
1084 static const char * const ltc4282_in_strs[] = {
1085 	"VSOURCE", "VDD", "VGPIO"
1086 };
1087 
1088 static int ltc4282_read_labels(struct device *dev,
1089 			       enum hwmon_sensor_types type,
1090 			       u32 attr, int channel, const char **str)
1091 {
1092 	switch (type) {
1093 	case hwmon_in:
1094 		*str = ltc4282_in_strs[channel];
1095 		return 0;
1096 	case hwmon_curr:
1097 		*str = "ISENSE";
1098 		return 0;
1099 	case hwmon_power:
1100 		*str = "Power";
1101 		return 0;
1102 	default:
1103 		return -EOPNOTSUPP;
1104 	}
1105 }
1106 
1107 static ssize_t ltc4282_energy_show(struct device *dev,
1108 				   struct device_attribute *da, char *buf)
1109 {
1110 	struct ltc4282_state *st = dev_get_drvdata(dev);
1111 	u64 energy;
1112 	int ret;
1113 
1114 	guard(mutex)(&st->lock);
1115 	if (!st->energy_en)
1116 		return -ENODATA;
1117 
1118 	ret = ltc4282_read_energy(st, &energy);
1119 	if (ret < 0)
1120 		return ret;
1121 
1122 	return sysfs_emit(buf, "%llu\n", energy);
1123 }
1124 
1125 static const struct clk_ops ltc4282_ops = {
1126 	.recalc_rate = ltc4282_recalc_rate,
1127 	.round_rate = ltc4282_round_rate,
1128 	.set_rate = ltc4282_set_rate,
1129 	.disable = ltc4282_disable,
1130 };
1131 
1132 static int ltc428_clk_provider_setup(struct ltc4282_state *st,
1133 				     struct device *dev)
1134 {
1135 	struct clk_init_data init;
1136 	int ret;
1137 
1138 	if (!IS_ENABLED(CONFIG_COMMON_CLK))
1139 		return 0;
1140 
1141 	init.name =  devm_kasprintf(dev, GFP_KERNEL, "%s-clk",
1142 				    fwnode_get_name(dev_fwnode(dev)));
1143 	if (!init.name)
1144 		return -ENOMEM;
1145 
1146 	init.ops = &ltc4282_ops;
1147 	init.flags = CLK_GET_RATE_NOCACHE;
1148 	st->clk_hw.init = &init;
1149 
1150 	ret = devm_clk_hw_register(dev, &st->clk_hw);
1151 	if (ret)
1152 		return ret;
1153 
1154 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
1155 					   &st->clk_hw);
1156 }
1157 
1158 static int ltc428_clks_setup(struct ltc4282_state *st, struct device *dev)
1159 {
1160 	unsigned long rate;
1161 	struct clk *clkin;
1162 	u32 val;
1163 	int ret;
1164 
1165 	ret = ltc428_clk_provider_setup(st, dev);
1166 	if (ret)
1167 		return ret;
1168 
1169 	clkin = devm_clk_get_optional_enabled(dev, NULL);
1170 	if (IS_ERR(clkin))
1171 		return dev_err_probe(dev, PTR_ERR(clkin),
1172 				     "Failed to get clkin");
1173 	if (!clkin)
1174 		return 0;
1175 
1176 	rate = clk_get_rate(clkin);
1177 	if (!in_range(rate, LTC4282_CLKIN_MIN, LTC4282_CLKIN_RANGE))
1178 		return dev_err_probe(dev, -EINVAL,
1179 				     "Invalid clkin range(%lu) [%lu %lu]\n",
1180 				     rate, LTC4282_CLKIN_MIN,
1181 				     LTC4282_CLKIN_MAX);
1182 
1183 	/*
1184 	 * Clocks faster than 250KHZ should be reduced to 250KHZ. The clock
1185 	 * frequency is divided by twice the value in the register.
