1 /*
2 * Driver for the Texas Instruments / Burr Brown INA209
3 * Bidirectional Current/Power Monitor
4 *
5 * Copyright (C) 2012 Guenter Roeck <linux@roeck-us.net>
6 *
7 * Derived from Ira W. Snyder's original driver submission
8 * Copyright (C) 2008 Paul Hays <Paul.Hays@cattail.ca>
9 * Copyright (C) 2008-2009 Ira W. Snyder <iws@ovro.caltech.edu>
10 *
11 * Aligned with ina2xx driver
12 * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
13 * Thanks to Jan Volkering
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; version 2 of the License.
18 *
19 * Datasheet:
20 * http://www.ti.com/lit/gpn/ina209
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/err.h>
27 #include <linux/slab.h>
28 #include <linux/bug.h>
29 #include <linux/i2c.h>
30 #include <linux/hwmon.h>
31 #include <linux/hwmon-sysfs.h>
32
33 #include <linux/platform_data/ina2xx.h>
34
35 /* register definitions */
36 #define INA209_CONFIGURATION 0x00
37 #define INA209_STATUS 0x01
38 #define INA209_STATUS_MASK 0x02
39 #define INA209_SHUNT_VOLTAGE 0x03
40 #define INA209_BUS_VOLTAGE 0x04
41 #define INA209_POWER 0x05
42 #define INA209_CURRENT 0x06
43 #define INA209_SHUNT_VOLTAGE_POS_PEAK 0x07
44 #define INA209_SHUNT_VOLTAGE_NEG_PEAK 0x08
45 #define INA209_BUS_VOLTAGE_MAX_PEAK 0x09
46 #define INA209_BUS_VOLTAGE_MIN_PEAK 0x0a
47 #define INA209_POWER_PEAK 0x0b
48 #define INA209_SHUNT_VOLTAGE_POS_WARN 0x0c
49 #define INA209_SHUNT_VOLTAGE_NEG_WARN 0x0d
50 #define INA209_POWER_WARN 0x0e
51 #define INA209_BUS_VOLTAGE_OVER_WARN 0x0f
52 #define INA209_BUS_VOLTAGE_UNDER_WARN 0x10
53 #define INA209_POWER_OVER_LIMIT 0x11
54 #define INA209_BUS_VOLTAGE_OVER_LIMIT 0x12
55 #define INA209_BUS_VOLTAGE_UNDER_LIMIT 0x13
56 #define INA209_CRITICAL_DAC_POS 0x14
57 #define INA209_CRITICAL_DAC_NEG 0x15
58 #define INA209_CALIBRATION 0x16
59
60 #define INA209_REGISTERS 0x17
61
62 #define INA209_CONFIG_DEFAULT 0x3c47 /* PGA=8, full range */
63 #define INA209_SHUNT_DEFAULT 10000 /* uOhm */
64
65 struct ina209_data {
66 struct i2c_client *client;
67
68 struct mutex update_lock;
69 bool valid;
70 unsigned long last_updated; /* in jiffies */
71
72 u16 regs[INA209_REGISTERS]; /* All chip registers */
73
74 u16 config_orig; /* Original configuration */
75 u16 calibration_orig; /* Original calibration */
76 u16 update_interval;
77 };
78
ina209_update_device(struct device * dev)79 static struct ina209_data *ina209_update_device(struct device *dev)
80 {
81 struct ina209_data *data = dev_get_drvdata(dev);
82 struct i2c_client *client = data->client;
83 struct ina209_data *ret = data;
84 s32 val;
85 int i;
86
87 mutex_lock(&data->update_lock);
88
89 if (!data->valid ||
90 time_after(jiffies, data->last_updated + data->update_interval)) {
91 for (i = 0; i < ARRAY_SIZE(data->regs); i++) {
92 val = i2c_smbus_read_word_swapped(client, i);
93 if (val < 0) {
94 ret = ERR_PTR(val);
95 goto abort;
96 }
