xref: /linux/drivers/hwmon/ina2xx.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for Texas Instruments INA219, INA226 power monitor chips
4  *
5  * INA219:
6  * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
7  * Datasheet: http://www.ti.com/product/ina219
8  *
9  * INA220:
10  * Bi-Directional Current/Power Monitor with I2C Interface
11  * Datasheet: http://www.ti.com/product/ina220
12  *
13  * INA226:
14  * Bi-Directional Current/Power Monitor with I2C Interface
15  * Datasheet: http://www.ti.com/product/ina226
16  *
17  * INA230:
18  * Bi-directional Current/Power Monitor with I2C Interface
19  * Datasheet: http://www.ti.com/product/ina230
20  *
21  * Copyright (C) 2012 Lothar Felten <lothar.felten@gmail.com>
22  * Thanks to Jan Volkering
23  */
24 
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/err.h>
29 #include <linux/slab.h>
30 #include <linux/i2c.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/jiffies.h>
34 #include <linux/of_device.h>
35 #include <linux/of.h>
36 #include <linux/delay.h>
37 #include <linux/util_macros.h>
38 #include <linux/regmap.h>
39 
40 #include <linux/platform_data/ina2xx.h>
41 
42 /* common register definitions */
43 #define INA2XX_CONFIG			0x00
44 #define INA2XX_SHUNT_VOLTAGE		0x01 /* readonly */
45 #define INA2XX_BUS_VOLTAGE		0x02 /* readonly */
46 #define INA2XX_POWER			0x03 /* readonly */
47 #define INA2XX_CURRENT			0x04 /* readonly */
48 #define INA2XX_CALIBRATION		0x05
49 
50 /* INA226 register definitions */
51 #define INA226_MASK_ENABLE		0x06
52 #define INA226_ALERT_LIMIT		0x07
53 #define INA226_DIE_ID			0xFF
54 
55 /* register count */
56 #define INA219_REGISTERS		6
57 #define INA226_REGISTERS		8
58 
59 #define INA2XX_MAX_REGISTERS		8
60 
61 /* settings - depend on use case */
62 #define INA219_CONFIG_DEFAULT		0x399F	/* PGA=8 */
63 #define INA226_CONFIG_DEFAULT		0x4527	/* averages=16 */
64 
65 /* worst case is 68.10 ms (~14.6Hz, ina219) */
66 #define INA2XX_CONVERSION_RATE		15
67 #define INA2XX_MAX_DELAY		69 /* worst case delay in ms */
68 
69 #define INA2XX_RSHUNT_DEFAULT		10000
70 
71 /* bit mask for reading the averaging setting in the configuration register */
72 #define INA226_AVG_RD_MASK		0x0E00
73 
74 #define INA226_READ_AVG(reg)		(((reg) & INA226_AVG_RD_MASK) >> 9)
75 #define INA226_SHIFT_AVG(val)		((val) << 9)
76 
77 /* common attrs, ina226 attrs and NULL */
78 #define INA2XX_MAX_ATTRIBUTE_GROUPS	3
79 
80 /*
81  * Both bus voltage and shunt voltage conversion times for ina226 are set
82  * to 0b0100 on POR, which translates to 2200 microseconds in total.
83  */
84 #define INA226_TOTAL_CONV_TIME_DEFAULT	2200
85 
86 static struct regmap_config ina2xx_regmap_config = {
87 	.reg_bits = 8,
88 	.val_bits = 16,
89 };
90 
91 enum ina2xx_ids { ina219, ina226 };
92 
93 struct ina2xx_config {
94 	u16 config_default;
95 	int calibration_value;
96 	int registers;
97 	int shunt_div;
98 	int bus_voltage_shift;
99 	int bus_voltage_lsb;	/* uV */
100 	int power_lsb_factor;
101 };
102 
103 struct ina2xx_data {
104 	const struct ina2xx_config *config;
105 
106 	long rshunt;
107 	long current_lsb_uA;
108 	long power_lsb_uW;
109 	struct mutex config_lock;
110 	struct regmap *regmap;
111 
112 	const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
113 };
114 
115 static const struct ina2xx_config ina2xx_config[] = {
116 	[ina219] = {
117 		.config_default = INA219_CONFIG_DEFAULT,
118 		.calibration_value = 4096,
119 		.registers = INA219_REGISTERS,
120 		.shunt_div = 100,
121 		.bus_voltage_shift = 3,
122 		.bus_voltage_lsb = 4000,
123 		.power_lsb_factor = 20,
124 	},
125 	[ina226] = {
126 		.config_default = INA226_CONFIG_DEFAULT,
127 		.calibration_value = 2048,
128 		.registers = INA226_REGISTERS,
129 		.shunt_div = 400,
130 		.bus_voltage_shift = 0,
131 		.bus_voltage_lsb = 1250,
132 		.power_lsb_factor = 25,
133 	},
134 };
135 
136 /*
137  * Available averaging rates for ina226. The indices correspond with
138  * the bit values expected by the chip (according to the ina226 datasheet,
139  * table 3 AVG bit settings, found at
140  * http://www.ti.com/lit/ds/symlink/ina226.pdf.
