xref: /linux/drivers/hwmon/ltc2992.c (revision ec89572766744e844df24c27d31c97b4c00f4e07)
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 
ltc2992_read_reg(struct ltc2992_state * st,u8 addr,const u8 reg_len)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 
ltc2992_write_reg(struct ltc2992_state * st,u8 addr,const u8 reg_len,u32 val)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 
ltc2992_gpio_get(struct gpio_chip * chip,unsigned int offset)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 
ltc2992_gpio_get_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)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 
ltc2992_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)259 static int ltc2992_gpio_set(struct gpio_chip *chip, unsigned int offset,
260 			    int value)
261 {
262 	struct ltc2992_state *st = gpiochip_get_data(chip);
263 	unsigned long gpio_ctrl;
264 	int reg, ret;
265 
266 	mutex_lock(&st->gpio_mutex);
267 	reg = ltc2992_read_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1);
268 	if (reg < 0) {
269 		mutex_unlock(&st->gpio_mutex);
270 		return reg;
271 	}
272 
273 	gpio_ctrl = reg;
274 	assign_bit(ltc2992_gpio_addr_map[offset].ctrl_bit, &gpio_ctrl, value);
275 
276 	ret = ltc2992_write_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1,
277 				gpio_ctrl);
278 	mutex_unlock(&st->gpio_mutex);
279 
280 	return ret;
281 }
282 
ltc2992_gpio_set_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)283 static int ltc2992_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
284 				     unsigned long *bits)
285 {
286 	struct ltc2992_state *st = gpiochip_get_data(chip);
287 	unsigned long gpio_ctrl_io = 0;
288 	unsigned long gpio_ctrl = 0;
289 	unsigned int gpio_nr;
290 	int ret;
291 
292 	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
293 		if (gpio_nr < 3)
294 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl_io, true);
295 
296 		if (gpio_nr == 3)
297 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl, true);
298 	}
299 
300 	mutex_lock(&st->gpio_mutex);
301 	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, gpio_ctrl_io);
302 	if (ret)
303 		goto out;
304 
305 	ret = ltc2992_write_reg(st, LTC2992_GPIO_CTRL, 1, gpio_ctrl);
306 out:
307 	mutex_unlock(&st->gpio_mutex);
308 	return ret;
309 }
310 
ltc2992_config_gpio(struct ltc2992_state * st)311 static int ltc2992_config_gpio(struct ltc2992_state *st)
312 {
313 	const char *name = dev_name(&st->client->dev);
314 	char *gpio_name;
315 	int ret;
316 	int i;
317 
318 	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, 0);
319 	if (ret < 0)
320 		return ret;
321 
322 	mutex_init(&st->gpio_mutex);
323 
324 	for (i = 0; i < ARRAY_SIZE(st->gpio_names); i++) {
325 		gpio_name = devm_kasprintf(&st->client->dev, GFP_KERNEL, "ltc2992-%x-%s",
326 					   st->client->addr, ltc2992_gpio_names[i]);
327 		if (!gpio_name)
328 			return -ENOMEM;
329 
330 		st->gpio_names[i] = gpio_name;
331 	}
332 
333 	st->gc.label = name;
334 	st->gc.parent = &st->client->dev;
335 	st->gc.owner = THIS_MODULE;
336 	st->gc.can_sleep = true;
337 	st->gc.base = -1;
338 	st->gc.names = st->gpio_names;
339 	st->gc.ngpio = ARRAY_SIZE(st->gpio_names);
340 	st->gc.get = ltc2992_gpio_get;
341 	st->gc.get_multiple = ltc2992_gpio_get_multiple;
342 	st->gc.set = ltc2992_gpio_set;
343 	st->gc.set_multiple = ltc2992_gpio_set_multiple;
344 
345 	ret = devm_gpiochip_add_data(&st->client->dev, &st->gc, st);
346 	if (ret)
347 		dev_err(&st->client->dev, "GPIO registering failed (%d)\n", ret);
348 
349 	return ret;
350 }
351 
ltc2992_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)352 static umode_t ltc2992_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
353 				  int channel)
354 {
