xref: /linux/drivers/hwmon/pmbus/mp2975.c (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers
4  *
5  * Copyright (C) 2020 Nvidia Technologies Ltd.
6  */
7 
8 #include <linux/err.h>
9 #include <linux/i2c.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/of_device.h>
14 #include "pmbus.h"
15 
16 /* Vendor specific registers. */
17 #define MP2975_MFR_APS_HYS_R2		0x0d
18 #define MP2975_MFR_SLOPE_TRIM3		0x1d
19 #define MP2975_MFR_VR_MULTI_CONFIG_R1	0x0d
20 #define MP2975_MFR_VR_MULTI_CONFIG_R2	0x1d
21 #define MP2975_MFR_APS_DECAY_ADV	0x56
22 #define MP2975_MFR_DC_LOOP_CTRL		0x59
23 #define MP2975_MFR_OCP_UCP_PHASE_SET	0x65
24 #define MP2975_MFR_VR_CONFIG1		0x68
25 #define MP2975_MFR_READ_CS1_2		0x82
26 #define MP2975_MFR_READ_CS3_4		0x83
27 #define MP2975_MFR_READ_CS5_6		0x84
28 #define MP2975_MFR_READ_CS7_8		0x85
29 #define MP2975_MFR_READ_CS9_10		0x86
30 #define MP2975_MFR_READ_CS11_12		0x87
31 #define MP2975_MFR_READ_IOUT_PK		0x90
32 #define MP2975_MFR_READ_POUT_PK		0x91
33 #define MP2975_MFR_READ_VREF_R1		0xa1
34 #define MP2975_MFR_READ_VREF_R2		0xa3
35 #define MP2975_MFR_OVP_TH_SET		0xe5
36 #define MP2975_MFR_UVP_SET		0xe6
37 
38 #define MP2973_MFR_RESO_SET		0xc7
39 
40 #define MP2975_VOUT_FORMAT		BIT(15)
41 #define MP2975_VID_STEP_SEL_R1		BIT(4)
42 #define MP2975_IMVP9_EN_R1		BIT(13)
43 #define MP2975_VID_STEP_SEL_R2		BIT(3)
44 #define MP2975_IMVP9_EN_R2		BIT(12)
45 #define MP2975_PRT_THRES_DIV_OV_EN	BIT(14)
46 #define MP2975_DRMOS_KCS		GENMASK(13, 12)
47 #define MP2975_PROT_DEV_OV_OFF		10
48 #define MP2975_PROT_DEV_OV_ON		5
49 #define MP2975_SENSE_AMPL		BIT(11)
50 #define MP2975_SENSE_AMPL_UNIT		1
51 #define MP2975_SENSE_AMPL_HALF		2
52 #define MP2975_VIN_UV_LIMIT_UNIT	8
53 
54 #define MP2973_VOUT_FORMAT_R1		GENMASK(7, 6)
55 #define MP2973_VOUT_FORMAT_R2		GENMASK(4, 3)
56 #define MP2973_VOUT_FORMAT_DIRECT_R1	BIT(7)
57 #define MP2973_VOUT_FORMAT_LINEAR_R1	BIT(6)
58 #define MP2973_VOUT_FORMAT_DIRECT_R2	BIT(4)
59 #define MP2973_VOUT_FORMAT_LINEAR_R2	BIT(3)
60 
61 #define MP2973_MFR_VR_MULTI_CONFIG_R1	0x0d
62 #define MP2973_MFR_VR_MULTI_CONFIG_R2	0x1d
63 #define MP2973_VID_STEP_SEL_R1		BIT(4)
64 #define MP2973_IMVP9_EN_R1		BIT(14)
65 #define MP2973_VID_STEP_SEL_R2		BIT(3)
66 #define MP2973_IMVP9_EN_R2		BIT(13)
67 
68 #define MP2973_MFR_OCP_TOTAL_SET	0x5f
69 #define MP2973_OCP_TOTAL_CUR_MASK	GENMASK(6, 0)
70 #define MP2973_MFR_OCP_LEVEL_RES	BIT(15)
71 
72 #define MP2973_MFR_READ_IOUT_PK		0x90
73 #define MP2973_MFR_READ_POUT_PK		0x91
74 
75 #define MP2975_MAX_PHASE_RAIL1	8
76 #define MP2975_MAX_PHASE_RAIL2	4
77 
78 #define MP2973_MAX_PHASE_RAIL1	14
79 #define MP2973_MAX_PHASE_RAIL2	6
80 
81 #define MP2971_MAX_PHASE_RAIL1	8
82 #define MP2971_MAX_PHASE_RAIL2	3
83 
84 #define MP2975_PAGE_NUM		2
85 
86 #define MP2975_RAIL2_FUNC	(PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
87 				 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | \
88 				 PMBUS_HAVE_POUT | PMBUS_PHASE_VIRTUAL)
89 
90 enum chips {
91 	mp2971, mp2973, mp2975
92 };
93 
94 static const int mp2975_max_phases[][MP2975_PAGE_NUM] = {
95 	[mp2975] = { MP2975_MAX_PHASE_RAIL1, MP2975_MAX_PHASE_RAIL2 },
96 	[mp2973] = { MP2973_MAX_PHASE_RAIL1, MP2973_MAX_PHASE_RAIL2 },
97 	[mp2971] = { MP2971_MAX_PHASE_RAIL1, MP2971_MAX_PHASE_RAIL2 },
98 };
99 
100 struct mp2975_data {
101 	struct pmbus_driver_info info;
102 	enum chips chip_id;
103 	int vout_scale;
104 	int max_phases[MP2975_PAGE_NUM];
