xref: /openbmc/linux/drivers/hwmon/pmbus/ibm-cffps.c (revision 83146efc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2017 IBM Corp.
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/bitops.h>
8 #include <linux/debugfs.h>
9 #include <linux/device.h>
10 #include <linux/fs.h>
11 #include <linux/i2c.h>
12 #include <linux/jiffies.h>
13 #include <linux/leds.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/of.h>
17 #include <linux/pmbus.h>
18 
19 #include "pmbus.h"
20 
21 #define CFFPS_CCIN_CMD				0xBD
22 #define CFFPS_FW_CMD				0xFA
23 #define CFFPS1_FW_NUM_BYTES			4
24 #define CFFPS2_FW_NUM_WORDS			3
25 #define CFFPS_SYS_CONFIG_CMD			0xDA
26 #define CFFPS_12VCS_VOUT_CMD			0xDE
27 
28 #define CFFPS_INPUT_HISTORY_CMD			0xD6
29 #define CFFPS_INPUT_HISTORY_SIZE		101
30 
31 #define CFFPS_CCIN_REVISION			GENMASK(7, 0)
32 #define CFFPS_CCIN_REVISION_LEGACY		 0xde
33 #define CFFPS_CCIN_VERSION			GENMASK(15, 8)
34 #define CFFPS_CCIN_VERSION_1			 0x2b
35 #define CFFPS_CCIN_VERSION_2			 0x2e
36 #define CFFPS_CCIN_VERSION_3			 0x51
37 
38 /* STATUS_MFR_SPECIFIC bits */
39 #define CFFPS_MFR_FAN_FAULT			BIT(0)
40 #define CFFPS_MFR_THERMAL_FAULT			BIT(1)
41 #define CFFPS_MFR_OV_FAULT			BIT(2)
42 #define CFFPS_MFR_UV_FAULT			BIT(3)
43 #define CFFPS_MFR_PS_KILL			BIT(4)
44 #define CFFPS_MFR_OC_FAULT			BIT(5)
45 #define CFFPS_MFR_VAUX_FAULT			BIT(6)
46 #define CFFPS_MFR_CURRENT_SHARE_WARNING		BIT(7)
47 
48 #define CFFPS_LED_BLINK				(BIT(0) | BIT(6))
49 #define CFFPS_LED_ON				(BIT(1) | BIT(6))
50 #define CFFPS_LED_OFF				(BIT(2) | BIT(6))
51 #define CFFPS_BLINK_RATE_MS			250
52 
53 enum {
54 	CFFPS_DEBUGFS_MAX_POWER_OUT = 0,
55 	CFFPS_DEBUGFS_CCIN,
56 	CFFPS_DEBUGFS_FW,
57 	CFFPS_DEBUGFS_ON_OFF_CONFIG,
58 	CFFPS_DEBUGFS_NUM_ENTRIES
59 };
60 
61 enum versions { cffps1, cffps2, cffps_unknown };
62 
63 struct ibm_cffps {
64 	enum versions version;
65 	struct i2c_client *client;
66 
67 	u8 input_history[CFFPS_INPUT_HISTORY_SIZE];
68 
69 	int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];
70 
71 	char led_name[32];
72 	u8 led_state;
73 	struct led_classdev led;
74 };
75 
76 #define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])
77 
78 static ssize_t ibm_cffps_debugfs_read_input_history(struct file *file, char __user *buf,
79 						    size_t count, loff_t *ppos)
80 {
81 	int rc;
82 	u8 cmd = CFFPS_INPUT_HISTORY_CMD;
83 	struct ibm_cffps *psu = file->private_data;
84 	struct i2c_msg msg[2] = {
85 		{
86 			.addr = psu->client->addr,
87 			.flags = psu->client->flags,
88 			.len = 1,
89 			.buf = &cmd,
90 		}, {
91 			.addr = psu->client->addr,
92 			.flags = psu->client->flags | I2C_M_RD,
93 			.len = CFFPS_INPUT_HISTORY_SIZE,
94 			.buf = psu->input_history,
95 		},
96 	};
97 
98 	if (!*ppos) {
99 		rc = pmbus_lock_interruptible(psu->client);
100 		if (rc)
101 			return rc;
102 
103 		rc = pmbus_set_page(psu->client, 0, 0xff);
104 		if (rc) {
105 			pmbus_unlock(psu->client);
106 			return rc;
107 		}
108 
109 		/*
110 		 * Use a raw i2c transfer, since we need more bytes
111 		 * than Linux I2C supports through smbus xfr (only 32).