1186 	 */
1187 	val = rate / (2 * LTC4282_CLKIN_MIN);
1188 
1189 	return regmap_update_bits(st->map, LTC4282_CLK_DIV,
1190 				  LTC4282_CLK_DIV_MASK,
1191 				  FIELD_PREP(LTC4282_CLK_DIV_MASK, val));
1192 }
1193 
1194 static const int ltc4282_curr_lim_uv[] = {
1195 	12500, 15625, 18750, 21875, 25000, 28125, 31250, 34375
1196 };
1197 
1198 static int ltc4282_get_defaults(struct ltc4282_state *st, u32 *vin_mode)
1199 {
1200 	u32 reg_val, ilm_adjust;
1201 	int ret;
1202 
1203 	ret = regmap_read(st->map, LTC4282_ADC_CTRL, &reg_val);
1204 	if (ret)
1205 		return ret;
1206 
1207 	st->energy_en = !FIELD_GET(LTC4282_METER_HALT_MASK, reg_val);
1208 
1209 	ret = regmap_read(st->map, LTC4282_CTRL_MSB, &reg_val);
1210 	if (ret)
1211 		return ret;
1212 
1213 	*vin_mode = FIELD_GET(LTC4282_CTRL_VIN_MODE_MASK, reg_val);
1214 
1215 	ret = regmap_read(st->map, LTC4282_ILIM_ADJUST, &reg_val);
1216 	if (ret)
1217 		return ret;
1218 
1219 	ilm_adjust = FIELD_GET(LTC4282_ILIM_ADJUST_MASK, reg_val);
1220 	st->vsense_max = ltc4282_curr_lim_uv[ilm_adjust];
1221 
1222 	st->in0_1_cache[LTC4282_CHAN_VSOURCE].en = FIELD_GET(LTC4282_VDD_MONITOR_MASK,
1223 							     ilm_adjust);
1224 	if (!st->in0_1_cache[LTC4282_CHAN_VSOURCE].en) {
1225 		st->in0_1_cache[LTC4282_CHAN_VDD].en = true;
1226 		return regmap_read(st->map, LTC4282_VSOURCE_MAX,
1227 				   &st->in0_1_cache[LTC4282_CHAN_VSOURCE].in_max_raw);
1228 	}
1229 
1230 	return regmap_read(st->map, LTC4282_VSOURCE_MAX,
1231 			   &st->in0_1_cache[LTC4282_CHAN_VDD].in_max_raw);
1232 }
1233 
1234 /*
1235  * Set max limits for ISENSE and Power as that depends on the max voltage on
1236  * rsense that is defined in ILIM_ADJUST. This is specially important for power
1237  * because for some rsense and vfsout values, if we allow the default raw 255
1238  * value, that would overflow long in 32bit archs when reading back the max
1239  * power limit.
1240  *
1241  * Also set meaningful historic values for VDD and VSOURCE
1242  * (0 would not mean much).
1243  */
1244 static int ltc4282_set_max_limits(struct ltc4282_state *st)
1245 {
1246 	int ret;
1247 
1248 	ret = ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MAX, 40 * MILLI,
1249 					 st->vsense_max);
1250 	if (ret)
1251 		return ret;
1252 
1253 	/* Power is given by ISENSE * Vout. */
1254 	st->power_max = DIV_ROUND_CLOSEST(st->vsense_max * DECA * MILLI, st->rsense) * st->vfs_out;
1255 	ret = ltc4282_write_power_byte(st, LTC4282_POWER_MAX, st->power_max);
1256 	if (ret)
1257 		return ret;
1258 
1259 	if (st->in0_1_cache[LTC4282_CHAN_VDD].en) {
1260 		st->in0_1_cache[LTC4282_CHAN_VSOURCE].in_lowest = st->vfs_out;
1261 		return __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
1262 						  st->vdd, 0, st->vfs_out);
1263 	}
1264 
1265 	st->in0_1_cache[LTC4282_CHAN_VDD].in_lowest = st->vdd;
1266 	return __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
1267 					  st->vfs_out, 0, st->vfs_out);
1268 }
1269 
1270 static const char * const ltc4282_gpio1_modes[] = {
1271 	"power_bad", "power_good"
1272 };
1273 
1274 static const char * const ltc4282_gpio2_modes[] = {
1275 	"adc_input", "stress_fet"
1276 };
1277 