105 	int vid_step[MP2975_PAGE_NUM];
106 	int vref[MP2975_PAGE_NUM];
107 	int vref_off[MP2975_PAGE_NUM];
108 	int vout_max[MP2975_PAGE_NUM];
109 	int vout_ov_fixed[MP2975_PAGE_NUM];
110 	int curr_sense_gain[MP2975_PAGE_NUM];
111 };
112 
113 static const struct i2c_device_id mp2975_id[] = {
114 	{"mp2971", mp2971},
115 	{"mp2973", mp2973},
116 	{"mp2975", mp2975},
117 	{}
118 };
119 
120 MODULE_DEVICE_TABLE(i2c, mp2975_id);
121 
122 static const struct regulator_desc __maybe_unused mp2975_reg_desc[] = {
123 	PMBUS_REGULATOR("vout", 0),
124 	PMBUS_REGULATOR("vout", 1),
125 };
126 
127 #define to_mp2975_data(x)  container_of(x, struct mp2975_data, info)
128 
129 static int mp2975_read_byte_data(struct i2c_client *client, int page, int reg)
130 {
131 	switch (reg) {
132 	case PMBUS_VOUT_MODE:
133 		/*
134 		 * Report direct format as configured by MFR_DC_LOOP_CTRL.
135 		 * Unlike on MP2971/MP2973 the reported VOUT_MODE isn't automatically
136 		 * internally updated, but always reads as PB_VOUT_MODE_VID.
137 		 */
138 		return PB_VOUT_MODE_DIRECT;
139 	default:
140 		return -ENODATA;
141 	}
142 }
143 
144 static int
145 mp2975_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg,
146 			u16 mask)
147 {
148 	int ret = pmbus_read_word_data(client, page, phase, reg);
149 
150 	return (ret > 0) ? ret & mask : ret;
151 }
152 
153 static int
154 mp2975_vid2direct(int vrf, int val)
155 {
156 	switch (vrf) {
157 	case vr12:
158 		if (val >= 0x01)
159 			return 250 + (val - 1) * 5;
160 		break;
161 	case vr13:
162 		if (val >= 0x01)
163 			return 500 + (val - 1) * 10;
164 		break;
165 	case imvp9:
166 		if (val >= 0x01)
167 			return 200 + (val - 1) * 10;
168 		break;
169 	default:
170 		return -EINVAL;
171 	}
172 	return 0;
173 }
174 
175 #define MAX_LIN_MANTISSA	(1023 * 1000)
176 #define MIN_LIN_MANTISSA	(511 * 1000)
177 
178 /* Converts a milli-unit DIRECT value to LINEAR11 format */
179 static u16 mp2975_data2reg_linear11(s64 val)
180 {
181 	s16 exponent = 0, mantissa;
182 	bool negative = false;
183 
184 	/* simple case */
185 	if (val == 0)
186 		return 0;
187 
188 	/* Reduce large mantissa until it fits into 10 bit */
189 	while (val >= MAX_LIN_MANTISSA && exponent < 15) {
190 		exponent++;
191 		val >>= 1;
192 	}
193 	/* Increase small mantissa to improve precision */
194 	while (val < MIN_LIN_MANTISSA && exponent > -15) {
195 		exponent--;
196 		val <<= 1;
197 	}
198 
199 	/* Convert mantissa from milli-units to units */
200 	mantissa = clamp_val(DIV_ROUND_CLOSEST_ULL(val, 1000), 0, 0x3ff);
201 
202 	/* restore sign */
203 	if (negative)
204 		mantissa = -mantissa;
205 
206 	/* Convert to 5 bit exponent, 11 bit mantissa */
207 	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
208 }
209 
210 static int
211 mp2975_read_phase(struct i2c_client *client, struct mp2975_data *data,
212 		  int page, int phase, u8 reg)
213 {
214 	int ph_curr, ret;
215 
216 	ret = pmbus_read_word_data(client, page, phase, reg);
217 	if (ret < 0)
218 		return ret;
219 
220 	if (!((phase + 1) % MP2975_PAGE_NUM))
221 		ret >>= 8;
222 	ret &= 0xff;
223 
224 	/*
225 	 * Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs)
226 	 * where:
227 	 * - Kcs is the DrMOS current sense gain of power stage, which is
228 	 *   obtained from the register MP2975_MFR_VR_CONFIG1, bits 13-12 with
229 	 *   the following selection of DrMOS (data->curr_sense_gain[page]):
230 	 *   00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A.
