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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 	gpio_nr = 0;
252 	for_each_set_bit_from(gpio_nr, mask, LTC2992_GPIO_NR) {
253 		if (test_bit(LTC2992_GPIO_BIT(gpio_nr), &gpio_status))
254 			set_bit(gpio_nr, bits);
255 	}
256 
257 	return 0;
258 }
259 
ltc2992_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)260 static void ltc2992_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
261 {
262 	struct ltc2992_state *st = gpiochip_get_data(chip);
263 	unsigned long gpio_ctrl;
264 	int reg;
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;
271 	}
272 
273 	gpio_ctrl = reg;
274 	assign_bit(ltc2992_gpio_addr_map[offset].ctrl_bit, &gpio_ctrl, value);
275 
276 	ltc2992_write_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1, gpio_ctrl);
277 	mutex_unlock(&st->gpio_mutex);
278 }
279 
ltc2992_gpio_set_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)280 static void ltc2992_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
281 				      unsigned long *bits)
282 {
283 	struct ltc2992_state *st = gpiochip_get_data(chip);
284 	unsigned long gpio_ctrl_io = 0;
285 	unsigned long gpio_ctrl = 0;
286 	unsigned int gpio_nr;
287 
288 	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
289 		if (gpio_nr < 3)
290 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl_io, true);
291 
292 		if (gpio_nr == 3)
293 			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl, true);
294 	}
295 
296 	mutex_lock(&st->gpio_mutex);
297 	ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, gpio_ctrl_io);
298 	ltc2992_write_reg(st, LTC2992_GPIO_CTRL, 1, gpio_ctrl);
299 	mutex_unlock(&st->gpio_mutex);
300 }
301 
ltc2992_config_gpio(struct ltc2992_state * st)302 static int ltc2992_config_gpio(struct ltc2992_state *st)
303 {
304 	const char *name = dev_name(&st->client->dev);
305 	char *gpio_name;
306 	int ret;
307 	int i;
308 
309 	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, 0);
310 	if (ret < 0)
311 		return ret;
312 
313 	mutex_init(&st->gpio_mutex);
314 
315 	for (i = 0; i < ARRAY_SIZE(st->gpio_names); i++) {
316 		gpio_name = devm_kasprintf(&st->client->dev, GFP_KERNEL, "ltc2992-%x-%s",
317 					   st->client->addr, ltc2992_gpio_names[i]);
318 		if (!gpio_name)
319 			return -ENOMEM;
320 
321 		st->gpio_names[i] = gpio_name;
322 	}
323 
324 	st->gc.label = name;
325 	st->gc.parent = &st->client->dev;
326 	st->gc.owner = THIS_MODULE;
327 	st->gc.can_sleep = true;
328 	st->gc.base = -1;
329 	st->gc.names = st->gpio_names;
330 	st->gc.ngpio = ARRAY_SIZE(st->gpio_names);
331 	st->gc.get = ltc2992_gpio_get;
332 	st->gc.get_multiple = ltc2992_gpio_get_multiple;
333 	st->gc.set = ltc2992_gpio_set;
334 	st->gc.set_multiple = ltc2992_gpio_set_multiple;
335 
336 	ret = devm_gpiochip_add_data(&st->client->dev, &st->gc, st);
337 	if (ret)
338 		dev_err(&st->client->dev, "GPIO registering failed (%d)\n", ret);
339 
340 	return ret;
341 }
342 
ltc2992_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)343 static umode_t ltc2992_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
344 				  int channel)
345 {
346 	const struct ltc2992_state *st = data;
347 
348 	switch (type) {
349 	case hwmon_chip:
350 		switch (attr) {
351 		case hwmon_chip_in_reset_history:
352 			return 0200;
353 		}
354 		break;
355 	case hwmon_in:
356 		switch (attr) {
357 		case hwmon_in_input:
358 		case hwmon_in_lowest:
359 		case hwmon_in_highest:
360 		case hwmon_in_min_alarm:
361 		case hwmon_in_max_alarm:
362 			return 0444;
363 		case hwmon_in_min:
364 		case hwmon_in_max:
365 			return 0644;
366 		}
367 		break;
368 	case hwmon_curr:
369 		switch (attr) {
370 		case hwmon_curr_input:
