xref: /linux/drivers/hwmon/pmbus/mp2975.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
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/bitops.h>
9 #include <linux/err.h>
10 #include <linux/i2c.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/module.h>
15 
16 #include "pmbus.h"
17 
18 /* Vendor specific registers. */
19 #define MP2975_MFR_APS_HYS_R2		0x0d
20 #define MP2975_MFR_SLOPE_TRIM3		0x1d
21 #define MP2975_MFR_VR_MULTI_CONFIG_R1	0x0d
22 #define MP2975_MFR_VR_MULTI_CONFIG_R2	0x1d
23 #define MP2975_MFR_APS_DECAY_ADV	0x56
24 #define MP2975_MFR_DC_LOOP_CTRL		0x59
25 #define MP2975_MFR_OCP_UCP_PHASE_SET	0x65
26 #define MP2975_MFR_VR_CONFIG1		0x68
27 #define MP2975_MFR_READ_CS1_2		0x82
28 #define MP2975_MFR_READ_CS3_4		0x83
29 #define MP2975_MFR_READ_CS5_6		0x84
30 #define MP2975_MFR_READ_CS7_8		0x85
31 #define MP2975_MFR_READ_CS9_10		0x86
32 #define MP2975_MFR_READ_CS11_12		0x87
33 #define MP2975_MFR_READ_IOUT_PK		0x90
34 #define MP2975_MFR_READ_POUT_PK		0x91
35 #define MP2975_MFR_READ_VREF_R1		0xa1
36 #define MP2975_MFR_READ_VREF_R2		0xa3
37 #define MP2975_MFR_OVP_TH_SET		0xe5
38 #define MP2975_MFR_UVP_SET		0xe6
39 
40 #define MP2973_MFR_RESO_SET		0xc7
41 
42 #define MP2975_VOUT_FORMAT		BIT(15)
43 #define MP2975_VID_STEP_SEL_R1		BIT(4)
44 #define MP2975_IMVP9_EN_R1		BIT(13)
45 #define MP2975_VID_STEP_SEL_R2		BIT(3)
46 #define MP2975_IMVP9_EN_R2		BIT(12)
47 #define MP2975_PRT_THRES_DIV_OV_EN	BIT(14)
48 #define MP2975_DRMOS_KCS		GENMASK(13, 12)
49 #define MP2975_PROT_DEV_OV_OFF		10
50 #define MP2975_PROT_DEV_OV_ON		5
51 #define MP2975_SENSE_AMPL		BIT(11)
52 #define MP2975_SENSE_AMPL_UNIT		1
53 #define MP2975_SENSE_AMPL_HALF		2
54 #define MP2975_VIN_UV_LIMIT_UNIT	8
55 
56 #define MP2973_VOUT_FORMAT_R1		GENMASK(7, 6)
57 #define MP2973_VOUT_FORMAT_R2		GENMASK(4, 3)
58 #define MP2973_VOUT_FORMAT_DIRECT_R1	BIT(7)
59 #define MP2973_VOUT_FORMAT_LINEAR_R1	BIT(6)
60 #define MP2973_VOUT_FORMAT_DIRECT_R2	BIT(4)
61 #define MP2973_VOUT_FORMAT_LINEAR_R2	BIT(3)
62 
63 #define MP2973_MFR_VR_MULTI_CONFIG_R1	0x0d
64 #define MP2973_MFR_VR_MULTI_CONFIG_R2	0x1d
65 #define MP2973_VID_STEP_SEL_R1		BIT(4)
66 #define MP2973_IMVP9_EN_R1		BIT(14)
67 #define MP2973_VID_STEP_SEL_R2		BIT(3)
68 #define MP2973_IMVP9_EN_R2		BIT(13)
69 
70 #define MP2973_MFR_OCP_TOTAL_SET	0x5f
71 #define MP2973_OCP_TOTAL_CUR_MASK	GENMASK(6, 0)
72 #define MP2973_MFR_OCP_LEVEL_RES	BIT(15)
73 
74 #define MP2973_MFR_READ_IOUT_PK		0x90
75 #define MP2973_MFR_READ_POUT_PK		0x91
76 
77 #define MP2975_MAX_PHASE_RAIL1	8
78 #define MP2975_MAX_PHASE_RAIL2	4
79 
80 #define MP2973_MAX_PHASE_RAIL1	14
81 #define MP2973_MAX_PHASE_RAIL2	6
82 
83 #define MP2971_MAX_PHASE_RAIL1	8
84 #define MP2971_MAX_PHASE_RAIL2	3
85 
86 #define MP2975_PAGE_NUM		2
87 
88 #define MP2975_RAIL2_FUNC	(PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
89 				 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | \
90 				 PMBUS_HAVE_POUT | PMBUS_PHASE_VIRTUAL)
91 
92 enum chips {
93 	mp2971, mp2973, mp2975
94 };
95 
96 static const int mp2975_max_phases[][MP2975_PAGE_NUM] = {
97 	[mp2975] = { MP2975_MAX_PHASE_RAIL1, MP2975_MAX_PHASE_RAIL2 },
98 	[mp2973] = { MP2973_MAX_PHASE_RAIL1, MP2973_MAX_PHASE_RAIL2 },
99 	[mp2971] = { MP2971_MAX_PHASE_RAIL1, MP2971_MAX_PHASE_RAIL2 },
100 };
101 
102 struct mp2975_driver_info {
103 	const struct pmbus_driver_info *info;
104 	enum chips chip_id;
105 };
106 
107 struct mp2975_data {
108 	struct pmbus_driver_info info;
109 	enum chips chip_id;
110 	int vout_scale;
111 	int max_phases[MP2975_PAGE_NUM];
112 	int vid_step[MP2975_PAGE_NUM];
113 	int vref[MP2975_PAGE_NUM];
114 	int vref_off[MP2975_PAGE_NUM];
115 	int vout_max[MP2975_PAGE_NUM];
116 	int vout_ov_fixed[MP2975_PAGE_NUM];
117 	int curr_sense_gain[MP2975_PAGE_NUM];
118 };
119 
120 static const struct regulator_desc __maybe_unused mp2975_reg_desc[] = {
121 	PMBUS_REGULATOR("vout", 0),
122 	PMBUS_REGULATOR("vout", 1),
123 };
124 
125 #define to_mp2975_data(x)  container_of(x, struct mp2975_data, info)
126 
127 static int mp2975_read_byte_data(struct i2c_client *client, int page, int reg)
128 {
129 	switch (reg) {
130 	case PMBUS_VOUT_MODE:
131 		/*
132 		 * Report direct format as configured by MFR_DC_LOOP_CTRL.