97 data->regs[i] = val;
98 }
99 data->last_updated = jiffies;
100 data->valid = true;
101 }
102 abort:
103 mutex_unlock(&data->update_lock);
104 return ret;
105 }
106
107 /*
108 * Read a value from a device register and convert it to the
109 * appropriate sysfs units
110 */
ina209_from_reg(const u8 reg,const u16 val)111 static long ina209_from_reg(const u8 reg, const u16 val)
112 {
113 switch (reg) {
114 case INA209_SHUNT_VOLTAGE:
115 case INA209_SHUNT_VOLTAGE_POS_PEAK:
116 case INA209_SHUNT_VOLTAGE_NEG_PEAK:
117 case INA209_SHUNT_VOLTAGE_POS_WARN:
118 case INA209_SHUNT_VOLTAGE_NEG_WARN:
119 /* LSB=10 uV. Convert to mV. */
120 return DIV_ROUND_CLOSEST((s16)val, 100);
121
122 case INA209_BUS_VOLTAGE:
123 case INA209_BUS_VOLTAGE_MAX_PEAK:
124 case INA209_BUS_VOLTAGE_MIN_PEAK:
125 case INA209_BUS_VOLTAGE_OVER_WARN:
126 case INA209_BUS_VOLTAGE_UNDER_WARN:
127 case INA209_BUS_VOLTAGE_OVER_LIMIT:
128 case INA209_BUS_VOLTAGE_UNDER_LIMIT:
129 /* LSB=4 mV, last 3 bits unused */
130 return (val >> 3) * 4;
131
132 case INA209_CRITICAL_DAC_POS:
133 /* LSB=1 mV, in the upper 8 bits */
134 return val >> 8;
135
136 case INA209_CRITICAL_DAC_NEG:
137 /* LSB=1 mV, in the upper 8 bits */
138 return -1 * (val >> 8);
139
140 case INA209_POWER:
141 case INA209_POWER_PEAK:
142 case INA209_POWER_WARN:
143 case INA209_POWER_OVER_LIMIT:
144 /* LSB=20 mW. Convert to uW */
145 return val * 20 * 1000L;
146
147 case INA209_CURRENT:
148 /* LSB=1 mA (selected). Is in mA */
149 return (s16)val;
150 }
151
152 /* programmer goofed */
153 WARN_ON_ONCE(1);
154 return 0;
155 }
156
157 /*
158 * Take a value and convert it to register format, clamping the value
159 * to the appropriate range.
160 */
ina209_to_reg(u8 reg,u16 old,long val)161 static int ina209_to_reg(u8 reg, u16 old, long val)
162 {
163 switch (reg) {
164 case INA209_SHUNT_VOLTAGE_POS_WARN:
165 case INA209_SHUNT_VOLTAGE_NEG_WARN:
166 /* Limit to +- 320 mV, 10 uV LSB */
167 return clamp_val(val, -320, 320) * 100;
168
169 case INA209_BUS_VOLTAGE_OVER_WARN:
170 case INA209_BUS_VOLTAGE_UNDER_WARN:
171 case INA209_BUS_VOLTAGE_OVER_LIMIT:
172 case INA209_BUS_VOLTAGE_UNDER_LIMIT:
173 /*
174 * Limit to 0-32000 mV, 4 mV LSB
175 *
176 * The last three bits aren't part of the value, but we'll
177 * preserve them in their original state.
178 */
179 return (DIV_ROUND_CLOSEST(clamp_val(val, 0, 32000), 4) << 3)
180 | (old & 0x7);
181
182 case INA209_CRITICAL_DAC_NEG:
183 /*
184 * Limit to -255-0 mV, 1 mV LSB
185 * Convert the value to a positive value for the register
186 *
187 * The value lives in the top 8 bits only, be careful
188 * and keep original value of other bits.
189 */
190 return (clamp_val(-val, 0, 255) << 8) | (old & 0xff);
191
192 case INA209_CRITICAL_DAC_POS:
193 /*
194 * Limit to 0-255 mV, 1 mV LSB
195 *
196 * The value lives in the top 8 bits only, be careful
197 * and keep original value of other bits.