231 	 * - Rcs is the internal phase current sense resistor which is constant
232 	 *   value 1kΩ.
233 	 */
234 	ph_curr = ret * 100 - 9800;
235 
236 	/*
237 	 * Current phase sensing, providing by the device is not accurate
238 	 * for the light load. This because sampling of current occurrence of
239 	 * bit weight has a big deviation for light load. For handling such
240 	 * case phase current is represented as the maximum between the value
241 	 * calculated  above and total rail current divided by number phases.
242 	 */
243 	ret = pmbus_read_word_data(client, page, phase, PMBUS_READ_IOUT);
244 	if (ret < 0)
245 		return ret;
246 
247 	return max_t(int, DIV_ROUND_CLOSEST(ret, data->info.phases[page]),
248 		     DIV_ROUND_CLOSEST(ph_curr, data->curr_sense_gain[page]));
249 }
250 
251 static int
252 mp2975_read_phases(struct i2c_client *client, struct mp2975_data *data,
253 		   int page, int phase)
254 {
255 	int ret;
256 
257 	if (page) {
258 		switch (phase) {
259 		case 0 ... 1:
260 			ret = mp2975_read_phase(client, data, page, phase,
261 						MP2975_MFR_READ_CS7_8);
262 			break;
263 		case 2 ... 3:
264 			ret = mp2975_read_phase(client, data, page, phase,
265 						MP2975_MFR_READ_CS9_10);
266 			break;
267 		case 4 ... 5:
268 			ret = mp2975_read_phase(client, data, page, phase,
269 						MP2975_MFR_READ_CS11_12);
270 			break;
271 		default:
272 			return -ENODATA;
273 		}
274 	} else {
275 		switch (phase) {
276 		case 0 ... 1:
277 			ret = mp2975_read_phase(client, data, page, phase,
278 						MP2975_MFR_READ_CS1_2);
279 			break;
280 		case 2 ... 3:
281 			ret = mp2975_read_phase(client, data, page, phase,
282 						MP2975_MFR_READ_CS3_4);
283 			break;
284 		case 4 ... 5:
285 			ret = mp2975_read_phase(client, data, page, phase,
286 						MP2975_MFR_READ_CS5_6);
287 			break;
288 		case 6 ... 7:
289 			ret = mp2975_read_phase(client, data, page, phase,
290 						MP2975_MFR_READ_CS7_8);
291 			break;
292 		case 8 ... 9:
293 			ret = mp2975_read_phase(client, data, page, phase,
294 						MP2975_MFR_READ_CS9_10);
295 			break;
296 		case 10 ... 11:
297 			ret = mp2975_read_phase(client, data, page, phase,
298 						MP2975_MFR_READ_CS11_12);
299 			break;
300 		default:
301 			return -ENODATA;
302 		}
303 	}
304 	return ret;
305 }
306 
307 static int mp2973_read_word_data(struct i2c_client *client, int page,
308 				 int phase, int reg)
309 {
310 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
311 	struct mp2975_data *data = to_mp2975_data(info);
312 	int ret;
313 
314 	switch (reg) {
315 	case PMBUS_STATUS_WORD:
316 		/* MP2973 & MP2971 return PGOOD instead of PB_STATUS_POWER_GOOD_N. */
317 		ret = pmbus_read_word_data(client, page, phase, reg);
318 		ret ^= PB_STATUS_POWER_GOOD_N;
319 		break;
320 	case PMBUS_OT_FAULT_LIMIT:
321 		ret = mp2975_read_word_helper(client, page, phase, reg,
322 					      GENMASK(7, 0));
323 		break;
324 	case PMBUS_VIN_OV_FAULT_LIMIT:
325 		ret = mp2975_read_word_helper(client, page, phase, reg,
326 					      GENMASK(7, 0));
327 		if (ret < 0)
328 			return ret;
329 
330 		ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
331 		break;
332 	case PMBUS_VOUT_OV_FAULT_LIMIT:
333 		/*
334 		 * MP2971 and mp2973 only supports tracking (ovp1) mode.
