1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Texas Instruments INA238 power monitor chip
4 * Datasheet: https://www.ti.com/product/ina238
5 *
6 * Copyright (C) 2021 Nathan Rossi <nathan.rossi@digi.com>
7 */
8
9#include <linux/bitops.h>
10#include <linux/err.h>
11#include <linux/hwmon.h>
12#include <linux/i2c.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/regmap.h>
18
19/* INA238 register definitions */
20#define INA238_CONFIG 0x0
21#define INA238_ADC_CONFIG 0x1
22#define INA238_SHUNT_CALIBRATION 0x2
23#define SQ52206_SHUNT_TEMPCO 0x3
24#define INA238_SHUNT_VOLTAGE 0x4
25#define INA238_BUS_VOLTAGE 0x5
26#define INA238_DIE_TEMP 0x6
27#define INA238_CURRENT 0x7
28#define INA238_POWER 0x8
29#define SQ52206_ENERGY 0x9
30#define SQ52206_CHARGE 0xa
31#define INA238_DIAG_ALERT 0xb
32#define INA238_SHUNT_OVER_VOLTAGE 0xc
33#define INA238_SHUNT_UNDER_VOLTAGE 0xd
34#define INA238_BUS_OVER_VOLTAGE 0xe
35#define INA238_BUS_UNDER_VOLTAGE 0xf
36#define INA238_TEMP_LIMIT 0x10
37#define INA238_POWER_LIMIT 0x11
38#define SQ52206_POWER_PEAK 0x20
39#define INA238_DEVICE_ID 0x3f /* not available on INA237 */
40
41#define INA238_CONFIG_ADCRANGE BIT(4)
42#define SQ52206_CONFIG_ADCRANGE_HIGH BIT(4)
43#define SQ52206_CONFIG_ADCRANGE_LOW BIT(3)
44
45#define INA238_DIAG_ALERT_TMPOL BIT(7)
46#define INA238_DIAG_ALERT_SHNTOL BIT(6)
47#define INA238_DIAG_ALERT_SHNTUL BIT(5)
48#define INA238_DIAG_ALERT_BUSOL BIT(4)
49#define INA238_DIAG_ALERT_BUSUL BIT(3)
50#define INA238_DIAG_ALERT_POL BIT(2)
51
52#define INA238_REGISTERS 0x20
53
54#define INA238_RSHUNT_DEFAULT 2500 /* uOhm */
55
56/* Default configuration of device on reset. */
57#define INA238_CONFIG_DEFAULT 0
58#define SQ52206_CONFIG_DEFAULT 0x0005
59/* 16 sample averaging, 1052us conversion time, continuous mode */
60#define INA238_ADC_CONFIG_DEFAULT 0xfb6a
61/* Configure alerts to be based on averaged value (SLOWALERT) */
62#define INA238_DIAG_ALERT_DEFAULT 0x2000
63#define INA238_DIAG_ALERT_APOL BIT(12)
64/*
65 * This driver uses a fixed calibration value in order to scale current/power
66 * based on a fixed shunt resistor value. This allows for conversion within the
67 * device to avoid integer limits whilst current/power accuracy is scaled
68 * relative to the shunt resistor value within the driver. This is similar to
69 * how the ina2xx driver handles current/power scaling.
70 *
71 * To achieve the best possible dynamic range, the value of the shunt voltage
72 * register should match the value of the current register. With that, the shunt
73 * voltage of 0x7fff = 32,767 uV = 163,785 uV matches the maximum current,
74 * and no accuracy is lost. Experiments with a real chip show that this is
75 * achieved by setting the SHUNT_CAL register to a value of 0x1000 = 4,096.
76 * Per datasheet,
77 * SHUNT_CAL = 819.2 x 10^6 x CURRENT_LSB x Rshunt
78 * = 819,200,000 x CURRENT_LSB x Rshunt
79 * With SHUNT_CAL set to 4,096, we get
80 * CURRENT_LSB = 4,096 / (819,200,000 x Rshunt)
81 * Assuming an Rshunt value of 5 mOhm, we get
82 * CURRENT_LSB = 4,096 / (819,200,000 x 0.005) = 1mA
83 * and thus a dynamic range of 1mA ... 32,767mA, which is sufficient for most
84 * applications. The actual dynamic range is of course determined by the actual
85 * shunt resistor value.
