xref: /openbmc/linux/drivers/hwmon/tmp513.c (revision aad29a73199b7fbccfbabea3f1ee627ad1924f52)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Texas Instruments TMP512, TMP513 power monitor chips
4  *
5  * TMP513:
6  * Thermal/Power Management with Triple Remote and
7  * Local Temperature Sensor and Current Shunt Monitor
8  * Datasheet: https://www.ti.com/lit/gpn/tmp513
9  *
10  * TMP512:
11  * Thermal/Power Management with Dual Remote
12  *	and Local Temperature Sensor and Current Shunt Monitor
13  * Datasheet: https://www.ti.com/lit/gpn/tmp512
14  *
15  * Copyright (C) 2019 Eric Tremblay <etremblay@distech-controls.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License as published by
19  * the Free Software Foundation; version 2 of the License.
20  */
21 
22 #include <linux/bitops.h>
23 #include <linux/bug.h>
24 #include <linux/device.h>
25 #include <linux/err.h>
26 #include <linux/hwmon.h>
27 #include <linux/i2c.h>
28 #include <linux/init.h>
29 #include <linux/math.h>
30 #include <linux/module.h>
31 #include <linux/property.h>
32 #include <linux/regmap.h>
33 #include <linux/slab.h>
34 #include <linux/types.h>
35 #include <linux/units.h>
36 
37 // Common register definition
38 #define TMP51X_SHUNT_CONFIG		0x00
39 #define TMP51X_TEMP_CONFIG		0x01
40 #define TMP51X_STATUS			0x02
41 #define TMP51X_SMBUS_ALERT		0x03
42 #define TMP51X_SHUNT_CURRENT_RESULT	0x04
43 #define TMP51X_BUS_VOLTAGE_RESULT	0x05
44 #define TMP51X_POWER_RESULT		0x06
45 #define TMP51X_BUS_CURRENT_RESULT	0x07
46 #define TMP51X_LOCAL_TEMP_RESULT	0x08
47 #define TMP51X_REMOTE_TEMP_RESULT_1	0x09
48 #define TMP51X_REMOTE_TEMP_RESULT_2	0x0A
49 #define TMP51X_SHUNT_CURRENT_H_LIMIT	0x0C
50 #define TMP51X_SHUNT_CURRENT_L_LIMIT	0x0D
51 #define TMP51X_BUS_VOLTAGE_H_LIMIT	0x0E
52 #define TMP51X_BUS_VOLTAGE_L_LIMIT	0x0F
53 #define TMP51X_POWER_LIMIT		0x10
54 #define TMP51X_LOCAL_TEMP_LIMIT	0x11
55 #define TMP51X_REMOTE_TEMP_LIMIT_1	0x12
56 #define TMP51X_REMOTE_TEMP_LIMIT_2	0x13
57 #define TMP51X_SHUNT_CALIBRATION	0x15
58 #define TMP51X_N_FACTOR_AND_HYST_1	0x16
59 #define TMP51X_N_FACTOR_2		0x17
60 #define TMP51X_MAN_ID_REG		0xFE
61 #define TMP51X_DEVICE_ID_REG		0xFF
62 
63 // TMP513 specific register definition
64 #define TMP513_REMOTE_TEMP_RESULT_3	0x0B
65 #define TMP513_REMOTE_TEMP_LIMIT_3	0x14
66 #define TMP513_N_FACTOR_3		0x18
67 
68 // Common attrs, and NULL
69 #define TMP51X_MANUFACTURER_ID		0x55FF
70 
71 #define TMP512_DEVICE_ID		0x22FF
72 #define TMP513_DEVICE_ID		0x23FF
73 
74 // Default config
75 #define TMP51X_SHUNT_CONFIG_DEFAULT	0x399F
76 #define TMP51X_SHUNT_VALUE_DEFAULT	1000
77 #define TMP51X_VBUS_RANGE_DEFAULT	TMP51X_VBUS_RANGE_32V
78 #define TMP51X_PGA_DEFAULT		8
79 #define TMP51X_MAX_REGISTER_ADDR	0xFF
80 
81 #define TMP512_TEMP_CONFIG_DEFAULT	0xBF80
82 #define TMP513_TEMP_CONFIG_DEFAULT	0xFF80
83 
84 // Mask and shift
85 #define CURRENT_SENSE_VOLTAGE_320_MASK	0x1800
