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1 | /* | |
2 | * Driver for Texas Instruments INA219, INA226 power monitor chips | |
3 | * | |
4 | * INA219: | |
5 | * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface | |
6 | * Datasheet: http://www.ti.com/product/ina219 | |
7 | * | |
8 | * INA220: | |
9 | * Bi-Directional Current/Power Monitor with I2C Interface | |
10 | * Datasheet: http://www.ti.com/product/ina220 | |
11 | * | |
12 | * INA226: | |
13 | * Bi-Directional Current/Power Monitor with I2C Interface | |
14 | * Datasheet: http://www.ti.com/product/ina226 | |
15 | * | |
16 | * INA230: | |
17 | * Bi-directional Current/Power Monitor with I2C Interface | |
18 | * Datasheet: http://www.ti.com/product/ina230 | |
19 | * | |
20 | * Copyright (C) 2012 Lothar Felten <l-felten@ti.com> | |
21 | * Thanks to Jan Volkering | |
22 | * | |
23 | * This program is free software; you can redistribute it and/or modify | |
24 | * it under the terms of the GNU General Public License as published by | |
25 | * the Free Software Foundation; version 2 of the License. | |
26 | */ | |
27 | ||
28 | #include <linux/kernel.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/err.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/i2c.h> | |
34 | #include <linux/hwmon.h> | |
35 | #include <linux/hwmon-sysfs.h> | |
36 | #include <linux/jiffies.h> | |
37 | #include <linux/of_device.h> | |
38 | #include <linux/of.h> | |
39 | #include <linux/delay.h> | |
40 | #include <linux/util_macros.h> | |
41 | #include <linux/regmap.h> | |
42 | ||
43 | #include <linux/platform_data/ina2xx.h> | |
44 | ||
45 | /* common register definitions */ | |
46 | #define INA2XX_CONFIG 0x00 | |
47 | #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ | |
48 | #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ | |
49 | #define INA2XX_POWER 0x03 /* readonly */ | |
50 | #define INA2XX_CURRENT 0x04 /* readonly */ | |
51 | #define INA2XX_CALIBRATION 0x05 | |
52 | ||
53 | /* INA226 register definitions */ | |
54 | #define INA226_MASK_ENABLE 0x06 | |
55 | #define INA226_ALERT_LIMIT 0x07 | |
56 | #define INA226_DIE_ID 0xFF | |
57 | ||
58 | /* register count */ | |
59 | #define INA219_REGISTERS 6 | |
60 | #define INA226_REGISTERS 8 | |
61 | ||
62 | #define INA2XX_MAX_REGISTERS 8 | |
63 | ||
64 | /* settings - depend on use case */ | |
65 | #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ | |
66 | #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ | |
67 | ||
68 | /* worst case is 68.10 ms (~14.6Hz, ina219) */ | |
69 | #define INA2XX_CONVERSION_RATE 15 | |
70 | #define INA2XX_MAX_DELAY 69 /* worst case delay in ms */ | |
71 | ||
72 | #define INA2XX_RSHUNT_DEFAULT 10000 | |
73 | ||
74 | /* bit mask for reading the averaging setting in the configuration register */ | |
75 | #define INA226_AVG_RD_MASK 0x0E00 | |
76 | ||
77 | #define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9) | |
78 | #define INA226_SHIFT_AVG(val) ((val) << 9) | |
79 | ||
80 | /* common attrs, ina226 attrs and NULL */ | |
81 | #define INA2XX_MAX_ATTRIBUTE_GROUPS 3 | |
82 | ||
83 | /* | |
84 | * Both bus voltage and shunt voltage conversion times for ina226 are set | |
85 | * to 0b0100 on POR, which translates to 2200 microseconds in total. | |
86 | */ | |
87 | #define INA226_TOTAL_CONV_TIME_DEFAULT 2200 | |
88 | ||
89 | static struct regmap_config ina2xx_regmap_config = { | |
90 | .reg_bits = 8, | |
91 | .val_bits = 16, | |
92 | }; | |
93 | ||
94 | enum ina2xx_ids { ina219, ina226 }; | |
95 | ||
96 | struct ina2xx_config { | |
97 | u16 config_default; | |
98 | int calibration_value; | |
99 | int registers; | |