371 		case hwmon_curr_lowest:
372 		case hwmon_curr_highest:
373 		case hwmon_curr_min_alarm:
374 		case hwmon_curr_max_alarm:
375 			if (st->r_sense_uohm[channel])
376 				return 0444;
377 			break;
378 		case hwmon_curr_min:
379 		case hwmon_curr_max:
380 			if (st->r_sense_uohm[channel])
381 				return 0644;
382 			break;
383 		}
384 		break;
385 	case hwmon_power:
386 		switch (attr) {
387 		case hwmon_power_input:
388 		case hwmon_power_input_lowest:
389 		case hwmon_power_input_highest:
390 		case hwmon_power_min_alarm:
391 		case hwmon_power_max_alarm:
392 			if (st->r_sense_uohm[channel])
393 				return 0444;
394 			break;
395 		case hwmon_power_min:
396 		case hwmon_power_max:
397 			if (st->r_sense_uohm[channel])
398 				return 0644;
399 			break;
400 		}
401 		break;
402 	default:
403 		break;
404 	}
405 
406 	return 0;
407 }
408 
ltc2992_get_voltage(struct ltc2992_state * st,u32 reg,u32 scale,long * val)409 static int ltc2992_get_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long *val)
410 {
411 	int reg_val;
412 
413 	reg_val = ltc2992_read_reg(st, reg, 2);
414 	if (reg_val < 0)
415 		return reg_val;
416 
417 	reg_val = reg_val >> 4;
418 	*val = DIV_ROUND_CLOSEST(reg_val * scale, 1000);
419 
420 	return 0;
421 }
422 
ltc2992_set_voltage(struct ltc2992_state * st,u32 reg,u32 scale,long val)423 static int ltc2992_set_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long val)
424 {
425 	val = DIV_ROUND_CLOSEST(val * 1000, scale);
426 	val = val << 4;
427 
428 	return ltc2992_write_reg(st, reg, 2, val);
429 }
430 
ltc2992_read_gpio_alarm(struct ltc2992_state * st,int nr_gpio,u32 attr,long * val)431 static int ltc2992_read_gpio_alarm(struct ltc2992_state *st, int nr_gpio, u32 attr, long *val)
432 {
433 	int reg_val;
434 	u32 mask;
435 
436 	if (attr == hwmon_in_max_alarm)
437 		mask = ltc2992_gpio_addr_map[nr_gpio].max_alarm_msk;
438 	else
439 		mask = ltc2992_gpio_addr_map[nr_gpio].min_alarm_msk;
440 
441 	reg_val = ltc2992_read_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1);
442 	if (reg_val < 0)
443 		return reg_val;
444 
445 	*val = !!(reg_val & mask);
446 	reg_val &= ~mask;
447 
448 	return ltc2992_write_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1, reg_val);
449 }
450 
ltc2992_read_gpios_in(struct device * dev,u32 attr,int nr_gpio,long * val)451 static int ltc2992_read_gpios_in(struct device *dev, u32 attr, int nr_gpio, long *val)
452 {
453 	struct ltc2992_state *st = dev_get_drvdata(dev);
454 	u32 reg;
455 
456 	switch (attr) {
457 	case hwmon_in_input:
458 		reg = ltc2992_gpio_addr_map[nr_gpio].data;
459 		break;
460 	case hwmon_in_lowest:
461 		reg = ltc2992_gpio_addr_map[nr_gpio].min;
462 		break;
463 	case hwmon_in_highest:
464 		reg = ltc2992_gpio_addr_map[nr_gpio].max;
465 		break;
466 	case hwmon_in_min:
467 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
468 		break;
469 	case hwmon_in_max:
470 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
471 		break;
472 	case hwmon_in_min_alarm:
473 	case hwmon_in_max_alarm:
474 		return ltc2992_read_gpio_alarm(st, nr_gpio, attr, val);
475 	default:
476 		return -EOPNOTSUPP;
477 	}
478 
479 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
480 }
481 
ltc2992_read_in_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)482 static int ltc2992_read_in_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
483 {
484 	int reg_val;
485 	u32 mask;
486 
487 	if (attr == hwmon_in_max_alarm)
488 		mask = LTC2992_SENSE_FAULT_MSK(1);
489 	else
490 		mask = LTC2992_SENSE_FAULT_MSK(0);
491 
492 	reg_val = ltc2992_read_reg(st, LTC2992_SENSE_FAULT(channel), 1);
493 	if (reg_val < 0)
494 		return reg_val;
495 
496 	*val = !!(reg_val & mask);