86 #define CURRENT_SENSE_VOLTAGE_160_MASK	0x1000
87 #define CURRENT_SENSE_VOLTAGE_80_MASK	0x0800
88 #define CURRENT_SENSE_VOLTAGE_40_MASK	0
89 
90 #define TMP51X_BUS_VOLTAGE_MASK		0x2000
91 #define TMP51X_NFACTOR_MASK		0xFF00
92 #define TMP51X_HYST_MASK		0x00FF
93 
94 #define TMP51X_BUS_VOLTAGE_SHIFT	3
95 #define TMP51X_TEMP_SHIFT		3
96 
97 // Alarms
98 #define TMP51X_SHUNT_CURRENT_H_LIMIT_POS	15
99 #define TMP51X_SHUNT_CURRENT_L_LIMIT_POS	14
100 #define TMP51X_BUS_VOLTAGE_H_LIMIT_POS		13
101 #define TMP51X_BUS_VOLTAGE_L_LIMIT_POS		12
102 #define TMP51X_POWER_LIMIT_POS			11
103 #define TMP51X_LOCAL_TEMP_LIMIT_POS		10
104 #define TMP51X_REMOTE_TEMP_LIMIT_1_POS		9
105 #define TMP51X_REMOTE_TEMP_LIMIT_2_POS		8
106 #define TMP513_REMOTE_TEMP_LIMIT_3_POS		7
107 
108 #define TMP51X_VBUS_RANGE_32V		(32 * MICRO)
109 #define TMP51X_VBUS_RANGE_16V		(16 * MICRO)
110 
111 // Max and Min value
112 #define MAX_BUS_VOLTAGE_32_LIMIT	32764
113 #define MAX_BUS_VOLTAGE_16_LIMIT	16382
114 
115 // Max possible value is -256 to +256 but datasheet indicated -40 to 125.
116 #define MAX_TEMP_LIMIT			125000
117 #define MIN_TEMP_LIMIT			-40000
118 
119 #define MAX_TEMP_HYST			127500
120 
121 static const u8 TMP51X_TEMP_INPUT[4] = {
122 	TMP51X_LOCAL_TEMP_RESULT,
123 	TMP51X_REMOTE_TEMP_RESULT_1,
124 	TMP51X_REMOTE_TEMP_RESULT_2,
125 	TMP513_REMOTE_TEMP_RESULT_3
126 };
127 
128 static const u8 TMP51X_TEMP_CRIT[4] = {
129 	TMP51X_LOCAL_TEMP_LIMIT,
130 	TMP51X_REMOTE_TEMP_LIMIT_1,
131 	TMP51X_REMOTE_TEMP_LIMIT_2,
132 	TMP513_REMOTE_TEMP_LIMIT_3
133 };
134 
135 static const u8 TMP51X_TEMP_CRIT_ALARM[4] = {
136 	TMP51X_LOCAL_TEMP_LIMIT_POS,
137 	TMP51X_REMOTE_TEMP_LIMIT_1_POS,
138 	TMP51X_REMOTE_TEMP_LIMIT_2_POS,
139 	TMP513_REMOTE_TEMP_LIMIT_3_POS
140 };
141 
142 static const u8 TMP51X_TEMP_CRIT_HYST[4] = {
143 	TMP51X_N_FACTOR_AND_HYST_1,
144 	TMP51X_N_FACTOR_AND_HYST_1,
145 	TMP51X_N_FACTOR_AND_HYST_1,
146 	TMP51X_N_FACTOR_AND_HYST_1
147 };
148 
149 static const u8 TMP51X_CURR_INPUT[2] = {
150 	TMP51X_SHUNT_CURRENT_RESULT,
151 	TMP51X_BUS_CURRENT_RESULT
152 };
153 
154 static struct regmap_config tmp51x_regmap_config = {
155 	.reg_bits = 8,
156 	.val_bits = 16,
157 	.max_register = TMP51X_MAX_REGISTER_ADDR,
158 };
159 
160 enum tmp51x_ids {
161 	tmp512, tmp513
162 };
163 
164 struct tmp51x_data {
165 	u16 shunt_config;
166 	u16 pga_gain;
167 	u32 vbus_range_uvolt;
168 
169 	u16 temp_config;
170 	u32 nfactor[3];
171 
172 	u32 shunt_uohms;
173 
174 	u32 curr_lsb_ua;
175 	u32 pwr_lsb_uw;
176 
177 	enum tmp51x_ids id;
178 	struct regmap *regmap;
179 };
180 
181 // Set the shift based on the gain: 8 -> 1, 4 -> 2, 2 -> 3, 1 -> 4
tmp51x_get_pga_shift(struct tmp51x_data * data)182 static inline u8 tmp51x_get_pga_shift(struct tmp51x_data *data)
183 {
184 	return 5 - ffs(data->pga_gain);
185 }
186 
tmp51x_get_value(struct tmp51x_data * data,u8 reg,u8 pos,unsigned int regval,long * val)187 static int tmp51x_get_value(struct tmp51x_data *data, u8 reg, u8 pos,
