xref: /linux/drivers/hwmon/pmbus/max20730.c (revision de80193308f43d3ae52cd3561e8ba77cd1437311)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for MAX20710, MAX20730, MAX20734, and MAX20743 Integrated,
4  * Step-Down Switching Regulators
5  *
6  * Copyright 2019 Google LLC.
7  * Copyright 2020 Maxim Integrated
8  */
9 
10 #include <linux/bits.h>
11 #include <linux/debugfs.h>
12 #include <linux/err.h>
13 #include <linux/i2c.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/of.h>
19 #include <linux/pmbus.h>
20 #include <linux/util_macros.h>
21 #include "pmbus.h"
22 
23 enum chips {
24 	max20710,
25 	max20730,
26 	max20734,
27 	max20743
28 };
29 
30 enum {
31 	MAX20730_DEBUGFS_VOUT_MIN = 0,
32 	MAX20730_DEBUGFS_FREQUENCY,
33 	MAX20730_DEBUGFS_PG_DELAY,
34 	MAX20730_DEBUGFS_INTERNAL_GAIN,
35 	MAX20730_DEBUGFS_BOOT_VOLTAGE,
36 	MAX20730_DEBUGFS_OUT_V_RAMP_RATE,
37 	MAX20730_DEBUGFS_OC_PROTECT_MODE,
38 	MAX20730_DEBUGFS_SS_TIMING,
39 	MAX20730_DEBUGFS_IMAX,
40 	MAX20730_DEBUGFS_OPERATION,
41 	MAX20730_DEBUGFS_ON_OFF_CONFIG,
42 	MAX20730_DEBUGFS_SMBALERT_MASK,
43 	MAX20730_DEBUGFS_VOUT_MODE,
44 	MAX20730_DEBUGFS_VOUT_COMMAND,
45 	MAX20730_DEBUGFS_VOUT_MAX,
46 	MAX20730_DEBUGFS_NUM_ENTRIES
47 };
48 
49 struct max20730_data {
50 	enum chips id;
51 	struct pmbus_driver_info info;
52 	struct mutex lock;	/* Used to protect against parallel writes */
53 	u16 mfr_devset1;
54 	u16 mfr_devset2;
55 	u16 mfr_voutmin;
56 	u32 vout_voltage_divider[2];
57 };
58 
59 #define to_max20730_data(x)  container_of(x, struct max20730_data, info)
60 
61 #define VOLT_FROM_REG(val)	DIV_ROUND_CLOSEST((val), 1 << 9)
62 
63 #define PMBUS_SMB_ALERT_MASK	0x1B
64 
65 #define MAX20730_MFR_VOUT_MIN	0xd1
66 #define MAX20730_MFR_DEVSET1	0xd2
67 #define MAX20730_MFR_DEVSET2	0xd3
68 
69 #define MAX20730_MFR_VOUT_MIN_MASK		GENMASK(9, 0)
70 #define MAX20730_MFR_VOUT_MIN_BIT_POS		0
71 
72 #define MAX20730_MFR_DEVSET1_RGAIN_MASK		(BIT(13) | BIT(14))
73 #define MAX20730_MFR_DEVSET1_OTP_MASK		(BIT(11) | BIT(12))
74 #define MAX20730_MFR_DEVSET1_VBOOT_MASK		(BIT(8) | BIT(9))
75 #define MAX20730_MFR_DEVSET1_OCP_MASK		(BIT(5) | BIT(6))
76 #define MAX20730_MFR_DEVSET1_FSW_MASK		GENMASK(4, 2)
77 #define MAX20730_MFR_DEVSET1_TSTAT_MASK		(BIT(0) | BIT(1))
78 
79 #define MAX20730_MFR_DEVSET1_RGAIN_BIT_POS	13
80 #define MAX20730_MFR_DEVSET1_OTP_BIT_POS	11
81 #define MAX20730_MFR_DEVSET1_VBOOT_BIT_POS	8
82 #define MAX20730_MFR_DEVSET1_OCP_BIT_POS	5
83 #define MAX20730_MFR_DEVSET1_FSW_BIT_POS	2
84 #define MAX20730_MFR_DEVSET1_TSTAT_BIT_POS	0
85 
86 #define MAX20730_MFR_DEVSET2_IMAX_MASK		GENMASK(10, 8)
87 #define MAX20730_MFR_DEVSET2_VRATE		(BIT(6) | BIT(7))
88 #define MAX20730_MFR_DEVSET2_OCPM_MASK		BIT(5)
89 #define MAX20730_MFR_DEVSET2_SS_MASK		(BIT(0) | BIT(1))
90 
91 #define MAX20730_MFR_DEVSET2_IMAX_BIT_POS	8
92 #define MAX20730_MFR_DEVSET2_VRATE_BIT_POS	6
93 #define MAX20730_MFR_DEVSET2_OCPM_BIT_POS	5
94 #define MAX20730_MFR_DEVSET2_SS_BIT_POS		0
95 
96 #define DEBUG_FS_DATA_MAX			16
97 
98 struct max20730_debugfs_data {
99 	struct i2c_client *client;
100 	int debugfs_entries[MAX20730_DEBUGFS_NUM_ENTRIES];
101 };
102 
103 #define to_psu(x, y) container_of((x), \
104 			struct max20730_debugfs_data, debugfs_entries[(y)])
105 