1278 static int ltc4282_gpio_setup(struct ltc4282_state *st, struct device *dev)
1279 {
1280 	const char *func = NULL;
1281 	int ret;
1282 
1283 	ret = device_property_read_string(dev, "adi,gpio1-mode", &func);
1284 	if (!ret) {
1285 		ret = match_string(ltc4282_gpio1_modes,
1286 				   ARRAY_SIZE(ltc4282_gpio1_modes), func);
1287 		if (ret < 0)
1288 			return dev_err_probe(dev, ret,
1289 					     "Invalid func(%s) for gpio1\n",
1290 					     func);
1291 
1292 		ret = regmap_update_bits(st->map, LTC4282_GPIO_CONFIG,
1293 					 LTC4282_GPIO_1_CONFIG_MASK,
1294 					 FIELD_PREP(LTC4282_GPIO_1_CONFIG_MASK, ret));
1295 		if (ret)
1296 			return ret;
1297 	}
1298 
1299 	ret = device_property_read_string(dev, "adi,gpio2-mode", &func);
1300 	if (!ret) {
1301 		ret = match_string(ltc4282_gpio2_modes,
1302 				   ARRAY_SIZE(ltc4282_gpio2_modes), func);
1303 		if (ret < 0)
1304 			return dev_err_probe(dev, ret,
1305 					     "Invalid func(%s) for gpio2\n",
1306 					     func);
1307 		if (!ret) {
1308 			/* setting the bit to 1 so the ADC to monitors GPIO2 */
1309 			ret = regmap_set_bits(st->map, LTC4282_ILIM_ADJUST,
1310 					      LTC4282_GPIO_MODE_MASK);
1311 		} else {
1312 			ret = regmap_update_bits(st->map, LTC4282_GPIO_CONFIG,
1313 						 LTC4282_GPIO_2_FET_STRESS_MASK,
1314 						 FIELD_PREP(LTC4282_GPIO_2_FET_STRESS_MASK, 1));
1315 		}
1316 
1317 		if (ret)
1318 			return ret;
1319 	}
1320 
1321 	if (!device_property_read_bool(dev, "adi,gpio3-monitor-enable"))
1322 		return 0;
1323 
1324 	if (func && !strcmp(func, "adc_input"))
1325 		return dev_err_probe(dev, -EINVAL,
1326 				     "Cannot have both gpio2 and gpio3 muxed into the ADC");
1327 
1328 	return regmap_clear_bits(st->map, LTC4282_ILIM_ADJUST,
1329 				 LTC4282_GPIO_MODE_MASK);
1330 }
1331 
1332 static const char * const ltc4282_dividers[] = {
1333 	"external", "vdd_5_percent", "vdd_10_percent", "vdd_15_percent"
1334 };
1335 
1336 /* This maps the Vout full scale for the given Vin mode */
1337 static const u16 ltc4282_vfs_milli[] = { 5540, 8320, 16640, 33280 };
1338 
1339 static const u16 ltc4282_vdd_milli[] = { 3300, 5000, 12000, 24000 };
1340 
1341 enum {
1342 	LTC4282_VIN_3_3V,
1343 	LTC4282_VIN_5V,
1344 	LTC4282_VIN_12V,
1345 	LTC4282_VIN_24V,
1346 };
1347 
1348 static int ltc4282_setup(struct ltc4282_state *st, struct device *dev)
1349 {
1350 	const char *divider;
1351 	u32 val, vin_mode;
1352 	int ret;
1353 
1354 	/* The part has an eeprom so let's get the needed defaults from it */
1355 	ret = ltc4282_get_defaults(st, &vin_mode);
1356 	if (ret)
1357 		return ret;
1358 
1359 	ret = device_property_read_u32(dev, "adi,rsense-nano-ohms",
1360 				       &st->rsense);
1361 	if (ret)
1362 		return dev_err_probe(dev, ret,
1363 				     "Failed to read adi,rsense-nano-ohms\n");
1364 	if (st->rsense < CENTI)
1365 		return dev_err_probe(dev, -EINVAL,
1366 				     "adi,rsense-nano-ohms too small (< %lu)\n",
1367 				     CENTI);
1368 
1369 	/*
1370 	 * The resolution for rsense is tenths of micro (eg: 62.5 uOhm) which
1371 	 * means we need nano in the bindings. However, to make things easier to
1372 	 * handle (with respect to overflows) we divide it by 100 as we don't
1373 	 * really need the last two digits.