335 		 */
336 		ret = mp2975_read_word_helper(client, page, phase,
337 					      MP2975_MFR_OVP_TH_SET,
338 					      GENMASK(2, 0));
339 		if (ret < 0)
340 			return ret;
341 
342 		ret = data->vout_max[page] + 50 * (ret + 1);
343 		break;
344 	case PMBUS_VOUT_UV_FAULT_LIMIT:
345 		ret = mp2975_read_word_helper(client, page, phase, reg,
346 					      GENMASK(8, 0));
347 		if (ret < 0)
348 			return ret;
349 		ret = mp2975_vid2direct(info->vrm_version[page], ret);
350 		break;
351 	case PMBUS_VIRT_READ_POUT_MAX:
352 		ret = pmbus_read_word_data(client, page, phase,
353 					   MP2973_MFR_READ_POUT_PK);
354 		break;
355 	case PMBUS_VIRT_READ_IOUT_MAX:
356 		ret = pmbus_read_word_data(client, page, phase,
357 					   MP2973_MFR_READ_IOUT_PK);
358 		break;
359 	case PMBUS_IOUT_OC_FAULT_LIMIT:
360 		ret = mp2975_read_word_helper(client, page, phase,
361 					      MP2973_MFR_OCP_TOTAL_SET,
362 					      GENMASK(15, 0));
363 		if (ret < 0)
364 			return ret;
365 
366 		if (ret & MP2973_MFR_OCP_LEVEL_RES)
367 			ret = 2 * (ret & MP2973_OCP_TOTAL_CUR_MASK);
368 		else
369 			ret = ret & MP2973_OCP_TOTAL_CUR_MASK;
370 
371 		ret = mp2975_data2reg_linear11(ret * info->phases[page] * 1000);
372 		break;
373 	case PMBUS_UT_WARN_LIMIT:
374 	case PMBUS_UT_FAULT_LIMIT:
375 	case PMBUS_VIN_UV_WARN_LIMIT:
376 	case PMBUS_VIN_UV_FAULT_LIMIT:
377 	case PMBUS_VOUT_UV_WARN_LIMIT:
378 	case PMBUS_VOUT_OV_WARN_LIMIT:
379 	case PMBUS_VIN_OV_WARN_LIMIT:
380 	case PMBUS_IIN_OC_FAULT_LIMIT:
381 	case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
382 	case PMBUS_IOUT_OC_WARN_LIMIT:
383 	case PMBUS_IOUT_UC_FAULT_LIMIT:
384 	case PMBUS_POUT_OP_FAULT_LIMIT:
385 	case PMBUS_POUT_OP_WARN_LIMIT:
386 	case PMBUS_PIN_OP_WARN_LIMIT:
387 		return -ENXIO;
388 	default:
389 		return -ENODATA;
390 	}
391 
392 	return ret;
393 }
394 
395 static int mp2975_read_word_data(struct i2c_client *client, int page,
396 				 int phase, int reg)
397 {
398 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
399 	struct mp2975_data *data = to_mp2975_data(info);
400 	int ret;
401 
402 	switch (reg) {
403 	case PMBUS_OT_FAULT_LIMIT:
404 		ret = mp2975_read_word_helper(client, page, phase, reg,
405 					      GENMASK(7, 0));
406 		break;
407 	case PMBUS_VIN_OV_FAULT_LIMIT:
408 		ret = mp2975_read_word_helper(client, page, phase, reg,
409 					      GENMASK(7, 0));
410 		if (ret < 0)
411 			return ret;
412 
413 		ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
414 		break;
415 	case PMBUS_VOUT_OV_FAULT_LIMIT:
416 		/*
417 		 * Register provides two values for over-voltage protection
418 		 * threshold for fixed (ovp2) and tracking (ovp1) modes. The
419 		 * minimum of these two values is provided as over-voltage
420 		 * fault alarm.
421 		 */
422 		ret = mp2975_read_word_helper(client, page, phase,
423 					      MP2975_MFR_OVP_TH_SET,
424 					      GENMASK(2, 0));
425 		if (ret < 0)
426 			return ret;
427 
428 		ret = min_t(int, data->vout_max[page] + 50 * (ret + 1),
429 			    data->vout_ov_fixed[page]);
430 		break;
431 	case PMBUS_VOUT_UV_FAULT_LIMIT:
432 		ret = mp2975_read_word_helper(client, page, phase,
433 					      MP2975_MFR_UVP_SET,
434 					      GENMASK(2, 0));
435 		if (ret < 0)
436 			return ret;
437 
438 		ret = DIV_ROUND_CLOSEST(data->vref[page] * 10 - 50 *
439 					(ret + 1) * data->vout_scale, 10);
440 		break;
441 	case PMBUS_VIRT_READ_POUT_MAX:
442 		ret = mp2975_read_word_helper(client, page, phase,
443 					      MP2975_MFR_READ_POUT_PK,
444 					      GENMASK(12, 0));
445 		if (ret < 0)
446 			return ret;
447 
448 		ret = DIV_ROUND_CLOSEST(ret, 4);
449 		break;
450 	case PMBUS_VIRT_READ_IOUT_MAX:
451 		ret = mp2975_read_word_helper(client, page, phase,
452 					      MP2975_MFR_READ_IOUT_PK,
453 					      GENMASK(12, 0));
454 		if (ret < 0)
455 			return ret;
456 
457 		ret = DIV_ROUND_CLOSEST(ret, 4);
458 		break;
459 	case PMBUS_READ_IOUT:
460 		ret = mp2975_read_phases(client, data, page, phase);
461 		if (ret < 0)
462 			return ret;
463 
464 		break;
465 	case PMBUS_UT_WARN_LIMIT:
466 	case PMBUS_UT_FAULT_LIMIT:
467 	case PMBUS_VIN_UV_WARN_LIMIT:
468 	case PMBUS_VIN_UV_FAULT_LIMIT:
469 	case PMBUS_VOUT_UV_WARN_LIMIT:
470 	case PMBUS_VOUT_OV_WARN_LIMIT:
471 	case PMBUS_VIN_OV_WARN_LIMIT:
472 	case PMBUS_IIN_OC_FAULT_LIMIT:
473 	case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
474 	case PMBUS_IIN_OC_WARN_LIMIT:
475 	case PMBUS_IOUT_OC_WARN_LIMIT:
476 	case PMBUS_IOUT_OC_FAULT_LIMIT:
477 	case PMBUS_IOUT_UC_FAULT_LIMIT:
478 	case PMBUS_POUT_OP_FAULT_LIMIT:
479 	case PMBUS_POUT_OP_WARN_LIMIT:
480 	case PMBUS_PIN_OP_WARN_LIMIT:
481 		return -ENXIO;
482 	default:
483 		return -ENODATA;
484 	}
485 
486 	return ret;
487 }
488 
489 static int mp2975_identify_multiphase_rail2(struct i2c_client *client,
490 					    struct mp2975_data *data)
491 {
492 	int ret;
493 
494 	/*
495 	 * Identify multiphase for rail 2 - could be from 0 to data->max_phases[1].