100 | int shunt_div; | |
101 | int bus_voltage_shift; | |
102 | int bus_voltage_lsb; /* uV */ | |
103 | int power_lsb_factor; | |
104 | }; | |
105 | ||
106 | struct ina2xx_data { | |
107 | const struct ina2xx_config *config; | |
108 | ||
109 | long rshunt; | |
110 | long current_lsb_uA; | |
111 | long power_lsb_uW; | |
112 | struct mutex config_lock; | |
113 | struct regmap *regmap; | |
114 | ||
115 | const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS]; | |
116 | }; | |
117 | ||
118 | static const struct ina2xx_config ina2xx_config[] = { | |
119 | [ina219] = { | |
120 | .config_default = INA219_CONFIG_DEFAULT, | |
121 | .calibration_value = 4096, | |
122 | .registers = INA219_REGISTERS, | |
123 | .shunt_div = 100, | |
124 | .bus_voltage_shift = 3, | |
125 | .bus_voltage_lsb = 4000, | |
126 | .power_lsb_factor = 20, | |
127 | }, | |
128 | [ina226] = { | |
129 | .config_default = INA226_CONFIG_DEFAULT, | |
130 | .calibration_value = 2048, | |
131 | .registers = INA226_REGISTERS, | |
132 | .shunt_div = 400, | |
133 | .bus_voltage_shift = 0, | |
134 | .bus_voltage_lsb = 1250, | |
135 | .power_lsb_factor = 25, | |
136 | }, | |
137 | }; | |
138 | ||
139 | /* | |
140 | * Available averaging rates for ina226. The indices correspond with | |
141 | * the bit values expected by the chip (according to the ina226 datasheet, | |
142 | * table 3 AVG bit settings, found at | |
143 | * http://www.ti.com/lit/ds/symlink/ina226.pdf. | |
144 | */ | |
145 | static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 }; | |
146 | ||
147 | static int ina226_reg_to_interval(u16 config) | |
148 | { | |
149 | int avg = ina226_avg_tab[INA226_READ_AVG(config)]; | |
150 | ||
151 | /* | |
152 | * Multiply the total conversion time by the number of averages. | |
153 | * Return the result in milliseconds. | |
154 | */ | |
155 | return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000); | |
156 | } | |
157 | ||
158 | /* | |
159 | * Return the new, shifted AVG field value of CONFIG register, | |
160 | * to use with regmap_update_bits | |
161 | */ | |
162 | static u16 ina226_interval_to_reg(int interval) | |
163 | { | |
164 | int avg, avg_bits; | |
165 | ||
166 | avg = DIV_ROUND_CLOSEST(interval * 1000, | |
167 | INA226_TOTAL_CONV_TIME_DEFAULT); | |
168 | avg_bits = find_closest(avg, ina226_avg_tab, | |
169 | ARRAY_SIZE(ina226_avg_tab)); | |
170 | ||
171 | return INA226_SHIFT_AVG(avg_bits); | |
172 | } | |
173 | ||
174 | /* | |
175 | * Calibration register is set to the best value, which eliminates | |
176 | * truncation errors on calculating current register in hardware. | |
177 | * According to datasheet (eq. 3) the best values are 2048 for | |
178 | * ina226 and 4096 for ina219. They are hardcoded as calibration_value. | |
179 | */ | |
180 | static int ina2xx_calibrate(struct ina2xx_data *data) | |
181 | { | |
182 | return regmap_write(data->regmap, INA2XX_CALIBRATION, | |
183 | data->config->calibration_value); | |
184 | } | |
185 | ||
186 | /* | |
187 | * Initialize the configuration and calibration registers. | |
188 | */ | |
189 | static int ina2xx_init(struct ina2xx_data *data) | |
190 | { | |
191 | int ret = regmap_write(data->regmap, INA2XX_CONFIG, | |
192 | data->config->config_default); | |
193 | if (ret < 0) | |
194 | return ret; | |
195 | ||
196 | return ina2xx_calibrate(data); | |
197 | } | |
198 | ||
199 | static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval) | |
200 | { | |
201 | struct ina2xx_data *data = dev_get_drvdata(dev); | |
202 | int ret, retry; | |
203 | ||
204 | dev_dbg(dev, "Starting register %d read\n", reg); | |
205 | ||
206 | for (retry = 5; retry; retry--) { | |