497 	reg_val &= ~mask;
498 
499 	return ltc2992_write_reg(st, LTC2992_SENSE_FAULT(channel), 1, reg_val);
500 }
501 
ltc2992_read_in(struct device * dev,u32 attr,int channel,long * val)502 static int ltc2992_read_in(struct device *dev, u32 attr, int channel, long *val)
503 {
504 	struct ltc2992_state *st = dev_get_drvdata(dev);
505 	u32 reg;
506 
507 	if (channel > 1)
508 		return ltc2992_read_gpios_in(dev, attr, channel - 2, val);
509 
510 	switch (attr) {
511 	case hwmon_in_input:
512 		reg = LTC2992_SENSE(channel);
513 		break;
514 	case hwmon_in_lowest:
515 		reg = LTC2992_SENSE_MIN(channel);
516 		break;
517 	case hwmon_in_highest:
518 		reg = LTC2992_SENSE_MAX(channel);
519 		break;
520 	case hwmon_in_min:
521 		reg = LTC2992_SENSE_MIN_THRESH(channel);
522 		break;
523 	case hwmon_in_max:
524 		reg = LTC2992_SENSE_MAX_THRESH(channel);
525 		break;
526 	case hwmon_in_min_alarm:
527 	case hwmon_in_max_alarm:
528 		return ltc2992_read_in_alarm(st, channel, val, attr);
529 	default:
530 		return -EOPNOTSUPP;
531 	}
532 
533 	return ltc2992_get_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
534 }
535 
ltc2992_get_current(struct ltc2992_state * st,u32 reg,u32 channel,long * val)536 static int ltc2992_get_current(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
537 {
538 	int reg_val;
539 
540 	reg_val = ltc2992_read_reg(st, reg, 2);
541 	if (reg_val < 0)
542 		return reg_val;
543 
544 	reg_val = reg_val >> 4;
545 	*val = DIV_ROUND_CLOSEST(reg_val * LTC2992_IADC_NANOV_LSB, st->r_sense_uohm[channel]);
546 
547 	return 0;
548 }
549 
ltc2992_set_current(struct ltc2992_state * st,u32 reg,u32 channel,long val)550 static int ltc2992_set_current(struct ltc2992_state *st, u32 reg, u32 channel, long val)
551 {
552 	u32 reg_val;
553 
554 	reg_val = DIV_ROUND_CLOSEST(val * st->r_sense_uohm[channel], LTC2992_IADC_NANOV_LSB);
555 	reg_val = reg_val << 4;
556 
557 	return ltc2992_write_reg(st, reg, 2, reg_val);
558 }
559 
ltc2992_read_curr_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)560 static int ltc2992_read_curr_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
561 {
562 	int reg_val;
563 	u32 mask;
564 
565 	if (attr == hwmon_curr_max_alarm)
566 		mask = LTC2992_DSENSE_FAULT_MSK(1);
567 	else
568 		mask = LTC2992_DSENSE_FAULT_MSK(0);
569 
570 	reg_val = ltc2992_read_reg(st, LTC2992_DSENSE_FAULT(channel), 1);
571 	if (reg_val < 0)
572 		return reg_val;
573 
574 	*val = !!(reg_val & mask);
575 
576 	reg_val &= ~mask;
577 	return ltc2992_write_reg(st, LTC2992_DSENSE_FAULT(channel), 1, reg_val);
578 }
579 
ltc2992_read_curr(struct device * dev,u32 attr,int channel,long * val)580 static int ltc2992_read_curr(struct device *dev, u32 attr, int channel, long *val)
581 {
582 	struct ltc2992_state *st = dev_get_drvdata(dev);
583 	u32 reg;
584 
585 	switch (attr) {
586 	case hwmon_curr_input:
587 		reg = LTC2992_DSENSE(channel);
588 		break;
589 	case hwmon_curr_lowest:
590 		reg = LTC2992_DSENSE_MIN(channel);
591 		break;
592 	case hwmon_curr_highest:
593 		reg = LTC2992_DSENSE_MAX(channel);
594 		break;
595 	case hwmon_curr_min:
596 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
597 		break;
598 	case hwmon_curr_max:
599 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
600 		break;
601 	case hwmon_curr_min_alarm:
602 	case hwmon_curr_max_alarm:
603 		return ltc2992_read_curr_alarm(st, channel, val, attr);
604 	default:
605 		return -EOPNOTSUPP;
606 	}
607 
608 	return ltc2992_get_current(st, reg, channel, val);
609 }
610 
ltc2992_get_power(struct ltc2992_state * st,u32 reg,u32 channel,long * val)611 static int ltc2992_get_power(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
612 {
