xref: /linux/drivers/hwmon/ina2xx.c (revision fab183d632628381b466a41479489541ac0e29a0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for Texas Instruments INA219, INA226 and register-layout compatible
4  * current/power monitor chips with I2C Interface
5  *
6  * Copyright (C) 2012 Lothar Felten <lothar.felten@gmail.com>
7  * Thanks to Jan Volkering
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/bits.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/hwmon.h>
16 #include <linux/i2c.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/limits.h>
20 #include <linux/module.h>
21 #include <linux/property.h>
22 #include <linux/regmap.h>
23 #include <linux/slab.h>
24 #include <linux/sysfs.h>
25 #include <linux/util_macros.h>
26 
27 /* common register definitions */
28 #define INA2XX_CONFIG			0x00
29 #define INA2XX_SHUNT_VOLTAGE		0x01 /* readonly */
30 #define INA2XX_BUS_VOLTAGE		0x02 /* readonly */
31 #define INA2XX_POWER			0x03 /* readonly */
32 #define INA2XX_CURRENT			0x04 /* readonly */
33 #define INA2XX_CALIBRATION		0x05
34 
35 /* INA226 register definitions */
36 #define INA226_MASK_ENABLE		0x06
37 #define INA226_ALERT_LIMIT		0x07
38 
39 /* SY24655 register definitions */
40 #define SY24655_EIN				0x0A
41 #define SY24655_ACCUM_CONFIG	0x0D
42 #define INA2XX_MAX_REGISTERS		0x0D
43 
44 /* settings - depend on use case */
45 #define INA219_CONFIG_DEFAULT		0x399F	/* PGA=8 */
46 #define INA226_CONFIG_DEFAULT		0x4527	/* averages=16 */
47 #define INA260_CONFIG_DEFAULT		0x6527	/* averages=16 */
48 #define SY24655_CONFIG_DEFAULT		0x4527	/* averages=16 */
49 
50 /* (only for sy24655) */
51 #define SY24655_ACCUM_CONFIG_DEFAULT	0x044C	/* continuous mode, clear after read*/
52 
53 /* worst case is 68.10 ms (~14.6Hz, ina219) */
54 #define INA2XX_CONVERSION_RATE		15
55 #define INA2XX_MAX_DELAY		69 /* worst case delay in ms */
56 
57 #define INA2XX_RSHUNT_DEFAULT		10000
58 #define INA260_RSHUNT			2000
59 
60 /* bit mask for reading the averaging setting in the configuration register */
61 #define INA226_AVG_RD_MASK		GENMASK(11, 9)
62 
63 #define INA226_READ_AVG(reg)		FIELD_GET(INA226_AVG_RD_MASK, reg)
64 
65 #define INA226_ALERT_LATCH_ENABLE	BIT(0)
66 #define INA226_ALERT_POLARITY		BIT(1)
67 
68 /* bit number of alert functions in Mask/Enable Register */
69 #define INA226_SHUNT_OVER_VOLTAGE_MASK	BIT(15)
70 #define INA226_SHUNT_UNDER_VOLTAGE_MASK	BIT(14)
71 #define INA226_BUS_OVER_VOLTAGE_MASK	BIT(13)
72 #define INA226_BUS_UNDER_VOLTAGE_MASK	BIT(12)
73 #define INA226_POWER_OVER_LIMIT_MASK	BIT(11)
74 
75 /* bit mask for alert config bits of Mask/Enable Register */
76 #define INA226_ALERT_CONFIG_MASK	GENMASK(15, 10)
77 #define INA226_ALERT_FUNCTION_FLAG	BIT(4)
78 
79 /*
80  * Both bus voltage and shunt voltage conversion times for ina226 are set
81  * to 0b0100 on POR, which translates to 2200 microseconds in total.