86 *
87 * Power and energy values are scaled accordingly.
88 */
89#define INA238_CALIBRATION_VALUE 4096
90#define INA238_FIXED_SHUNT 5000
91
92#define INA238_SHUNT_VOLTAGE_LSB 5000 /* 5 uV/lsb, in nV */
93#define INA238_BUS_VOLTAGE_LSB 3125000 /* 3.125 mV/lsb, in nV */
94#define SQ52206_BUS_VOLTAGE_LSB 3750000 /* 3.75 mV/lsb, in nV */
95
96#define NUNIT_PER_MUNIT 1000000 /* n[AV] -> m[AV] */
97
98static const struct regmap_config ina238_regmap_config = {
99 .max_register = INA238_REGISTERS,
100 .reg_bits = 8,
101 .val_bits = 16,
102};
103
104enum ina238_ids { ina228, ina237, ina238, ina700, ina780, sq52206 };
105
106struct ina238_config {
107 bool has_20bit_voltage_current; /* vshunt, vbus and current are 20-bit fields */
108 bool has_power_highest; /* chip detection power peak */
109 bool has_energy; /* chip detection energy */
110 u8 temp_resolution; /* temperature register resolution in bit */
111 u16 config_default; /* Power-on default state */
112 u32 power_calculate_factor; /* fixed parameter for power calculation, from datasheet */
113 u32 bus_voltage_lsb; /* bus voltage LSB, in nV */
114 int current_lsb; /* current LSB, in uA */
115};
116
117struct ina238_data {
118 const struct ina238_config *config;
119 struct i2c_client *client;
120 struct regmap *regmap;
121 u32 rshunt;
122 int gain;
123 u32 voltage_lsb[2]; /* shunt, bus voltage LSB, in nV */
124 int current_lsb; /* current LSB, in uA */
125 int power_lsb; /* power LSB, in uW */
126 int energy_lsb; /* energy LSB, in uJ */
127};
128
129static const struct ina238_config ina238_config[] = {
130 [ina228] = {
131 .has_20bit_voltage_current = true,
132 .has_energy = true,
133 .has_power_highest = false,
134 .power_calculate_factor = 20,
135 .config_default = INA238_CONFIG_DEFAULT,
136 .bus_voltage_lsb = INA238_BUS_VOLTAGE_LSB,
137 .temp_resolution = 16,
138 },
139 [ina237] = {
140 .has_20bit_voltage_current = false,
141 .has_energy = false,
142 .has_power_highest = false,
143 .power_calculate_factor = 20,
144 .config_default = INA238_CONFIG_DEFAULT,
145 .bus_voltage_lsb = INA238_BUS_VOLTAGE_LSB,
146 .temp_resolution = 12,
147 },
148 [ina238] = {
149 .has_20bit_voltage_current = false,
150 .has_energy = false,
151 .has_power_highest = false,
152 .power_calculate_factor = 20,
153 .config_default = INA238_CONFIG_DEFAULT,
154 .bus_voltage_lsb = INA238_BUS_VOLTAGE_LSB,
155 .temp_resolution = 12,
156 },
157 [ina700] = {
158 .has_20bit_voltage_current = false,
159 .has_energy = true,
160 .has_power_highest = false,
161 .power_calculate_factor = 20,
162 .config_default = INA238_CONFIG_DEFAULT,
163 .bus_voltage_lsb = INA238_BUS_VOLTAGE_LSB,
164 .temp_resolution = 12,
165 .current_lsb = 480,
166 },
167 [ina780] = {
168 .has_20bit_voltage_current = false,
169 .has_energy = true,
170 .has_power_highest = false,
171 .power_calculate_factor = 20,
172 .config_default = INA238_CONFIG_DEFAULT,
173 .bus_voltage_lsb = INA238_BUS_VOLTAGE_LSB,
174 .temp_resolution = 12,
175 .current_lsb = 2400,
176 },
177 [sq52206] = {
178 .has_20bit_voltage_current = false,
179 .has_energy = true,
180 .has_power_highest = true,
181 .power_calculate_factor = 24,
182 .config_default = SQ52206_CONFIG_DEFAULT,
183 .bus_voltage_lsb = SQ52206_BUS_VOLTAGE_LSB,