188 			    unsigned int regval, long *val)
189 {
190 	switch (reg) {
191 	case TMP51X_STATUS:
192 		*val = (regval >> pos) & 1;
193 		break;
194 	case TMP51X_SHUNT_CURRENT_RESULT:
195 	case TMP51X_SHUNT_CURRENT_H_LIMIT:
196 	case TMP51X_SHUNT_CURRENT_L_LIMIT:
197 		/*
198 		 * The valus is read in voltage in the chip but reported as
199 		 * current to the user.
200 		 * 2's complement number shifted by one to four depending
201 		 * on the pga gain setting. 1lsb = 10uV
202 		 */
203 		*val = sign_extend32(regval,
204 				     reg == TMP51X_SHUNT_CURRENT_RESULT ?
205 				     16 - tmp51x_get_pga_shift(data) : 15);
206 		*val = DIV_ROUND_CLOSEST(*val * 10 * (long)MILLI, (long)data->shunt_uohms);
207 
208 		break;
209 	case TMP51X_BUS_VOLTAGE_RESULT:
210 	case TMP51X_BUS_VOLTAGE_H_LIMIT:
211 	case TMP51X_BUS_VOLTAGE_L_LIMIT:
212 		// 1lsb = 4mV
213 		*val = (regval >> TMP51X_BUS_VOLTAGE_SHIFT) * 4;
214 		break;
215 	case TMP51X_POWER_RESULT:
216 	case TMP51X_POWER_LIMIT:
217 		// Power = (current * BusVoltage) / 5000
218 		*val = regval * data->pwr_lsb_uw;
219 		break;
220 	case TMP51X_BUS_CURRENT_RESULT:
221 		// Current = (ShuntVoltage * CalibrationRegister) / 4096
222 		*val = sign_extend32(regval, 15) * (long)data->curr_lsb_ua;
223 		*val = DIV_ROUND_CLOSEST(*val, (long)MILLI);
224 		break;
225 	case TMP51X_LOCAL_TEMP_RESULT:
226 	case TMP51X_REMOTE_TEMP_RESULT_1:
227 	case TMP51X_REMOTE_TEMP_RESULT_2:
228 	case TMP513_REMOTE_TEMP_RESULT_3:
229 	case TMP51X_LOCAL_TEMP_LIMIT:
230 	case TMP51X_REMOTE_TEMP_LIMIT_1:
231 	case TMP51X_REMOTE_TEMP_LIMIT_2:
232 	case TMP513_REMOTE_TEMP_LIMIT_3:
233 		// 1lsb = 0.0625 degrees centigrade
234 		*val = sign_extend32(regval, 15) >> TMP51X_TEMP_SHIFT;
235 		*val = DIV_ROUND_CLOSEST(*val * 625, 10);
236 		break;
237 	case TMP51X_N_FACTOR_AND_HYST_1:
238 		// 1lsb = 0.5 degrees centigrade
239 		*val = (regval & TMP51X_HYST_MASK) * 500;
240 		break;
241 	default:
242 		// Programmer goofed
243 		WARN_ON_ONCE(1);
244 		*val = 0;
245 		return -EOPNOTSUPP;
246 	}
247 
248 	return 0;
249 }
250 
tmp51x_set_value(struct tmp51x_data * data,u8 reg,long val)251 static int tmp51x_set_value(struct tmp51x_data *data, u8 reg, long val)
252 {
253 	int regval, max_val;
254 	u32 mask = 0;
255 
256 	switch (reg) {
257 	case TMP51X_SHUNT_CURRENT_H_LIMIT:
258 	case TMP51X_SHUNT_CURRENT_L_LIMIT:
259 		/*
260 		 * The user enter current value and we convert it to
261 		 * voltage. 1lsb = 10uV
262 		 */
263 		val = DIV_ROUND_CLOSEST(val * (long)data->shunt_uohms, 10 * (long)MILLI);
264 		max_val = U16_MAX >> tmp51x_get_pga_shift(data);
265 		regval = clamp_val(val, -max_val, max_val);
266 		break;
267 	case TMP51X_BUS_VOLTAGE_H_LIMIT:
268 	case TMP51X_BUS_VOLTAGE_L_LIMIT:
269 		// 1lsb = 4mV
270 		max_val = (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) ?