82  */
83 #define INA226_TOTAL_CONV_TIME_DEFAULT	2200
84 
ina2xx_writeable_reg(struct device * dev,unsigned int reg)85 static bool ina2xx_writeable_reg(struct device *dev, unsigned int reg)
86 {
87 	switch (reg) {
88 	case INA2XX_CONFIG:
89 	case INA2XX_CALIBRATION:
90 	case INA226_MASK_ENABLE:
91 	case INA226_ALERT_LIMIT:
92 	case SY24655_ACCUM_CONFIG:
93 		return true;
94 	default:
95 		return false;
96 	}
97 }
98 
ina2xx_volatile_reg(struct device * dev,unsigned int reg)99 static bool ina2xx_volatile_reg(struct device *dev, unsigned int reg)
100 {
101 	switch (reg) {
102 	case INA2XX_SHUNT_VOLTAGE:
103 	case INA2XX_BUS_VOLTAGE:
104 	case INA2XX_POWER:
105 	case INA2XX_CURRENT:
106 		return true;
107 	default:
108 		return false;
109 	}
110 }
111 
112 static const struct regmap_config ina2xx_regmap_config = {
113 	.reg_bits = 8,
114 	.val_bits = 16,
115 	.use_single_write = true,
116 	.use_single_read = true,
117 	.max_register = INA2XX_MAX_REGISTERS,
118 	.cache_type = REGCACHE_MAPLE,
119 	.volatile_reg = ina2xx_volatile_reg,
120 	.writeable_reg = ina2xx_writeable_reg,
121 };
122 
123 enum ina2xx_ids {
124 	ina219,
125 	ina226,
126 	ina232,
127 	ina234,
128 	ina260,
129 	sy24655
130 };
131 
132 struct ina2xx_config {
133 	u16 config_default;
134 	bool has_alerts;	/* chip supports alerts and limits */
135 	bool has_ishunt;	/* chip has internal shunt resistor */
136 	bool has_power_average;	/* chip supports average power */
137 	bool has_update_interval;
138 	int calibration_value;
139 	int shunt_div;
140 	int shunt_voltage_shift;
141 	int bus_voltage_shift;
142 	int bus_voltage_lsb;	/* uV */
143 	int power_lsb_factor;
144 	int current_shift;
145 };
146 
147 struct ina2xx_data {
148 	const struct ina2xx_config *config;
149 	enum ina2xx_ids chip;
150 
151 	long rshunt;
152 	long current_lsb_uA;
153 	long power_lsb_uW;
154 	struct regmap *regmap;
155 	struct i2c_client *client;
156 };
157 
158 static const struct ina2xx_config ina2xx_config[] = {
159 	[ina219] = {
160 		.config_default = INA219_CONFIG_DEFAULT,
161 		.calibration_value = 4096,
162 		.shunt_div = 100,
163 		.shunt_voltage_shift = 0,
164 		.bus_voltage_shift = 3,
165 		.bus_voltage_lsb = 4000,
166 		.power_lsb_factor = 20,
167 		.has_alerts = false,
168 		.has_ishunt = false,
169 		.has_power_average = false,
170 		.current_shift = 0,
171 		.has_update_interval = false,
172 	},
173 	[ina226] = {
174 		.config_default = INA226_CONFIG_DEFAULT,
175 		.calibration_value = 2048,
176 		.shunt_div = 400,
177 		.shunt_voltage_shift = 0,
178 		.bus_voltage_shift = 0,
179 		.bus_voltage_lsb = 1250,
180 		.power_lsb_factor = 25,
181 		.has_alerts = true,
182 		.has_ishunt = false,
183 		.has_power_average = false,
184 		.current_shift = 0,
185 		.has_update_interval = true,
186 	},
187 	[ina234] = {
188 		.config_default = INA226_CONFIG_DEFAULT,
189 		.calibration_value = 2048,
190 		.shunt_div = 25, /* 2.5 µV/LSB raw ADC reading from INA2XX_SHUNT_VOLTAGE */
191 		.shunt_voltage_shift = 4,
192 		.bus_voltage_shift = 4,
193 		.bus_voltage_lsb = 25600,
194 		.power_lsb_factor = 32,
195 		.has_alerts = true,
196 		.has_ishunt = false,
197 		.has_power_average = false,
198 		.current_shift = 4,
199 		.has_update_interval = true,
200 	},
201 	[ina232] = {
202 		.config_default = INA226_CONFIG_DEFAULT,
203 		.calibration_value = 2048,
204 		.shunt_div = 400,
205 		.shunt_voltage_shift = 0,
206 		.bus_voltage_shift = 0,
207 		.bus_voltage_lsb = 1600,
208 		.power_lsb_factor = 32,
209 		.has_alerts = true,
210 		.has_ishunt = false,
211 		.has_power_average = false,
212 		.current_shift = 0,
213 		.has_update_interval = true,
214 	},
215 	[ina260] = {
216 		.config_default = INA260_CONFIG_DEFAULT,
217 		.shunt_div = 400,
218 		.shunt_voltage_shift = 0,
219 		.bus_voltage_shift = 0,
220 		.bus_voltage_lsb = 1250,
221 		.power_lsb_factor = 8,
222 		.has_alerts = true,
223 		.has_ishunt = true,
224 		.has_power_average = false,
225 		.current_shift = 0,
226 		.has_update_interval = true,
227 	},
228 	[sy24655] = {
229 		.config_default = SY24655_CONFIG_DEFAULT,
230 		.calibration_value = 4096,
231 		.shunt_div = 400,
232 		.shunt_voltage_shift = 0,
233 		.bus_voltage_shift = 0,
234 		.bus_voltage_lsb = 1250,
235 		.power_lsb_factor = 25,
236 		.has_alerts = true,
237 		.has_ishunt = false,
238 		.has_power_average = true,
239 		.current_shift = 0,
240 		.has_update_interval = false,
241 	},
242 };
243 
244 /*
245  * Available averaging rates for ina226. The indices correspond with
246  * the bit values expected by the chip (according to the ina226 datasheet,
247  * table 3 AVG bit settings, found at
248  * https://www.ti.com/lit/ds/symlink/ina226.pdf.
249  */
250 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
251 
ina226_reg_to_interval(u16 config)252 static int ina226_reg_to_interval(u16 config)
253 {
254 	int avg = ina226_avg_tab[INA226_READ_AVG(config)];
255 
256 	/*
257 	 * Multiply the total conversion time by the number of averages.
258 	 * Return the result in milliseconds.
259 	 */
260 	return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
261 }
262 
263 /*
264  * Return the new, shifted AVG field value of CONFIG register,
265  * to use with regmap_update_bits
266  */
ina226_interval_to_reg(long interval)267 static u16 ina226_interval_to_reg(long interval)
268 {
269 	int avg, avg_bits;
270 
271 	/*
272 	 * The maximum supported interval is 1,024 * (2 * 8.244ms) ~= 16.8s.