184 .temp_resolution = 16,
185 },
186};
187
188static int ina238_read_reg24(const struct i2c_client *client, u8 reg, u32 *val)
189{
190 u8 data[3];
191 int err;
192
193 /* 24-bit register read */
194 err = i2c_smbus_read_i2c_block_data(client, command: reg, length: 3, values: data);
195 if (err < 0)
196 return err;
197 if (err != 3)
198 return -EIO;
199 *val = (data[0] << 16) | (data[1] << 8) | data[2];
200
201 return 0;
202}
203
204static int ina238_read_reg40(const struct i2c_client *client, u8 reg, u64 *val)
205{
206 u8 data[5];
207 u32 low;
208 int err;
209
210 /* 40-bit register read */
211 err = i2c_smbus_read_i2c_block_data(client, command: reg, length: 5, values: data);
212 if (err < 0)
213 return err;
214 if (err != 5)
215 return -EIO;
216 low = (data[1] << 24) | (data[2] << 16) | (data[3] << 8) | data[4];
217 *val = ((long long)data[0] << 32) | low;
218
219 return 0;
220}
221
222static int ina238_read_field_s20(const struct i2c_client *client, u8 reg, s32 *val)
223{
224 u32 regval;
225 int err;
226
227 err = ina238_read_reg24(client, reg, val: &regval);
228 if (err)
229 return err;
230
231 /* bits 3-0 Reserved, always zero */
232 regval >>= 4;
233
234 *val = sign_extend32(value: regval, index: 19);
235
236 return 0;
237}
238
239static int ina228_read_voltage(struct ina238_data *data, int channel, long *val)
240{
241 int reg = channel ? INA238_BUS_VOLTAGE : INA238_CURRENT;
242 u32 lsb = data->voltage_lsb[channel];
243 u32 factor = NUNIT_PER_MUNIT;
244 int err, regval;
245
246 if (data->config->has_20bit_voltage_current) {
247 err = ina238_read_field_s20(client: data->client, reg, val: &regval);
248 if (err)
249 return err;
250 /* Adjust accuracy: LSB in units of 500 pV */
251 lsb /= 8;
252 factor *= 2;
253 } else {
254 err = regmap_read(map: data->regmap, reg, val: &regval);
255 if (err)
256 return err;
257 regval = (s16)regval;
258 }
259
260 *val = DIV_S64_ROUND_CLOSEST((s64)regval * lsb, factor);
261 return 0;
262}
263
264static int ina238_read_in(struct device *dev, u32 attr, int channel,
265 long *val)
266{
267 struct ina238_data *data = dev_get_drvdata(dev);
268 int reg, mask = 0;
269 int regval;
270 int err;
271
272 if (attr == hwmon_in_input)
273 return ina228_read_voltage(data, channel, val);
274
275 switch (channel) {
276 case 0:
277 switch (attr) {
278 case hwmon_in_max:
279 reg = INA238_SHUNT_OVER_VOLTAGE;
280 break;
281 case hwmon_in_min:
282 reg = INA238_SHUNT_UNDER_VOLTAGE;
283 break;
284 case hwmon_in_max_alarm:
285 reg = INA238_DIAG_ALERT;
286 mask = INA238_DIAG_ALERT_SHNTOL;
287 break;
288 case hwmon_in_min_alarm:
289 reg = INA238_DIAG_ALERT;
290 mask = INA238_DIAG_ALERT_SHNTUL;
291 break;
292 default:
293 return -EOPNOTSUPP;
294 }
295 break;
296 case 1:
297 switch (attr) {
298 case hwmon_in_max:
299 reg = INA238_BUS_OVER_VOLTAGE;
300 break;
301 case hwmon_in_min:
302 reg = INA238_BUS_UNDER_VOLTAGE;
303 break;
304 case hwmon_in_max_alarm:
305 reg = INA238_DIAG_ALERT;
306 mask = INA238_DIAG_ALERT_BUSOL;
307 break;
308 case hwmon_in_min_alarm:
309 reg = INA238_DIAG_ALERT;
310 mask = INA238_DIAG_ALERT_BUSUL;
311 break;
312 default:
313 return -EOPNOTSUPP;
314 }
315 break;
316 default:
317 return -EOPNOTSUPP;
318 }
319