106 #ifdef CONFIG_DEBUG_FS
107 static ssize_t max20730_debugfs_read(struct file *file, char __user *buf,
108 				     size_t count, loff_t *ppos)
109 {
110 	int ret, len;
111 	int *idxp = file->private_data;
112 	int idx = *idxp;
113 	struct max20730_debugfs_data *psu = to_psu(idxp, idx);
114 	const struct pmbus_driver_info *info;
115 	const struct max20730_data *data;
116 	char tbuf[DEBUG_FS_DATA_MAX] = { 0 };
117 	char *result = tbuf;
118 	u16 val;
119 
120 	info = pmbus_get_driver_info(psu->client);
121 	data = to_max20730_data(info);
122 
123 	switch (idx) {
124 	case MAX20730_DEBUGFS_VOUT_MIN:
125 		ret = VOLT_FROM_REG(data->mfr_voutmin * 10000);
126 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d.%d\n",
127 				ret / 10000, ret % 10000);
128 		break;
129 	case MAX20730_DEBUGFS_FREQUENCY:
130 		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_FSW_MASK)
131 			>> MAX20730_MFR_DEVSET1_FSW_BIT_POS;
132 
133 		if (val == 0)
134 			ret = 400;
135 		else if (val == 1)
136 			ret = 500;
137 		else if (val == 2 || val == 3)
138 			ret = 600;
139 		else if (val == 4)
140 			ret = 700;
141 		else if (val == 5)
142 			ret = 800;
143 		else
144 			ret = 900;
145 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
146 		break;
147 	case MAX20730_DEBUGFS_PG_DELAY:
148 		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_TSTAT_MASK)
149 			>> MAX20730_MFR_DEVSET1_TSTAT_BIT_POS;
150 
151 		if (val == 0)
152 			result = "2000\n";
153 		else if (val == 1)
154 			result = "125\n";
155 		else if (val == 2)
156 			result = "62.5\n";
157 		else
158 			result = "32\n";
159 		break;
160 	case MAX20730_DEBUGFS_INTERNAL_GAIN:
161 		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_RGAIN_MASK)
162 			>> MAX20730_MFR_DEVSET1_RGAIN_BIT_POS;
163 
164 		if (data->id == max20734) {
165 			/* AN6209 */
166 			if (val == 0)
167 				result = "0.8\n";
168 			else if (val == 1)
169 				result = "3.2\n";
170 			else if (val == 2)
171 				result = "1.6\n";
172 			else
173 				result = "6.4\n";
174 		} else if (data->id == max20730 || data->id == max20710) {
175 			/* AN6042 or AN6140 */
176 			if (val == 0)
177 				result = "0.9\n";
178 			else if (val == 1)
179 				result = "3.6\n";
180 			else if (val == 2)
181 				result = "1.8\n";
182 			else
183 				result = "7.2\n";
184 		} else if (data->id == max20743) {
185 			/* AN6042 */
186 			if (val == 0)
187 				result = "0.45\n";
188 			else if (val == 1)
189 				result = "1.8\n";
190 			else if (val == 2)
191 				result = "0.9\n";
192 			else
193 				result = "3.6\n";
194 		} else {
195 			result = "Not supported\n";
196 		}
197 		break;
198 	case MAX20730_DEBUGFS_BOOT_VOLTAGE:
199 		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_VBOOT_MASK)
200 			>> MAX20730_MFR_DEVSET1_VBOOT_BIT_POS;
201 
202 		if (val == 0)
203 			result = "0.6484\n";
204 		else if (val == 1)
205 			result = "0.8984\n";
206 		else if (val == 2)
207 			result = "1.0\n";
208 		else
209 			result = "Invalid\n";
210 		break;
211 	case MAX20730_DEBUGFS_OUT_V_RAMP_RATE:
212 		val = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_VRATE)
213 			>> MAX20730_MFR_DEVSET2_VRATE_BIT_POS;
214 
215 		if (val == 0)
216 			result = "4\n";
217 		else if (val == 1)
218 			result = "2\n";