273 	 * Clamp to 32 seconds before calculations to avoid overflows.
274 	 */
275 	interval = clamp_val(interval, 0, 32000);
276 
277 	avg = DIV_ROUND_CLOSEST(interval * 1000,
278 				INA226_TOTAL_CONV_TIME_DEFAULT);
279 	avg_bits = find_closest(avg, ina226_avg_tab,
280 				ARRAY_SIZE(ina226_avg_tab));
281 
282 	return FIELD_PREP(INA226_AVG_RD_MASK, avg_bits);
283 }
284 
ina2xx_get_value(struct ina2xx_data * data,u8 reg,unsigned int regval)285 static long ina2xx_get_value(struct ina2xx_data *data, u8 reg,
286 			     unsigned int regval)
287 {
288 	s64 val64;
289 	long val;
290 
291 	switch (reg) {
292 	case INA2XX_SHUNT_VOLTAGE:
293 		/* signed register */
294 		val = DIV_ROUND_CLOSEST((s16)regval >> data->config->shunt_voltage_shift,
295 					data->config->shunt_div);
296 		break;
297 	case INA2XX_BUS_VOLTAGE:
298 		val = DIV_ROUND_CLOSEST((regval >> data->config->bus_voltage_shift) *
299 					data->config->bus_voltage_lsb, 1000);
300 		break;
301 	case INA2XX_POWER:
302 		val = min_t(u64, (u64)regval * data->power_lsb_uW, LONG_MAX);
303 		break;
304 	case INA2XX_CURRENT:
305 		/* signed register, result in mA */
306 		val64 = (s64)((s16)regval >> data->config->current_shift) *
307 		  data->current_lsb_uA;
308 		if (val64 < 0)
309 			val64 = -DIV_ROUND_CLOSEST_ULL(-val64, 1000);
310 		else
311 			val64 = DIV_ROUND_CLOSEST_ULL(val64, 1000);
312 		val = clamp_val(val64, LONG_MIN, LONG_MAX);
313 		break;
314 	case INA2XX_CALIBRATION:
315 		val = regval;
316 		break;
317 	default:
318 		/* programmer goofed */
319 		WARN_ON_ONCE(1);
320 		val = 0;
321 		break;
322 	}
323 
324 	return val;
325 }
326 
327 /*
328  * Read and convert register value from chip. If the register value is 0,
329  * check if the chip has been power cycled or reset. If so, re-initialize it.
330  */
ina2xx_read_init(struct device * dev,int reg,long * val)331 static int ina2xx_read_init(struct device *dev, int reg, long *val)
332 {
333 	struct ina2xx_data *data = dev_get_drvdata(dev);
334 	struct regmap *regmap = data->regmap;
335 	unsigned int regval;
336 	int ret, retry;
337 
338 	if (data->config->has_ishunt) {
339 		/* No calibration needed */
340 		ret = regmap_read(regmap, reg, &regval);
341 		if (ret < 0)
342 			return ret;
343 		*val = ina2xx_get_value(data, reg, regval);
344 		return 0;
345 	}
346 
347 	for (retry = 5; retry; retry--) {
348 		ret = regmap_read(regmap, reg, &regval);
349 		if (ret < 0)
350 			return ret;
351 
352 		/*
353 		 * If the current value in the calibration register is 0, the
354 		 * power and current registers will also remain at 0. In case
355 		 * the chip has been reset let's check the calibration
356 		 * register and reinitialize if needed.
357 		 * We do that extra read of the calibration register if there
358 		 * is some hint of a chip reset.
359 		 */
360 		if (regval == 0) {
361 			unsigned int cal;
362 
363 			ret = regmap_read_bypassed(regmap, INA2XX_CALIBRATION, &cal);
364 			if (ret < 0)
365 				return ret;
366 
367 			if (cal == 0) {
368 				dev_warn(dev, "chip not calibrated, reinitializing\n");
369 
370 				regcache_mark_dirty(regmap);
371 				regcache_sync(regmap);
372 
373 				/*
374 				 * Let's make sure the power and current
375 				 * registers have been updated before trying
376 				 * again.
377 				 */
378 				msleep(INA2XX_MAX_DELAY);
379 				continue;
380 			}
381 		}
382 		*val = ina2xx_get_value(data, reg, regval);
383 		return 0;
384 	}
385 
386 	/*
387 	 * If we're here then although all write operations succeeded, the
388 	 * chip still returns 0 in the calibration register. Nothing more we
389 	 * can do here.
390 	 */
391 	dev_err(dev, "unable to reinitialize the chip\n");
392 	return -ENODEV;
393 }
394 
395 /*
396  * Turns alert limit values into register values.
397  * Opposite of the formula in ina2xx_get_value().