141  */
142 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
143 
144 static int ina226_reg_to_interval(u16 config)
145 {
146 	int avg = ina226_avg_tab[INA226_READ_AVG(config)];
147 
148 	/*
149 	 * Multiply the total conversion time by the number of averages.
150 	 * Return the result in milliseconds.
151 	 */
152 	return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
153 }
154 
155 /*
156  * Return the new, shifted AVG field value of CONFIG register,
157  * to use with regmap_update_bits
158  */
159 static u16 ina226_interval_to_reg(int interval)
160 {
161 	int avg, avg_bits;
162 
163 	avg = DIV_ROUND_CLOSEST(interval * 1000,
164 				INA226_TOTAL_CONV_TIME_DEFAULT);
165 	avg_bits = find_closest(avg, ina226_avg_tab,
166 				ARRAY_SIZE(ina226_avg_tab));
167 
168 	return INA226_SHIFT_AVG(avg_bits);
169 }
170 
171 /*
172  * Calibration register is set to the best value, which eliminates
173  * truncation errors on calculating current register in hardware.
174  * According to datasheet (eq. 3) the best values are 2048 for
175  * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
176  */
177 static int ina2xx_calibrate(struct ina2xx_data *data)
178 {
179 	return regmap_write(data->regmap, INA2XX_CALIBRATION,
180 			    data->config->calibration_value);
181 }
182 
183 /*
184  * Initialize the configuration and calibration registers.
185  */
186 static int ina2xx_init(struct ina2xx_data *data)
187 {
188 	int ret = regmap_write(data->regmap, INA2XX_CONFIG,
189 			       data->config->config_default);
190 	if (ret < 0)
191 		return ret;
192 
193 	return ina2xx_calibrate(data);
194 }
195 
196 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
197 {
198 	struct ina2xx_data *data = dev_get_drvdata(dev);
199 	int ret, retry;
200 
201 	dev_dbg(dev, "Starting register %d read\n", reg);
202 
203 	for (retry = 5; retry; retry--) {
204 
205 		ret = regmap_read(data->regmap, reg, regval);
206 		if (ret < 0)
207 			return ret;
208 
209 		dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);
210 
211 		/*
212 		 * If the current value in the calibration register is 0, the
213 		 * power and current registers will also remain at 0. In case
214 		 * the chip has been reset let's check the calibration
215 		 * register and reinitialize if needed.
216 		 * We do that extra read of the calibration register if there
217 		 * is some hint of a chip reset.
218 		 */
219 		if (*regval == 0) {
220 			unsigned int cal;
221 
222 			ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
223 					  &cal);
224 			if (ret < 0)
225 				return ret;
226 
227 			if (cal == 0) {
228 				dev_warn(dev, "chip not calibrated, reinitializing\n");
229 
230 				ret = ina2xx_init(data);
231 				if (ret < 0)
232 					return ret;
233 				/*
234 				 * Let's make sure the power and current
235 				 * registers have been updated before trying
236 				 * again.
237 				 */
238 				msleep(INA2XX_MAX_DELAY);
239 				continue;
240 			}
241 		}
242 		return 0;
243 	}
244 
245 	/*
246 	 * If we're here then although all write operations succeeded, the
247 	 * chip still returns 0 in the calibration register. Nothing more we
248 	 * can do here.