133 		 * Unlike on MP2971/MP2973 the reported VOUT_MODE isn't automatically
134 		 * internally updated, but always reads as PB_VOUT_MODE_VID.
135 		 */
136 		return PB_VOUT_MODE_DIRECT;
137 	default:
138 		return -ENODATA;
139 	}
140 }
141 
142 static int
143 mp2975_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg,
144 			u16 mask)
145 {
146 	int ret = pmbus_read_word_data(client, page, phase, reg);
147 
148 	return (ret > 0) ? ret & mask : ret;
149 }
150 
151 static int
152 mp2975_vid2direct(int vrf, int val)
153 {
154 	switch (vrf) {
155 	case vr12:
156 		if (val >= 0x01)
157 			return 250 + (val - 1) * 5;
158 		break;
159 	case vr13:
160 		if (val >= 0x01)
161 			return 500 + (val - 1) * 10;
162 		break;
163 	case imvp9:
164 		if (val >= 0x01)
165 			return 200 + (val - 1) * 10;
166 		break;
167 	default:
168 		return -EINVAL;
169 	}
170 	return 0;
171 }
172 
173 #define MAX_LIN_MANTISSA	(1023 * 1000)
174 #define MIN_LIN_MANTISSA	(511 * 1000)
175 
176 /* Converts a milli-unit DIRECT value to LINEAR11 format */
177 static u16 mp2975_data2reg_linear11(s64 val)
178 {
179 	s16 exponent = 0, mantissa;
180 	bool negative = false;
181 
182 	/* simple case */
183 	if (val == 0)
184 		return 0;
185 
186 	/* Reduce large mantissa until it fits into 10 bit */
187 	while (val >= MAX_LIN_MANTISSA && exponent < 15) {
188 		exponent++;
189 		val >>= 1;
190 	}
191 	/* Increase small mantissa to improve precision */
192 	while (val < MIN_LIN_MANTISSA && exponent > -15) {
193 		exponent--;
194 		val <<= 1;
195 	}
196 
197 	/* Convert mantissa from milli-units to units */
198 	mantissa = clamp_val(DIV_ROUND_CLOSEST_ULL(val, 1000), 0, 0x3ff);
199 
200 	/* restore sign */
201 	if (negative)
202 		mantissa = -mantissa;
203 
204 	/* Convert to 5 bit exponent, 11 bit mantissa */
205 	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
206 }
207 
208 static int
209 mp2975_read_phase(struct i2c_client *client, struct mp2975_data *data,
210 		  int page, int phase, u8 reg)
211 {
212 	int ph_curr, ret;
213 
214 	ret = pmbus_read_word_data(client, page, phase, reg);
215 	if (ret < 0)
216 		return ret;
217 
218 	if (!((phase + 1) % MP2975_PAGE_NUM))
219 		ret >>= 8;
220 	ret &= 0xff;
221 
222 	/*
223 	 * Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs)
224 	 * where:
225 	 * - Kcs is the DrMOS current sense gain of power stage, which is
226 	 *   obtained from the register MP2975_MFR_VR_CONFIG1, bits 13-12 with
227 	 *   the following selection of DrMOS (data->curr_sense_gain[page]):
228 	 *   00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A.
229 	 * - Rcs is the internal phase current sense resistor which is constant
230 	 *   value 1kΩ.
231 	 */
232 	ph_curr = ret * 100 - 9800;
233 
234 	/*
235 	 * Current phase sensing, providing by the device is not accurate
236 	 * for the light load. This because sampling of current occurrence of
237 	 * bit weight has a big deviation for light load. For handling such
238 	 * case phase current is represented as the maximum between the value
239 	 * calculated  above and total rail current divided by number phases.