219 		else if (val == 2)
220 			result = "1\n";
221 		else
222 			result = "Invalid\n";
223 		break;
224 	case MAX20730_DEBUGFS_OC_PROTECT_MODE:
225 		ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_OCPM_MASK)
226 			>> MAX20730_MFR_DEVSET2_OCPM_BIT_POS;
227 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
228 		break;
229 	case MAX20730_DEBUGFS_SS_TIMING:
230 		val = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_SS_MASK)
231 			>> MAX20730_MFR_DEVSET2_SS_BIT_POS;
232 
233 		if (val == 0)
234 			result = "0.75\n";
235 		else if (val == 1)
236 			result = "1.5\n";
237 		else if (val == 2)
238 			result = "3\n";
239 		else
240 			result = "6\n";
241 		break;
242 	case MAX20730_DEBUGFS_IMAX:
243 		ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_IMAX_MASK)
244 			>> MAX20730_MFR_DEVSET2_IMAX_BIT_POS;
245 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
246 		break;
247 	case MAX20730_DEBUGFS_OPERATION:
248 		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_OPERATION);
249 		if (ret < 0)
250 			return ret;
251 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
252 		break;
253 	case MAX20730_DEBUGFS_ON_OFF_CONFIG:
254 		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_ON_OFF_CONFIG);
255 		if (ret < 0)
256 			return ret;
257 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
258 		break;
259 	case MAX20730_DEBUGFS_SMBALERT_MASK:
260 		ret = i2c_smbus_read_word_data(psu->client,
261 					       PMBUS_SMB_ALERT_MASK);
262 		if (ret < 0)
263 			return ret;
264 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
265 		break;
266 	case MAX20730_DEBUGFS_VOUT_MODE:
267 		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_VOUT_MODE);
268 		if (ret < 0)
269 			return ret;
270 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX, "%d\n", ret);
271 		break;
272 	case MAX20730_DEBUGFS_VOUT_COMMAND:
273 		ret = i2c_smbus_read_word_data(psu->client, PMBUS_VOUT_COMMAND);
274 		if (ret < 0)
275 			return ret;
276 
277 		ret = VOLT_FROM_REG(ret * 10000);
278 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX,
279 				"%d.%d\n", ret / 10000, ret % 10000);
280 		break;
281 	case MAX20730_DEBUGFS_VOUT_MAX:
282 		ret = i2c_smbus_read_word_data(psu->client, PMBUS_VOUT_MAX);
283 		if (ret < 0)
284 			return ret;
285 
286 		ret = VOLT_FROM_REG(ret * 10000);
287 		len = scnprintf(tbuf, DEBUG_FS_DATA_MAX,
288 				"%d.%d\n", ret / 10000, ret % 10000);
289 		break;
290 	default:
291 		result = "Invalid\n";
292 	}
293 
294 	len = strlen(result);
295 	return simple_read_from_buffer(buf, count, ppos, result, len);
296 }
297 
298 static const struct file_operations max20730_fops = {
299 	.llseek = noop_llseek,
300 	.read = max20730_debugfs_read,
301 	.write = NULL,
302 	.open = simple_open,
303 };
304 
305 static int max20730_init_debugfs(struct i2c_client *client,
306 				 struct max20730_data *data)
307 {
308 	int ret, i;
309 	struct dentry *debugfs;
310 	struct dentry *max20730_dir;
311 	struct max20730_debugfs_data *psu;
312 
313 	ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET2);
314 	if (ret < 0)
315 		return ret;
316 	data->mfr_devset2 = ret;
317 
318 	ret = i2c_smbus_read_word_data(client, MAX20730_MFR_VOUT_MIN);
319 	if (ret < 0)
320 		return ret;
321 	data->mfr_voutmin = ret;