398  */
ina226_alert_to_reg(struct ina2xx_data * data,int reg,long val)399 static u16 ina226_alert_to_reg(struct ina2xx_data *data, int reg, long val)
400 {
401 	long limit;
402 
403 	switch (reg) {
404 	case INA2XX_SHUNT_VOLTAGE:
405 		val = min_t(long, val, DIV_ROUND_CLOSEST(SHRT_MAX, data->config->shunt_div));
406 		return min_t(long, (val * data->config->shunt_div) << data->config->shunt_voltage_shift,
407 			     SHRT_MAX);
408 	case INA2XX_BUS_VOLTAGE:
409 		val = min_t(long, val, 130000);
410 		return min_t(long,
411 			     DIV_ROUND_CLOSEST((val * 1000) << data->config->bus_voltage_shift,
412 					       data->config->bus_voltage_lsb),
413 			     USHRT_MAX);
414 	case INA2XX_POWER:
415 		val = min_t(long, val, LONG_MAX - data->power_lsb_uW);
416 		return min_t(long, DIV_ROUND_CLOSEST(val, data->power_lsb_uW), USHRT_MAX);
417 	case INA2XX_CURRENT:
418 		limit = (LONG_MAX - (data->current_lsb_uA / 2)) / 1000;
419 		val = min_t(long, val, limit);
420 		/* signed register, result in mA */
421 		val = DIV_ROUND_CLOSEST(val * 1000, data->current_lsb_uA);
422 		limit = SHRT_MAX >> data->config->current_shift;
423 		return (u16)(min_t(long, val, limit) << data->config->current_shift);
424 	default:
425 		/* programmer goofed */
426 		WARN_ON_ONCE(1);
427 		return 0;
428 	}
429 }
430 
ina226_alert_limit_read(struct ina2xx_data * data,u32 mask,int reg,long * val)431 static int ina226_alert_limit_read(struct ina2xx_data *data, u32 mask, int reg, long *val)
432 {
433 	struct regmap *regmap = data->regmap;
434 	int regval;
435 	int ret;
436 
437 	ret = regmap_read(regmap, INA226_MASK_ENABLE, &regval);
438 	if (ret)
439 		return ret;
440 
441 	if (regval & mask) {
442 		ret = regmap_read(regmap, INA226_ALERT_LIMIT, &regval);
443 		if (ret)
444 			return ret;
445 		*val = ina2xx_get_value(data, reg, regval);
446 	} else {
447 		*val = 0;
448 	}
449 	return 0;
450 }
451 
ina226_alert_limit_write(struct ina2xx_data * data,u32 mask,int reg,long val)452 static int ina226_alert_limit_write(struct ina2xx_data *data, u32 mask, int reg, long val)
453 {
454 	struct regmap *regmap = data->regmap;
455 	int ret;
456 
457 	if (val < 0)
458 		return -EINVAL;
459 
460 	/*
461 	 * Clear all alerts first to avoid accidentally triggering ALERT pin
462 	 * due to register write sequence. Then, only enable the alert
463 	 * if the value is non-zero.
464 	 */
465 	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
466 				 INA226_ALERT_CONFIG_MASK, 0);
467 	if (ret < 0)
468 		return ret;
469 
470 	ret = regmap_write(regmap, INA226_ALERT_LIMIT,
471 			   ina226_alert_to_reg(data, reg, val));
472 	if (ret < 0)
473 		return ret;
474 
475 	if (val)
476 		return regmap_update_bits(regmap, INA226_MASK_ENABLE,
477 					  INA226_ALERT_CONFIG_MASK, mask);
478 	return 0;
479 }
480 
ina2xx_chip_read(struct device * dev,u32 attr,long * val)481 static int ina2xx_chip_read(struct device *dev, u32 attr, long *val)
482 {
483 	struct ina2xx_data *data = dev_get_drvdata(dev);
484 	u32 regval;
485 	int ret;
486 
487 	switch (attr) {
488 	case hwmon_chip_update_interval:
489 		ret = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
490 		if (ret)
491 			return ret;
492 
493 		*val = ina226_reg_to_interval(regval);
494 		break;
495 	default:
496 		return -EOPNOTSUPP;
497 	}
498 	return 0;
499 }
500 
ina226_alert_read(struct regmap * regmap,u32 mask,long * val)501 static int ina226_alert_read(struct regmap *regmap, u32 mask, long *val)
502 {
503 	unsigned int regval;
504 	int ret;
505 
506 	ret = regmap_read_bypassed(regmap, INA226_MASK_ENABLE, &regval);
507 	if (ret)
508 		return ret;
509 
510 	*val = (regval & mask) && (regval & INA226_ALERT_FUNCTION_FLAG);
511 
512 	return 0;
513 }
514 
ina2xx_in_read(struct device * dev,u32 attr,int channel,long * val)515 static int ina2xx_in_read(struct device *dev, u32 attr, int channel, long *val)
516 {
517 	int voltage_reg = channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE;
518 	u32 under_voltage_mask = channel ? INA226_BUS_UNDER_VOLTAGE_MASK
519 					 : INA226_SHUNT_UNDER_VOLTAGE_MASK;
520 	u32 over_voltage_mask = channel ? INA226_BUS_OVER_VOLTAGE_MASK
521 					: INA226_SHUNT_OVER_VOLTAGE_MASK;
522 	struct ina2xx_data *data = dev_get_drvdata(dev);
523 	struct regmap *regmap = data->regmap;
524 	unsigned int regval;
525 	int ret;
526 
527 	switch (attr) {
528 	case hwmon_in_input:
529 		ret = regmap_read(regmap, voltage_reg, &regval);
530 		if (ret)
531 			return ret;
532 		*val = ina2xx_get_value(data, voltage_reg, regval);
533 		break;
534 	case hwmon_in_lcrit:
535 		return ina226_alert_limit_read(data, under_voltage_mask,
536 					       voltage_reg, val);
537 	case hwmon_in_crit:
538 		return ina226_alert_limit_read(data, over_voltage_mask,
539 					       voltage_reg, val);
540 	case hwmon_in_lcrit_alarm:
541 		return ina226_alert_read(regmap, under_voltage_mask, val);
542 	case hwmon_in_crit_alarm:
543 		return ina226_alert_read(regmap, over_voltage_mask, val);
544 	default:
545 		return -EOPNOTSUPP;
546 	}
547 	return 0;
548 }
549 
550 /*
551  * Configuring the READ_EIN (bit 10) of the ACCUM_CONFIG register to 1
552  * can clear accumulator and sample_count after reading the EIN register.