320 err = regmap_read(map: data->regmap, reg, val: &regval);
321 if (err < 0)
322 return err;
323
324 if (mask)
325 *val = !!(regval & mask);
326 else
327 *val = DIV_S64_ROUND_CLOSEST((s64)(s16)regval * data->voltage_lsb[channel],
328 NUNIT_PER_MUNIT);
329
330 return 0;
331}
332
333static int ina238_write_in(struct device *dev, u32 attr, int channel, long val)
334{
335 struct ina238_data *data = dev_get_drvdata(dev);
336 static const int low_limits[2] = {-164, 0};
337 static const int high_limits[2] = {164, 150000};
338 static const u8 low_regs[2] = {INA238_SHUNT_UNDER_VOLTAGE, INA238_BUS_UNDER_VOLTAGE};
339 static const u8 high_regs[2] = {INA238_SHUNT_OVER_VOLTAGE, INA238_BUS_OVER_VOLTAGE};
340 int regval;
341
342 /* Initial clamp to avoid overflows */
343 val = clamp_val(val, low_limits[channel], high_limits[channel]);
344 val = DIV_S64_ROUND_CLOSEST((s64)val * NUNIT_PER_MUNIT, data->voltage_lsb[channel]);
345 /* Final clamp to register limits */
346 regval = clamp_val(val, S16_MIN, S16_MAX) & 0xffff;
347
348 switch (attr) {
349 case hwmon_in_min:
350 return regmap_write(map: data->regmap, reg: low_regs[channel], val: regval);
351 case hwmon_in_max:
352 return regmap_write(map: data->regmap, reg: high_regs[channel], val: regval);
353 default:
354 return -EOPNOTSUPP;
355 }
356}
357
358static int __ina238_read_curr(struct ina238_data *data, long *val)
359{
360 u32 lsb = data->current_lsb;
361 int err, regval;
362
363 if (data->config->has_20bit_voltage_current) {
364 err = ina238_read_field_s20(client: data->client, INA238_CURRENT, val: &regval);
365 if (err)
366 return err;
367 lsb /= 16; /* Adjust accuracy */
368 } else {
369 err = regmap_read(map: data->regmap, INA238_CURRENT, val: &regval);
370 if (err)
371 return err;
372 regval = (s16)regval;
373 }
374
375 *val = DIV_S64_ROUND_CLOSEST((s64)regval * lsb, 1000);
376 return 0;
377}
378
379static int ina238_read_curr(struct device *dev, u32 attr, long *val)
380{
381 struct ina238_data *data = dev_get_drvdata(dev);
382 int reg, mask = 0;
383 int regval;
384 int err;
385
386 if (attr == hwmon_curr_input)
387 return __ina238_read_curr(data, val);
388
389 switch (attr) {
390 case hwmon_curr_min:
391 reg = INA238_SHUNT_UNDER_VOLTAGE;
392 break;
393 case hwmon_curr_min_alarm:
394 reg = INA238_DIAG_ALERT;
395 mask = INA238_DIAG_ALERT_SHNTUL;
396 break;
397 case hwmon_curr_max:
398 reg = INA238_SHUNT_OVER_VOLTAGE;
399 break;
400 case hwmon_curr_max_alarm:
401 reg = INA238_DIAG_ALERT;
402 mask = INA238_DIAG_ALERT_SHNTOL;
403 break;
404 default:
405 return -EOPNOTSUPP;
406 }
407
408 err = regmap_read(map: data->regmap, reg, val: &regval);
409 if (err < 0)
410 return err;
411
412 if (mask)
413 *val = !!(regval & mask);
414 else
415 *val = DIV_S64_ROUND_CLOSEST((s64)(s16)regval * data->current_lsb, 1000);
416
417 return 0;
418}
419
420static int ina238_write_curr(struct device *dev, u32 attr, long val)
421{
422 struct ina238_data *data = dev_get_drvdata(dev);
423 int regval;
424
425 /* Set baseline range to avoid over/underflows */
426 val = clamp_val(val, -1000000, 1000000);
427 /* Scale */
428 val = DIV_ROUND_CLOSEST(val * 1000, data->current_lsb);
429 /* Clamp to register size */
430 regval = clamp_val(val, S16_MIN, S16_MAX) & 0xffff;
431
432 switch (attr) {