271 			MAX_BUS_VOLTAGE_32_LIMIT : MAX_BUS_VOLTAGE_16_LIMIT;
272 
273 		val = clamp_val(DIV_ROUND_CLOSEST(val, 4), 0, max_val);
274 		regval = val << TMP51X_BUS_VOLTAGE_SHIFT;
275 		break;
276 	case TMP51X_POWER_LIMIT:
277 		regval = clamp_val(DIV_ROUND_CLOSEST(val, data->pwr_lsb_uw), 0,
278 				   U16_MAX);
279 		break;
280 	case TMP51X_LOCAL_TEMP_LIMIT:
281 	case TMP51X_REMOTE_TEMP_LIMIT_1:
282 	case TMP51X_REMOTE_TEMP_LIMIT_2:
283 	case TMP513_REMOTE_TEMP_LIMIT_3:
284 		// 1lsb = 0.0625 degrees centigrade
285 		val = clamp_val(val, MIN_TEMP_LIMIT, MAX_TEMP_LIMIT);
286 		regval = DIV_ROUND_CLOSEST(val * 10, 625) << TMP51X_TEMP_SHIFT;
287 		break;
288 	case TMP51X_N_FACTOR_AND_HYST_1:
289 		// 1lsb = 0.5 degrees centigrade
290 		val = clamp_val(val, 0, MAX_TEMP_HYST);
291 		regval = DIV_ROUND_CLOSEST(val, 500);
292 		mask = TMP51X_HYST_MASK;
293 		break;
294 	default:
295 		// Programmer goofed
296 		WARN_ON_ONCE(1);
297 		return -EOPNOTSUPP;
298 	}
299 
300 	if (mask == 0)
301 		return regmap_write(data->regmap, reg, regval);
302 	else
303 		return regmap_update_bits(data->regmap, reg, mask, regval);
304 }
305 
tmp51x_get_reg(enum hwmon_sensor_types type,u32 attr,int channel)306 static u8 tmp51x_get_reg(enum hwmon_sensor_types type, u32 attr, int channel)
307 {
308 	switch (type) {
309 	case hwmon_temp:
310 		switch (attr) {
311 		case hwmon_temp_input:
312 			return TMP51X_TEMP_INPUT[channel];
313 		case hwmon_temp_crit_alarm:
314 			return TMP51X_STATUS;
315 		case hwmon_temp_crit:
316 			return TMP51X_TEMP_CRIT[channel];
317 		case hwmon_temp_crit_hyst:
318 			return TMP51X_TEMP_CRIT_HYST[channel];
319 		}
320 		break;
321 	case hwmon_in:
322 		switch (attr) {
323 		case hwmon_in_input:
324 			return TMP51X_BUS_VOLTAGE_RESULT;
325 		case hwmon_in_lcrit_alarm:
326 		case hwmon_in_crit_alarm:
327 			return TMP51X_STATUS;
328 		case hwmon_in_lcrit:
329 			return TMP51X_BUS_VOLTAGE_L_LIMIT;
330 		case hwmon_in_crit:
331 			return TMP51X_BUS_VOLTAGE_H_LIMIT;
332 		}
333 		break;
334 	case hwmon_curr:
335 		switch (attr) {
336 		case hwmon_curr_input:
337 			return TMP51X_CURR_INPUT[channel];
338 		case hwmon_curr_lcrit_alarm:
339 		case hwmon_curr_crit_alarm:
340 			return TMP51X_STATUS;
341 		case hwmon_curr_lcrit:
342 			return TMP51X_SHUNT_CURRENT_L_LIMIT;
343 		case hwmon_curr_crit:
344 			return TMP51X_SHUNT_CURRENT_H_LIMIT;
345 		}
346 		break;
347 	case hwmon_power:
348 		switch (attr) {
349 		case hwmon_power_input:
350 			return TMP51X_POWER_RESULT;
351 		case hwmon_power_crit_alarm:
352 			return TMP51X_STATUS;
353 		case hwmon_power_crit:
354 			return TMP51X_POWER_LIMIT;
355 		}
356 		break;
357 	default:
358 		break;
359 	}
360 
361 	return 0;
362 }
363 
tmp51x_get_status_pos(enum hwmon_sensor_types type,u32 attr,int channel)364 static u8 tmp51x_get_status_pos(enum hwmon_sensor_types type, u32 attr,
365 				int channel)
366 {
367 	switch (type) {