553  * This way, the average power between the last read and the current
554  * read can be obtained. By combining with accurate time data from
555  * outside, the energy consumption during that period can be calculated.
556  */
sy24655_average_power_read(struct ina2xx_data * data,u8 reg,long * val)557 static int sy24655_average_power_read(struct ina2xx_data *data, u8 reg, long *val)
558 {
559 	u8 template[6];
560 	int ret;
561 	long accumulator_24, sample_count;
562 	u64 val64;
563 
564 	/* 48-bit register read */
565 	ret = i2c_smbus_read_i2c_block_data(data->client, reg, 6, template);
566 	if (ret < 0)
567 		return ret;
568 	if (ret != 6)
569 		return -EIO;
570 	accumulator_24 = ((template[3] << 16) |
571 				(template[4] << 8) |
572 				template[5]);
573 	sample_count = ((template[0] << 16) |
574 				(template[1] << 8) |
575 				template[2]);
576 	if (sample_count <= 0) {
577 		*val = 0;
578 		return 0;
579 	}
580 
581 	val64 = (u64)DIV_ROUND_CLOSEST(accumulator_24, sample_count) * data->power_lsb_uW;
582 	*val = min_t(u64, val64, LONG_MAX);
583 
584 	return 0;
585 }
586 
ina2xx_power_read(struct device * dev,u32 attr,long * val)587 static int ina2xx_power_read(struct device *dev, u32 attr, long *val)
588 {
589 	struct ina2xx_data *data = dev_get_drvdata(dev);
590 
591 	switch (attr) {
592 	case hwmon_power_input:
593 		return ina2xx_read_init(dev, INA2XX_POWER, val);
594 	case hwmon_power_average:
595 		return sy24655_average_power_read(data, SY24655_EIN, val);
596 	case hwmon_power_crit:
597 		return ina226_alert_limit_read(data, INA226_POWER_OVER_LIMIT_MASK,
598 					       INA2XX_POWER, val);
599 	case hwmon_power_crit_alarm:
600 		return ina226_alert_read(data->regmap, INA226_POWER_OVER_LIMIT_MASK, val);
601 	default:
602 		return -EOPNOTSUPP;
603 	}
604 }
605 
ina2xx_curr_read(struct device * dev,u32 attr,long * val)606 static int ina2xx_curr_read(struct device *dev, u32 attr, long *val)
607 {
608 	struct ina2xx_data *data = dev_get_drvdata(dev);
609 	struct regmap *regmap = data->regmap;
610 	unsigned int regval;
611 	int ret;
612 
613 	/*
614 	 * While the chips supported by this driver do not directly support
615 	 * current limits, they do support setting shunt voltage limits.
616 	 * The shunt voltage divided by the shunt resistor value is the current.
617 	 * On top of that, calibration values are set such that in the shunt
618 	 * voltage register and the current register report the same values.
619 	 * That means we can report and configure current limits based on shunt
620 	 * voltage limits.
621 	 */
622 	switch (attr) {
623 	case hwmon_curr_input:
624 		/*
625 		 * Since the shunt voltage and the current register report the
626 		 * same values when the chip is calibrated, we can calculate
627 		 * the current directly from the shunt voltage without relying
628 		 * on chip calibration.