249 	 */
250 	dev_err(dev, "unable to reinitialize the chip\n");
251 	return -ENODEV;
252 }
253 
254 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
255 			    unsigned int regval)
256 {
257 	int val;
258 
259 	switch (reg) {
260 	case INA2XX_SHUNT_VOLTAGE:
261 		/* signed register */
262 		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
263 		break;
264 	case INA2XX_BUS_VOLTAGE:
265 		val = (regval >> data->config->bus_voltage_shift)
266 		  * data->config->bus_voltage_lsb;
267 		val = DIV_ROUND_CLOSEST(val, 1000);
268 		break;
269 	case INA2XX_POWER:
270 		val = regval * data->power_lsb_uW;
271 		break;
272 	case INA2XX_CURRENT:
273 		/* signed register, result in mA */
274 		val = (s16)regval * data->current_lsb_uA;
275 		val = DIV_ROUND_CLOSEST(val, 1000);
276 		break;
277 	case INA2XX_CALIBRATION:
278 		val = regval;
279 		break;
280 	default:
281 		/* programmer goofed */
282 		WARN_ON_ONCE(1);
283 		val = 0;
284 		break;
285 	}
286 
287 	return val;
288 }
289 
290 static ssize_t ina2xx_value_show(struct device *dev,
291 				 struct device_attribute *da, char *buf)
292 {
293 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
294 	struct ina2xx_data *data = dev_get_drvdata(dev);
295 	unsigned int regval;
296 
297 	int err = ina2xx_read_reg(dev, attr->index, &regval);
298 
299 	if (err < 0)
300 		return err;
301 
302 	return snprintf(buf, PAGE_SIZE, "%d\n",
303 			ina2xx_get_value(data, attr->index, regval));
304 }
305 
306 /*
307  * In order to keep calibration register value fixed, the product
308  * of current_lsb and shunt_resistor should also be fixed and equal
309  * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
310  * to keep the scale.
311  */
312 static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
313 {
314 	unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
315 						  data->config->shunt_div);
316 	if (val <= 0 || val > dividend)
317 		return -EINVAL;
318 
319 	mutex_lock(&data->config_lock);
320 	data->rshunt = val;
321 	data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
322 	data->power_lsb_uW = data->config->power_lsb_factor *
323 			     data->current_lsb_uA;
324 	mutex_unlock(&data->config_lock);
325 
326 	return 0;
327 }
328 
329 static ssize_t ina2xx_shunt_show(struct device *dev,
330 				 struct device_attribute *da, char *buf)
331 {
332 	struct ina2xx_data *data = dev_get_drvdata(dev);
333 
334 	return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt);
335 }
336 
337 static ssize_t ina2xx_shunt_store(struct device *dev,
338 				  struct device_attribute *da,
339 				  const char *buf, size_t count)
340 {
341 	unsigned long val;
342 	int status;
343 	struct ina2xx_data *data = dev_get_drvdata(dev);
344 
345 	status = kstrtoul(buf, 10, &val);
346 	if (status < 0)
347 		return status;
348 
349 	status = ina2xx_set_shunt(data, val);
350 	if (status < 0)
351 		return status;
352 	return count;
353 }
354 
355 static ssize_t ina226_interval_store(struct device *dev,
356 				     struct device_attribute *da,
357 				     const char *buf, size_t count)
358 {
359 	struct ina2xx_data *data = dev_get_drvdata(dev);
360 	unsigned long val;
361 	int status;
362 
363 	status = kstrtoul(buf, 10, &val);
364 	if (status < 0)
365 		return status;
366 
367 	if (val > INT_MAX || val == 0)
368 		return -EINVAL;
369 
370 	status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
371 				    INA226_AVG_RD_MASK,
372 				    ina226_interval_to_reg(val));
373 	if (status < 0)
374 		return status;
375 
376 	return count;
377 }
378 
379 static ssize_t ina226_interval_show(struct device *dev,
380 				    struct device_attribute *da, char *buf)
381 {
382 	struct ina2xx_data *data = dev_get_drvdata(dev);
383 	int status;
384 	unsigned int regval;
385 
386 	status = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
387 	if (status)
388 		return status;
389 
390 	return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
391 }
392 
393 /* shunt voltage */
394 static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE);
395 
396 /* bus voltage */