1374 	 */
1375 	st->rsense /= CENTI;
1376 
1377 	val = vin_mode;
1378 	ret = device_property_read_u32(dev, "adi,vin-mode-microvolt", &val);
1379 	if (!ret) {
1380 		switch (val) {
1381 		case 3300000:
1382 			val = LTC4282_VIN_3_3V;
1383 			break;
1384 		case 5000000:
1385 			val = LTC4282_VIN_5V;
1386 			break;
1387 		case 12000000:
1388 			val = LTC4282_VIN_12V;
1389 			break;
1390 		case 24000000:
1391 			val = LTC4282_VIN_24V;
1392 			break;
1393 		default:
1394 			return dev_err_probe(dev, -EINVAL,
1395 					     "Invalid val(%u) for vin-mode-microvolt\n",
1396 					     val);
1397 		}
1398 
1399 		ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
1400 					 LTC4282_CTRL_VIN_MODE_MASK,
1401 					 FIELD_PREP(LTC4282_CTRL_VIN_MODE_MASK, val));
1402 		if (ret)
1403 			return ret;
1404 
1405 		/* Foldback mode should also be set to the input voltage */
1406 		ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
1407 					 LTC4282_FOLDBACK_MODE_MASK,
1408 					 FIELD_PREP(LTC4282_FOLDBACK_MODE_MASK, val));
1409 		if (ret)
1410 			return ret;
1411 	}
1412 
1413 	st->vfs_out = ltc4282_vfs_milli[val];
1414 	st->vdd = ltc4282_vdd_milli[val];
1415 
1416 	ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt",
1417 				       &st->vsense_max);
1418 	if (!ret) {
1419 		int reg_val;
1420 
1421 		switch (val) {
1422 		case 12500:
1423 			reg_val = 0;
1424 			break;
1425 		case 15625:
1426 			reg_val = 1;
1427 			break;
1428 		case 18750:
1429 			reg_val = 2;
1430 			break;
1431 		case 21875:
1432 			reg_val = 3;
1433 			break;
1434 		case 25000:
1435 			reg_val = 4;
1436 			break;
1437 		case 28125:
1438 			reg_val = 5;
1439 			break;
1440 		case 31250:
1441 			reg_val = 6;
1442 			break;
1443 		case 34375:
1444 			reg_val = 7;
1445 			break;
1446 		default:
1447 			return dev_err_probe(dev, -EINVAL,
1448 					     "Invalid val(%u) for adi,current-limit-microvolt\n",
1449 					     st->vsense_max);
1450 		}
1451 
1452 		ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
1453 					 LTC4282_ILIM_ADJUST_MASK,
1454 					 FIELD_PREP(LTC4282_ILIM_ADJUST_MASK, reg_val));
1455 		if (ret)
1456 			return ret;
1457 	}
1458 
1459 	ret = ltc4282_set_max_limits(st);
1460 	if (ret)
1461 		return ret;
1462 
1463 	ret = device_property_read_string(dev, "adi,overvoltage-dividers",
1464 					  &divider);
1465 	if (!ret) {
1466 		int div = match_string(ltc4282_dividers,
1467 				       ARRAY_SIZE(ltc4282_dividers), divider);
1468 		if (div < 0)
1469 			return dev_err_probe(dev, -EINVAL,
1470 					     "Invalid val(%s) for adi,overvoltage-divider\n",
1471 					     divider);
1472 
1473 		ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
1474 					 LTC4282_CTRL_OV_MODE_MASK,
1475 					 FIELD_PREP(LTC4282_CTRL_OV_MODE_MASK, div));
1476 	}
1477 
1478 	ret = device_property_read_string(dev, "adi,undervoltage-dividers",
1479 					  &divider);
1480 	if (!ret) {
1481 		int div = match_string(ltc4282_dividers,
1482 				       ARRAY_SIZE(ltc4282_dividers), divider);
1483 		if (div < 0)
1484 			return dev_err_probe(dev, -EINVAL,
1485 					     "Invalid val(%s) for adi,undervoltage-divider\n",
1486 					     divider);
1487 
1488 		ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
1489 					 LTC4282_CTRL_UV_MODE_MASK,
1490 					 FIELD_PREP(LTC4282_CTRL_UV_MODE_MASK, div));