629 		 */
630 		ret = regmap_read(regmap, INA2XX_SHUNT_VOLTAGE, &regval);
631 		if (ret)
632 			return ret;
633 		*val = ina2xx_get_value(data, INA2XX_CURRENT, regval);
634 		return 0;
635 	case hwmon_curr_lcrit:
636 		return ina226_alert_limit_read(data, INA226_SHUNT_UNDER_VOLTAGE_MASK,
637 					       INA2XX_CURRENT, val);
638 	case hwmon_curr_crit:
639 		return ina226_alert_limit_read(data, INA226_SHUNT_OVER_VOLTAGE_MASK,
640 					       INA2XX_CURRENT, val);
641 	case hwmon_curr_lcrit_alarm:
642 		return ina226_alert_read(regmap, INA226_SHUNT_UNDER_VOLTAGE_MASK, val);
643 	case hwmon_curr_crit_alarm:
644 		return ina226_alert_read(regmap, INA226_SHUNT_OVER_VOLTAGE_MASK, val);
645 	default:
646 		return -EOPNOTSUPP;
647 	}
648 }
649 
ina2xx_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)650 static int ina2xx_read(struct device *dev, enum hwmon_sensor_types type,
651 		       u32 attr, int channel, long *val)
652 {
653 	switch (type) {
654 	case hwmon_chip:
655 		return ina2xx_chip_read(dev, attr, val);
656 	case hwmon_in:
657 		return ina2xx_in_read(dev, attr, channel, val);
658 	case hwmon_power:
659 		return ina2xx_power_read(dev, attr, val);
660 	case hwmon_curr:
661 		return ina2xx_curr_read(dev, attr, val);
662 	default:
663 		return -EOPNOTSUPP;
664 	}
665 }
666 
ina2xx_chip_write(struct device * dev,u32 attr,long val)667 static int ina2xx_chip_write(struct device *dev, u32 attr, long val)
668 {
669 	struct ina2xx_data *data = dev_get_drvdata(dev);
670 
671 	switch (attr) {
672 	case hwmon_chip_update_interval:
673 		return regmap_update_bits(data->regmap, INA2XX_CONFIG,
674 					  INA226_AVG_RD_MASK,
675 					  ina226_interval_to_reg(val));
676 	default:
677 		return -EOPNOTSUPP;
678 	}
679 }
680 
ina2xx_in_write(struct device * dev,u32 attr,int channel,long val)681 static int ina2xx_in_write(struct device *dev, u32 attr, int channel, long val)
682 {
683 	struct ina2xx_data *data = dev_get_drvdata(dev);
684 
685 	switch (attr) {
686 	case hwmon_in_lcrit:
687 		return ina226_alert_limit_write(data,
688 			channel ? INA226_BUS_UNDER_VOLTAGE_MASK : INA226_SHUNT_UNDER_VOLTAGE_MASK,
689 			channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE,
690 			val);
691 	case hwmon_in_crit:
692 		return ina226_alert_limit_write(data,
693 			channel ? INA226_BUS_OVER_VOLTAGE_MASK : INA226_SHUNT_OVER_VOLTAGE_MASK,
694 			channel ? INA2XX_BUS_VOLTAGE : INA2XX_SHUNT_VOLTAGE,
695 			val);
696 	default:
697 		return -EOPNOTSUPP;
698 	}
699 	return 0;
700 }
701 
ina2xx_power_write(struct device * dev,u32 attr,long val)702 static int ina2xx_power_write(struct device *dev, u32 attr, long val)
703 {
704 	struct ina2xx_data *data = dev_get_drvdata(dev);
705 
706 	switch (attr) {
707 	case hwmon_power_crit:
708 		return ina226_alert_limit_write(data, INA226_POWER_OVER_LIMIT_MASK,
709 						INA2XX_POWER, val);
710 	default:
711 		return -EOPNOTSUPP;
712 	}
713 	return 0;
714 }
715 
ina2xx_curr_write(struct device * dev,u32 attr,long val)716 static int ina2xx_curr_write(struct device *dev, u32 attr, long val)
717 {
718 	struct ina2xx_data *data = dev_get_drvdata(dev);
719 
720 	switch (attr) {
721 	case hwmon_curr_lcrit:
722 		return ina226_alert_limit_write(data, INA226_SHUNT_UNDER_VOLTAGE_MASK,
723 						INA2XX_CURRENT, val);
724 	case hwmon_curr_crit:
725 		return ina226_alert_limit_write(data, INA226_SHUNT_OVER_VOLTAGE_MASK,
726 						INA2XX_CURRENT, val);
727 	default:
728 		return -EOPNOTSUPP;
729 	}
730 	return 0;
731 }
732 
ina2xx_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)733 static int ina2xx_write(struct device *dev, enum hwmon_sensor_types type,
734 			u32 attr, int channel, long val)
735 {
736 	switch (type) {
737 	case hwmon_chip:
738 		return ina2xx_chip_write(dev, attr, val);
739 	case hwmon_in:
740 		return ina2xx_in_write(dev, attr, channel, val);
741 	case hwmon_power:
742 		return ina2xx_power_write(dev, attr, val);
743 	case hwmon_curr:
744 		return ina2xx_curr_write(dev, attr, val);
745 	default:
746 		return -EOPNOTSUPP;
747 	}
748 }
749 
ina2xx_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)750 static umode_t ina2xx_is_visible(const void *_data, enum hwmon_sensor_types type,
751 				 u32 attr, int channel)
752 {
753 	const struct ina2xx_data *data = _data;
754 	bool has_alerts = data->config->has_alerts;
755 	bool has_power_average = data->config->has_power_average;
756 	bool has_update_interval = data->config->has_update_interval;
757 
758 	switch (type) {
759 	case hwmon_in:
760 		switch (attr) {
761 		case hwmon_in_input:
762 			return 0444;
763 		case hwmon_in_lcrit:
764 		case hwmon_in_crit:
765 			if (has_alerts)
766 				return 0644;
767 			break;
768 		case hwmon_in_lcrit_alarm:
769 		case hwmon_in_crit_alarm:
770 			if (has_alerts)
771 				return 0444;
772 			break;
773 		default:
774 			break;
775 		}
776 		break;
777 	case hwmon_curr:
778 		switch (attr) {
779 		case hwmon_curr_input:
780 			return 0444;
781 		case hwmon_curr_lcrit:
782 		case hwmon_curr_crit:
783 			if (has_alerts)
784 				return 0644;
785 			break;
786 		case hwmon_curr_lcrit_alarm:
787 		case hwmon_curr_crit_alarm:
788 			if (has_alerts)
789 				return 0444;
790 			break;
791 		default:
792 			break;
793 		}
794 		break;