207 | ||
208 | ret = regmap_read(data->regmap, reg, regval); | |
209 | if (ret < 0) | |
210 | return ret; | |
211 | ||
212 | dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval); | |
213 | ||
214 | /* | |
215 | * If the current value in the calibration register is 0, the | |
216 | * power and current registers will also remain at 0. In case | |
217 | * the chip has been reset let's check the calibration | |
218 | * register and reinitialize if needed. | |
219 | * We do that extra read of the calibration register if there | |
220 | * is some hint of a chip reset. | |
221 | */ | |
222 | if (*regval == 0) { | |
223 | unsigned int cal; | |
224 | ||
225 | ret = regmap_read(data->regmap, INA2XX_CALIBRATION, | |
226 | &cal); | |
227 | if (ret < 0) | |
228 | return ret; | |
229 | ||
230 | if (cal == 0) { | |
231 | dev_warn(dev, "chip not calibrated, reinitializing\n"); | |
232 | ||
233 | ret = ina2xx_init(data); | |
234 | if (ret < 0) | |
235 | return ret; | |
236 | /* | |
237 | * Let's make sure the power and current | |
238 | * registers have been updated before trying | |
239 | * again. | |
240 | */ | |
241 | msleep(INA2XX_MAX_DELAY); | |
242 | continue; | |
243 | } | |
244 | } | |
245 | return 0; | |
246 | } | |
247 | ||
248 | /* | |
249 | * If we're here then although all write operations succeeded, the | |
250 | * chip still returns 0 in the calibration register. Nothing more we | |
251 | * can do here. | |
252 | */ | |
253 | dev_err(dev, "unable to reinitialize the chip\n"); | |
254 | return -ENODEV; | |
255 | } | |
256 | ||
257 | static int ina2xx_get_value(struct ina2xx_data *data, u8 reg, | |
258 | unsigned int regval) | |
259 | { | |
260 | int val; | |
261 | ||
262 | switch (reg) { | |
263 | case INA2XX_SHUNT_VOLTAGE: | |
264 | /* signed register */ | |
265 | val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div); | |
266 | break; | |
267 | case INA2XX_BUS_VOLTAGE: | |
268 | val = (regval >> data->config->bus_voltage_shift) | |
269 | * data->config->bus_voltage_lsb; | |
270 | val = DIV_ROUND_CLOSEST(val, 1000); | |
271 | break; | |
272 | case INA2XX_POWER: | |
273 | val = regval * data->power_lsb_uW; | |
274 | break; | |
275 | case INA2XX_CURRENT: | |
276 | /* signed register, result in mA */ | |
277 | val = regval * data->current_lsb_uA; | |
278 | val = DIV_ROUND_CLOSEST(val, 1000); | |
279 | break; | |
280 | case INA2XX_CALIBRATION: | |
281 | val = regval; | |
282 | break; | |
283 | default: | |
284 | /* programmer goofed */ | |
285 | WARN_ON_ONCE(1); | |
286 | val = 0; | |
287 | break; | |
288 | } | |
289 | ||
290 | return val; | |
291 | } | |
292 | ||
293 | static ssize_t ina2xx_show_value(struct device *dev, | |
294 | struct device_attribute *da, char *buf) | |
295 | { | |
296 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
297 | struct ina2xx_data *data = dev_get_drvdata(dev); | |
298 | unsigned int regval; | |
299 | ||
300 | int err = ina2xx_read_reg(dev, attr->index, ®val); | |
301 | ||
302 | if (err < 0) | |
303 | return err; | |
304 | ||
305 | return snprintf(buf, PAGE_SIZE, "%d\n", | |
306 | ina2xx_get_value(data, attr->index, regval)); | |
307 | } | |
308 | ||
309 | /* | |
310 | * In order to keep calibration register value fixed, the product | |
311 | * of current_lsb and shunt_resistor should also be fixed and equal | |
312 | * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order | |
313 | * to keep the scale. | |
314 | */ | |
315 | static int ina2xx_set_shunt(struct ina2xx_data *data, long val) | |
316 | { | |
317 | unsigned int dividend = DIV_ROUND_CLOSEST(1000000000, | |
318 | data->config->shunt_div); | |