198 */
199 return (clamp_val(val, 0, 255) << 8) | (old & 0xff);
200
201 case INA209_POWER_WARN:
202 case INA209_POWER_OVER_LIMIT:
203 /* 20 mW LSB */
204 return DIV_ROUND_CLOSEST(val, 20 * 1000);
205 }
206
207 /* Other registers are read-only, return access error */
208 return -EACCES;
209 }
210
ina209_interval_from_reg(u16 reg)211 static int ina209_interval_from_reg(u16 reg)
212 {
213 return 68 >> (15 - ((reg >> 3) & 0x0f));
214 }
215
ina209_reg_from_interval(u16 config,long interval)216 static u16 ina209_reg_from_interval(u16 config, long interval)
217 {
218 int i, adc;
219
220 if (interval <= 0) {
221 adc = 8;
222 } else {
223 adc = 15;
224 for (i = 34 + 34 / 2; i; i >>= 1) {
225 if (i < interval)
226 break;
227 adc--;
228 }
229 }
230 return (config & 0xf807) | (adc << 3) | (adc << 7);
231 }
232
ina209_set_interval(struct device * dev,struct device_attribute * da,const char * buf,size_t count)233 static ssize_t ina209_set_interval(struct device *dev,
234 struct device_attribute *da,
235 const char *buf, size_t count)
236 {
237 struct ina209_data *data = ina209_update_device(dev);
238 long val;
239 u16 regval;
240 int ret;
241
242 if (IS_ERR(data))
243 return PTR_ERR(data);
244
245 ret = kstrtol(buf, 10, &val);
246 if (ret < 0)
247 return ret;
248
249 mutex_lock(&data->update_lock);
250 regval = ina209_reg_from_interval(data->regs[INA209_CONFIGURATION],
251 val);
252 i2c_smbus_write_word_swapped(data->client, INA209_CONFIGURATION,
253 regval);
254 data->regs[INA209_CONFIGURATION] = regval;
255 data->update_interval = ina209_interval_from_reg(regval);
256 mutex_unlock(&data->update_lock);
257 return count;
258 }
259
ina209_show_interval(struct device * dev,struct device_attribute * da,char * buf)260 static ssize_t ina209_show_interval(struct device *dev,
261 struct device_attribute *da, char *buf)
262 {
263 struct ina209_data *data = dev_get_drvdata(dev);
264
265 return snprintf(buf, PAGE_SIZE, "%d\n", data->update_interval);
266 }
267
268 /*
269 * History is reset by writing 1 into bit 0 of the respective peak register.
270 * Since more than one peak register may be affected by the scope of a
271 * reset_history attribute write, use a bit mask in attr->index to identify
272 * which registers are affected.
273 */
274 static u16 ina209_reset_history_regs[] = {
275 INA209_SHUNT_VOLTAGE_POS_PEAK,
276 INA209_SHUNT_VOLTAGE_NEG_PEAK,
277 INA209_BUS_VOLTAGE_MAX_PEAK,
278 INA209_BUS_VOLTAGE_MIN_PEAK,
279 INA209_POWER_PEAK
280 };
281
ina209_reset_history(struct device * dev,struct device_attribute * da,const char * buf,size_t count)282 static ssize_t ina209_reset_history(struct device *dev,
283 struct device_attribute *da,
284 const char *buf,
285 size_t count)
286 {
287 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
288 struct ina209_data *data = dev_get_drvdata(dev);
289 struct i2c_client *client = data->client;
290 u32 mask = attr->index;
291 long val;
292 int i, ret;
293
294 ret = kstrtol(buf, 10, &val);
295 if (ret < 0)
296 return ret;
297
298 mutex_lock(&data->update_lock);
299 for (i = 0; i < ARRAY_SIZE(ina209_reset_history_regs); i++) {
300 if (mask & (1 << i))
301 i2c_smbus_write_word_swapped(client,
302 ina209_reset_history_regs[i], 1);
303 }
304 data->valid = false;
305 mutex_unlock(&data->update_lock);
306 return count;
307 }
308
ina209_set_value(struct device * dev,struct device_attribute * da,const char * buf,size_t count)309 static ssize_t ina209_set_value(struct device *dev,
310 struct device_attribute *da,
311 const char *buf,
312 size_t count)
313 {
314 struct ina209_data *data = ina209_update_device(dev);
315 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
316 int reg = attr->index;
317 long val;
318 int ret;
319
320 if (IS_ERR(data))
321 return PTR_ERR(data);
322