240 	 */
241 	ret = pmbus_read_word_data(client, page, phase, PMBUS_READ_IOUT);
242 	if (ret < 0)
243 		return ret;
244 
245 	return max_t(int, DIV_ROUND_CLOSEST(ret, data->info.phases[page]),
246 		     DIV_ROUND_CLOSEST(ph_curr, data->curr_sense_gain[page]));
247 }
248 
249 static int
250 mp2975_read_phases(struct i2c_client *client, struct mp2975_data *data,
251 		   int page, int phase)
252 {
253 	int ret;
254 
255 	if (page) {
256 		switch (phase) {
257 		case 0 ... 1:
258 			ret = mp2975_read_phase(client, data, page, phase,
259 						MP2975_MFR_READ_CS7_8);
260 			break;
261 		case 2 ... 3:
262 			ret = mp2975_read_phase(client, data, page, phase,
263 						MP2975_MFR_READ_CS9_10);
264 			break;
265 		case 4 ... 5:
266 			ret = mp2975_read_phase(client, data, page, phase,
267 						MP2975_MFR_READ_CS11_12);
268 			break;
269 		default:
270 			return -ENODATA;
271 		}
272 	} else {
273 		switch (phase) {
274 		case 0 ... 1:
275 			ret = mp2975_read_phase(client, data, page, phase,
276 						MP2975_MFR_READ_CS1_2);
277 			break;
278 		case 2 ... 3:
279 			ret = mp2975_read_phase(client, data, page, phase,
280 						MP2975_MFR_READ_CS3_4);
281 			break;
282 		case 4 ... 5:
283 			ret = mp2975_read_phase(client, data, page, phase,
284 						MP2975_MFR_READ_CS5_6);
285 			break;
286 		case 6 ... 7:
287 			ret = mp2975_read_phase(client, data, page, phase,
288 						MP2975_MFR_READ_CS7_8);
289 			break;
290 		case 8 ... 9:
291 			ret = mp2975_read_phase(client, data, page, phase,
292 						MP2975_MFR_READ_CS9_10);
293 			break;
294 		case 10 ... 11:
295 			ret = mp2975_read_phase(client, data, page, phase,
296 						MP2975_MFR_READ_CS11_12);
297 			break;
298 		default:
299 			return -ENODATA;
300 		}
301 	}
302 	return ret;
303 }
304 
305 static int mp2973_read_word_data(struct i2c_client *client, int page,
306 				 int phase, int reg)
307 {
308 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
309 	struct mp2975_data *data = to_mp2975_data(info);
310 	int ret;
311 
312 	switch (reg) {
313 	case PMBUS_STATUS_WORD:
314 		/* MP2973 & MP2971 return PGOOD instead of PB_STATUS_POWER_GOOD_N. */
315 		ret = pmbus_read_word_data(client, page, phase, reg);
316 		ret ^= PB_STATUS_POWER_GOOD_N;
317 		break;
318 	case PMBUS_OT_FAULT_LIMIT:
319 		ret = mp2975_read_word_helper(client, page, phase, reg,
320 					      GENMASK(7, 0));
321 		break;
322 	case PMBUS_VIN_OV_FAULT_LIMIT:
323 		ret = mp2975_read_word_helper(client, page, phase, reg,
324 					      GENMASK(7, 0));
325 		if (ret < 0)
326 			return ret;
327 
328 		ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
329 		break;
330 	case PMBUS_VOUT_OV_FAULT_LIMIT:
331 		/*
332 		 * MP2971 and mp2973 only supports tracking (ovp1) mode.
333 		 */
334 		ret = mp2975_read_word_helper(client, page, phase,
335 					      MP2975_MFR_OVP_TH_SET,
336 					      GENMASK(2, 0));
337 		if (ret < 0)
338 			return ret;
339 
340 		ret = data->vout_max[page] + 50 * (ret + 1);
341 		break;
342 	case PMBUS_VOUT_UV_FAULT_LIMIT:
343 		ret = mp2975_read_word_helper(client, page, phase, reg,
344 					      GENMASK(8, 0));
345 		if (ret < 0)
346 			return ret;
347 		ret = mp2975_vid2direct(info->vrm_version[page], ret);
348 		break;
349 	case PMBUS_VIRT_READ_POUT_MAX:
350 		ret = pmbus_read_word_data(client, page, phase,
351 					   MP2973_MFR_READ_POUT_PK);
352 		break;
353 	case PMBUS_VIRT_READ_IOUT_MAX:
354 		ret = pmbus_read_word_data(client, page, phase,
355 					   MP2973_MFR_READ_IOUT_PK);
356 		break;
357 	case PMBUS_IOUT_OC_FAULT_LIMIT:
358 		ret = mp2975_read_word_helper(client, page, phase,
359 					      MP2973_MFR_OCP_TOTAL_SET,
360 					      GENMASK(15, 0));
361 		if (ret < 0)
362 			return ret;
363 
364 		if (ret & MP2973_MFR_OCP_LEVEL_RES)
365 			ret = 2 * (ret & MP2973_OCP_TOTAL_CUR_MASK);
366 		else
367 			ret = ret & MP2973_OCP_TOTAL_CUR_MASK;
368 
369 		ret = mp2975_data2reg_linear11(ret * info->phases[page] * 1000);
370 		break;
371 	case PMBUS_UT_WARN_LIMIT:
372 	case PMBUS_UT_FAULT_LIMIT:
373 	case PMBUS_VIN_UV_WARN_LIMIT:
374 	case PMBUS_VIN_UV_FAULT_LIMIT:
375 	case PMBUS_VOUT_UV_WARN_LIMIT:
376 	case PMBUS_VOUT_OV_WARN_LIMIT:
377 	case PMBUS_VIN_OV_WARN_LIMIT:
378 	case PMBUS_IIN_OC_FAULT_LIMIT:
379 	case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
380 	case PMBUS_IOUT_OC_WARN_LIMIT:
381 	case PMBUS_IOUT_UC_FAULT_LIMIT:
382 	case PMBUS_POUT_OP_FAULT_LIMIT:
383 	case PMBUS_POUT_OP_WARN_LIMIT:
384 	case PMBUS_PIN_OP_WARN_LIMIT:
385 		return -ENXIO;
386 	default:
387 		return -ENODATA;
388 	}
389 
390 	return ret;
391 }
392 
393 static int mp2973_write_word_data(struct i2c_client *client, int page,
394 				  int reg, u16 word)
395 {
396 	u8 target, mask;
397 	long ret;
398 
399 	if (reg != PMBUS_SMBALERT_MASK)
400 		return -ENODATA;
401 
402 	/*
403 	 * Vendor-specific SMBALERT_MASK register with 16 maskable bits.