496 	 * In case phase number is zero – only page zero is supported
497 	 */
498 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
499 	if (ret < 0)
500 		return ret;
501 
502 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R2);
503 	if (ret < 0)
504 		return ret;
505 
506 	ret &= GENMASK(2, 0);
507 	return (ret >= data->max_phases[1]) ? data->max_phases[1] : ret;
508 }
509 
510 static void mp2975_set_phase_rail1(struct pmbus_driver_info *info)
511 {
512 	int i;
513 
514 	for (i = 0 ; i < info->phases[0]; i++)
515 		info->pfunc[i] = PMBUS_HAVE_IOUT;
516 }
517 
518 static void
519 mp2975_set_phase_rail2(struct pmbus_driver_info *info, int num_phases)
520 {
521 	int i;
522 
523 	/* Set phases for rail 2 from upper to lower. */
524 	for (i = 1; i <= num_phases; i++)
525 		info->pfunc[MP2975_MAX_PHASE_RAIL1 - i] = PMBUS_HAVE_IOUT;
526 }
527 
528 static int
529 mp2975_identify_multiphase(struct i2c_client *client, struct mp2975_data *data,
530 			   struct pmbus_driver_info *info)
531 {
532 	int num_phases2, ret;
533 
534 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
535 	if (ret < 0)
536 		return ret;
537 
538 	/* Identify multiphase for rail 1 - could be from 1 to data->max_phases[0]. */
539 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R1);
540 	if (ret <= 0)
541 		return ret;
542 
543 	info->phases[0] = ret & GENMASK(3, 0);
544 
545 	/*
546 	 * The device provides a total of $n PWM pins, and can be configured
547 	 * to different phase count applications for rail 1 and rail 2.
548 	 * Rail 1 can be set to $n phases, while rail 2 can be set to less than
549 	 * that. When rail 1’s phase count is configured as 0, rail
550 	 * 1 operates with 1-phase DCM. When rail 2 phase count is configured
551 	 * as 0, rail 2 is disabled.
552 	 */
553 	if (info->phases[0] > data->max_phases[0])
554 		return -EINVAL;
555 
556 	if (data->chip_id == mp2975) {
557 		mp2975_set_phase_rail1(info);
558 		num_phases2 = min(data->max_phases[0] - info->phases[0],
559 				  data->max_phases[1]);
560 		if (info->phases[1] && info->phases[1] <= num_phases2)
561 			mp2975_set_phase_rail2(info, num_phases2);
562 	}
563 
564 	return 0;
565 }
566 
567 static int
568 mp2975_identify_vid(struct i2c_client *client, struct mp2975_data *data,
569 		    struct pmbus_driver_info *info, u32 reg, int page,
570 		    u32 imvp_bit, u32 vr_bit)
571 {
572 	int ret;
573 
574 	/* Identify VID mode and step selection. */
575 	ret = i2c_smbus_read_word_data(client, reg);
576 	if (ret < 0)
577 		return ret;
578 
579 	if (ret & imvp_bit) {
580 		info->vrm_version[page] = imvp9;
581 		data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
582 	} else if (ret & vr_bit) {
583 		info->vrm_version[page] = vr12;
584 		data->vid_step[page] = MP2975_PROT_DEV_OV_ON;
585 	} else {
586 		info->vrm_version[page] = vr13;
587 		data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
588 	}
589 
590 	return 0;
591 }
592 
593 static int
594 mp2975_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
595 			  struct pmbus_driver_info *info)
596 {
597 	int ret;
598 
599 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
600 	if (ret < 0)
601 		return ret;
602 
603 	/* Identify VID mode for rail 1. */
604 	ret = mp2975_identify_vid(client, data, info,
605 				  MP2975_MFR_VR_MULTI_CONFIG_R1, 0,
606 				  MP2975_IMVP9_EN_R1, MP2975_VID_STEP_SEL_R1);
607 	if (ret < 0)
608 		return ret;
609 
610 	/* Identify VID mode for rail 2, if connected. */