613 	int reg_val;
614 
615 	reg_val = ltc2992_read_reg(st, reg, 3);
616 	if (reg_val < 0)
617 		return reg_val;
618 
619 	*val = mul_u64_u32_div(reg_val, LTC2992_VADC_UV_LSB * LTC2992_IADC_NANOV_LSB,
620 			       st->r_sense_uohm[channel] * 1000);
621 
622 	return 0;
623 }
624 
ltc2992_set_power(struct ltc2992_state * st,u32 reg,u32 channel,long val)625 static int ltc2992_set_power(struct ltc2992_state *st, u32 reg, u32 channel, long val)
626 {
627 	u32 reg_val;
628 
629 	reg_val = mul_u64_u32_div(val, st->r_sense_uohm[channel] * 1000,
630 				  LTC2992_VADC_UV_LSB * LTC2992_IADC_NANOV_LSB);
631 
632 	return ltc2992_write_reg(st, reg, 3, reg_val);
633 }
634 
ltc2992_read_power_alarm(struct ltc2992_state * st,int channel,long * val,u32 attr)635 static int ltc2992_read_power_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
636 {
637 	int reg_val;
638 	u32 mask;
639 
640 	if (attr == hwmon_power_max_alarm)
641 		mask = LTC2992_POWER_FAULT_MSK(1);
642 	else
643 		mask = LTC2992_POWER_FAULT_MSK(0);
644 
645 	reg_val = ltc2992_read_reg(st, LTC2992_POWER_FAULT(channel), 1);
646 	if (reg_val < 0)
647 		return reg_val;
648 
649 	*val = !!(reg_val & mask);
650 	reg_val &= ~mask;
651 
652 	return ltc2992_write_reg(st, LTC2992_POWER_FAULT(channel), 1, reg_val);
653 }
654 
ltc2992_read_power(struct device * dev,u32 attr,int channel,long * val)655 static int ltc2992_read_power(struct device *dev, u32 attr, int channel, long *val)
656 {
657 	struct ltc2992_state *st = dev_get_drvdata(dev);
658 	u32 reg;
659 
660 	switch (attr) {
661 	case hwmon_power_input:
662 		reg = LTC2992_POWER(channel);
663 		break;
664 	case hwmon_power_input_lowest:
665 		reg = LTC2992_POWER_MIN(channel);
666 		break;
667 	case hwmon_power_input_highest:
668 		reg = LTC2992_POWER_MAX(channel);
669 		break;
670 	case hwmon_power_min:
671 		reg = LTC2992_POWER_MIN_THRESH(channel);
672 		break;
673 	case hwmon_power_max:
674 		reg = LTC2992_POWER_MAX_THRESH(channel);
675 		break;
676 	case hwmon_power_min_alarm:
677 	case hwmon_power_max_alarm:
678 		return ltc2992_read_power_alarm(st, channel, val, attr);
679 	default:
680 		return -EOPNOTSUPP;
681 	}
682 
683 	return ltc2992_get_power(st, reg, channel, val);
684 }
685 
ltc2992_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)686 static int ltc2992_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
687 			long *val)
688 {
689 	switch (type) {
690 	case hwmon_in:
691 		return ltc2992_read_in(dev, attr, channel, val);
692 	case hwmon_curr:
693 		return ltc2992_read_curr(dev, attr, channel, val);
694 	case hwmon_power:
695 		return ltc2992_read_power(dev, attr, channel, val);
696 	default:
697 		return -EOPNOTSUPP;
698 	}
699 }
700 
ltc2992_write_curr(struct device * dev,u32 attr,int channel,long val)701 static int ltc2992_write_curr(struct device *dev, u32 attr, int channel, long val)
702 {
703 	struct ltc2992_state *st = dev_get_drvdata(dev);
704 	u32 reg;
705 
706 	switch (attr) {
707 	case hwmon_curr_min:
708 		reg = LTC2992_DSENSE_MIN_THRESH(channel);
709 		break;
710 	case hwmon_curr_max:
711 		reg = LTC2992_DSENSE_MAX_THRESH(channel);
712 		break;
713 	default:
714 		return -EOPNOTSUPP;
715 	}
716 
717 	return ltc2992_set_current(st, reg, channel, val);
718 }
719 
ltc2992_write_gpios_in(struct device * dev,u32 attr,int nr_gpio,long val)720 static int ltc2992_write_gpios_in(struct device *dev, u32 attr, int nr_gpio, long val)
721 {
722 	struct ltc2992_state *st = dev_get_drvdata(dev);
723 	u32 reg;
724 
725 	switch (attr) {
726 	case hwmon_in_min:
727 		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
728 		break;
729 	case hwmon_in_max:
730 		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