404 	 */
405 	ret = pmbus_read_word_data(client, 0, 0, PMBUS_SMBALERT_MASK);
406 	if (ret < 0)
407 		return ret;
408 
409 	target = word & 0xff;
410 	mask = word >> 8;
411 
412 /*
413  * Set/Clear 'bit' in 'ret' based on condition followed by define for each bit in SMBALERT_MASK.
414  * Also bit 2 & 15 are reserved.
415  */
416 
417 #define MP2973_TEMP_OT		0
418 #define MP2973_VIN_UVLO		1
419 #define MP2973_VIN_OVP		3
420 #define MP2973_MTP_FAULT	4
421 #define MP2973_OTHER_COMM	5
422 #define MP2973_MTP_BLK_TRIG	6
423 #define MP2973_PACKET_ERROR	7
424 #define MP2973_INVALID_DATA	8
425 #define MP2973_INVALID_COMMAND	9
426 #define MP2973_IOUT_OC_LV	10
427 #define MP2973_IOUT_OC		11
428 #define MP2973_VOUT_MAX_MIN_WARNING 12
429 #define MP2973_VOLTAGE_UV	13
430 #define MP2973_VOLTAGE_OV	14
431 
432 	switch (target) {
433 	case PMBUS_STATUS_CML:
434 		__assign_bit(MP2973_INVALID_DATA, &ret, !(mask & PB_CML_FAULT_INVALID_DATA));
435 		__assign_bit(MP2973_INVALID_COMMAND, &ret, !(mask & PB_CML_FAULT_INVALID_COMMAND));
436 		__assign_bit(MP2973_OTHER_COMM, &ret, !(mask & PB_CML_FAULT_OTHER_COMM));
437 		__assign_bit(MP2973_PACKET_ERROR, &ret, !(mask & PB_CML_FAULT_PACKET_ERROR));
438 		break;
439 	case PMBUS_STATUS_VOUT:
440 		__assign_bit(MP2973_VOLTAGE_UV, &ret, !(mask & PB_VOLTAGE_UV_FAULT));
441 		__assign_bit(MP2973_VOLTAGE_OV, &ret, !(mask & PB_VOLTAGE_OV_FAULT));
442 		break;
443 	case PMBUS_STATUS_IOUT:
444 		__assign_bit(MP2973_IOUT_OC, &ret, !(mask & PB_IOUT_OC_FAULT));
445 		__assign_bit(MP2973_IOUT_OC_LV, &ret, !(mask & PB_IOUT_OC_LV_FAULT));
446 		break;
447 	case PMBUS_STATUS_TEMPERATURE:
448 		__assign_bit(MP2973_TEMP_OT, &ret, !(mask & PB_TEMP_OT_FAULT));
449 		break;
450 	/*
451 	 * Map remaining bits to MFR specific to let the PMBUS core mask
452 	 * those bits by default.
453 	 */
454 	case PMBUS_STATUS_MFR_SPECIFIC:
455 		__assign_bit(MP2973_VIN_UVLO, &ret, !(mask & BIT(1)));
456 		__assign_bit(MP2973_VIN_OVP, &ret, !(mask & BIT(3)));
457 		__assign_bit(MP2973_MTP_FAULT, &ret, !(mask & BIT(4)));
458 		__assign_bit(MP2973_MTP_BLK_TRIG, &ret, !(mask & BIT(6)));
459 		break;
460 	default:
461 		return 0;
462 	}
463 
464 	return pmbus_write_word_data(client, 0, PMBUS_SMBALERT_MASK, ret);
465 }
466 
467 static int mp2975_read_word_data(struct i2c_client *client, int page,
468 				 int phase, int reg)
469 {
470 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
471 	struct mp2975_data *data = to_mp2975_data(info);
472 	int ret;
473 
474 	switch (reg) {
475 	case PMBUS_OT_FAULT_LIMIT:
476 		ret = mp2975_read_word_helper(client, page, phase, reg,
477 					      GENMASK(7, 0));
478 		break;
479 	case PMBUS_VIN_OV_FAULT_LIMIT:
480 		ret = mp2975_read_word_helper(client, page, phase, reg,
481 					      GENMASK(7, 0));
482 		if (ret < 0)
483 			return ret;
484 
485 		ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
486 		break;
487 	case PMBUS_VOUT_OV_FAULT_LIMIT:
488 		/*
489 		 * Register provides two values for over-voltage protection
490 		 * threshold for fixed (ovp2) and tracking (ovp1) modes. The
491 		 * minimum of these two values is provided as over-voltage
492 		 * fault alarm.