433 case hwmon_curr_min:
434 return regmap_write(map: data->regmap, INA238_SHUNT_UNDER_VOLTAGE,
435 val: regval);
436 case hwmon_curr_max:
437 return regmap_write(map: data->regmap, INA238_SHUNT_OVER_VOLTAGE,
438 val: regval);
439 default:
440 return -EOPNOTSUPP;
441 }
442}
443
444static int ina238_read_power(struct device *dev, u32 attr, long *val)
445{
446 struct ina238_data *data = dev_get_drvdata(dev);
447 long long power;
448 int regval;
449 int err;
450
451 switch (attr) {
452 case hwmon_power_input:
453 err = ina238_read_reg24(client: data->client, INA238_POWER, val: &regval);
454 if (err)
455 return err;
456
457 power = (long long)regval * data->power_lsb;
458 /* Clamp value to maximum value of long */
459 *val = clamp_val(power, 0, LONG_MAX);
460 break;
461 case hwmon_power_input_highest:
462 err = ina238_read_reg24(client: data->client, SQ52206_POWER_PEAK, val: &regval);
463 if (err)
464 return err;
465
466 power = (long long)regval * data->power_lsb;
467 /* Clamp value to maximum value of long */
468 *val = clamp_val(power, 0, LONG_MAX);
469 break;
470 case hwmon_power_max:
471 err = regmap_read(map: data->regmap, INA238_POWER_LIMIT, val: &regval);
472 if (err)
473 return err;
474
475 /*
476 * Truncated 24-bit compare register, lower 8-bits are
477 * truncated. Same conversion to/from uW as POWER register.
478 */
479 power = ((long long)regval << 8) * data->power_lsb;
480 /* Clamp value to maximum value of long */
481 *val = clamp_val(power, 0, LONG_MAX);
482 break;
483 case hwmon_power_max_alarm:
484 err = regmap_read(map: data->regmap, INA238_DIAG_ALERT, val: &regval);
485 if (err)
486 return err;
487
488 *val = !!(regval & INA238_DIAG_ALERT_POL);
489 break;
490 default:
491 return -EOPNOTSUPP;
492 }
493
494 return 0;
495}
496
497static int ina238_write_power_max(struct device *dev, long val)
498{
499 struct ina238_data *data = dev_get_drvdata(dev);
500
501 /*
502 * Unsigned postive values. Compared against the 24-bit power register,
503 * lower 8-bits are truncated. Same conversion to/from uW as POWER
504 * register.
505 * The first clamp_val() is to establish a baseline to avoid overflows.
506 */
507 val = clamp_val(val, 0, LONG_MAX / 2);
508 val = DIV_ROUND_CLOSEST(val, data->power_lsb);
509 val = clamp_val(val >> 8, 0, U16_MAX);
510
511 return regmap_write(map: data->regmap, INA238_POWER_LIMIT, val);
512}
513
514static int ina238_temp_from_reg(s16 regval, u8 resolution)
515{
516 return ((regval >> (16 - resolution)) * 1000) >> (resolution - 9);
517}
518
519static int ina238_read_temp(struct device *dev, u32 attr, long *val)
520{
521 struct ina238_data *data = dev_get_drvdata(dev);
522 int regval;
523 int err;
524
525 switch (attr) {
526 case hwmon_temp_input:
527 err = regmap_read(map: data->regmap, INA238_DIE_TEMP, val: &regval);
528 if (err)
529 return err;
530 *val = ina238_temp_from_reg(regval, resolution: data->config->temp_resolution);
531 break;
532 case hwmon_temp_max:
533 err = regmap_read(map: data->regmap, INA238_TEMP_LIMIT, val: &regval);
534 if (err)
535 return err;
536 /* Signed, result in mC */
537 *val = ina238_temp_from_reg(regval, resolution: data->config->temp_resolution);
538 break;
539 case hwmon_temp_max_alarm:
540 err = regmap_read(map: data->regmap, INA238_DIAG_ALERT, val: &regval);
541 if (err)
542 return err;
543
544 *val = !!(regval & INA238_DIAG_ALERT_TMPOL);
545 break;
546 default:
547 return -EOPNOTSUPP;
548 }
549
550 return 0;
551}
552
553static u16 ina238_temp_to_reg(long val, u8 resolution)
554{
555 int fraction = 1000 - DIV_ROUND_CLOSEST(1000, BIT(resolution - 9));
556
557 val = clamp_val(val, -255000 - fraction, 255000 + fraction);
558
559 return (DIV_ROUND_CLOSEST(val << (resolution - 9), 1000) << (16 - resolution)) & 0xffff;
560}
561
562static int ina238_write_temp_max(struct device *dev, long val)
563{
564 struct ina238_data *data = dev_get_drvdata(dev);
565 int regval;
566
567 regval = ina238_temp_to_reg(val, resolution: data->config->temp_resolution);
568 return regmap_write(map: data->regmap, INA238_TEMP_LIMIT, val: regval);
569}
570
571static int ina238_read_energy(struct device *dev, s64 *energy)
572{
573 struct ina238_data *data = dev_get_drvdata(dev);
574 u64 regval;
575 int ret;
576
577 ret = ina238_read_reg40(client: data->client, SQ52206_ENERGY, val: &regval);
578 if (ret)
579 return ret;
580
581 /* result in uJ */
582 *energy = regval * data->energy_lsb;
583 return 0;
584}
585
586static int ina238_read(struct device *dev, enum hwmon_sensor_types type,
587 u32 attr, int channel, long *val)
588{
589 switch (type) {
590 case hwmon_in:
591 return ina238_read_in(dev, attr, channel, val);
592 case hwmon_curr:
593 return ina238_read_curr(dev, attr, val);
594 case hwmon_power:
595 return ina238_read_power(dev, attr, val);
596 case hwmon_energy64:
597 return ina238_read_energy(dev, energy: (s64 *)val);
598 case hwmon_temp:
599 return ina238_read_temp(dev, attr, val);
600 default:
601 return -EOPNOTSUPP;
602 }
603 return 0;
604}
605
606static int ina238_write(struct device *dev, enum hwmon_sensor_types type,
607 u32 attr, int channel, long val)
608{
609 switch (type) {
610 case hwmon_in:
611 return ina238_write_in(dev, attr, channel, val);
612 case hwmon_curr:
613 return ina238_write_curr(dev, attr, val);
614 case hwmon_power:
615 return ina238_write_power_max(dev, val);
616 case hwmon_temp:
617 return ina238_write_temp_max(dev, val);
618 default:
619 return -EOPNOTSUPP;
620 }
621}
622
623static umode_t ina238_is_visible(const void *drvdata,
624 enum hwmon_sensor_types type,
625 u32 attr, int channel)
626{
627 const struct ina238_data *data = drvdata;
628 bool has_power_highest = data->config->has_power_highest;
629 bool has_energy = data->config->has_energy;
630
631 switch (type) {
632 case hwmon_in:
633 switch (attr) {
634 case hwmon_in_input:
635 case hwmon_in_max_alarm:
636 case hwmon_in_min_alarm:
637 return 0444;
638 case hwmon_in_max:
639 case hwmon_in_min:
640 return 0644;
641 default:
642 return 0;
643 }
644 case hwmon_curr:
645 switch (attr) {
646 case hwmon_curr_input:
647 case hwmon_curr_max_alarm:
648 case hwmon_curr_min_alarm:
649 return 0444;
650 case hwmon_curr_max:
651 case hwmon_curr_min:
652 return 0644;
653 default:
654 return 0;
655 }
656 case hwmon_power:
657 switch (attr) {
658 case hwmon_power_input:
659 case hwmon_power_max_alarm:
660 return 0444;
661 case hwmon_power_max:
662 return 0644;
663 case hwmon_power_input_highest:
664 if (has_power_highest)