795 	case hwmon_power:
796 		switch (attr) {
797 		case hwmon_power_input:
798 			return 0444;
799 		case hwmon_power_crit:
800 			if (has_alerts)
801 				return 0644;
802 			break;
803 		case hwmon_power_crit_alarm:
804 			if (has_alerts)
805 				return 0444;
806 			break;
807 		case hwmon_power_average:
808 			if (has_power_average)
809 				return 0444;
810 			break;
811 		default:
812 			break;
813 		}
814 		break;
815 	case hwmon_chip:
816 		switch (attr) {
817 		case hwmon_chip_update_interval:
818 			if (has_update_interval)
819 				return 0644;
820 			break;
821 		default:
822 			break;
823 		}
824 		break;
825 	default:
826 		break;
827 	}
828 	return 0;
829 }
830 
831 static const struct hwmon_channel_info * const ina2xx_info[] = {
832 	HWMON_CHANNEL_INFO(chip,
833 			   HWMON_C_UPDATE_INTERVAL),
834 	HWMON_CHANNEL_INFO(in,
835 			   HWMON_I_INPUT | HWMON_I_CRIT | HWMON_I_CRIT_ALARM |
836 			   HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM,
837 			   HWMON_I_INPUT | HWMON_I_CRIT | HWMON_I_CRIT_ALARM |
838 			   HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM
839 			   ),
840 	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_CRIT | HWMON_C_CRIT_ALARM |
841 			   HWMON_C_LCRIT | HWMON_C_LCRIT_ALARM),
842 	HWMON_CHANNEL_INFO(power,
843 			   HWMON_P_INPUT | HWMON_P_CRIT | HWMON_P_CRIT_ALARM |
844 			   HWMON_P_AVERAGE),
845 	NULL
846 };
847 
848 static const struct hwmon_ops ina2xx_hwmon_ops = {
849 	.is_visible = ina2xx_is_visible,
850 	.read = ina2xx_read,
851 	.write = ina2xx_write,
852 };
853 
854 static const struct hwmon_chip_info ina2xx_chip_info = {
855 	.ops = &ina2xx_hwmon_ops,
856 	.info = ina2xx_info,
857 };
858 
859 /* shunt resistance */
860 
861 /*
862  * In order to keep calibration register value fixed, the product
863  * of current_lsb and shunt_resistor should also be fixed and equal
864  * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
865  * to keep the scale.
866  */
ina2xx_set_shunt(struct ina2xx_data * data,unsigned long val)867 static int ina2xx_set_shunt(struct ina2xx_data *data, unsigned long val)
868 {
869 	unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
870 						  data->config->shunt_div);
871 	if (!val || val > dividend)
872 		return -EINVAL;
873 
874 	data->rshunt = val;
875 	data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
876 	data->power_lsb_uW = data->config->power_lsb_factor *
877 			     data->current_lsb_uA;
878 
879 	return 0;
880 }
881 
shunt_resistor_show(struct device * dev,struct device_attribute * da,char * buf)882 static ssize_t shunt_resistor_show(struct device *dev,
883 				   struct device_attribute *da, char *buf)
884 {
885 	struct ina2xx_data *data = dev_get_drvdata(dev);
886 
887 	return sysfs_emit(buf, "%li\n", data->rshunt);
888 }
889 
shunt_resistor_store(struct device * dev,struct device_attribute * da,const char * buf,size_t count)890 static ssize_t shunt_resistor_store(struct device *dev,
891 				    struct device_attribute *da,
892 				    const char *buf, size_t count)
893 {
894 	struct ina2xx_data *data = dev_get_drvdata(dev);
895 	unsigned long val;
896 	int status;
897 
898 	status = kstrtoul(buf, 10, &val);
899 	if (status < 0)
900 		return status;
901 
902 	scoped_guard(hwmon_lock, dev) {
903 		status = ina2xx_set_shunt(data, val);
904 		if (status < 0)
905 			return status;
906 	}
907 	return count;
908 }
909 
910 static DEVICE_ATTR_RW(shunt_resistor);
911 
912 /* pointers to created device attributes */
913 static struct attribute *ina2xx_attrs[] = {
914 	&dev_attr_shunt_resistor.attr,
915 	NULL,
916 };
917 ATTRIBUTE_GROUPS(ina2xx);
918 
919 /*
920  * Initialize chip
921  */
ina2xx_init(struct device * dev,struct ina2xx_data * data)922 static int ina2xx_init(struct device *dev, struct ina2xx_data *data)
923 {
924 	struct regmap *regmap = data->regmap;
925 	u32 shunt;
926 	int ret;
927 
928 	if (data->config->has_ishunt)
929 		shunt = INA260_RSHUNT;
930 	else if (device_property_read_u32(dev, "shunt-resistor", &shunt) < 0)
931 		shunt = INA2XX_RSHUNT_DEFAULT;
932 
933 	ret = ina2xx_set_shunt(data, shunt);
934 	if (ret < 0)
935 		return ret;
936 
937 	ret = regmap_write(regmap, INA2XX_CONFIG, data->config->config_default);
938 	if (ret < 0)
939 		return ret;
940 
941 	if (data->config->has_alerts) {
942 		bool active_high = device_property_read_bool(dev, "ti,alert-polarity-active-high");
943 
944 		regmap_update_bits(regmap, INA226_MASK_ENABLE,
945 				   INA226_ALERT_LATCH_ENABLE | INA226_ALERT_POLARITY,
946 				   INA226_ALERT_LATCH_ENABLE |
947 						FIELD_PREP(INA226_ALERT_POLARITY, active_high));
948 	}
949 	if (data->config->has_power_average) {
950 		if (data->chip == sy24655) {
951 			/*
952 			 * Initialize the power accumulation method to continuous
953 			 * mode and clear the EIN register after each read of the
954 			 * EIN register
955 			 */
956 			ret = regmap_write(regmap, SY24655_ACCUM_CONFIG,
957 					   SY24655_ACCUM_CONFIG_DEFAULT);
958 			if (ret < 0)
959 				return ret;
960 		}
961 	}
962 
963 	if (data->config->has_ishunt)
964 		return 0;
965 
966 	/*
967 	 * Calibration register is set to the best value, which eliminates
968 	 * truncation errors on calculating current register in hardware.