493 		 */
494 		ret = mp2975_read_word_helper(client, page, phase,
495 					      MP2975_MFR_OVP_TH_SET,
496 					      GENMASK(2, 0));
497 		if (ret < 0)
498 			return ret;
499 
500 		ret = min_t(int, data->vout_max[page] + 50 * (ret + 1),
501 			    data->vout_ov_fixed[page]);
502 		break;
503 	case PMBUS_VOUT_UV_FAULT_LIMIT:
504 		ret = mp2975_read_word_helper(client, page, phase,
505 					      MP2975_MFR_UVP_SET,
506 					      GENMASK(2, 0));
507 		if (ret < 0)
508 			return ret;
509 
510 		ret = DIV_ROUND_CLOSEST(data->vref[page] * 10 - 50 *
511 					(ret + 1) * data->vout_scale, 10);
512 		break;
513 	case PMBUS_VIRT_READ_POUT_MAX:
514 		ret = mp2975_read_word_helper(client, page, phase,
515 					      MP2975_MFR_READ_POUT_PK,
516 					      GENMASK(12, 0));
517 		if (ret < 0)
518 			return ret;
519 
520 		ret = DIV_ROUND_CLOSEST(ret, 4);
521 		break;
522 	case PMBUS_VIRT_READ_IOUT_MAX:
523 		ret = mp2975_read_word_helper(client, page, phase,
524 					      MP2975_MFR_READ_IOUT_PK,
525 					      GENMASK(12, 0));
526 		if (ret < 0)
527 			return ret;
528 
529 		ret = DIV_ROUND_CLOSEST(ret, 4);
530 		break;
531 	case PMBUS_READ_IOUT:
532 		ret = mp2975_read_phases(client, data, page, phase);
533 		if (ret < 0)
534 			return ret;
535 
536 		break;
537 	case PMBUS_UT_WARN_LIMIT:
538 	case PMBUS_UT_FAULT_LIMIT:
539 	case PMBUS_VIN_UV_WARN_LIMIT:
540 	case PMBUS_VIN_UV_FAULT_LIMIT:
541 	case PMBUS_VOUT_UV_WARN_LIMIT:
542 	case PMBUS_VOUT_OV_WARN_LIMIT:
543 	case PMBUS_VIN_OV_WARN_LIMIT:
544 	case PMBUS_IIN_OC_FAULT_LIMIT:
545 	case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
546 	case PMBUS_IIN_OC_WARN_LIMIT:
547 	case PMBUS_IOUT_OC_WARN_LIMIT:
548 	case PMBUS_IOUT_OC_FAULT_LIMIT:
549 	case PMBUS_IOUT_UC_FAULT_LIMIT:
550 	case PMBUS_POUT_OP_FAULT_LIMIT:
551 	case PMBUS_POUT_OP_WARN_LIMIT:
552 	case PMBUS_PIN_OP_WARN_LIMIT:
553 		return -ENXIO;
554 	default:
555 		return -ENODATA;
556 	}
557 
558 	return ret;
559 }
560 
561 static int mp2975_identify_multiphase_rail2(struct i2c_client *client,
562 					    struct mp2975_data *data)
563 {
564 	int ret;
565 
566 	/*
567 	 * Identify multiphase for rail 2 - could be from 0 to data->max_phases[1].
568 	 * In case phase number is zero – only page zero is supported
569 	 */
570 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
571 	if (ret < 0)
572 		return ret;
573 
574 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R2);
575 	if (ret < 0)
576 		return ret;
577 
578 	ret &= GENMASK(2, 0);
579 	return (ret >= data->max_phases[1]) ? data->max_phases[1] : ret;
580 }
581 
582 static void mp2975_set_phase_rail1(struct pmbus_driver_info *info)
583 {
584 	int i;
585 
586 	for (i = 0 ; i < info->phases[0]; i++)
587 		info->pfunc[i] = PMBUS_HAVE_IOUT;
588 }
589 
590 static void
591 mp2975_set_phase_rail2(struct pmbus_driver_info *info, int num_phases)
592 {
593 	int i;
594 
595 	/* Set phases for rail 2 from upper to lower. */
596 	for (i = 1; i <= num_phases; i++)
597 		info->pfunc[MP2975_MAX_PHASE_RAIL1 - i] = PMBUS_HAVE_IOUT;
598 }
599 
600 static int
601 mp2975_identify_multiphase(struct i2c_client *client, struct mp2975_data *data,
602 			   struct pmbus_driver_info *info)
603 {
604 	int num_phases2, ret;
605 
606 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
607 	if (ret < 0)
608 		return ret;
609 
610 	/* Identify multiphase for rail 1 - could be from 1 to data->max_phases[0]. */
611 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R1);
612 	if (ret <= 0)
613 		return ret;
614 
615 	info->phases[0] = ret & GENMASK(3, 0);
616 
617 	/*
618 	 * The device provides a total of $n PWM pins, and can be configured
619 	 * to different phase count applications for rail 1 and rail 2.
620 	 * Rail 1 can be set to $n phases, while rail 2 can be set to less than
621 	 * that. When rail 1’s phase count is configured as 0, rail
622 	 * 1 operates with 1-phase DCM. When rail 2 phase count is configured
623 	 * as 0, rail 2 is disabled.