665 return 0444;
666 return 0;
667 default:
668 return 0;
669 }
670 case hwmon_energy64:
671 /* hwmon_energy_input */
672 if (has_energy)
673 return 0444;
674 return 0;
675 case hwmon_temp:
676 switch (attr) {
677 case hwmon_temp_input:
678 case hwmon_temp_max_alarm:
679 return 0444;
680 case hwmon_temp_max:
681 return 0644;
682 default:
683 return 0;
684 }
685 default:
686 return 0;
687 }
688}
689
690#define INA238_HWMON_IN_CONFIG (HWMON_I_INPUT | \
691 HWMON_I_MAX | HWMON_I_MAX_ALARM | \
692 HWMON_I_MIN | HWMON_I_MIN_ALARM)
693
694static const struct hwmon_channel_info * const ina238_info[] = {
695 HWMON_CHANNEL_INFO(in,
696 /* 0: shunt voltage */
697 INA238_HWMON_IN_CONFIG,
698 /* 1: bus voltage */
699 INA238_HWMON_IN_CONFIG),
700 HWMON_CHANNEL_INFO(curr,
701 /* 0: current through shunt */
702 HWMON_C_INPUT | HWMON_C_MIN | HWMON_C_MIN_ALARM |
703 HWMON_C_MAX | HWMON_C_MAX_ALARM),
704 HWMON_CHANNEL_INFO(power,
705 /* 0: power */
706 HWMON_P_INPUT | HWMON_P_MAX |
707 HWMON_P_MAX_ALARM | HWMON_P_INPUT_HIGHEST),
708 HWMON_CHANNEL_INFO(energy64,
709 HWMON_E_INPUT),
710 HWMON_CHANNEL_INFO(temp,
711 /* 0: die temperature */
712 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_ALARM),
713 NULL
714};
715
716static const struct hwmon_ops ina238_hwmon_ops = {
717 .is_visible = ina238_is_visible,
718 .read = ina238_read,
719 .write = ina238_write,
720};
721
722static const struct hwmon_chip_info ina238_chip_info = {
723 .ops = &ina238_hwmon_ops,
724 .info = ina238_info,
725};
726
727static int ina238_probe(struct i2c_client *client)
728{
729 struct device *dev = &client->dev;
730 struct device *hwmon_dev;
731 struct ina238_data *data;
732 enum ina238_ids chip;
733 int config;
734 int ret;
735
736 chip = (uintptr_t)i2c_get_match_data(client);
737
738 data = devm_kzalloc(dev, size: sizeof(*data), GFP_KERNEL);
739 if (!data)
740 return -ENOMEM;
741
742 data->client = client;
743 /* set the device type */
744 data->config = &ina238_config[chip];
745
746 data->regmap = devm_regmap_init_i2c(client, &ina238_regmap_config);
747 if (IS_ERR(ptr: data->regmap)) {
748 dev_err(dev, "failed to allocate register map\n");
749 return PTR_ERR(ptr: data->regmap);
750 }
751
752 /* Setup CONFIG register */
753 config = data->config->config_default;
754 if (data->config->current_lsb) {
755 data->voltage_lsb[0] = INA238_SHUNT_VOLTAGE_LSB;
756 data->current_lsb = data->config->current_lsb;
757 } else {
758 /* load shunt value */
759 if (device_property_read_u32(dev, propname: "shunt-resistor", val: &data->rshunt) < 0)
760 data->rshunt = INA238_RSHUNT_DEFAULT;
761 if (data->rshunt == 0) {
762 dev_err(dev, "invalid shunt resister value %u\n", data->rshunt);
763 return -EINVAL;
764 }
765
766 /* load shunt gain value */
767 if (device_property_read_u32(dev, propname: "ti,shunt-gain", val: &data->gain) < 0)
768 data->gain = 4; /* Default of ADCRANGE = 0 */
769 if (data->gain != 1 && data->gain != 2 && data->gain != 4) {
770 dev_err(dev, "invalid shunt gain value %u\n", data->gain);
771 return -EINVAL;
772 }
773
774 /* Setup SHUNT_CALIBRATION register with fixed value */
775 ret = regmap_write(map: data->regmap, INA238_SHUNT_CALIBRATION,
776 INA238_CALIBRATION_VALUE);
777 if (ret < 0) {