323 ret = kstrtol(buf, 10, &val);
324 if (ret < 0)
325 return ret;
326
327 mutex_lock(&data->update_lock);
328 ret = ina209_to_reg(reg, data->regs[reg], val);
329 if (ret < 0) {
330 count = ret;
331 goto abort;
332 }
333 i2c_smbus_write_word_swapped(data->client, reg, ret);
334 data->regs[reg] = ret;
335 abort:
336 mutex_unlock(&data->update_lock);
337 return count;
338 }
339
ina209_show_value(struct device * dev,struct device_attribute * da,char * buf)340 static ssize_t ina209_show_value(struct device *dev,
341 struct device_attribute *da,
342 char *buf)
343 {
344 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
345 struct ina209_data *data = ina209_update_device(dev);
346 long val;
347
348 if (IS_ERR(data))
349 return PTR_ERR(data);
350
351 val = ina209_from_reg(attr->index, data->regs[attr->index]);
352 return snprintf(buf, PAGE_SIZE, "%ld\n", val);
353 }
354
ina209_show_alarm(struct device * dev,struct device_attribute * da,char * buf)355 static ssize_t ina209_show_alarm(struct device *dev,
356 struct device_attribute *da,
357 char *buf)
358 {
359 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
360 struct ina209_data *data = ina209_update_device(dev);
361 const unsigned int mask = attr->index;
362 u16 status;
363
364 if (IS_ERR(data))
365 return PTR_ERR(data);
366
367 status = data->regs[INA209_STATUS];
368
369 /*
370 * All alarms are in the INA209_STATUS register. To avoid a long
371 * switch statement, the mask is passed in attr->index
372 */
373 return snprintf(buf, PAGE_SIZE, "%u\n", !!(status & mask));
374 }
375
376 /* Shunt voltage, history, limits, alarms */
377 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina209_show_value, NULL,
378 INA209_SHUNT_VOLTAGE);
379 static SENSOR_DEVICE_ATTR(in0_input_highest, S_IRUGO, ina209_show_value, NULL,
380 INA209_SHUNT_VOLTAGE_POS_PEAK);
381 static SENSOR_DEVICE_ATTR(in0_input_lowest, S_IRUGO, ina209_show_value, NULL,
382 INA209_SHUNT_VOLTAGE_NEG_PEAK);
383 static SENSOR_DEVICE_ATTR(in0_reset_history, S_IWUSR, NULL,
384 ina209_reset_history, (1 << 0) | (1 << 1));
385 static SENSOR_DEVICE_ATTR(in0_max, S_IRUGO | S_IWUSR, ina209_show_value,
386 ina209_set_value, INA209_SHUNT_VOLTAGE_POS_WARN);
387 static SENSOR_DEVICE_ATTR(in0_min, S_IRUGO | S_IWUSR, ina209_show_value,
388 ina209_set_value, INA209_SHUNT_VOLTAGE_NEG_WARN);
389 static SENSOR_DEVICE_ATTR(in0_crit_max, S_IRUGO | S_IWUSR, ina209_show_value,
390 ina209_set_value, INA209_CRITICAL_DAC_POS);
391 static SENSOR_DEVICE_ATTR(in0_crit_min, S_IRUGO | S_IWUSR, ina209_show_value,
392 ina209_set_value, INA209_CRITICAL_DAC_NEG);
393
394 static SENSOR_DEVICE_ATTR(in0_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
395 1 << 11);
396 static SENSOR_DEVICE_ATTR(in0_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
397 1 << 12);
398 static SENSOR_DEVICE_ATTR(in0_crit_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
399 1 << 6);
400 static SENSOR_DEVICE_ATTR(in0_crit_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
401 1 << 7);
402
403 /* Bus voltage, history, limits, alarms */
404 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina209_show_value, NULL,
405 INA209_BUS_VOLTAGE);
406 static SENSOR_DEVICE_ATTR(in1_input_highest, S_IRUGO, ina209_show_value, NULL,
407 INA209_BUS_VOLTAGE_MAX_PEAK);
408 static SENSOR_DEVICE_ATTR(in1_input_lowest, S_IRUGO, ina209_show_value, NULL,
409 INA209_BUS_VOLTAGE_MIN_PEAK);
410 static SENSOR_DEVICE_ATTR(in1_reset_history, S_IWUSR, NULL,
411 ina209_reset_history, (1 << 2) | (1 << 3));
412 static SENSOR_DEVICE_ATTR(in1_max, S_IRUGO | S_IWUSR, ina209_show_value,
413 ina209_set_value, INA209_BUS_VOLTAGE_OVER_WARN);
414 static SENSOR_DEVICE_ATTR(in1_min, S_IRUGO | S_IWUSR, ina209_show_value,
415 ina209_set_value, INA209_BUS_VOLTAGE_UNDER_WARN);