624 	 */
625 	if (info->phases[0] > data->max_phases[0])
626 		return -EINVAL;
627 
628 	if (data->chip_id == mp2975) {
629 		mp2975_set_phase_rail1(info);
630 		num_phases2 = min(data->max_phases[0] - info->phases[0],
631 				  data->max_phases[1]);
632 		if (info->phases[1] && info->phases[1] <= num_phases2)
633 			mp2975_set_phase_rail2(info, num_phases2);
634 	}
635 
636 	return 0;
637 }
638 
639 static int
640 mp2975_identify_vid(struct i2c_client *client, struct mp2975_data *data,
641 		    struct pmbus_driver_info *info, u32 reg, int page,
642 		    u32 imvp_bit, u32 vr_bit)
643 {
644 	int ret;
645 
646 	/* Identify VID mode and step selection. */
647 	ret = i2c_smbus_read_word_data(client, reg);
648 	if (ret < 0)
649 		return ret;
650 
651 	if (ret & imvp_bit) {
652 		info->vrm_version[page] = imvp9;
653 		data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
654 	} else if (ret & vr_bit) {
655 		info->vrm_version[page] = vr12;
656 		data->vid_step[page] = MP2975_PROT_DEV_OV_ON;
657 	} else {
658 		info->vrm_version[page] = vr13;
659 		data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
660 	}
661 
662 	return 0;
663 }
664 
665 static int
666 mp2975_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
667 			  struct pmbus_driver_info *info)
668 {
669 	int ret;
670 
671 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
672 	if (ret < 0)
673 		return ret;
674 
675 	/* Identify VID mode for rail 1. */
676 	ret = mp2975_identify_vid(client, data, info,
677 				  MP2975_MFR_VR_MULTI_CONFIG_R1, 0,
678 				  MP2975_IMVP9_EN_R1, MP2975_VID_STEP_SEL_R1);
679 	if (ret < 0)
680 		return ret;
681 
682 	/* Identify VID mode for rail 2, if connected. */
683 	if (info->phases[1])
684 		ret = mp2975_identify_vid(client, data, info,
685 					  MP2975_MFR_VR_MULTI_CONFIG_R2, 1,
686 					  MP2975_IMVP9_EN_R2,
687 					  MP2975_VID_STEP_SEL_R2);
688 
689 	return ret;
690 }
691 
692 static int
693 mp2973_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
694 			  struct pmbus_driver_info *info)
695 {
696 	int ret;
697 
698 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
699 	if (ret < 0)
700 		return ret;
701 
702 	/* Identify VID mode for rail 1. */
703 	ret = mp2975_identify_vid(client, data, info,
704 				  MP2973_MFR_VR_MULTI_CONFIG_R1, 0,
705 				  MP2973_IMVP9_EN_R1, MP2973_VID_STEP_SEL_R1);
706 
707 	if (ret < 0)
708 		return ret;
709 
710 	/* Identify VID mode for rail 2, if connected. */
711 	if (info->phases[1])
712 		ret = mp2975_identify_vid(client, data, info,
713 					  MP2973_MFR_VR_MULTI_CONFIG_R2, 1,
714 					  MP2973_IMVP9_EN_R2,
715 					  MP2973_VID_STEP_SEL_R2);
716 
717 	return ret;
718 }
719 
720 static int
721 mp2975_current_sense_gain_get(struct i2c_client *client,
722 			      struct mp2975_data *data)
723 {
724 	int i, ret;
725 
726 	/*
727 	 * Obtain DrMOS current sense gain of power stage from the register
728 	 * MP2975_MFR_VR_CONFIG1, bits 13-12. The value is selected as below:
729 	 * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other
730 	 * values are invalid.
731 	 */
732 	for (i = 0 ; i < data->info.pages; i++) {
733 		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
734 		if (ret < 0)
735 			return ret;
736 		ret = i2c_smbus_read_word_data(client,
737 					       MP2975_MFR_VR_CONFIG1);
738 		if (ret < 0)
739 			return ret;
740 
741 		switch ((ret & MP2975_DRMOS_KCS) >> 12) {
742 		case 0:
743 			data->curr_sense_gain[i] = 50;
744 			break;
745 		case 1:
746 			data->curr_sense_gain[i] = 85;
747 			break;
748 		case 2:
749 			data->curr_sense_gain[i] = 97;
750 			break;
751 		default:
752 			data->curr_sense_gain[i] = 100;
753 			break;
754 		}
755 	}
756 
757 	return 0;
758 }
759 
760 static int
761 mp2975_vref_get(struct i2c_client *client, struct mp2975_data *data,
762 		struct pmbus_driver_info *info)
763 {
764 	int ret;
765 
766 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 3);
767 	if (ret < 0)
768 		return ret;
769 
770 	/* Get voltage reference value for rail 1. */
771 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R1);
772 	if (ret < 0)
773 		return ret;
774 
775 	data->vref[0] = ret * data->vid_step[0];
776 
777 	/* Get voltage reference value for rail 2, if connected. */
778 	if (data->info.pages == MP2975_PAGE_NUM) {