731 		break;
732 	default:
733 		return -EOPNOTSUPP;
734 	}
735 
736 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
737 }
738 
ltc2992_write_in(struct device * dev,u32 attr,int channel,long val)739 static int ltc2992_write_in(struct device *dev, u32 attr, int channel, long val)
740 {
741 	struct ltc2992_state *st = dev_get_drvdata(dev);
742 	u32 reg;
743 
744 	if (channel > 1)
745 		return ltc2992_write_gpios_in(dev, attr, channel - 2, val);
746 
747 	switch (attr) {
748 	case hwmon_in_min:
749 		reg = LTC2992_SENSE_MIN_THRESH(channel);
750 		break;
751 	case hwmon_in_max:
752 		reg = LTC2992_SENSE_MAX_THRESH(channel);
753 		break;
754 	default:
755 		return -EOPNOTSUPP;
756 	}
757 
758 	return ltc2992_set_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
759 }
760 
ltc2992_write_power(struct device * dev,u32 attr,int channel,long val)761 static int ltc2992_write_power(struct device *dev, u32 attr, int channel, long val)
762 {
763 	struct ltc2992_state *st = dev_get_drvdata(dev);
764 	u32 reg;
765 
766 	switch (attr) {
767 	case hwmon_power_min:
768 		reg = LTC2992_POWER_MIN_THRESH(channel);
769 		break;
770 	case hwmon_power_max:
771 		reg = LTC2992_POWER_MAX_THRESH(channel);
772 		break;
773 	default:
774 		return -EOPNOTSUPP;
775 	}
776 
777 	return ltc2992_set_power(st, reg, channel, val);
778 }
779 
ltc2992_write_chip(struct device * dev,u32 attr,int channel,long val)780 static int ltc2992_write_chip(struct device *dev, u32 attr, int channel, long val)
781 {
782 	struct ltc2992_state *st = dev_get_drvdata(dev);
783 
784 	switch (attr) {
785 	case hwmon_chip_in_reset_history:
786 		return regmap_update_bits(st->regmap, LTC2992_CTRLB, LTC2992_RESET_HISTORY,
787 					  LTC2992_RESET_HISTORY);
788 	default:
789 		return -EOPNOTSUPP;
790 	}
791 }
792 
ltc2992_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)793 static int ltc2992_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
794 			 long val)
795 {
796 	switch (type) {
797 	case hwmon_chip:
798 		return ltc2992_write_chip(dev, attr, channel, val);
799 	case hwmon_in:
800 		return ltc2992_write_in(dev, attr, channel, val);
801 	case hwmon_curr:
802 		return ltc2992_write_curr(dev, attr, channel, val);
803 	case hwmon_power:
804 		return ltc2992_write_power(dev, attr, channel, val);
805 	default:
806 		return -EOPNOTSUPP;
807 	}
808 }
809 
810 static const struct hwmon_ops ltc2992_hwmon_ops = {
811 	.is_visible = ltc2992_is_visible,
812 	.read = ltc2992_read,
813 	.write = ltc2992_write,
814 };
815 
816 static const u32 ltc2992_chip_config[] = {
817 	HWMON_C_IN_RESET_HISTORY,
818 	0
819 };
820 
821 static const struct hwmon_channel_info ltc2992_chip = {
822 	.type = hwmon_chip,
823 	.config = ltc2992_chip_config,
824 };
825 
826 static const u32 ltc2992_in_config[] = {
827 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
828 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
829 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
830 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
831 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
832 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
833 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
834 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
835 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
836 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
837 	HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN | HWMON_I_MAX |
838 	HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
839 	0
840 };
841 
842 static const struct hwmon_channel_info ltc2992_in = {
843 	.type = hwmon_in,
844 	.config = ltc2992_in_config,
845 };
846 
847 static const u32 ltc2992_curr_config[] = {