355 	const struct ltc2992_state *st = data;
356 
357 	switch (type) {
358 	case hwmon_chip:
359 		switch (attr) {
360 		case hwmon_chip_in_reset_history:
361 			return 0200;
362 		}
363 		break;
364 	case hwmon_in:
365 		switch (attr) {
366 		case hwmon_in_input:
367 		case hwmon_in_lowest:
368 		case hwmon_in_highest:
369 		case hwmon_in_min_alarm:
370 		case hwmon_in_max_alarm:
371 			return 0444;
372 		case hwmon_in_min:
373 		case hwmon_in_max:
374 			return 0644;
375 		}
376 		break;
377 	case hwmon_curr:
378 		switch (attr) {
379 		case hwmon_curr_input:
380 		case hwmon_curr_lowest:
381 		case hwmon_curr_highest:
382 		case hwmon_curr_min_alarm:
383 		case hwmon_curr_max_alarm:
384 			if (st->r_sense_uohm[channel])
385 				return 0444;
386 			break;
387 		case hwmon_curr_min:
388 		case hwmon_curr_max:
389 			if (st->r_sense_uohm[channel])
390 				return 0644;
391 			break;
392 		}
393 		break;
394 	case hwmon_power:
395 		switch (attr) {
396 		case hwmon_power_input:
397 		case hwmon_power_input_lowest:
398 		case hwmon_power_input_highest:
399 		case hwmon_power_min_alarm:
400 		case hwmon_power_max_alarm:
401 			if (st->r_sense_uohm[channel])
402 				return 0444;
403 			break;
404 		case hwmon_power_min:
405 		case hwmon_power_max:
406 			if (st->r_sense_uohm[channel])
407 				return 0644;
408 			break;
409 		}
410 		break;
411 	default:
412 		break;
413 	}
414 
415 	return 0;
416 }
417 
ltc2992_get_voltage(struct ltc2992_state * st,u32 reg,u32 scale,long * val)418 static int ltc2992_get_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long *val)
419 {
420 	int reg_val;
421 
422 	reg_val = ltc2992_read_reg(st, reg, 2);
423 	if (reg_val < 0)
424 		return reg_val;
425 
426 	reg_val = reg_val >> 4;
427 	*val = DIV_ROUND_CLOSEST(reg_val * scale, 1000);
428 
429 	return 0;
430 }
431 
ltc2992_set_voltage(struct ltc2992_state * st,u32 reg,u32 scale,long val)432 static int ltc2992_set_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long val)
433 {
434 	u32 reg_val;
435 	long vmax;
436 
437 	vmax = DIV_ROUND_CLOSEST_ULL(0xFFFULL * scale, 1000);
438 	val = max(val, 0L);
439 	val = min(val, vmax);
440 	reg_val = min(DIV_ROUND_CLOSEST_ULL((u64)val * 1000, scale),
441 		      0xFFFULL) << 4;
442 
443 	return ltc2992_write_reg(st, reg, 2, reg_val);
444 }
445 
ltc2992_read_gpio_alarm(struct ltc2992_state * st,int nr_gpio,u32 attr,long * val)446 static int ltc2992_read_gpio_alarm(struct ltc2992_state *st, int nr_gpio, u32 attr, long *val)
447 {
448 	int reg_val;
449 	u32 mask;
450 
451 	if (attr == hwmon_in_max_alarm)
452 		mask = ltc2992_gpio_addr_map[nr_gpio].max_alarm_msk;
453 	else
454 		mask = ltc2992_gpio_addr_map[nr_gpio].min_alarm_msk;
455 
456 	reg_val = ltc2992_read_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1);
457 	if (reg_val < 0)
458 		return reg_val;
459 
460 	*val = !!(reg_val & mask);
461 	reg_val &= ~mask;
462 
463 	return ltc2992_write_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1, reg_val);
464 }
465 
ltc2992_read_gpios_in(struct device * dev,u32 attr,int nr_gpio,long * val)466 static int ltc2992_read_gpios_in(struct device *dev, u32 attr, int nr_gpio, long *val)
467 {
468 	struct ltc2992_state *st = dev_get_drvdata(dev);
469 	u32 reg;
470 
471 	switch (attr) {
472 	case hwmon_in_input:
473 		reg = ltc2992_gpio_addr_map[nr_gpio].data;
474 		break;
475 	case hwmon_in_lowest:
476 		reg = ltc2992_gpio_addr_map[nr_gpio].min;
477 		break;
478 	case hwmon_in_highest:
479 		reg = ltc2992_gpio_addr_map[nr_gpio].max;
480 		break;
481 	case hwmon_in_min:
482 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
483 		break;
484 	case hwmon_in_max:
485 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
486 		break;
487 	case hwmon_in_min_alarm:
488 	case hwmon_in_max_alarm:
489 		return ltc2992_read_gpio_alarm(st, nr_gpio, attr, val);
490 	default:
491 		return -EOPNOTSUPP;
492 	}
493 
494 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
495 }
496 
ltc2992_read_in_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)497 static int ltc2992_read_in_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
498 {
499 	int reg_val;
500 	u32 mask;
501 
502 	if (attr == hwmon_in_max_alarm)
503 		mask = LTC2992_SENSE_FAULT_MSK(1);
504 	else
505 		mask = LTC2992_SENSE_FAULT_MSK(0);
506 
507 	reg_val = ltc2992_read_reg(st, LTC2992_SENSE_FAULT(channel), 1);
508 	if (reg_val < 0)
509 		return reg_val;
510 
511 	*val = !!(reg_val & mask);
512 	reg_val &= ~mask;
513 
514 	return ltc2992_write_reg(st, LTC2992_SENSE_FAULT(channel), 1, reg_val);
515 }
516 
ltc2992_read_in(struct device * dev,u32 attr,int channel,long * val)517 static int ltc2992_read_in(struct device *dev, u32 attr, int channel, long *val)
518 {
519 	struct ltc2992_state *st = dev_get_drvdata(dev);
520 	u32 reg;
521 
522 	if (channel > 1)
523 		return ltc2992_read_gpios_in(dev, attr, channel - 2, val);
524 
525 	switch (attr) {
526 	case hwmon_in_input:
527 		reg = LTC2992_SENSE(channel);
528 		break;
529 	case hwmon_in_lowest:
530 		reg = LTC2992_SENSE_MIN(channel);
531 		break;
532 	case hwmon_in_highest:
533 		reg = LTC2992_SENSE_MAX(channel);
534 		break;
535 	case hwmon_in_min:
536 		reg = LTC2992_SENSE_MIN_THRESH(channel);
537 		break;
538 	case hwmon_in_max:
539 		reg = LTC2992_SENSE_MAX_THRESH(channel);
540 		break;
541 	case hwmon_in_min_alarm:
542 	case hwmon_in_max_alarm:
543 		return ltc2992_read_in_alarm(st, channel, val, attr);
544 	default:
545 		return -EOPNOTSUPP;
546 	}
547 
548 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
549 }
550 
ltc2992_get_current(struct ltc2992_state * st,u32 reg,u32 channel,long * val)551 static int ltc2992_get_current(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
552 {
553 	int reg_val;
554 
555 	reg_val = ltc2992_read_reg(st, reg, 2);
556 	if (reg_val < 0)
557 		return reg_val;
558 
559 	reg_val = reg_val >> 4;
560 	*val = DIV_ROUND_CLOSEST(reg_val * LTC2992_IADC_NANOV_LSB, st->r_sense_uohm[channel]);
561 
562 	return 0;
563 }
564 
ltc2992_set_current(struct ltc2992_state * st,u32 reg,u32 channel,long val)565 static int ltc2992_set_current(struct ltc2992_state *st, u32 reg, u32 channel, long val)
566 {
567 	u32 reg_val;
568 	long cmax;
569 
570 	cmax = DIV_ROUND_CLOSEST_ULL(0xFFFULL * LTC2992_IADC_NANOV_LSB,
571 				     st->r_sense_uohm[channel]);
572 	val = max(val, 0L);
573 	val = min(val, cmax);
574 	reg_val = min(DIV_ROUND_CLOSEST_ULL((u64)val * st->r_sense_uohm[channel],
575 					    LTC2992_IADC_NANOV_LSB),
576 		      0xFFFULL) << 4;
577 
578 	return ltc2992_write_reg(st, reg, 2, reg_val);
579 }
580 
ltc2992_read_curr_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)581 static int ltc2992_read_curr_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
582 {
583 	int reg_val;
584 	u32 mask;
585 
586 	if (attr == hwmon_curr_max_alarm)
587 		mask = LTC2992_DSENSE_FAULT_MSK(1);
588 	else
589 		mask = LTC2992_DSENSE_FAULT_MSK(0);
590 
591 	reg_val = ltc2992_read_reg(st, LTC2992_DSENSE_FAULT(channel), 1);
592 	if (reg_val < 0)
593 		return reg_val;
594 
595 	*val = !!(reg_val & mask);
596 
597 	reg_val &= ~mask;
598 	return ltc2992_write_reg(st, LTC2992_DSENSE_FAULT(channel), 1, reg_val);
599 }
600 
ltc2992_read_curr(struct device * dev,u32 attr,int channel,long * val)601 static int ltc2992_read_curr(struct device *dev, u32 attr, int channel, long *val)
602 {
603 	struct ltc2992_state *st = dev_get_drvdata(dev);
604 	u32 reg;
605 
606 	switch (attr) {
607 	case hwmon_curr_input:
608 		reg = LTC2992_DSENSE(channel);