1491 	}
1492 
1493 	if (device_property_read_bool(dev, "adi,overcurrent-retry")) {
1494 		ret = regmap_set_bits(st->map, LTC4282_CTRL_LSB,
1495 				      LTC4282_CTRL_OC_RETRY_MASK);
1496 		if (ret)
1497 			return ret;
1498 	}
1499 
1500 	if (device_property_read_bool(dev, "adi,overvoltage-retry-disable")) {
1501 		ret = regmap_clear_bits(st->map, LTC4282_CTRL_LSB,
1502 					LTC4282_CTRL_OV_RETRY_MASK);
1503 		if (ret)
1504 			return ret;
1505 	}
1506 
1507 	if (device_property_read_bool(dev, "adi,undervoltage-retry-disable")) {
1508 		ret = regmap_clear_bits(st->map, LTC4282_CTRL_LSB,
1509 					LTC4282_CTRL_UV_RETRY_MASK);
1510 		if (ret)
1511 			return ret;
1512 	}
1513 
1514 	if (device_property_read_bool(dev, "adi,fault-log-enable")) {
1515 		ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL,
1516 				      LTC4282_FAULT_LOG_EN_MASK);
1517 		if (ret)
1518 			return ret;
1519 	}
1520 
1521 	if (device_property_read_bool(dev, "adi,fault-log-enable")) {
1522 		ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL, LTC4282_FAULT_LOG_EN_MASK);
1523 		if (ret)
1524 			return ret;
1525 	}
1526 
1527 	ret = device_property_read_u32(dev, "adi,fet-bad-timeout-ms", &val);
1528 	if (!ret) {
1529 		if (val > LTC4282_FET_BAD_MAX_TIMEOUT)
1530 			return dev_err_probe(dev, -EINVAL,
1531 					     "Invalid value(%u) for adi,fet-bad-timeout-ms",
1532 					     val);
1533 
1534 		ret = regmap_write(st->map, LTC4282_FET_BAD_FAULT_TIMEOUT, val);
1535 		if (ret)
1536 			return ret;
1537 	}
1538 
1539 	return ltc4282_gpio_setup(st, dev);
1540 }
1541 
1542 static bool ltc4282_readable_reg(struct device *dev, unsigned int reg)
1543 {
1544 	if (reg == LTC4282_RESERVED_1 || reg == LTC4282_RESERVED_2)
1545 		return false;
1546 
1547 	return true;
1548 }
1549 
1550 static bool ltc4282_writable_reg(struct device *dev, unsigned int reg)
1551 {
1552 	if (reg == LTC4282_STATUS_LSB || reg == LTC4282_STATUS_MSB)
1553 		return false;
1554 	if (reg == LTC4282_RESERVED_1 || reg == LTC4282_RESERVED_2)
1555 		return false;
1556 
1557 	return true;
1558 }
1559 
1560 static const struct regmap_config ltc4282_regmap_config = {
1561 	.reg_bits = 8,
1562 	.val_bits = 8,
1563 	.max_register = LTC4282_RESERVED_3,
1564 	.readable_reg = ltc4282_readable_reg,
1565 	.writeable_reg = ltc4282_writable_reg,
1566 };
1567 
1568 static const struct hwmon_channel_info * const ltc4282_info[] = {
1569 	HWMON_CHANNEL_INFO(in,
1570 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
1571 			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
1572 			   HWMON_I_MAX_ALARM | HWMON_I_ENABLE |
1573 			   HWMON_I_RESET_HISTORY | HWMON_I_FAULT |
1574 			   HWMON_I_LABEL,
1575 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
1576 			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
1577 			   HWMON_I_MAX_ALARM | HWMON_I_LCRIT_ALARM |
1578 			   HWMON_I_CRIT_ALARM | HWMON_I_ENABLE |
1579 			   HWMON_I_RESET_HISTORY | HWMON_I_LABEL,
1580 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
1581 			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
1582 			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
1583 			   HWMON_I_LABEL),
1584 	HWMON_CHANNEL_INFO(curr,
1585 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST |
1586 			   HWMON_C_MAX | HWMON_C_MIN | HWMON_C_MIN_ALARM |
1587 			   HWMON_C_MAX_ALARM | HWMON_C_CRIT_ALARM |
1588 			   HWMON_C_RESET_HISTORY | HWMON_C_LABEL),
1589 	HWMON_CHANNEL_INFO(power,
1590 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST |
1591 			   HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN |
1592 			   HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
1593 			   HWMON_P_RESET_HISTORY | HWMON_P_LABEL),
1594 	HWMON_CHANNEL_INFO(energy,
1595 			   HWMON_E_ENABLE),
1596 	NULL
1597 };
1598 
1599 static const struct hwmon_ops ltc4282_hwmon_ops = {
1600 	.read = ltc4282_read,
1601 	.write = ltc4282_write,
1602 	.is_visible = ltc4282_is_visible,
1603 	.read_string = ltc4282_read_labels,
1604 };
1605 
1606 static const struct hwmon_chip_info ltc2947_chip_info = {
1607 	.ops = &ltc4282_hwmon_ops,
1608 	.info = ltc4282_info,
1609 };
1610 
1611 /* energy attributes are 6bytes wide so we need u64 */
1612 static SENSOR_DEVICE_ATTR_RO(energy1_input, ltc4282_energy, 0);
1613 
1614 static struct attribute *ltc4282_attrs[] = {
1615 	&sensor_dev_attr_energy1_input.dev_attr.attr,
1616 	NULL
1617 };
1618 ATTRIBUTE_GROUPS(ltc4282);
1619 
1620 static int ltc4282_show_fault_log(void *arg, u64 *val, u32 mask)
1621 {
1622 	struct ltc4282_state *st = arg;
1623 	long alarm;
1624 	int ret;
1625 
1626 	ret = ltc4282_read_alarm(st, LTC4282_FAULT_LOG,	mask, &alarm);
1627 	if (ret)
1628 		return ret;
1629 
1630 	*val = alarm;
1631 
1632 	return 0;
1633 }
1634 
1635 static int ltc4282_show_curr1_crit_fault_log(void *arg, u64 *val)
1636 {
1637 	return ltc4282_show_fault_log(arg, val, LTC4282_OC_FAULT_MASK);
1638 }
1639 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_curr1_crit_fault_log,
1640 			 ltc4282_show_curr1_crit_fault_log, NULL, "%llu\n");
1641 
1642 static int ltc4282_show_in1_lcrit_fault_log(void *arg, u64 *val)
1643 {
1644 	return ltc4282_show_fault_log(arg, val, LTC4282_UV_FAULT_MASK);
1645 }
1646 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_in1_lcrit_fault_log,
1647 			 ltc4282_show_in1_lcrit_fault_log, NULL, "%llu\n");
1648 
1649 static int ltc4282_show_in1_crit_fault_log(void *arg, u64 *val)
1650 {
1651 	return ltc4282_show_fault_log(arg, val, LTC4282_OV_FAULT_MASK);
1652 }
1653 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_in1_crit_fault_log,
1654 			 ltc4282_show_in1_crit_fault_log, NULL, "%llu\n");
1655 
1656 static int ltc4282_show_fet_bad_fault_log(void *arg, u64 *val)
1657 {
1658 	return ltc4282_show_fault_log(arg, val, LTC4282_FET_BAD_FAULT_MASK);
1659 }
1660 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_fet_bad_fault_log,
1661 			 ltc4282_show_fet_bad_fault_log, NULL, "%llu\n");
1662 
1663 static int ltc4282_show_fet_short_fault_log(void *arg, u64 *val)
1664 {
1665 	return ltc4282_show_fault_log(arg, val, LTC4282_FET_SHORT_FAULT_MASK);
1666 }
1667 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_fet_short_fault_log,
1668 			 ltc4282_show_fet_short_fault_log, NULL, "%llu\n");
1669 
1670 static int ltc4282_show_power1_bad_fault_log(void *arg, u64 *val)
1671 {
1672 	return ltc4282_show_fault_log(arg, val, LTC4282_POWER_BAD_FAULT_MASK);
1673 }
1674 DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_power1_bad_fault_log,
1675 			 ltc4282_show_power1_bad_fault_log, NULL, "%llu\n");
1676 