611 	if (info->phases[1])
612 		ret = mp2975_identify_vid(client, data, info,
613 					  MP2975_MFR_VR_MULTI_CONFIG_R2, 1,
614 					  MP2975_IMVP9_EN_R2,
615 					  MP2975_VID_STEP_SEL_R2);
616 
617 	return ret;
618 }
619 
620 static int
621 mp2973_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
622 			  struct pmbus_driver_info *info)
623 {
624 	int ret;
625 
626 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
627 	if (ret < 0)
628 		return ret;
629 
630 	/* Identify VID mode for rail 1. */
631 	ret = mp2975_identify_vid(client, data, info,
632 				  MP2973_MFR_VR_MULTI_CONFIG_R1, 0,
633 				  MP2973_IMVP9_EN_R1, MP2973_VID_STEP_SEL_R1);
634 
635 	if (ret < 0)
636 		return ret;
637 
638 	/* Identify VID mode for rail 2, if connected. */
639 	if (info->phases[1])
640 		ret = mp2975_identify_vid(client, data, info,
641 					  MP2973_MFR_VR_MULTI_CONFIG_R2, 1,
642 					  MP2973_IMVP9_EN_R2,
643 					  MP2973_VID_STEP_SEL_R2);
644 
645 	return ret;
646 }
647 
648 static int
649 mp2975_current_sense_gain_get(struct i2c_client *client,
650 			      struct mp2975_data *data)
651 {
652 	int i, ret;
653 
654 	/*
655 	 * Obtain DrMOS current sense gain of power stage from the register
656 	 * MP2975_MFR_VR_CONFIG1, bits 13-12. The value is selected as below:
657 	 * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other
658 	 * values are invalid.
659 	 */
660 	for (i = 0 ; i < data->info.pages; i++) {
661 		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
662 		if (ret < 0)
663 			return ret;
664 		ret = i2c_smbus_read_word_data(client,
665 					       MP2975_MFR_VR_CONFIG1);
666 		if (ret < 0)
667 			return ret;
668 
669 		switch ((ret & MP2975_DRMOS_KCS) >> 12) {
670 		case 0:
671 			data->curr_sense_gain[i] = 50;
672 			break;
673 		case 1:
674 			data->curr_sense_gain[i] = 85;
675 			break;
676 		case 2:
677 			data->curr_sense_gain[i] = 97;
678 			break;
679 		default:
680 			data->curr_sense_gain[i] = 100;
681 			break;
682 		}
683 	}
684 
685 	return 0;
686 }
687 
688 static int
689 mp2975_vref_get(struct i2c_client *client, struct mp2975_data *data,
690 		struct pmbus_driver_info *info)
691 {
692 	int ret;
693 
694 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 3);
695 	if (ret < 0)
696 		return ret;
697 
698 	/* Get voltage reference value for rail 1. */
699 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R1);
700 	if (ret < 0)
701 		return ret;
702 
703 	data->vref[0] = ret * data->vid_step[0];
704 
705 	/* Get voltage reference value for rail 2, if connected. */
706 	if (data->info.pages == MP2975_PAGE_NUM) {
707 		ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R2);
708 		if (ret < 0)
709 			return ret;
710 
711 		data->vref[1] = ret * data->vid_step[1];
712 	}
713 	return 0;
714 }
715 
716 static int
717 mp2975_vref_offset_get(struct i2c_client *client, struct mp2975_data *data,
718 		       int page)
719 {
720 	int ret;
721 
722 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_OVP_TH_SET);
723 	if (ret < 0)
724 		return ret;
725 
726 	switch ((ret & GENMASK(5, 3)) >> 3) {
727 	case 1:
728 		data->vref_off[page] = 140;
729 		break;
730 	case 2:
731 		data->vref_off[page] = 220;
732 		break;
733 	case 4:
734 		data->vref_off[page] = 400;
735 		break;
736 	default:
737 		return -EINVAL;
738 	}
739 	return 0;
740 }
741 
742 static int
743 mp2975_vout_max_get(struct i2c_client *client, struct mp2975_data *data,