778 dev_err(dev, "error configuring the device: %d\n", ret);
779 return -ENODEV;
780 }
781 if (chip == sq52206) {
782 if (data->gain == 1) /* ADCRANGE = 10/11 is /1 */
783 config |= SQ52206_CONFIG_ADCRANGE_HIGH;
784 else if (data->gain == 2) /* ADCRANGE = 01 is /2 */
785 config |= SQ52206_CONFIG_ADCRANGE_LOW;
786 } else if (data->gain == 1) { /* ADCRANGE = 1 is /1 */
787 config |= INA238_CONFIG_ADCRANGE;
788 }
789 data->voltage_lsb[0] = INA238_SHUNT_VOLTAGE_LSB * data->gain / 4;
790 data->current_lsb = DIV_U64_ROUND_CLOSEST(250ULL * INA238_FIXED_SHUNT * data->gain,
791 data->rshunt);
792 }
793
794 ret = regmap_write(map: data->regmap, INA238_CONFIG, val: config);
795 if (ret < 0) {
796 dev_err(dev, "error configuring the device: %d\n", ret);
797 return -ENODEV;
798 }
799
800 /* Setup ADC_CONFIG register */
801 ret = regmap_write(map: data->regmap, INA238_ADC_CONFIG,
802 INA238_ADC_CONFIG_DEFAULT);
803 if (ret < 0) {
804 dev_err(dev, "error configuring the device: %d\n", ret);
805 return -ENODEV;
806 }
807
808 /* Setup alert/alarm configuration */
809 config = INA238_DIAG_ALERT_DEFAULT;
810 if (device_property_read_bool(dev, propname: "ti,alert-polarity-active-high"))
811 config |= INA238_DIAG_ALERT_APOL;
812
813 ret = regmap_write(map: data->regmap, INA238_DIAG_ALERT, val: config);
814 if (ret < 0) {
815 dev_err(dev, "error configuring the device: %d\n", ret);
816 return -ENODEV;
817 }
818
819 data->voltage_lsb[1] = data->config->bus_voltage_lsb;
820
821 data->power_lsb = DIV_ROUND_CLOSEST(data->current_lsb *
822 data->config->power_calculate_factor,
823 100);
824
825 data->energy_lsb = data->power_lsb * 16;
826
827 hwmon_dev = devm_hwmon_device_register_with_info(dev, name: client->name, drvdata: data,
828 info: &ina238_chip_info, NULL);
829 if (IS_ERR(ptr: hwmon_dev))
830 return PTR_ERR(ptr: hwmon_dev);
831
832 if (data->rshunt)
833 dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n",
834 client->name, data->rshunt, data->gain);
835
836 return 0;
837}
838
839static const struct i2c_device_id ina238_id[] = {
840 { "ina228", ina228 },
841 { "ina237", ina237 },
842 { "ina238", ina238 },
843 { "ina700", ina700 },
844 { "ina780", ina780 },
845 { "sq52206", sq52206 },
846 { }
847};
848MODULE_DEVICE_TABLE(i2c, ina238_id);
849
850static const struct of_device_id __maybe_unused ina238_of_match[] = {
851 {
852 .compatible = "ti,ina228",
853 .data = (void *)ina228
854 },
855 {
856 .compatible = "ti,ina237",
857 .data = (void *)ina237
858 },
859 {
860 .compatible = "ti,ina238",
861 .data = (void *)ina238
862 },
863 {
864 .compatible = "ti,ina700",
865 .data = (void *)ina700
866 },
867 {
868 .compatible = "ti,ina780",
869 .data = (void *)ina780
870 },
871 {
872 .compatible = "silergy,sq52206",
873 .data = (void *)sq52206
874 },
875 { }
876};
877MODULE_DEVICE_TABLE(of, ina238_of_match);
878
879static struct i2c_driver ina238_driver = {
880 .driver = {
881 .name = "ina238",
882 .of_match_table = of_match_ptr(ina238_of_match),
883 },
884 .probe = ina238_probe,
885 .id_table = ina238_id,
886};
887
888module_i2c_driver(ina238_driver);
889
890MODULE_AUTHOR("Nathan Rossi <nathan.rossi@digi.com>");
891MODULE_DESCRIPTION("ina238 driver");
892MODULE_LICENSE("GPL");
893

source code of linux/drivers/hwmon/ina238.c