779 		ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R2);
780 		if (ret < 0)
781 			return ret;
782 
783 		data->vref[1] = ret * data->vid_step[1];
784 	}
785 	return 0;
786 }
787 
788 static int
789 mp2975_vref_offset_get(struct i2c_client *client, struct mp2975_data *data,
790 		       int page)
791 {
792 	int ret;
793 
794 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_OVP_TH_SET);
795 	if (ret < 0)
796 		return ret;
797 
798 	switch ((ret & GENMASK(5, 3)) >> 3) {
799 	case 1:
800 		data->vref_off[page] = 140;
801 		break;
802 	case 2:
803 		data->vref_off[page] = 220;
804 		break;
805 	case 4:
806 		data->vref_off[page] = 400;
807 		break;
808 	default:
809 		return -EINVAL;
810 	}
811 	return 0;
812 }
813 
814 static int
815 mp2975_vout_max_get(struct i2c_client *client, struct mp2975_data *data,
816 		    struct pmbus_driver_info *info, int page)
817 {
818 	int ret;
819 
820 	/* Get maximum reference voltage of VID-DAC in VID format. */
821 	ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_MAX);
822 	if (ret < 0)
823 		return ret;
824 
825 	data->vout_max[page] = mp2975_vid2direct(info->vrm_version[page], ret &
826 						 GENMASK(8, 0));
827 	return 0;
828 }
829 
830 static int
831 mp2975_set_vout_format(struct i2c_client *client,
832 		       struct mp2975_data *data, int page)
833 {
834 	int ret, i;
835 
836 	/* Enable DIRECT VOUT format 1mV/LSB */
837 	if (data->chip_id == mp2975) {
838 		ret = i2c_smbus_read_word_data(client, MP2975_MFR_DC_LOOP_CTRL);
839 		if (ret < 0)
840 			return ret;
841 		if (ret & MP2975_VOUT_FORMAT) {
842 			ret &= ~MP2975_VOUT_FORMAT;
843 			ret = i2c_smbus_write_word_data(client, MP2975_MFR_DC_LOOP_CTRL, ret);
844 		}
845 	} else {
846 		ret = i2c_smbus_read_word_data(client, MP2973_MFR_RESO_SET);
847 		if (ret < 0)
848 			return ret;
849 		i = ret;
850 
851 		if (page == 0) {
852 			i &= ~MP2973_VOUT_FORMAT_R1;
853 			i |= MP2973_VOUT_FORMAT_DIRECT_R1;
854 		} else {
855 			i &= ~MP2973_VOUT_FORMAT_R2;
856 			i |= MP2973_VOUT_FORMAT_DIRECT_R2;
857 		}
858 		if (i != ret)
859 			ret = i2c_smbus_write_word_data(client, MP2973_MFR_RESO_SET, i);
860 	}
861 	return ret;
862 }
863 
864 static int
865 mp2975_vout_ov_scale_get(struct i2c_client *client, struct mp2975_data *data,
866 			 struct pmbus_driver_info *info)
867 {
868 	int thres_dev, sense_ampl, ret;
869 
870 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
871 	if (ret < 0)
872 		return ret;
873 
874 	/*
875 	 * Get divider for over- and under-voltage protection thresholds
876 	 * configuration from the Advanced Options of Auto Phase Shedding and
877 	 * decay register.
878 	 */
879 	ret = i2c_smbus_read_word_data(client, MP2975_MFR_APS_DECAY_ADV);
880 	if (ret < 0)
881 		return ret;
882 	thres_dev = ret & MP2975_PRT_THRES_DIV_OV_EN ? MP2975_PROT_DEV_OV_ON :
883 						       MP2975_PROT_DEV_OV_OFF;
884 
885 	/* Select the gain of remote sense amplifier. */
886 	ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_SCALE_LOOP);
887 	if (ret < 0)
888 		return ret;
889 	sense_ampl = ret & MP2975_SENSE_AMPL ? MP2975_SENSE_AMPL_HALF :
890 					       MP2975_SENSE_AMPL_UNIT;
891 
892 	data->vout_scale = sense_ampl * thres_dev;
893 
894 	return 0;
895 }
896 
897 static int
898 mp2975_vout_per_rail_config_get(struct i2c_client *client,
899 				struct mp2975_data *data,
900 				struct pmbus_driver_info *info)
901 {
902 	int i, ret;
903 
904 	for (i = 0; i < data->info.pages; i++) {
905 		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
906 		if (ret < 0)
907 			continue;
908 
909 		/* Set VOUT format for READ_VOUT command : direct. */
910 		ret = mp2975_set_vout_format(client, data, i);
911 		if (ret < 0)
912 			return ret;
913 
914 		/* Obtain maximum voltage values. */
915 		ret = mp2975_vout_max_get(client, data, info, i);
916 		if (ret < 0)
917 			return ret;
918 
919 		/* Skip if reading Vref is unsupported */
920 		if (data->chip_id != mp2975)
921 			continue;
922 
923 		/* Obtain voltage reference offsets. */
924 		ret = mp2975_vref_offset_get(client, data, i);
925 		if (ret < 0)
926 			return ret;
927 
928 		/*
929 		 * Set over-voltage fixed value. Thresholds are provided as
930 		 * fixed value, and tracking value. The minimum of them are
931 		 * exposed as over-voltage critical threshold.