397 static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE);
398 
399 /* calculated current */
400 static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
401 
402 /* calculated power */
403 static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER);
404 
405 /* shunt resistance */
406 static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION);
407 
408 /* update interval (ina226 only) */
409 static SENSOR_DEVICE_ATTR_RW(update_interval, ina226_interval, 0);
410 
411 /* pointers to created device attributes */
412 static struct attribute *ina2xx_attrs[] = {
413 	&sensor_dev_attr_in0_input.dev_attr.attr,
414 	&sensor_dev_attr_in1_input.dev_attr.attr,
415 	&sensor_dev_attr_curr1_input.dev_attr.attr,
416 	&sensor_dev_attr_power1_input.dev_attr.attr,
417 	&sensor_dev_attr_shunt_resistor.dev_attr.attr,
418 	NULL,
419 };
420 
421 static const struct attribute_group ina2xx_group = {
422 	.attrs = ina2xx_attrs,
423 };
424 
425 static struct attribute *ina226_attrs[] = {
426 	&sensor_dev_attr_update_interval.dev_attr.attr,
427 	NULL,
428 };
429 
430 static const struct attribute_group ina226_group = {
431 	.attrs = ina226_attrs,
432 };
433 
434 static int ina2xx_probe(struct i2c_client *client,
435 			const struct i2c_device_id *id)
436 {
437 	struct device *dev = &client->dev;
438 	struct ina2xx_data *data;
439 	struct device *hwmon_dev;
440 	u32 val;
441 	int ret, group = 0;
442 	enum ina2xx_ids chip;
443 
444 	if (client->dev.of_node)
445 		chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
446 	else
447 		chip = id->driver_data;
448 
449 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
450 	if (!data)
451 		return -ENOMEM;
452 
453 	/* set the device type */
454 	data->config = &ina2xx_config[chip];
455 	mutex_init(&data->config_lock);
456 
457 	if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
458 		struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
459 
460 		if (pdata)
461 			val = pdata->shunt_uohms;
462 		else
463 			val = INA2XX_RSHUNT_DEFAULT;
464 	}
465 
466 	ina2xx_set_shunt(data, val);
467 
468 	ina2xx_regmap_config.max_register = data->config->registers;
469 
470 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
471 	if (IS_ERR(data->regmap)) {
472 		dev_err(dev, "failed to allocate register map\n");
473 		return PTR_ERR(data->regmap);
474 	}
475 
476 	ret = ina2xx_init(data);
477 	if (ret < 0) {
478 		dev_err(dev, "error configuring the device: %d\n", ret);
479 		return -ENODEV;
480 	}
481 
482 	data->groups[group++] = &ina2xx_group;
483 	if (chip == ina226)
484 		data->groups[group++] = &ina226_group;
485 
486 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
487 							   data, data->groups);
488 	if (IS_ERR(hwmon_dev))
489 		return PTR_ERR(hwmon_dev);
490 
491 	dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
492 		 client->name, data->rshunt);
493 
494 	return 0;
495 }
496 
497 static const struct i2c_device_id ina2xx_id[] = {
498 	{ "ina219", ina219 },
499 	{ "ina220", ina219 },
500 	{ "ina226", ina226 },
501 	{ "ina230", ina226 },
502 	{ "ina231", ina226 },
503 	{ }
504 };
505 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
506 
507 static const struct of_device_id __maybe_unused ina2xx_of_match[] = {
508 	{
509 		.compatible = "ti,ina219",
510 		.data = (void *)ina219
511 	},
512 	{
513 		.compatible = "ti,ina220",
514 		.data = (void *)ina219
515 	},
516 	{
517 		.compatible = "ti,ina226",
518 		.data = (void *)ina226
519 	},
520 	{
521 		.compatible = "ti,ina230",
522 		.data = (void *)ina226
523 	},
524 	{
525 		.compatible = "ti,ina231",
526 		.data = (void *)ina226
527 	},
528 	{ },
529 };
530 MODULE_DEVICE_TABLE(of, ina2xx_of_match);
531 
532 static struct i2c_driver ina2xx_driver = {
533 	.driver = {
534 		.name	= "ina2xx",
535 		.of_match_table = of_match_ptr(ina2xx_of_match),
536 	},
537 	.probe		= ina2xx_probe,
538 	.id_table	= ina2xx_id,
539 };
540 
541 module_i2c_driver(ina2xx_driver);
542 
543 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
544 MODULE_DESCRIPTION("ina2xx driver");
545 MODULE_LICENSE("GPL");
546