609 		break;
610 	case hwmon_curr_lowest:
611 		reg = LTC2992_DSENSE_MIN(channel);
612 		break;
613 	case hwmon_curr_highest:
614 		reg = LTC2992_DSENSE_MAX(channel);
615 		break;
616 	case hwmon_curr_min:
617 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
618 		break;
619 	case hwmon_curr_max:
620 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
621 		break;
622 	case hwmon_curr_min_alarm:
623 	case hwmon_curr_max_alarm:
624 		return ltc2992_read_curr_alarm(st, channel, val, attr);
625 	default:
626 		return -EOPNOTSUPP;
627 	}
628 
629 	return ltc2992_get_current(st, reg, channel, val);
630 }
631 
ltc2992_get_power(struct ltc2992_state * st,u32 reg,u32 channel,long * val)632 static int ltc2992_get_power(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
633 {
634 	int reg_val;
635 
636 	reg_val = ltc2992_read_reg(st, reg, 3);
637 	if (reg_val < 0)
638 		return reg_val;
639 
640 	*val = mul_u64_u32_div(reg_val,
641 			       LTC2992_VADC_UV_LSB / 1000 *
642 			       LTC2992_IADC_NANOV_LSB,
643 			       st->r_sense_uohm[channel]);
644 
645 	return 0;
646 }
647 
ltc2992_set_power(struct ltc2992_state * st,u32 reg,u32 channel,long val)648 static int ltc2992_set_power(struct ltc2992_state *st, u32 reg, u32 channel, long val)
649 {
650 	u32 reg_val;
651 	u64 pmax, uval;
652 
653 	uval = max(val, 0L);
654 	pmax = mul_u64_u32_div(0xFFFFFFULL,
655 			       LTC2992_VADC_UV_LSB / 1000 *
656 			       LTC2992_IADC_NANOV_LSB,
657 			       st->r_sense_uohm[channel]);
658 	uval = min(uval, pmax);
659 	reg_val = min(mul_u64_u32_div(uval, st->r_sense_uohm[channel],
660 				      LTC2992_VADC_UV_LSB / 1000 *
661 				      LTC2992_IADC_NANOV_LSB),
662 		      0xFFFFFFULL);
663 
664 	return ltc2992_write_reg(st, reg, 3, reg_val);
665 }
666 
ltc2992_read_power_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)667 static int ltc2992_read_power_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
668 {
669 	int reg_val;
670 	u32 mask;
671 
672 	if (attr == hwmon_power_max_alarm)
673 		mask = LTC2992_POWER_FAULT_MSK(1);
674 	else
675 		mask = LTC2992_POWER_FAULT_MSK(0);
676 
677 	reg_val = ltc2992_read_reg(st, LTC2992_POWER_FAULT(channel), 1);
678 	if (reg_val < 0)
679 		return reg_val;
680 
681 	*val = !!(reg_val & mask);
682 	reg_val &= ~mask;
683 
684 	return ltc2992_write_reg(st, LTC2992_POWER_FAULT(channel), 1, reg_val);
685 }
686 
ltc2992_read_power(struct device * dev,u32 attr,int channel,long * val)687 static int ltc2992_read_power(struct device *dev, u32 attr, int channel, long *val)
688 {
689 	struct ltc2992_state *st = dev_get_drvdata(dev);
690 	u32 reg;
691 
692 	switch (attr) {
693 	case hwmon_power_input:
694 		reg = LTC2992_POWER(channel);
695 		break;
696 	case hwmon_power_input_lowest:
697 		reg = LTC2992_POWER_MIN(channel);
698 		break;
699 	case hwmon_power_input_highest:
700 		reg = LTC2992_POWER_MAX(channel);
701 		break;
702 	case hwmon_power_min:
703 		reg = LTC2992_POWER_MIN_THRESH(channel);
704 		break;
705 	case hwmon_power_max:
706 		reg = LTC2992_POWER_MAX_THRESH(channel);
707 		break;
708 	case hwmon_power_min_alarm:
709 	case hwmon_power_max_alarm:
710 		return ltc2992_read_power_alarm(st, channel, val, attr);
711 	default:
712 		return -EOPNOTSUPP;
713 	}
714 
715 	return ltc2992_get_power(st, reg, channel, val);
716 }
717 
ltc2992_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)718 static int ltc2992_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
719 			long *val)
720 {
721 	switch (type) {
722 	case hwmon_in:
723 		return ltc2992_read_in(dev, attr, channel, val);
724 	case hwmon_curr:
725 		return ltc2992_read_curr(dev, attr, channel, val);
726 	case hwmon_power:
727 		return ltc2992_read_power(dev, attr, channel, val);