744 		    struct pmbus_driver_info *info, int page)
745 {
746 	int ret;
747 
748 	/* Get maximum reference voltage of VID-DAC in VID format. */
749 	ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_MAX);
750 	if (ret < 0)
751 		return ret;
752 
753 	data->vout_max[page] = mp2975_vid2direct(info->vrm_version[page], ret &
754 						 GENMASK(8, 0));
755 	return 0;
756 }
757 
758 static int
759 mp2975_set_vout_format(struct i2c_client *client,
760 		       struct mp2975_data *data, int page)
761 {
762 	int ret, i;
763 
764 	/* Enable DIRECT VOUT format 1mV/LSB */
765 	if (data->chip_id == mp2975) {
766 		ret = i2c_smbus_read_word_data(client, MP2975_MFR_DC_LOOP_CTRL);
767 		if (ret < 0)
768 			return ret;
769 		if (ret & MP2975_VOUT_FORMAT) {
770 			ret &= ~MP2975_VOUT_FORMAT;
771 			ret = i2c_smbus_write_word_data(client, MP2975_MFR_DC_LOOP_CTRL, ret);
772 		}
773 	} else {
774 		ret = i2c_smbus_read_word_data(client, MP2973_MFR_RESO_SET);
775 		if (ret < 0)
776 			return ret;
777 		i = ret;
778 
779 		if (page == 0) {
780 			i &= ~MP2973_VOUT_FORMAT_R1;
781 			i |= MP2973_VOUT_FORMAT_DIRECT_R1;
782 		} else {
783 			i &= ~MP2973_VOUT_FORMAT_R2;
784 			i |= MP2973_VOUT_FORMAT_DIRECT_R2;
785 		}
786 		if (i != ret)
787 			ret = i2c_smbus_write_word_data(client, MP2973_MFR_RESO_SET, i);
788 	}
789 	return ret;
790 }
791 
792 static int
793 mp2975_vout_ov_scale_get(struct i2c_client *client, struct mp2975_data *data,
794 			 struct pmbus_driver_info *info)
795 {
796 	int thres_dev, sense_ampl, ret;
797 
798 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
799 	if (ret < 0)
800 		return ret;
801 
802 	/*
803 	 * Get divider for over- and under-voltage protection thresholds
804 	 * configuration from the Advanced Options of Auto Phase Shedding and
805 	 * decay register.
806 	 */
807 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_APS_DECAY_ADV);
808 	if (ret < 0)
809 		return ret;
810 	thres_dev = ret & MP2975_PRT_THRES_DIV_OV_EN ? MP2975_PROT_DEV_OV_ON :
811 						       MP2975_PROT_DEV_OV_OFF;
812 
813 	/* Select the gain of remote sense amplifier. */
814 	ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_SCALE_LOOP);
815 	if (ret < 0)
816 		return ret;
817 	sense_ampl = ret & MP2975_SENSE_AMPL ? MP2975_SENSE_AMPL_HALF :
818 					       MP2975_SENSE_AMPL_UNIT;
819 
820 	data->vout_scale = sense_ampl * thres_dev;
821 
822 	return 0;
823 }
824 
825 static int
826 mp2975_vout_per_rail_config_get(struct i2c_client *client,
827 				struct mp2975_data *data,
828 				struct pmbus_driver_info *info)
829 {
830 	int i, ret;
831 
832 	for (i = 0; i < data->info.pages; i++) {
833 		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
834 		if (ret < 0)
835 			continue;
836 
837 		/* Set VOUT format for READ_VOUT command : direct. */
838 		ret = mp2975_set_vout_format(client, data, i);
839 		if (ret < 0)
840 			return ret;
841 
842 		/* Obtain maximum voltage values. */
843 		ret = mp2975_vout_max_get(client, data, info, i);
844 		if (ret < 0)
845 			return ret;
846 
847 		/* Skip if reading Vref is unsupported */
848 		if (data->chip_id != mp2975)
849 			continue;
850 
851 		/* Obtain voltage reference offsets. */
852 		ret = mp2975_vref_offset_get(client, data, i);
853 		if (ret < 0)
854 			return ret;
855 
856 		/*
857 		 * Set over-voltage fixed value. Thresholds are provided as
858 		 * fixed value, and tracking value. The minimum of them are
859 		 * exposed as over-voltage critical threshold.