932 		 */
933 		data->vout_ov_fixed[i] = data->vref[i] +
934 					 DIV_ROUND_CLOSEST(data->vref_off[i] *
935 							   data->vout_scale,
936 							   10);
937 	}
938 
939 	return 0;
940 }
941 
942 static const struct pmbus_driver_info mp2975_info = {
943 	.pages = 1,
944 	.format[PSC_VOLTAGE_IN] = linear,
945 	.format[PSC_VOLTAGE_OUT] = direct,
946 	.format[PSC_TEMPERATURE] = direct,
947 	.format[PSC_CURRENT_IN] = linear,
948 	.format[PSC_CURRENT_OUT] = direct,
949 	.format[PSC_POWER] = direct,
950 	.m[PSC_TEMPERATURE] = 1,
951 	.m[PSC_VOLTAGE_OUT] = 1,
952 	.R[PSC_VOLTAGE_OUT] = 3,
953 	.m[PSC_CURRENT_OUT] = 1,
954 	.m[PSC_POWER] = 1,
955 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
956 		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
957 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
958 		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_PHASE_VIRTUAL,
959 	.read_byte_data = mp2975_read_byte_data,
960 	.read_word_data = mp2975_read_word_data,
961 #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR)
962 	.num_regulators = 1,
963 	.reg_desc = mp2975_reg_desc,
964 #endif
965 };
966 
967 static const struct pmbus_driver_info mp2973_info = {
968 	.pages = 1,
969 	.format[PSC_VOLTAGE_IN] = linear,
970 	.format[PSC_VOLTAGE_OUT] = direct,
971 	.format[PSC_TEMPERATURE] = linear,
972 	.format[PSC_CURRENT_IN] = linear,
973 	.format[PSC_CURRENT_OUT] = linear,
974 	.format[PSC_POWER] = linear,
975 	.m[PSC_VOLTAGE_OUT] = 1,
976 	.R[PSC_VOLTAGE_OUT] = 3,
977 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
978 		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
979 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
980 		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
981 	.read_word_data = mp2973_read_word_data,
982 	.write_word_data = mp2973_write_word_data,
983 #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR)
984 	.num_regulators = 1,
985 	.reg_desc = mp2975_reg_desc,
986 #endif
987 };
988 
989 static const struct mp2975_driver_info mp2975_ddinfo[] = {
990 	[mp2975] = { .info = &mp2975_info, .chip_id = mp2975 },
991 	[mp2973] = { .info = &mp2973_info, .chip_id = mp2973 },
992 	[mp2971] = { .info = &mp2973_info, .chip_id = mp2971 },
993 };
994 
995 static int mp2975_probe(struct i2c_client *client)
996 {
997 	const struct mp2975_driver_info *ddinfo;
998 	struct pmbus_driver_info *info;
999 	struct mp2975_data *data;
1000 	int ret;
1001 
1002 	ddinfo = i2c_get_match_data(client);
1003 	if (!ddinfo)
1004 		return -ENODEV;
1005 
1006 	data = devm_kzalloc(&client->dev, sizeof(struct mp2975_data),
1007 			    GFP_KERNEL);
1008 	if (!data)
1009 		return -ENOMEM;
1010 
1011 	data->chip_id = ddinfo->chip_id;
1012 
1013 	memcpy(data->max_phases, mp2975_max_phases[data->chip_id],
1014 	       sizeof(data->max_phases));
1015 
1016 	memcpy(&data->info, ddinfo->info, sizeof(data->info));
1017 
1018 	info = &data->info;
1019 
1020 	/* Identify multiphase configuration for rail 2. */
1021 	ret = mp2975_identify_multiphase_rail2(client, data);
1022 	if (ret < 0)
1023 		return ret;
1024 
1025 	if (ret) {
1026 		/* Two rails are connected. */
1027 		data->info.pages = MP2975_PAGE_NUM;
1028 		data->info.phases[1] = ret;
1029 		data->info.func[1] = MP2975_RAIL2_FUNC;
1030 		if (IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR))
1031 			data->info.num_regulators = MP2975_PAGE_NUM;
1032 	}
1033 
1034 	/* Identify multiphase configuration. */
1035 	ret = mp2975_identify_multiphase(client, data, info);
1036 	if (ret)
1037 		return ret;
1038 
1039 	if (data->chip_id == mp2975) {
1040 		/* Identify VID setting per rail. */
1041 		ret = mp2975_identify_rails_vid(client, data, info);
1042 		if (ret < 0)
1043 			return ret;
1044 
1045 		/* Obtain current sense gain of power stage. */
1046 		ret = mp2975_current_sense_gain_get(client, data);
1047 		if (ret)
1048 			return ret;
1049 
1050 		/* Obtain voltage reference values. */
1051 		ret = mp2975_vref_get(client, data, info);
1052 		if (ret)
1053 			return ret;
1054 
1055 		/* Obtain vout over-voltage scales. */
1056 		ret = mp2975_vout_ov_scale_get(client, data, info);
1057 		if (ret < 0)
1058 			return ret;
1059 	} else {
1060 		/* Identify VID setting per rail. */
1061 		ret = mp2973_identify_rails_vid(client, data, info);
1062 		if (ret < 0)
1063 			return ret;
1064 	}
1065 
1066 	/* Obtain offsets, maximum and format for vout. */
1067 	ret = mp2975_vout_per_rail_config_get(client, data, info);
1068 	if (ret)
1069 		return ret;
1070 
1071 	return pmbus_do_probe(client, info);
1072 }
1073 
1074 static const struct of_device_id mp2975_of_match[] = {
1075 	{.compatible = "mps,mp2971", .data = &mp2975_ddinfo[mp2971]},
1076 	{.compatible = "mps,mp2973", .data = &mp2975_ddinfo[mp2973]},
1077 	{.compatible = "mps,mp2975", .data = &mp2975_ddinfo[mp2975]},
1078 	{}
1079 };
1080 MODULE_DEVICE_TABLE(of, mp2975_of_match);
1081 
1082 static const struct i2c_device_id mp2975_id[] = {
1083 	{"mp2971", (kernel_ulong_t)&mp2975_ddinfo[mp2971]},
1084 	{"mp2973", (kernel_ulong_t)&mp2975_ddinfo[mp2973]},
1085 	{"mp2975", (kernel_ulong_t)&mp2975_ddinfo[mp2975]},
1086 	{}
1087 };
1088 MODULE_DEVICE_TABLE(i2c, mp2975_id);
1089 
1090 static struct i2c_driver mp2975_driver = {
1091 	.driver = {
1092 		.name = "mp2975",
1093 		.of_match_table = mp2975_of_match,
1094 	},
1095 	.probe = mp2975_probe,
1096 	.id_table = mp2975_id,
1097 };
1098 
1099 module_i2c_driver(mp2975_driver);
1100 
1101 MODULE_AUTHOR("Vadim Pasternak <vadimp@nvidia.com>");
1102 MODULE_DESCRIPTION("PMBus driver for MPS MP2975 device");
1103 MODULE_LICENSE("GPL");
1104 MODULE_IMPORT_NS(PMBUS);
1105