368 	case hwmon_temp:
369 		switch (attr) {
370 		case hwmon_temp_crit_alarm:
371 			return TMP51X_TEMP_CRIT_ALARM[channel];
372 		}
373 		break;
374 	case hwmon_in:
375 		switch (attr) {
376 		case hwmon_in_lcrit_alarm:
377 			return TMP51X_BUS_VOLTAGE_L_LIMIT_POS;
378 		case hwmon_in_crit_alarm:
379 			return TMP51X_BUS_VOLTAGE_H_LIMIT_POS;
380 		}
381 		break;
382 	case hwmon_curr:
383 		switch (attr) {
384 		case hwmon_curr_lcrit_alarm:
385 			return TMP51X_SHUNT_CURRENT_L_LIMIT_POS;
386 		case hwmon_curr_crit_alarm:
387 			return TMP51X_SHUNT_CURRENT_H_LIMIT_POS;
388 		}
389 		break;
390 	case hwmon_power:
391 		switch (attr) {
392 		case hwmon_power_crit_alarm:
393 			return TMP51X_POWER_LIMIT_POS;
394 		}
395 		break;
396 	default:
397 		break;
398 	}
399 
400 	return 0;
401 }
402 
tmp51x_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)403 static int tmp51x_read(struct device *dev, enum hwmon_sensor_types type,
404 		       u32 attr, int channel, long *val)
405 {
406 	struct tmp51x_data *data = dev_get_drvdata(dev);
407 	int ret;
408 	u32 regval;
409 	u8 pos = 0, reg = 0;
410 
411 	reg = tmp51x_get_reg(type, attr, channel);
412 	if (reg == 0)
413 		return -EOPNOTSUPP;
414 
415 	if (reg == TMP51X_STATUS)
416 		pos = tmp51x_get_status_pos(type, attr, channel);
417 
418 	ret = regmap_read(data->regmap, reg, &regval);
419 	if (ret < 0)
420 		return ret;
421 
422 	return tmp51x_get_value(data, reg, pos, regval, val);
423 }
424 
tmp51x_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)425 static int tmp51x_write(struct device *dev, enum hwmon_sensor_types type,
426 			u32 attr, int channel, long val)
427 {
428 	u8 reg = 0;
429 
430 	reg = tmp51x_get_reg(type, attr, channel);
431 	if (reg == 0)
432 		return -EOPNOTSUPP;
433 
434 	return tmp51x_set_value(dev_get_drvdata(dev), reg, val);
435 }
436 
tmp51x_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)437 static umode_t tmp51x_is_visible(const void *_data,
438 				 enum hwmon_sensor_types type, u32 attr,
439 				 int channel)
440 {
441 	const struct tmp51x_data *data = _data;
442 
443 	switch (type) {
444 	case hwmon_temp:
445 		if (data->id == tmp512 && channel == 3)
446 			return 0;
447 		switch (attr) {
448 		case hwmon_temp_input:
449 		case hwmon_temp_crit_alarm:
450 			return 0444;
451 		case hwmon_temp_crit:
452 			return 0644;
453 		case hwmon_temp_crit_hyst:
454 			if (channel == 0)
455 				return 0644;
456 			return 0444;
457 		}
458 		break;
459 	case hwmon_in:
460 		switch (attr) {
461 		case hwmon_in_input:
462 		case hwmon_in_lcrit_alarm:
463 		case hwmon_in_crit_alarm:
464 			return 0444;
465 		case hwmon_in_lcrit:
466 		case hwmon_in_crit:
467 			return 0644;
468 		}
469 		break;
470 	case hwmon_curr:
471 		if (!data->shunt_uohms)
472 			return 0;
473 
474 		switch (attr) {
475 		case hwmon_curr_input:
476 		case hwmon_curr_lcrit_alarm:
477 		case hwmon_curr_crit_alarm:
478 			return 0444;
479 		case hwmon_curr_lcrit:
480 		case hwmon_curr_crit:
481 			return 0644;
482 		}
483 		break;
484 	case hwmon_power:
485 		if (!data->shunt_uohms)
486 			return 0;
487 
488 		switch (attr) {
489 		case hwmon_power_input:
490 		case hwmon_power_crit_alarm:
491 			return 0444;
492 		case hwmon_power_crit:
493 			return 0644;
494 		}
495 		break;
496 	default:
497 		break;
498 	}
499 	return 0;
500 }
501 
502 static const struct hwmon_channel_info * const tmp51x_info[] = {
503 	HWMON_CHANNEL_INFO(temp,
504 			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
505 			   HWMON_T_CRIT_HYST,
506 			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
507 			   HWMON_T_CRIT_HYST,
508 			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
509 			   HWMON_T_CRIT_HYST,
510 			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
511 			   HWMON_T_CRIT_HYST),
512 	HWMON_CHANNEL_INFO(in,
513 			   HWMON_I_INPUT | HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM |
514 			   HWMON_I_CRIT | HWMON_I_CRIT_ALARM),
515 	HWMON_CHANNEL_INFO(curr,
516 			   HWMON_C_INPUT | HWMON_C_LCRIT | HWMON_C_LCRIT_ALARM |
517 			   HWMON_C_CRIT | HWMON_C_CRIT_ALARM,
518 			   HWMON_C_INPUT),
519 	HWMON_CHANNEL_INFO(power,
520 			   HWMON_P_INPUT | HWMON_P_CRIT | HWMON_P_CRIT_ALARM),
521 	NULL
522 };
523 
524 static const struct hwmon_ops tmp51x_hwmon_ops = {
525 	.is_visible = tmp51x_is_visible,
526 	.read = tmp51x_read,
527 	.write = tmp51x_write,
528 };
529 
530 static const struct hwmon_chip_info tmp51x_chip_info = {
531 	.ops = &tmp51x_hwmon_ops,
532 	.info = tmp51x_info,
533 };
534 
535 /*
536  * Calibrate the tmp51x following the datasheet method
537  */
tmp51x_calibrate(struct tmp51x_data * data)538 static int tmp51x_calibrate(struct tmp51x_data *data)
539 {
540 	int vshunt_max = data->pga_gain * 40;
541 	u64 max_curr_ma;
542 	u32 div;
543 
544 	/*
545 	 * If shunt_uohms is equal to 0, the calibration should be set to 0.
546 	 * The consequence will be that the current and power measurement engine
547 	 * of the sensor will not work. Temperature and voltage sensing will
548 	 * continue to work.
549 	 */
550 	if (data->shunt_uohms == 0)
551 		return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION, 0);
552 
553 	max_curr_ma = DIV_ROUND_CLOSEST_ULL(vshunt_max * MICRO, data->shunt_uohms);
554 
555 	/*
556 	 * Calculate the minimal bit resolution for the current and the power.
557 	 * Those values will be used during register interpretation.
558 	 */
559 	data->curr_lsb_ua = DIV_ROUND_CLOSEST_ULL(max_curr_ma * MILLI, 32767);
560 	data->pwr_lsb_uw = 20 * data->curr_lsb_ua;
561 
562 	div = DIV_ROUND_CLOSEST_ULL(data->curr_lsb_ua * data->shunt_uohms, MICRO);
563 
564 	return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION,
565 			    DIV_ROUND_CLOSEST(40960, div));
566 }
567 
568 /*
569  * Initialize the configuration and calibration registers.