322 
323 	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
324 	if (!psu)
325 		return -ENOMEM;
326 	psu->client = client;
327 
328 	debugfs = pmbus_get_debugfs_dir(client);
329 	if (!debugfs)
330 		return -ENOENT;
331 
332 	max20730_dir = debugfs_create_dir(client->name, debugfs);
333 
334 	for (i = 0; i < MAX20730_DEBUGFS_NUM_ENTRIES; ++i)
335 		psu->debugfs_entries[i] = i;
336 
337 	debugfs_create_file("vout_min", 0444, max20730_dir,
338 			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MIN],
339 			    &max20730_fops);
340 	debugfs_create_file("frequency", 0444, max20730_dir,
341 			    &psu->debugfs_entries[MAX20730_DEBUGFS_FREQUENCY],
342 			    &max20730_fops);
343 	debugfs_create_file("power_good_delay", 0444, max20730_dir,
344 			    &psu->debugfs_entries[MAX20730_DEBUGFS_PG_DELAY],
345 			    &max20730_fops);
346 	debugfs_create_file("internal_gain", 0444, max20730_dir,
347 			    &psu->debugfs_entries[MAX20730_DEBUGFS_INTERNAL_GAIN],
348 			    &max20730_fops);
349 	debugfs_create_file("boot_voltage", 0444, max20730_dir,
350 			    &psu->debugfs_entries[MAX20730_DEBUGFS_BOOT_VOLTAGE],
351 			    &max20730_fops);
352 	debugfs_create_file("out_voltage_ramp_rate", 0444, max20730_dir,
353 			    &psu->debugfs_entries[MAX20730_DEBUGFS_OUT_V_RAMP_RATE],
354 			    &max20730_fops);
355 	debugfs_create_file("oc_protection_mode", 0444, max20730_dir,
356 			    &psu->debugfs_entries[MAX20730_DEBUGFS_OC_PROTECT_MODE],
357 			    &max20730_fops);
358 	debugfs_create_file("soft_start_timing", 0444, max20730_dir,
359 			    &psu->debugfs_entries[MAX20730_DEBUGFS_SS_TIMING],
360 			    &max20730_fops);
361 	debugfs_create_file("imax", 0444, max20730_dir,
362 			    &psu->debugfs_entries[MAX20730_DEBUGFS_IMAX],
363 			    &max20730_fops);
364 	debugfs_create_file("operation", 0444, max20730_dir,
365 			    &psu->debugfs_entries[MAX20730_DEBUGFS_OPERATION],
366 			    &max20730_fops);
367 	debugfs_create_file("on_off_config", 0444, max20730_dir,
368 			    &psu->debugfs_entries[MAX20730_DEBUGFS_ON_OFF_CONFIG],
369 			    &max20730_fops);
370 	debugfs_create_file("smbalert_mask", 0444, max20730_dir,
371 			    &psu->debugfs_entries[MAX20730_DEBUGFS_SMBALERT_MASK],
372 			    &max20730_fops);
373 	debugfs_create_file("vout_mode", 0444, max20730_dir,
374 			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MODE],
375 			    &max20730_fops);
376 	debugfs_create_file("vout_command", 0444, max20730_dir,
377 			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_COMMAND],
378 			    &max20730_fops);
379 	debugfs_create_file("vout_max", 0444, max20730_dir,
380 			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MAX],
381 			    &max20730_fops);
382 
383 	return 0;
384 }
385 #else
386 static int max20730_init_debugfs(struct i2c_client *client,
387 				 struct max20730_data *data)
388 {
389 	return 0;
390 }
391 #endif /* CONFIG_DEBUG_FS */
392 
393 static const struct i2c_device_id max20730_id[];
394 
395 /*
396  * Convert discreet value to direct data format. Strictly speaking, all passed
397  * values are constants, so we could do that calculation manually. On the
398  * downside, that would make the driver more difficult to maintain, so lets
399  * use this approach.