319 | if (val <= 0 || val > dividend) | |
320 | return -EINVAL; | |
321 | ||
322 | mutex_lock(&data->config_lock); | |
323 | data->rshunt = val; | |
324 | data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val); | |
325 | data->power_lsb_uW = data->config->power_lsb_factor * | |
326 | data->current_lsb_uA; | |
327 | mutex_unlock(&data->config_lock); | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
332 | static ssize_t ina2xx_store_shunt(struct device *dev, | |
333 | struct device_attribute *da, | |
334 | const char *buf, size_t count) | |
335 | { | |
336 | unsigned long val; | |
337 | int status; | |
338 | struct ina2xx_data *data = dev_get_drvdata(dev); | |
339 | ||
340 | status = kstrtoul(buf, 10, &val); | |
341 | if (status < 0) | |
342 | return status; | |
343 | ||
344 | status = ina2xx_set_shunt(data, val); | |
345 | if (status < 0) | |
346 | return status; | |
347 | return count; | |
348 | } | |
349 | ||
350 | static ssize_t ina226_set_interval(struct device *dev, | |
351 | struct device_attribute *da, | |
352 | const char *buf, size_t count) | |
353 | { | |
354 | struct ina2xx_data *data = dev_get_drvdata(dev); | |
355 | unsigned long val; | |
356 | int status; | |
357 | ||
358 | status = kstrtoul(buf, 10, &val); | |
359 | if (status < 0) | |
360 | return status; | |
361 | ||
362 | if (val > INT_MAX || val == 0) | |
363 | return -EINVAL; | |
364 | ||
365 | status = regmap_update_bits(data->regmap, INA2XX_CONFIG, | |
366 | INA226_AVG_RD_MASK, | |
367 | ina226_interval_to_reg(val)); | |
368 | if (status < 0) | |
369 | return status; | |
370 | ||
371 | return count; | |
372 | } | |
373 | ||
374 | static ssize_t ina226_show_interval(struct device *dev, | |
375 | struct device_attribute *da, char *buf) | |
376 | { | |
377 | struct ina2xx_data *data = dev_get_drvdata(dev); | |
378 | int status; | |
379 | unsigned int regval; | |
380 | ||
381 | status = regmap_read(data->regmap, INA2XX_CONFIG, ®val); | |
382 | if (status) | |
383 | return status; | |
384 | ||
385 | return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval)); | |
386 | } | |
387 | ||
388 | /* shunt voltage */ | |
389 | static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL, | |
390 | INA2XX_SHUNT_VOLTAGE); | |
391 | ||
392 | /* bus voltage */ | |
393 | static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL, | |
394 | INA2XX_BUS_VOLTAGE); | |
395 | ||
396 | /* calculated current */ | |
397 | static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL, | |
398 | INA2XX_CURRENT); | |
399 | ||
400 | /* calculated power */ | |
401 | static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL, | |
402 | INA2XX_POWER); | |
403 | ||
404 | /* shunt resistance */ | |
405 | static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR, | |
406 | ina2xx_show_value, ina2xx_store_shunt, | |
407 | INA2XX_CALIBRATION); | |
408 | ||
409 | /* update interval (ina226 only) */ | |
410 | static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, | |
411 | ina226_show_interval, ina226_set_interval, 0); | |
412 | ||
413 | /* pointers to created device attributes */ | |
414 | static struct attribute *ina2xx_attrs[] = { | |
415 | &sensor_dev_attr_in0_input.dev_attr.attr, | |
416 | &sensor_dev_attr_in1_input.dev_attr.attr, | |
417 | &sensor_dev_attr_curr1_input.dev_attr.attr, | |
418 | &sensor_dev_attr_power1_input.dev_attr.attr, | |
419 | &sensor_dev_attr_shunt_resistor.dev_attr.attr, | |
420 | NULL, | |
421 | }; | |
422 | ||
423 | static const struct attribute_group ina2xx_group = { | |
424 | .attrs = ina2xx_attrs, | |
425 | }; | |
426 | ||
427 | static struct attribute *ina226_attrs[] = { | |