570  */
tmp51x_init(struct tmp51x_data * data)571 static int tmp51x_init(struct tmp51x_data *data)
572 {
573 	unsigned int regval;
574 	int ret = regmap_write(data->regmap, TMP51X_SHUNT_CONFIG,
575 			       data->shunt_config);
576 	if (ret < 0)
577 		return ret;
578 
579 	ret = regmap_write(data->regmap, TMP51X_TEMP_CONFIG, data->temp_config);
580 	if (ret < 0)
581 		return ret;
582 
583 	// nFactor configuration
584 	ret = regmap_update_bits(data->regmap, TMP51X_N_FACTOR_AND_HYST_1,
585 				 TMP51X_NFACTOR_MASK, data->nfactor[0] << 8);
586 	if (ret < 0)
587 		return ret;
588 
589 	ret = regmap_write(data->regmap, TMP51X_N_FACTOR_2,
590 			   data->nfactor[1] << 8);
591 	if (ret < 0)
592 		return ret;
593 
594 	if (data->id == tmp513) {
595 		ret = regmap_write(data->regmap, TMP513_N_FACTOR_3,
596 				   data->nfactor[2] << 8);
597 		if (ret < 0)
598 			return ret;
599 	}
600 
601 	ret = tmp51x_calibrate(data);
602 	if (ret < 0)
603 		return ret;
604 
605 	// Read the status register before using as the datasheet propose
606 	return regmap_read(data->regmap, TMP51X_STATUS, &regval);
607 }
608 
609 static const struct i2c_device_id tmp51x_id[] = {
610 	{ "tmp512", tmp512 },
611 	{ "tmp513", tmp513 },
612 	{ }
613 };
614 MODULE_DEVICE_TABLE(i2c, tmp51x_id);
615 
616 static const struct of_device_id tmp51x_of_match[] = {
617 	{
618 		.compatible = "ti,tmp512",
619 		.data = (void *)tmp512
620 	},
621 	{
622 		.compatible = "ti,tmp513",
623 		.data = (void *)tmp513
624 	},
625 	{ },
626 };
627 MODULE_DEVICE_TABLE(of, tmp51x_of_match);
628 
tmp51x_vbus_range_to_reg(struct device * dev,struct tmp51x_data * data)629 static int tmp51x_vbus_range_to_reg(struct device *dev,
630 				    struct tmp51x_data *data)
631 {
632 	if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) {
633 		data->shunt_config |= TMP51X_BUS_VOLTAGE_MASK;
634 	} else if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_16V) {
635 		data->shunt_config &= ~TMP51X_BUS_VOLTAGE_MASK;
636 	} else {
637 		return dev_err_probe(dev, -EINVAL,
638 				     "ti,bus-range-microvolt is invalid: %u\n",
639 				     data->vbus_range_uvolt);
640 	}
641 	return 0;
642 }
643 
tmp51x_pga_gain_to_reg(struct device * dev,struct tmp51x_data * data)644 static int tmp51x_pga_gain_to_reg(struct device *dev, struct tmp51x_data *data)
645 {
646 	if (data->pga_gain == 8) {
647 		data->shunt_config |= CURRENT_SENSE_VOLTAGE_320_MASK;
648 	} else if (data->pga_gain == 4) {
649 		data->shunt_config |= CURRENT_SENSE_VOLTAGE_160_MASK;
650 	} else if (data->pga_gain == 2) {
651 		data->shunt_config |= CURRENT_SENSE_VOLTAGE_80_MASK;
652 	} else if (data->pga_gain == 1) {
653 		data->shunt_config |= CURRENT_SENSE_VOLTAGE_40_MASK;
654 	} else {
655 		return dev_err_probe(dev, -EINVAL,
656 				     "ti,pga-gain is invalid: %u\n", data->pga_gain);
657 	}
658 	return 0;
659 }
660 
tmp51x_read_properties(struct device * dev,struct tmp51x_data * data)661 static int tmp51x_read_properties(struct device *dev, struct tmp51x_data *data)
662 {
663 	int ret;
664 	u32 nfactor[3];
665 	u32 val;
666 
667 	ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
668 	data->shunt_uohms = (ret >= 0) ? val : TMP51X_SHUNT_VALUE_DEFAULT;
669 