400  */
401 static u16 val_to_direct(int v, enum pmbus_sensor_classes class,
402 			 const struct pmbus_driver_info *info)
403 {
404 	int R = info->R[class] - 3;	/* take milli-units into account */
405 	int b = info->b[class] * 1000;
406 	long d;
407 
408 	d = v * info->m[class] + b;
409 	/*
410 	 * R < 0 is true for all callers, so we don't need to bother
411 	 * about the R > 0 case.
412 	 */
413 	while (R < 0) {
414 		d = DIV_ROUND_CLOSEST(d, 10);
415 		R++;
416 	}
417 	return (u16)d;
418 }
419 
420 static long direct_to_val(u16 w, enum pmbus_sensor_classes class,
421 			  const struct pmbus_driver_info *info)
422 {
423 	int R = info->R[class] - 3;
424 	int b = info->b[class] * 1000;
425 	int m = info->m[class];
426 	long d = (s16)w;
427 
428 	if (m == 0)
429 		return 0;
430 
431 	while (R < 0) {
432 		d *= 10;
433 		R++;
434 	}
435 	d = (d - b) / m;
436 	return d;
437 }
438 
439 static u32 max_current[][5] = {
440 	[max20710] = { 6200, 8000, 9700, 11600 },
441 	[max20730] = { 13000, 16600, 20100, 23600 },
442 	[max20734] = { 21000, 27000, 32000, 38000 },
443 	[max20743] = { 18900, 24100, 29200, 34100 },
444 };
445 
446 static int max20730_read_word_data(struct i2c_client *client, int page,
447 				   int phase, int reg)
448 {
449 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
450 	const struct max20730_data *data = to_max20730_data(info);
451 	int ret = 0;
452 	u32 max_c;
453 
454 	switch (reg) {
455 	case PMBUS_OT_FAULT_LIMIT:
456 		switch ((data->mfr_devset1 >> 11) & 0x3) {
457 		case 0x0:
458 			ret = val_to_direct(150000, PSC_TEMPERATURE, info);
459 			break;
460 		case 0x1:
461 			ret = val_to_direct(130000, PSC_TEMPERATURE, info);
462 			break;
463 		default:
464 			ret = -ENODATA;
465 			break;
466 		}
467 		break;
468 	case PMBUS_IOUT_OC_FAULT_LIMIT:
469 		max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3];
470 		ret = val_to_direct(max_c, PSC_CURRENT_OUT, info);
471 		break;
472 	case PMBUS_READ_VOUT:
473 		ret = pmbus_read_word_data(client, page, phase, reg);
474 		if (ret > 0 && data->vout_voltage_divider[0] && data->vout_voltage_divider[1]) {
475 			u64 temp = DIV_ROUND_CLOSEST_ULL((u64)ret * data->vout_voltage_divider[1],
476 							 data->vout_voltage_divider[0]);
477 			ret = clamp_val(temp, 0, 0xffff);
478 		}
479 		break;
480 	default:
481 		ret = -ENODATA;
482 		break;
483 	}
484 	return ret;
485 }
486 
487 static int max20730_write_word_data(struct i2c_client *client, int page,
488 				    int reg, u16 word)
489 {
490 	struct pmbus_driver_info *info;
491 	struct max20730_data *data;
492 	u16 devset1;
493 	int ret = 0;
494 	int idx;
495 
496 	info = (struct pmbus_driver_info *)pmbus_get_driver_info(client);
497 	data = to_max20730_data(info);
498 
499 	mutex_lock(&data->lock);