728 	default:
729 		return -EOPNOTSUPP;
730 	}
731 }
732 
ltc2992_write_curr(struct device * dev,u32 attr,int channel,long val)733 static int ltc2992_write_curr(struct device *dev, u32 attr, int channel, long val)
734 {
735 	struct ltc2992_state *st = dev_get_drvdata(dev);
736 	u32 reg;
737 
738 	switch (attr) {
739 	case hwmon_curr_min:
740 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
741 		break;
742 	case hwmon_curr_max:
743 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
744 		break;
745 	default:
746 		return -EOPNOTSUPP;
747 	}
748 
749 	return ltc2992_set_current(st, reg, channel, val);
750 }
751 
ltc2992_write_gpios_in(struct device * dev,u32 attr,int nr_gpio,long val)752 static int ltc2992_write_gpios_in(struct device *dev, u32 attr, int nr_gpio, long val)
753 {
754 	struct ltc2992_state *st = dev_get_drvdata(dev);
755 	u32 reg;
756 
757 	switch (attr) {
758 	case hwmon_in_min:
759 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
760 		break;
761 	case hwmon_in_max:
762 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
763 		break;
764 	default:
765 		return -EOPNOTSUPP;
766 	}
767 
768 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
769 }
770 
ltc2992_write_in(struct device * dev,u32 attr,int channel,long val)771 static int ltc2992_write_in(struct device *dev, u32 attr, int channel, long val)
772 {
773 	struct ltc2992_state *st = dev_get_drvdata(dev);
774 	u32 reg;
775 
776 	if (channel > 1)
777 		return ltc2992_write_gpios_in(dev, attr, channel - 2, val);
778 
779 	switch (attr) {
780 	case hwmon_in_min:
781 		reg = LTC2992_SENSE_MIN_THRESH(channel);
782 		break;
783 	case hwmon_in_max:
784 		reg = LTC2992_SENSE_MAX_THRESH(channel);
785 		break;
786 	default:
787 		return -EOPNOTSUPP;
788 	}
789 
790 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
791 }
792 
ltc2992_write_power(struct device * dev,u32 attr,int channel,long val)793 static int ltc2992_write_power(struct device *dev, u32 attr, int channel, long val)
794 {
795 	struct ltc2992_state *st = dev_get_drvdata(dev);
796 	u32 reg;
797 
798 	switch (attr) {
799 	case hwmon_power_min:
800 		reg = LTC2992_POWER_MIN_THRESH(channel);
801 		break;
802 	case hwmon_power_max:
803 		reg = LTC2992_POWER_MAX_THRESH(channel);
804 		break;
805 	default:
806 		return -EOPNOTSUPP;
807 	}
808 
809 	return ltc2992_set_power(st, reg, channel, val);
810 }
811 
ltc2992_write_chip(struct device * dev,u32 attr,int channel,long val)812 static int ltc2992_write_chip(struct device *dev, u32 attr, int channel, long val)
813 {
814 	struct ltc2992_state *st = dev_get_drvdata(dev);
815 
816 	switch (attr) {
817 	case hwmon_chip_in_reset_history:
818 		return regmap_update_bits(st->regmap, LTC2992_CTRLB, LTC2992_RESET_HISTORY,
819 					  LTC2992_RESET_HISTORY);
820 	default:
821 		return -EOPNOTSUPP;
822 	}
823 }
824 
ltc2992_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)825 static int ltc2992_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
826 			 long val)
827 {
828 	switch (type) {
829 	case hwmon_chip:
830 		return ltc2992_write_chip(dev, attr, channel, val);
831 	case hwmon_in:
832 		return ltc2992_write_in(dev, attr, channel, val);
833 	case hwmon_curr:
834 		return ltc2992_write_curr(dev, attr, channel, val);
835 	case hwmon_power:
836 		return ltc2992_write_power(dev, attr, channel, val);
837 	default:
838 		return -EOPNOTSUPP;
839 	}
840 }
841 
842 static const struct hwmon_ops ltc2992_hwmon_ops = {
843 	.is_visible = ltc2992_is_visible,
844 	.read = ltc2992_read,
845 	.write = ltc2992_write,
846 };
847 
848 static const struct hwmon_channel_info * const ltc2992_info[] = {
849 	HWMON_CHANNEL_INFO(chip,
850 			   HWMON_C_IN_RESET_HISTORY),
851 	HWMON_CHANNEL_INFO(in,