1677 static void ltc4282_debugfs_remove(void *dir)
1678 {
1679 	debugfs_remove_recursive(dir);
1680 }
1681 
1682 static void ltc4282_debugfs_init(struct ltc4282_state *st,
1683 				 struct i2c_client *i2c,
1684 				 const struct device *hwmon)
1685 {
1686 	const char *debugfs_name;
1687 	struct dentry *dentry;
1688 	int ret;
1689 
1690 	if (!IS_ENABLED(CONFIG_DEBUG_FS))
1691 		return;
1692 
1693 	debugfs_name = devm_kasprintf(&i2c->dev, GFP_KERNEL, "ltc4282-%s",
1694 				      dev_name(hwmon));
1695 	if (!debugfs_name)
1696 		return;
1697 
1698 	dentry = debugfs_create_dir(debugfs_name, NULL);
1699 	if (IS_ERR(dentry))
1700 		return;
1701 
1702 	ret = devm_add_action_or_reset(&i2c->dev, ltc4282_debugfs_remove,
1703 				       dentry);
1704 	if (ret)
1705 		return;
1706 
1707 	debugfs_create_file_unsafe("power1_bad_fault_log", 0400, dentry, st,
1708 				   &ltc4282_power1_bad_fault_log);
1709 	debugfs_create_file_unsafe("in0_fet_short_fault_log", 0400, dentry, st,
1710 				   &ltc4282_fet_short_fault_log);
1711 	debugfs_create_file_unsafe("in0_fet_bad_fault_log", 0400, dentry, st,
1712 				   &ltc4282_fet_bad_fault_log);
1713 	debugfs_create_file_unsafe("in1_crit_fault_log", 0400, dentry, st,
1714 				   &ltc4282_in1_crit_fault_log);
1715 	debugfs_create_file_unsafe("in1_lcrit_fault_log", 0400, dentry, st,
1716 				   &ltc4282_in1_lcrit_fault_log);
1717 	debugfs_create_file_unsafe("curr1_crit_fault_log", 0400, dentry, st,
1718 				   &ltc4282_curr1_crit_fault_log);
1719 }
1720 
1721 static int ltc4282_probe(struct i2c_client *i2c)
1722 {
1723 	struct device *dev = &i2c->dev, *hwmon;
1724 	struct ltc4282_state *st;
1725 	int ret;
1726 
1727 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
1728 	if (!st)
1729 		return dev_err_probe(dev, -ENOMEM,
1730 				     "Failed to allocate memory\n");
1731 
1732 	st->map = devm_regmap_init_i2c(i2c, &ltc4282_regmap_config);
1733 	if (IS_ERR(st->map))
1734 		return dev_err_probe(dev, PTR_ERR(st->map),
1735 				     "failed regmap init\n");
1736 
1737 	/* Soft reset */
1738 	ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL, LTC4282_RESET_MASK);
1739 	if (ret)
1740 		return ret;
1741 
1742 	/* Yes, it's big but it is as specified in the datasheet */
1743 	msleep(3200);
1744 
1745 	ret = ltc428_clks_setup(st, dev);
1746 	if (ret)
1747 		return ret;
1748 
1749 	ret = ltc4282_setup(st, dev);
1750 	if (ret)
1751 		return ret;
1752 
1753 	mutex_init(&st->lock);
1754 	hwmon = devm_hwmon_device_register_with_info(dev, "ltc4282", st,
1755 						     &ltc2947_chip_info,
1756 						     ltc4282_groups);
1757 	if (IS_ERR(hwmon))
1758 		return PTR_ERR(hwmon);
1759 
1760 	ltc4282_debugfs_init(st, i2c, hwmon);
1761 
1762 	return 0;
1763 }
1764 
1765 static const struct of_device_id ltc4282_of_match[] = {
1766 	{ .compatible = "adi,ltc4282" },
1767 	{}
1768 };
1769 MODULE_DEVICE_TABLE(of, ltc4282_of_match);
1770 
1771 static struct i2c_driver ltc4282_driver = {
1772 	.driver = {
1773 		.name = "ltc4282",
1774 		.of_match_table = ltc4282_of_match,
1775 	},
1776 	.probe = ltc4282_probe,
1777 };
1778 module_i2c_driver(ltc4282_driver);
1779 
1780 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1781 MODULE_DESCRIPTION("LTC4282 I2C High Current Hot Swap Controller");
1782 MODULE_LICENSE("GPL");
1783