500 	devset1 = data->mfr_devset1;
501 
502 	switch (reg) {
503 	case PMBUS_OT_FAULT_LIMIT:
504 		devset1 &= ~(BIT(11) | BIT(12));
505 		if (direct_to_val(word, PSC_TEMPERATURE, info) < 140000)
506 			devset1 |= BIT(11);
507 		break;
508 	case PMBUS_IOUT_OC_FAULT_LIMIT:
509 		devset1 &= ~(BIT(5) | BIT(6));
510 
511 		idx = find_closest(direct_to_val(word, PSC_CURRENT_OUT, info),
512 				   max_current[data->id], 4);
513 		devset1 |= (idx << 5);
514 		break;
515 	default:
516 		ret = -ENODATA;
517 		break;
518 	}
519 
520 	if (!ret && devset1 != data->mfr_devset1) {
521 		ret = i2c_smbus_write_word_data(client, MAX20730_MFR_DEVSET1,
522 						devset1);
523 		if (!ret) {
524 			data->mfr_devset1 = devset1;
525 			pmbus_clear_cache(client);
526 		}
527 	}
528 	mutex_unlock(&data->lock);
529 	return ret;
530 }
531 
532 static const struct pmbus_driver_info max20730_info[] = {
533 	[max20710] = {
534 		.pages = 1,
535 		.read_word_data = max20730_read_word_data,
536 		.write_word_data = max20730_write_word_data,
537 
538 		/* Source : Maxim AN6140 and AN6042 */
539 		.format[PSC_TEMPERATURE] = direct,
540 		.m[PSC_TEMPERATURE] = 21,
541 		.b[PSC_TEMPERATURE] = 5887,
542 		.R[PSC_TEMPERATURE] = -1,
543 
544 		.format[PSC_VOLTAGE_IN] = direct,
545 		.m[PSC_VOLTAGE_IN] = 3609,
546 		.b[PSC_VOLTAGE_IN] = 0,
547 		.R[PSC_VOLTAGE_IN] = -2,
548 
549 		.format[PSC_CURRENT_OUT] = direct,
550 		.m[PSC_CURRENT_OUT] = 153,
551 		.b[PSC_CURRENT_OUT] = 4976,
552 		.R[PSC_CURRENT_OUT] = -1,
553 
554 		.format[PSC_VOLTAGE_OUT] = linear,
555 
556 		.func[0] = PMBUS_HAVE_VIN |
557 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
558 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
559 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
560 			PMBUS_HAVE_STATUS_INPUT,
561 	},
562 	[max20730] = {
563 		.pages = 1,
564 		.read_word_data = max20730_read_word_data,
565 		.write_word_data = max20730_write_word_data,
566 
567 		/* Source : Maxim AN6042 */
568 		.format[PSC_TEMPERATURE] = direct,
569 		.m[PSC_TEMPERATURE] = 21,
570 		.b[PSC_TEMPERATURE] = 5887,
571 		.R[PSC_TEMPERATURE] = -1,
572 
573 		.format[PSC_VOLTAGE_IN] = direct,
574 		.m[PSC_VOLTAGE_IN] = 3609,
575 		.b[PSC_VOLTAGE_IN] = 0,
576 		.R[PSC_VOLTAGE_IN] = -2,
577 
578 		/*
579 		 * Values in the datasheet are adjusted for temperature and
580 		 * for the relationship between Vin and Vout.
581 		 * Unfortunately, the data sheet suggests that Vout measurement
582 		 * may be scaled with a resistor array. This is indeed the case
583 		 * at least on the evaulation boards. As a result, any in-driver
584 		 * adjustments would either be wrong or require elaborate means
585 		 * to configure the scaling. Instead of doing that, just report
586 		 * raw values and let userspace handle adjustments.