428 | &sensor_dev_attr_update_interval.dev_attr.attr, | |
429 | NULL, | |
430 | }; | |
431 | ||
432 | static const struct attribute_group ina226_group = { | |
433 | .attrs = ina226_attrs, | |
434 | }; | |
435 | ||
436 | static int ina2xx_probe(struct i2c_client *client, | |
437 | const struct i2c_device_id *id) | |
438 | { | |
439 | struct device *dev = &client->dev; | |
440 | struct ina2xx_data *data; | |
441 | struct device *hwmon_dev; | |
442 | u32 val; | |
443 | int ret, group = 0; | |
444 | enum ina2xx_ids chip; | |
445 | ||
446 | if (client->dev.of_node) | |
447 | chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev); | |
448 | else | |
449 | chip = id->driver_data; | |
450 | ||
451 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); | |
452 | if (!data) | |
453 | return -ENOMEM; | |
454 | ||
455 | /* set the device type */ | |
456 | data->config = &ina2xx_config[chip]; | |
457 | mutex_init(&data->config_lock); | |
458 | ||
459 | if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) { | |
460 | struct ina2xx_platform_data *pdata = dev_get_platdata(dev); | |
461 | ||
462 | if (pdata) | |
463 | val = pdata->shunt_uohms; | |
464 | else | |
465 | val = INA2XX_RSHUNT_DEFAULT; | |
466 | } | |
467 | ||
468 | ina2xx_set_shunt(data, val); | |
469 | ||
470 | ina2xx_regmap_config.max_register = data->config->registers; | |
471 | ||
472 | data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config); | |
473 | if (IS_ERR(data->regmap)) { | |
474 | dev_err(dev, "failed to allocate register map\n"); | |
475 | return PTR_ERR(data->regmap); | |
476 | } | |
477 | ||
478 | ret = ina2xx_init(data); | |
479 | if (ret < 0) { | |
480 | dev_err(dev, "error configuring the device: %d\n", ret); | |
481 | return -ENODEV; | |
482 | } | |
483 | ||
484 | data->groups[group++] = &ina2xx_group; | |
485 | if (id->driver_data == ina226) | |
486 | data->groups[group++] = &ina226_group; | |
487 | ||
488 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, | |
489 | data, data->groups); | |
490 | if (IS_ERR(hwmon_dev)) | |
491 | return PTR_ERR(hwmon_dev); | |
492 | ||
493 | dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n", | |
494 | id->name, data->rshunt); | |
495 | ||
496 | return 0; | |
497 | } | |
498 | ||
499 | static const struct i2c_device_id ina2xx_id[] = { | |
500 | { "ina219", ina219 }, | |
501 | { "ina220", ina219 }, | |
502 | { "ina226", ina226 }, | |
503 | { "ina230", ina226 }, | |
504 | { "ina231", ina226 }, | |
505 | { } | |
506 | }; | |
507 | MODULE_DEVICE_TABLE(i2c, ina2xx_id); | |
508 | ||
509 | static const struct of_device_id ina2xx_of_match[] = { | |
510 | { | |
511 | .compatible = "ti,ina219", | |
512 | .data = (void *)ina219 | |
513 | }, | |
514 | { | |
515 | .compatible = "ti,ina220", | |
516 | .data = (void *)ina219 | |
517 | }, | |
518 | { | |
519 | .compatible = "ti,ina226", | |
520 | .data = (void *)ina226 | |
521 | }, | |
522 | { | |
523 | .compatible = "ti,ina230", | |
524 | .data = (void *)ina226 | |
525 | }, | |
526 | { | |
527 | .compatible = "ti,ina231", | |
528 | .data = (void *)ina226 | |
529 | }, | |
530 | { }, | |
531 | }; | |
532 | MODULE_DEVICE_TABLE(of, ina2xx_of_match); | |
533 | ||
534 | static struct i2c_driver ina2xx_driver = { | |
535 | .driver = { | |
536 | .name = "ina2xx", | |
537 | .of_match_table = of_match_ptr(ina2xx_of_match), | |
538 | }, | |
539 | .probe = ina2xx_probe, | |
540 | .id_table = ina2xx_id, | |
541 | }; | |
542 | ||
543 | module_i2c_driver(ina2xx_driver); | |
544 | ||
545 | MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); | |
546 | MODULE_DESCRIPTION("ina2xx driver"); | |
547 | MODULE_LICENSE("GPL"); |