860 		 */
861 		data->vout_ov_fixed[i] = data->vref[i] +
862 					 DIV_ROUND_CLOSEST(data->vref_off[i] *
863 							   data->vout_scale,
864 							   10);
865 	}
866 
867 	return 0;
868 }
869 
870 static struct pmbus_driver_info mp2975_info = {
871 	.pages = 1,
872 	.format[PSC_VOLTAGE_IN] = linear,
873 	.format[PSC_VOLTAGE_OUT] = direct,
874 	.format[PSC_TEMPERATURE] = direct,
875 	.format[PSC_CURRENT_IN] = linear,
876 	.format[PSC_CURRENT_OUT] = direct,
877 	.format[PSC_POWER] = direct,
878 	.m[PSC_TEMPERATURE] = 1,
879 	.m[PSC_VOLTAGE_OUT] = 1,
880 	.R[PSC_VOLTAGE_OUT] = 3,
881 	.m[PSC_CURRENT_OUT] = 1,
882 	.m[PSC_POWER] = 1,
883 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
884 		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
885 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
886 		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_PHASE_VIRTUAL,
887 	.read_byte_data = mp2975_read_byte_data,
888 	.read_word_data = mp2975_read_word_data,
889 #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR)
890 	.num_regulators = 1,
891 	.reg_desc = mp2975_reg_desc,
892 #endif
893 };
894 
895 static struct pmbus_driver_info mp2973_info = {
896 	.pages = 1,
897 	.format[PSC_VOLTAGE_IN] = linear,
898 	.format[PSC_VOLTAGE_OUT] = direct,
899 	.format[PSC_TEMPERATURE] = linear,
900 	.format[PSC_CURRENT_IN] = linear,
901 	.format[PSC_CURRENT_OUT] = linear,
902 	.format[PSC_POWER] = linear,
903 	.m[PSC_VOLTAGE_OUT] = 1,
904 	.R[PSC_VOLTAGE_OUT] = 3,
905 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
906 		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
907 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
908 		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
909 	.read_word_data = mp2973_read_word_data,
910 #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR)
911 	.num_regulators = 1,
912 	.reg_desc = mp2975_reg_desc,
913 #endif
914 };
915 
916 static int mp2975_probe(struct i2c_client *client)
917 {
918 	struct pmbus_driver_info *info;
919 	struct mp2975_data *data;
920 	int ret;
921 
922 	data = devm_kzalloc(&client->dev, sizeof(struct mp2975_data),
923 			    GFP_KERNEL);
924 	if (!data)
925 		return -ENOMEM;
926 
927 	if (client->dev.of_node)
928 		data->chip_id = (enum chips)(unsigned long)of_device_get_match_data(&client->dev);
929 	else
930 		data->chip_id = i2c_match_id(mp2975_id, client)->driver_data;
931 
932 	memcpy(data->max_phases, mp2975_max_phases[data->chip_id],
933 	       sizeof(data->max_phases));
934 
935 	if (data->chip_id == mp2975)
936 		memcpy(&data->info, &mp2975_info, sizeof(*info));
937 	else
938 		memcpy(&data->info, &mp2973_info, sizeof(*info));
939 
940 	info = &data->info;
941 
942 	/* Identify multiphase configuration for rail 2. */
943 	ret = mp2975_identify_multiphase_rail2(client, data);
944 	if (ret < 0)
945 		return ret;
946 
947 	if (ret) {
948 		/* Two rails are connected. */
949 		data->info.pages = MP2975_PAGE_NUM;
950 		data->info.phases[1] = ret;
951 		data->info.func[1] = MP2975_RAIL2_FUNC;
952 		if (IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR))
953 			data->info.num_regulators = MP2975_PAGE_NUM;
954 	}
955 
956 	/* Identify multiphase configuration. */
957 	ret = mp2975_identify_multiphase(client, data, info);
958 	if (ret)
959 		return ret;
960 
961 	if (data->chip_id == mp2975) {
962 		/* Identify VID setting per rail. */
963 		ret = mp2975_identify_rails_vid(client, data, info);
964 		if (ret < 0)
965 			return ret;
966 
967 		/* Obtain current sense gain of power stage. */
968 		ret = mp2975_current_sense_gain_get(client, data);
969 		if (ret)
970 			return ret;
971 
972 		/* Obtain voltage reference values. */
973 		ret = mp2975_vref_get(client, data, info);
974 		if (ret)
975 			return ret;
976 
977 		/* Obtain vout over-voltage scales. */
978 		ret = mp2975_vout_ov_scale_get(client, data, info);
979 		if (ret < 0)
980 			return ret;
981 	} else {
982 		/* Identify VID setting per rail. */
983 		ret = mp2973_identify_rails_vid(client, data, info);
984 		if (ret < 0)
985 			return ret;
986 	}
987 
988 	/* Obtain offsets, maximum and format for vout. */
989 	ret = mp2975_vout_per_rail_config_get(client, data, info);
990 	if (ret)
991 		return ret;
992 
993 	return pmbus_do_probe(client, info);
994 }
995 
996 static const struct of_device_id __maybe_unused mp2975_of_match[] = {
997 	{.compatible = "mps,mp2971", .data = (void *)mp2971},
998 	{.compatible = "mps,mp2973", .data = (void *)mp2973},
999 	{.compatible = "mps,mp2975", .data = (void *)mp2975},
1000 	{}
1001 };
1002 MODULE_DEVICE_TABLE(of, mp2975_of_match);
1003 
1004 static struct i2c_driver mp2975_driver = {
1005 	.driver = {
1006 		.name = "mp2975",
1007 		.of_match_table = of_match_ptr(mp2975_of_match),
1008 	},
1009 	.probe = mp2975_probe,
1010 	.id_table = mp2975_id,
1011 };
1012 
1013 module_i2c_driver(mp2975_driver);
1014 
1015 MODULE_AUTHOR("Vadim Pasternak <vadimp@nvidia.com>");
1016 MODULE_DESCRIPTION("PMBus driver for MPS MP2975 device");
1017 MODULE_LICENSE("GPL");
1018 MODULE_IMPORT_NS(PMBUS);
1019