587 		 */
588 		.format[PSC_CURRENT_OUT] = direct,
589 		.m[PSC_CURRENT_OUT] = 153,
590 		.b[PSC_CURRENT_OUT] = 4976,
591 		.R[PSC_CURRENT_OUT] = -1,
592 
593 		.format[PSC_VOLTAGE_OUT] = linear,
594 
595 		.func[0] = PMBUS_HAVE_VIN |
596 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
597 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
598 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
599 			PMBUS_HAVE_STATUS_INPUT,
600 	},
601 	[max20734] = {
602 		.pages = 1,
603 		.read_word_data = max20730_read_word_data,
604 		.write_word_data = max20730_write_word_data,
605 
606 		/* Source : Maxim AN6209 */
607 		.format[PSC_TEMPERATURE] = direct,
608 		.m[PSC_TEMPERATURE] = 21,
609 		.b[PSC_TEMPERATURE] = 5887,
610 		.R[PSC_TEMPERATURE] = -1,
611 
612 		.format[PSC_VOLTAGE_IN] = direct,
613 		.m[PSC_VOLTAGE_IN] = 3592,
614 		.b[PSC_VOLTAGE_IN] = 0,
615 		.R[PSC_VOLTAGE_IN] = -2,
616 
617 		.format[PSC_CURRENT_OUT] = direct,
618 		.m[PSC_CURRENT_OUT] = 111,
619 		.b[PSC_CURRENT_OUT] = 3461,
620 		.R[PSC_CURRENT_OUT] = -1,
621 
622 		.format[PSC_VOLTAGE_OUT] = linear,
623 
624 		.func[0] = PMBUS_HAVE_VIN |
625 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
626 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
627 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
628 			PMBUS_HAVE_STATUS_INPUT,
629 	},
630 	[max20743] = {
631 		.pages = 1,
632 		.read_word_data = max20730_read_word_data,
633 		.write_word_data = max20730_write_word_data,
634 
635 		/* Source : Maxim AN6042 */
636 		.format[PSC_TEMPERATURE] = direct,
637 		.m[PSC_TEMPERATURE] = 21,
638 		.b[PSC_TEMPERATURE] = 5887,
639 		.R[PSC_TEMPERATURE] = -1,
640 
641 		.format[PSC_VOLTAGE_IN] = direct,
642 		.m[PSC_VOLTAGE_IN] = 3597,
643 		.b[PSC_VOLTAGE_IN] = 0,
644 		.R[PSC_VOLTAGE_IN] = -2,
645 
646 		.format[PSC_CURRENT_OUT] = direct,
647 		.m[PSC_CURRENT_OUT] = 95,
648 		.b[PSC_CURRENT_OUT] = 5014,
649 		.R[PSC_CURRENT_OUT] = -1,
650 
651 		.format[PSC_VOLTAGE_OUT] = linear,
652 
653 		.func[0] = PMBUS_HAVE_VIN |
654 			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
655 			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
656 			PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
657 			PMBUS_HAVE_STATUS_INPUT,
658 	},
659 };
660 
661 static int max20730_probe(struct i2c_client *client)
662 {
663 	struct device *dev = &client->dev;
664 	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
665 	struct max20730_data *data;
666 	enum chips chip_id;
667 	int ret;
668 
669 	if (!i2c_check_functionality(client->adapter,
670 				     I2C_FUNC_SMBUS_READ_BYTE_DATA |
671 				     I2C_FUNC_SMBUS_READ_WORD_DATA |
672 				     I2C_FUNC_SMBUS_BLOCK_DATA))
673 		return -ENODEV;
674 
675 	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
676 	if (ret < 0) {
677 		dev_err(&client->dev, "Failed to read Manufacturer ID\n");
678 		return ret;
679 	}
680 	if (ret != 5 || strncmp(buf, "MAXIM", 5)) {
681 		buf[ret] = '\0';
682 		dev_err(dev, "Unsupported Manufacturer ID '%s'\n", buf);
683 		return -ENODEV;
684 	}
685 
686 	/*
687 	 * The chips support reading PMBUS_MFR_MODEL. On both MAX20730
688 	 * and MAX20734, reading it returns M20743. Presumably that is
689 	 * the reason why the command is not documented. Unfortunately,
690 	 * that means that there is no reliable means to detect the chip.