416 static SENSOR_DEVICE_ATTR(in1_crit_max, S_IRUGO | S_IWUSR, ina209_show_value,
417 ina209_set_value, INA209_BUS_VOLTAGE_OVER_LIMIT);
418 static SENSOR_DEVICE_ATTR(in1_crit_min, S_IRUGO | S_IWUSR, ina209_show_value,
419 ina209_set_value, INA209_BUS_VOLTAGE_UNDER_LIMIT);
420
421 static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
422 1 << 14);
423 static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
424 1 << 15);
425 static SENSOR_DEVICE_ATTR(in1_crit_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
426 1 << 9);
427 static SENSOR_DEVICE_ATTR(in1_crit_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
428 1 << 10);
429
430 /* Power */
431 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina209_show_value, NULL,
432 INA209_POWER);
433 static SENSOR_DEVICE_ATTR(power1_input_highest, S_IRUGO, ina209_show_value,
434 NULL, INA209_POWER_PEAK);
435 static SENSOR_DEVICE_ATTR(power1_reset_history, S_IWUSR, NULL,
436 ina209_reset_history, 1 << 4);
437 static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO | S_IWUSR, ina209_show_value,
438 ina209_set_value, INA209_POWER_WARN);
439 static SENSOR_DEVICE_ATTR(power1_crit, S_IRUGO | S_IWUSR, ina209_show_value,
440 ina209_set_value, INA209_POWER_OVER_LIMIT);
441
442 static SENSOR_DEVICE_ATTR(power1_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
443 1 << 13);
444 static SENSOR_DEVICE_ATTR(power1_crit_alarm, S_IRUGO, ina209_show_alarm, NULL,
445 1 << 8);
446
447 /* Current */
448 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina209_show_value, NULL,
449 INA209_CURRENT);
450
451 static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
452 ina209_show_interval, ina209_set_interval, 0);
453
454 /*
455 * Finally, construct an array of pointers to members of the above objects,
456 * as required for sysfs_create_group()
457 */
458 static struct attribute *ina209_attrs[] = {
459 &sensor_dev_attr_in0_input.dev_attr.attr,
460 &sensor_dev_attr_in0_input_highest.dev_attr.attr,
461 &sensor_dev_attr_in0_input_lowest.dev_attr.attr,
462 &sensor_dev_attr_in0_reset_history.dev_attr.attr,
463 &sensor_dev_attr_in0_max.dev_attr.attr,
464 &sensor_dev_attr_in0_min.dev_attr.attr,
465 &sensor_dev_attr_in0_crit_max.dev_attr.attr,
466 &sensor_dev_attr_in0_crit_min.dev_attr.attr,
467 &sensor_dev_attr_in0_max_alarm.dev_attr.attr,
468 &sensor_dev_attr_in0_min_alarm.dev_attr.attr,
469 &sensor_dev_attr_in0_crit_max_alarm.dev_attr.attr,
470 &sensor_dev_attr_in0_crit_min_alarm.dev_attr.attr,
471
472 &sensor_dev_attr_in1_input.dev_attr.attr,
473 &sensor_dev_attr_in1_input_highest.dev_attr.attr,
474 &sensor_dev_attr_in1_input_lowest.dev_attr.attr,
475 &sensor_dev_attr_in1_reset_history.dev_attr.attr,
476 &sensor_dev_attr_in1_max.dev_attr.attr,
477 &sensor_dev_attr_in1_min.dev_attr.attr,
478 &sensor_dev_attr_in1_crit_max.dev_attr.attr,
479 &sensor_dev_attr_in1_crit_min.dev_attr.attr,
480 &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
481 &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
482 &sensor_dev_attr_in1_crit_max_alarm.dev_attr.attr,
483 &sensor_dev_attr_in1_crit_min_alarm.dev_attr.attr,
484
485 &sensor_dev_attr_power1_input.dev_attr.attr,
486 &sensor_dev_attr_power1_input_highest.dev_attr.attr,
487 &sensor_dev_attr_power1_reset_history.dev_attr.attr,
488 &sensor_dev_attr_power1_max.dev_attr.attr,
489 &sensor_dev_attr_power1_crit.dev_attr.attr,
490 &sensor_dev_attr_power1_max_alarm.dev_attr.attr,
491 &sensor_dev_attr_power1_crit_alarm.dev_attr.attr,
492
493 &sensor_dev_attr_curr1_input.dev_attr.attr,
494
495 &sensor_dev_attr_update_interval.dev_attr.attr,
496
497 NULL,
498 };
499 ATTRIBUTE_GROUPS(ina209);
500
ina209_restore_conf(struct i2c_client * client,struct ina209_data * data)501 static void ina209_restore_conf(struct i2c_client *client,