852 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
853 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
854 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
855 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
856 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
857 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
858 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
859 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
860 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
861 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
862 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
863 			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM),
864 	HWMON_CHANNEL_INFO(curr,
865 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
866 			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM,
867 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
868 			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM),
869 	HWMON_CHANNEL_INFO(power,
870 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
871 			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM,
872 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
873 			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM),
874 	NULL
875 };
876 
877 static const struct hwmon_chip_info ltc2992_chip_info = {
878 	.ops = &ltc2992_hwmon_ops,
879 	.info = ltc2992_info,
880 };
881 
882 static const struct regmap_config ltc2992_regmap_config = {
883 	.reg_bits = 8,
884 	.val_bits = 8,
885 	.max_register = 0xE8,
886 };
887 
ltc2992_parse_dt(struct ltc2992_state * st)888 static int ltc2992_parse_dt(struct ltc2992_state *st)
889 {
890 	u32 addr;
891 	u32 val;
892 	int ret;
893 
894 	device_for_each_child_node_scoped(&st->client->dev, child) {
895 		ret = fwnode_property_read_u32(child, "reg", &addr);
896 		if (ret < 0)
897 			return ret;
898 
899 		if (addr > 1)
900 			return -EINVAL;
901 
902 		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
903 		if (!ret) {
904 			if (!val)
905 				return dev_err_probe(&st->client->dev, -EINVAL,
906 						     "shunt resistor value cannot be zero\n");
907 
908 			st->r_sense_uohm[addr] = val;
909 		}
910 	}
911 
912 	return 0;
913 }
914 
ltc2992_i2c_probe(struct i2c_client * client)915 static int ltc2992_i2c_probe(struct i2c_client *client)
916 {
917 	struct device *hwmon_dev;
918 	struct ltc2992_state *st;
919 	int ret;
920 
921 	st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
922 	if (!st)
923 		return -ENOMEM;
924 
925 	st->client = client;
926 	st->regmap = devm_regmap_init_i2c(client, &ltc2992_regmap_config);
927 	if (IS_ERR(st->regmap))
928 		return PTR_ERR(st->regmap);
929 
930 	ret = ltc2992_parse_dt(st);
931 	if (ret < 0)
932 		return ret;
933 
934 	ret = ltc2992_config_gpio(st);
935 	if (ret < 0)
936 		return ret;
937 
938 	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, client->name, st,
939 							 &ltc2992_chip_info, NULL);
940 
941 	return PTR_ERR_OR_ZERO(hwmon_dev);
942 }
943 
944 static const struct of_device_id ltc2992_of_match[] = {
945 	{ .compatible = "adi,ltc2992" },
946 	{ }
947 };
948 MODULE_DEVICE_TABLE(of, ltc2992_of_match);
949 
950 static const struct i2c_device_id ltc2992_i2c_id[] = {
951 	{"ltc2992"},
952 	{}
953 };
954 MODULE_DEVICE_TABLE(i2c, ltc2992_i2c_id);
955 
956 static struct i2c_driver ltc2992_i2c_driver = {
957 	.driver = {
958 		.name = "ltc2992",
959 		.of_match_table = ltc2992_of_match,
960 	},
961 	.probe = ltc2992_i2c_probe,
962 	.id_table = ltc2992_i2c_id,
963 };
964 
965 module_i2c_driver(ltc2992_i2c_driver);
966 
967 MODULE_AUTHOR("Alexandru Tachici <alexandru.tachici@analog.com>");
968 MODULE_DESCRIPTION("Hwmon driver for Linear Technology 2992");
969 MODULE_LICENSE("Dual BSD/GPL");
970