691 	 * However, we can at least detect the chip series. Compare
692 	 * the returned value against 'M20743' and bail out if there is
693 	 * a mismatch. If that doesn't work for all chips, we may have
694 	 * to remove this check.
695 	 */
696 	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
697 	if (ret < 0) {
698 		dev_err(dev, "Failed to read Manufacturer Model\n");
699 		return ret;
700 	}
701 	if (ret != 6 || strncmp(buf, "M20743", 6)) {
702 		buf[ret] = '\0';
703 		dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
704 		return -ENODEV;
705 	}
706 
707 	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_REVISION, buf);
708 	if (ret < 0) {
709 		dev_err(dev, "Failed to read Manufacturer Revision\n");
710 		return ret;
711 	}
712 	if (ret != 1 || buf[0] != 'F') {
713 		buf[ret] = '\0';
714 		dev_err(dev, "Unsupported Manufacturer Revision '%s'\n", buf);
715 		return -ENODEV;
716 	}
717 
718 	if (client->dev.of_node)
719 		chip_id = (uintptr_t)of_device_get_match_data(dev);
720 	else
721 		chip_id = i2c_match_id(max20730_id, client)->driver_data;
722 
723 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
724 	if (!data)
725 		return -ENOMEM;
726 	data->id = chip_id;
727 	mutex_init(&data->lock);
728 	memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info));
729 	if (of_property_read_u32_array(client->dev.of_node, "vout-voltage-divider",
730 				       data->vout_voltage_divider,
731 				       ARRAY_SIZE(data->vout_voltage_divider)) != 0)
732 		memset(data->vout_voltage_divider, 0, sizeof(data->vout_voltage_divider));
733 	if (data->vout_voltage_divider[1] < data->vout_voltage_divider[0]) {
734 		dev_err(dev,
735 			"The total resistance of voltage divider is less than output resistance\n");
736 		return -EINVAL;
737 	}
738 
739 	ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1);
740 	if (ret < 0)
741 		return ret;
742 	data->mfr_devset1 = ret;
743 
744 	ret = pmbus_do_probe(client, &data->info);
745 	if (ret < 0)
746 		return ret;
747 
748 	ret = max20730_init_debugfs(client, data);
749 	if (ret)
750 		dev_warn(dev, "Failed to register debugfs: %d\n",
751 			 ret);
752 
753 	return 0;
754 }
755 
756 static const struct i2c_device_id max20730_id[] = {
757 	{ "max20710", max20710 },
758 	{ "max20730", max20730 },
759 	{ "max20734", max20734 },
760 	{ "max20743", max20743 },
761 	{ },
762 };
763 
764 MODULE_DEVICE_TABLE(i2c, max20730_id);
765 
766 static const struct of_device_id max20730_of_match[] = {
767 	{ .compatible = "maxim,max20710", .data = (void *)max20710 },
768 	{ .compatible = "maxim,max20730", .data = (void *)max20730 },
769 	{ .compatible = "maxim,max20734", .data = (void *)max20734 },
770 	{ .compatible = "maxim,max20743", .data = (void *)max20743 },
771 	{ },
772 };
773 
774 MODULE_DEVICE_TABLE(of, max20730_of_match);
775 
776 static struct i2c_driver max20730_driver = {
777 	.driver = {
778 		.name = "max20730",
779 		.of_match_table = max20730_of_match,
780 	},
781 	.probe = max20730_probe,
782 	.id_table = max20730_id,
783 };
784 
785 module_i2c_driver(max20730_driver);
786 
787 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
788 MODULE_DESCRIPTION("PMBus driver for Maxim MAX20710 / MAX20730 / MAX20734 / MAX20743");
789 MODULE_LICENSE("GPL");
790 MODULE_IMPORT_NS(PMBUS);
791