502 struct ina209_data *data)
503 {
504 /* Restore initial configuration */
505 i2c_smbus_write_word_swapped(client, INA209_CONFIGURATION,
506 data->config_orig);
507 i2c_smbus_write_word_swapped(client, INA209_CALIBRATION,
508 data->calibration_orig);
509 }
510
ina209_init_client(struct i2c_client * client,struct ina209_data * data)511 static int ina209_init_client(struct i2c_client *client,
512 struct ina209_data *data)
513 {
514 struct ina2xx_platform_data *pdata = dev_get_platdata(&client->dev);
515 u32 shunt;
516 int reg;
517
518 reg = i2c_smbus_read_word_swapped(client, INA209_CALIBRATION);
519 if (reg < 0)
520 return reg;
521 data->calibration_orig = reg;
522
523 reg = i2c_smbus_read_word_swapped(client, INA209_CONFIGURATION);
524 if (reg < 0)
525 return reg;
526 data->config_orig = reg;
527
528 if (pdata) {
529 if (pdata->shunt_uohms <= 0)
530 return -EINVAL;
531 shunt = pdata->shunt_uohms;
532 } else if (!of_property_read_u32(client->dev.of_node, "shunt-resistor",
533 &shunt)) {
534 if (shunt == 0)
535 return -EINVAL;
536 } else {
537 shunt = data->calibration_orig ?
538 40960000 / data->calibration_orig : INA209_SHUNT_DEFAULT;
539 }
540
541 i2c_smbus_write_word_swapped(client, INA209_CONFIGURATION,
542 INA209_CONFIG_DEFAULT);
543 data->update_interval = ina209_interval_from_reg(INA209_CONFIG_DEFAULT);
544
545 /*
546 * Calibrate current LSB to 1mA. Shunt is in uOhms.
547 * See equation 13 in datasheet.
548 */
549 i2c_smbus_write_word_swapped(client, INA209_CALIBRATION,
550 clamp_val(40960000 / shunt, 1, 65535));
551
552 /* Clear status register */
553 i2c_smbus_read_word_swapped(client, INA209_STATUS);
554
555 return 0;
556 }
557
ina209_probe(struct i2c_client * client,const struct i2c_device_id * id)558 static int ina209_probe(struct i2c_client *client,
559 const struct i2c_device_id *id)
560 {
561 struct i2c_adapter *adapter = client->adapter;
562 struct ina209_data *data;
563 struct device *hwmon_dev;
564 int ret;
565
566 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
567 return -ENODEV;
568
569 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
570 if (!data)
571 return -ENOMEM;
572
573 i2c_set_clientdata(client, data);
574 data->client = client;
575 mutex_init(&data->update_lock);
576
577 ret = ina209_init_client(client, data);
578 if (ret)
579 return ret;
580
581 hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
582 client->name,
583 data, ina209_groups);
584 if (IS_ERR(hwmon_dev)) {
585 ret = PTR_ERR(hwmon_dev);
586 goto out_restore_conf;
587 }
588
589 return 0;
590
591 out_restore_conf:
592 ina209_restore_conf(client, data);
593 return ret;
594 }
595
ina209_remove(struct i2c_client * client)596 static int ina209_remove(struct i2c_client *client)
597 {
598 struct ina209_data *data = i2c_get_clientdata(client);
599
600 ina209_restore_conf(client, data);
601
602 return 0;
603 }
604
605 static const struct i2c_device_id ina209_id[] = {
606 { "ina209", 0 },
607 { }
608 };
609 MODULE_DEVICE_TABLE(i2c, ina209_id);
610
611 static const struct of_device_id ina209_of_match[] = {
612 { .compatible = "ti,ina209" },
613 { },
614 };
615 MODULE_DEVICE_TABLE(of, ina209_of_match);
616
617 /* This is the driver that will be inserted */
618 static struct i2c_driver ina209_driver = {
619 .class = I2C_CLASS_HWMON,
620 .driver = {
621 .name = "ina209",
622 .of_match_table = of_match_ptr(ina209_of_match),
623 },
624 .probe = ina209_probe,
625 .remove = ina209_remove,
626 .id_table = ina209_id,
627 };
628
629 module_i2c_driver(ina209_driver);
630
631 MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>, Paul Hays <Paul.Hays@cattail.ca>, Guenter Roeck <linux@roeck-us.net>");
632 MODULE_DESCRIPTION("INA209 driver");
633 MODULE_LICENSE("GPL");
634