848 	HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN | HWMON_C_MAX |
849 	HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM,
850 	HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN | HWMON_C_MAX |
851 	HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM,
852 	0
853 };
854 
855 static const struct hwmon_channel_info ltc2992_curr = {
856 	.type = hwmon_curr,
857 	.config = ltc2992_curr_config,
858 };
859 
860 static const u32 ltc2992_power_config[] = {
861 	HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST | HWMON_P_MIN | HWMON_P_MAX |
862 	HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM,
863 	HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST | HWMON_P_MIN | HWMON_P_MAX |
864 	HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM,
865 	0
866 };
867 
868 static const struct hwmon_channel_info ltc2992_power = {
869 	.type = hwmon_power,
870 	.config = ltc2992_power_config,
871 };
872 
873 static const struct hwmon_channel_info *ltc2992_info[] = {
874 	&ltc2992_chip,
875 	&ltc2992_in,
876 	&ltc2992_curr,
877 	&ltc2992_power,
878 	NULL
879 };
880 
881 static const struct hwmon_chip_info ltc2992_chip_info = {
882 	.ops = &ltc2992_hwmon_ops,
883 	.info = ltc2992_info,
884 };
885 
886 static const struct regmap_config ltc2992_regmap_config = {
887 	.reg_bits = 8,
888 	.val_bits = 8,
889 	.max_register = 0xE8,
890 };
891 
ltc2992_parse_dt(struct ltc2992_state * st)892 static int ltc2992_parse_dt(struct ltc2992_state *st)
893 {
894 	struct fwnode_handle *fwnode;
895 	struct fwnode_handle *child;
896 	u32 addr;
897 	u32 val;
898 	int ret;
899 
900 	fwnode = dev_fwnode(&st->client->dev);
901 
902 	fwnode_for_each_available_child_node(fwnode, child) {
903 		ret = fwnode_property_read_u32(child, "reg", &addr);
904 		if (ret < 0) {
905 			fwnode_handle_put(child);
906 			return ret;
907 		}
908 
909 		if (addr > 1) {
910 			fwnode_handle_put(child);
911 			return -EINVAL;
912 		}
913 
914 		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
915 		if (!ret)
916 			st->r_sense_uohm[addr] = val;
917 	}
918 
919 	return 0;
920 }
921 
ltc2992_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)922 static int ltc2992_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
923 {
924 	struct device *hwmon_dev;
925 	struct ltc2992_state *st;
926 	int ret;
927 
928 	st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
929 	if (!st)
930 		return -ENOMEM;
931 
932 	st->client = client;
933 	st->regmap = devm_regmap_init_i2c(client, &ltc2992_regmap_config);
934 	if (IS_ERR(st->regmap))
935 		return PTR_ERR(st->regmap);
936 
937 	ret = ltc2992_parse_dt(st);
938 	if (ret < 0)
939 		return ret;
940 
941 	ret = ltc2992_config_gpio(st);
942 	if (ret < 0)
943 		return ret;
944 
945 	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, client->name, st,
946 							 &ltc2992_chip_info, NULL);
947 
948 	return PTR_ERR_OR_ZERO(hwmon_dev);
949 }
950 
951 static const struct of_device_id ltc2992_of_match[] = {
952 	{ .compatible = "adi,ltc2992" },
953 	{ }
954 };
955 MODULE_DEVICE_TABLE(of, ltc2992_of_match);
956 
957 static const struct i2c_device_id ltc2992_i2c_id[] = {
958 	{"ltc2992", 0},
959 	{}
960 };
961 MODULE_DEVICE_TABLE(i2c, ltc2992_i2c_id);
962 
963 static struct i2c_driver ltc2992_i2c_driver = {
964 	.driver = {
965 		.name = "ltc2992",
966 		.of_match_table = ltc2992_of_match,
967 	},
968 	.probe    = ltc2992_i2c_probe,
969 	.id_table = ltc2992_i2c_id,
970 };
971 
972 module_i2c_driver(ltc2992_i2c_driver);
973 
974 MODULE_AUTHOR("Alexandru Tachici <alexandru.tachici@analog.com>");
975 MODULE_DESCRIPTION("Hwmon driver for Linear Technology 2992");
976 MODULE_LICENSE("Dual BSD/GPL");
977