670 	ret = device_property_read_u32(dev, "ti,bus-range-microvolt", &val);
671 	data->vbus_range_uvolt = (ret >= 0) ? val : TMP51X_VBUS_RANGE_DEFAULT;
672 	ret = tmp51x_vbus_range_to_reg(dev, data);
673 	if (ret < 0)
674 		return ret;
675 
676 	ret = device_property_read_u32(dev, "ti,pga-gain", &val);
677 	data->pga_gain = (ret >= 0) ? val : TMP51X_PGA_DEFAULT;
678 	ret = tmp51x_pga_gain_to_reg(dev, data);
679 	if (ret < 0)
680 		return ret;
681 
682 	ret = device_property_read_u32_array(dev, "ti,nfactor", nfactor,
683 					    (data->id == tmp513) ? 3 : 2);
684 	if (ret >= 0)
685 		memcpy(data->nfactor, nfactor, (data->id == tmp513) ? 3 : 2);
686 
687 	// Check if shunt value is compatible with pga-gain
688 	if (data->shunt_uohms > data->pga_gain * 40 * MICRO) {
689 		return dev_err_probe(dev, -EINVAL,
690 				     "shunt-resistor: %u too big for pga_gain: %u\n",
691 				     data->shunt_uohms, data->pga_gain);
692 	}
693 
694 	return 0;
695 }
696 
tmp51x_use_default(struct tmp51x_data * data)697 static void tmp51x_use_default(struct tmp51x_data *data)
698 {
699 	data->vbus_range_uvolt = TMP51X_VBUS_RANGE_DEFAULT;
700 	data->pga_gain = TMP51X_PGA_DEFAULT;
701 	data->shunt_uohms = TMP51X_SHUNT_VALUE_DEFAULT;
702 }
703 
tmp51x_configure(struct device * dev,struct tmp51x_data * data)704 static int tmp51x_configure(struct device *dev, struct tmp51x_data *data)
705 {
706 	data->shunt_config = TMP51X_SHUNT_CONFIG_DEFAULT;
707 	data->temp_config = (data->id == tmp513) ?
708 			TMP513_TEMP_CONFIG_DEFAULT : TMP512_TEMP_CONFIG_DEFAULT;
709 
710 	if (dev->of_node)
711 		return tmp51x_read_properties(dev, data);
712 
713 	tmp51x_use_default(data);
714 
715 	return 0;
716 }
717 
tmp51x_probe(struct i2c_client * client)718 static int tmp51x_probe(struct i2c_client *client)
719 {
720 	struct device *dev = &client->dev;
721 	struct tmp51x_data *data;
722 	struct device *hwmon_dev;
723 	int ret;
724 
725 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
726 	if (!data)
727 		return -ENOMEM;
728 
729 	data->id = (uintptr_t)i2c_get_match_data(client);
730 
731 	ret = tmp51x_configure(dev, data);
732 	if (ret < 0)
733 		return dev_err_probe(dev, ret, "error configuring the device\n");
734 
735 	data->regmap = devm_regmap_init_i2c(client, &tmp51x_regmap_config);
736 	if (IS_ERR(data->regmap))
737 		return dev_err_probe(dev, PTR_ERR(data->regmap),
738 				     "failed to allocate register map\n");
739 
740 	ret = tmp51x_init(data);
741 	if (ret < 0)
742 		return dev_err_probe(dev, ret, "error configuring the device\n");
743 
744 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
745 							 data,
746 							 &tmp51x_chip_info,
747 							 NULL);
748 	if (IS_ERR(hwmon_dev))
749 		return PTR_ERR(hwmon_dev);
750 
751 	dev_dbg(dev, "power monitor %s\n", client->name);
752 
753 	return 0;
754 }
755 
756 static struct i2c_driver tmp51x_driver = {
757 	.driver = {
758 		.name	= "tmp51x",
759 		.of_match_table = tmp51x_of_match,
760 	},
761 	.probe		= tmp51x_probe,
762 	.id_table	= tmp51x_id,
763 };
764 
765 module_i2c_driver(tmp51x_driver);
766 
767 MODULE_AUTHOR("Eric Tremblay <etremblay@distechcontrols.com>");
768 MODULE_DESCRIPTION("tmp51x driver");
769 MODULE_LICENSE("GPL");
770