969 	 * According to datasheet (eq. 3) the best values are 2048 for
970 	 * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
971 	 */
972 	return regmap_write(regmap, INA2XX_CALIBRATION,
973 			    data->config->calibration_value);
974 }
975 
ina2xx_probe(struct i2c_client * client)976 static int ina2xx_probe(struct i2c_client *client)
977 {
978 	struct device *dev = &client->dev;
979 	struct ina2xx_data *data;
980 	struct device *hwmon_dev;
981 	enum ina2xx_ids chip;
982 	int ret;
983 
984 	chip = (uintptr_t)i2c_get_match_data(client);
985 
986 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
987 	if (!data)
988 		return -ENOMEM;
989 
990 	/* set the device type */
991 	data->client = client;
992 	data->config = &ina2xx_config[chip];
993 	data->chip = chip;
994 
995 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
996 	if (IS_ERR(data->regmap)) {
997 		dev_err(dev, "failed to allocate register map\n");
998 		return PTR_ERR(data->regmap);
999 	}
1000 
1001 	/*
1002 	 * Regulator core returns -ENODEV if the 'vs' is not available.
1003 	 * Hence the check for -ENODEV return code is necessary.
1004 	 */
1005 	ret = devm_regulator_get_enable_optional(dev, "vs");
1006 	if (ret < 0 && ret != -ENODEV)
1007 		return dev_err_probe(dev, ret, "failed to enable vs regulator\n");
1008 
1009 	ret = ina2xx_init(dev, data);
1010 	if (ret < 0)
1011 		return dev_err_probe(dev, ret, "failed to configure device\n");
1012 
1013 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
1014 							 data, &ina2xx_chip_info,
1015 							 data->config->has_ishunt ?
1016 								NULL : ina2xx_groups);
1017 	if (IS_ERR(hwmon_dev))
1018 		return PTR_ERR(hwmon_dev);
1019 
1020 	dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
1021 		 client->name, data->rshunt);
1022 
1023 	return 0;
1024 }
1025 
1026 static const struct i2c_device_id ina2xx_id[] = {
1027 	{ .name = "ina219", .driver_data = ina219 },
1028 	{ .name = "ina220", .driver_data = ina219 },
1029 	{ .name = "ina226", .driver_data = ina226 },
1030 	{ .name = "ina230", .driver_data = ina226 },
1031 	{ .name = "ina231", .driver_data = ina226 },
1032 	{ .name = "ina232", .driver_data = ina232 },
1033 	{ .name = "ina234", .driver_data = ina234 },
1034 	{ .name = "ina260", .driver_data = ina260 },
1035 	{ .name = "sy24655", .driver_data = sy24655 },
1036 	{ }
1037 };
1038 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
1039 
1040 static const struct of_device_id __maybe_unused ina2xx_of_match[] = {
1041 	{
1042 		.compatible = "silergy,sy24655",
1043 		.data = (void *)sy24655
1044 	},
1045 	{
1046 		.compatible = "ti,ina219",
1047 		.data = (void *)ina219
1048 	},
1049 	{
1050 		.compatible = "ti,ina220",
1051 		.data = (void *)ina219
1052 	},
1053 	{
1054 		.compatible = "ti,ina226",
1055 		.data = (void *)ina226
1056 	},
1057 	{
1058 		.compatible = "ti,ina230",
1059 		.data = (void *)ina226
1060 	},
1061 	{
1062 		.compatible = "ti,ina231",
1063 		.data = (void *)ina226
1064 	},
1065 	{
1066 		.compatible = "ti,ina232",
1067 		.data = (void *)ina232
1068 	},
1069 	{
1070 		.compatible = "ti,ina234",
1071 		.data = (void *)ina234
1072 	},
1073 	{
1074 		.compatible = "ti,ina260",
1075 		.data = (void *)ina260
1076 	},
1077 	{ }
1078 };
1079 MODULE_DEVICE_TABLE(of, ina2xx_of_match);
1080 
1081 static struct i2c_driver ina2xx_driver = {
1082 	.driver = {
1083 		.name	= "ina2xx",
1084 		.of_match_table = of_match_ptr(ina2xx_of_match),
1085 	},
1086 	.probe		= ina2xx_probe,
1087 	.id_table	= ina2xx_id,
1088 };
1089 
1090 module_i2c_driver(ina2xx_driver);
1091 
1092 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
1093 MODULE_DESCRIPTION("ina2xx driver");
1094 MODULE_LICENSE("GPL");
1095