112 		 */
113 		rc = i2c_transfer(psu->client->adapter, msg, 2);
114 		pmbus_unlock(psu->client);
115 		if (rc < 0)
116 			return rc;
117 	}
118 
119 	return simple_read_from_buffer(buf, count, ppos,
120 				       psu->input_history + 1,
121 				       psu->input_history[0]);
122 }
123 
124 static const struct file_operations ibm_cffps_input_history_fops = {
125 	.llseek = noop_llseek,
126 	.read = ibm_cffps_debugfs_read_input_history,
127 	.open = simple_open,
128 };
129 
130 static ssize_t ibm_cffps_debugfs_read(struct file *file, char __user *buf,
131 				      size_t count, loff_t *ppos)
132 {
133 	int i, rc;
134 	int *idxp = file->private_data;
135 	int idx = *idxp;
136 	struct ibm_cffps *psu = to_psu(idxp, idx);
137 	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
138 
139 	rc = pmbus_lock_interruptible(psu->client);
140 	if (rc)
141 		return rc;
142 
143 	rc = pmbus_set_page(psu->client, 0, 0xff);
144 	if (rc)
145 		goto unlock;
146 
147 	switch (idx) {
148 	case CFFPS_DEBUGFS_MAX_POWER_OUT:
149 		if (psu->version == cffps1)
150 			rc = i2c_smbus_read_word_swapped(psu->client, PMBUS_MFR_POUT_MAX);
151 		else
152 			rc = i2c_smbus_read_word_data(psu->client, PMBUS_MFR_POUT_MAX);
153 		if (rc >= 0)
154 			rc = snprintf(data, I2C_SMBUS_BLOCK_MAX, "%d", rc);
155 		break;
156 	case CFFPS_DEBUGFS_CCIN:
157 		rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
158 		if (rc >= 0)
159 			rc = snprintf(data, 5, "%04X", rc);
160 		break;
161 	case CFFPS_DEBUGFS_FW:
162 		switch (psu->version) {
163 		case cffps1:
164 			for (i = 0; i < CFFPS1_FW_NUM_BYTES; ++i) {
165 				rc = i2c_smbus_read_byte_data(psu->client, CFFPS_FW_CMD + i);
166 				if (rc < 0)
167 					goto unlock;
168 
169 				snprintf(&data[i * 2], 3, "%02X", rc);
170 			}
171 
172 			rc = i * 2;
173 			break;
174 		case cffps2:
175 			for (i = 0; i < CFFPS2_FW_NUM_WORDS; ++i) {
176 				rc = i2c_smbus_read_word_data(psu->client, CFFPS_FW_CMD + i);
177 				if (rc < 0)
178 					goto unlock;
179 
180 				snprintf(&data[i * 4], 5, "%04X", rc);
181 			}
182 
183 			rc = i * 4;
184 			break;
185 		default:
186 			rc = -EOPNOTSUPP;
187 			break;
188 		}
189 		break;
190 	case CFFPS_DEBUGFS_ON_OFF_CONFIG:
191 		rc = i2c_smbus_read_byte_data(psu->client, PMBUS_ON_OFF_CONFIG);
192 		if (rc >= 0)
193 			rc = snprintf(data, 3, "%02x", rc);
194 		break;
195 	default:
196 		rc = -EINVAL;
197 		break;
198 	}
199 
200 unlock:
201 	pmbus_unlock(psu->client);
202 	if (rc < 0)
203 		return rc;
204 
205 	data[rc] = '\n';
206 	rc += 2;
207 
208 	return simple_read_from_buffer(buf, count, ppos, data, rc);
209 }
210 
211 static ssize_t ibm_cffps_debugfs_write(struct file *file,
212 				       const char __user *buf, size_t count,
213 				       loff_t *ppos)
214 {
215 	u8 data;
216 	ssize_t rc;
217 	int *idxp = file->private_data;
218 	int idx = *idxp;
219 	struct ibm_cffps *psu = to_psu(idxp, idx);
220 
221 	switch (idx) {
222 	case CFFPS_DEBUGFS_ON_OFF_CONFIG:
223 		rc = simple_write_to_buffer(&data, 1, ppos, buf, count);
224 		if (rc <= 0)
225 			return rc;
226 
227 		rc = pmbus_lock_interruptible(psu->client);
228 		if (rc)
229 			return rc;
230 
231 		rc = pmbus_set_page(psu->client, 0, 0xff);
232 		if (rc) {
233 			pmbus_unlock(psu->client);
234 			return rc;
235 		}
236 
237 		rc = i2c_smbus_write_byte_data(psu->client, PMBUS_ON_OFF_CONFIG, data);
238 		pmbus_unlock(psu->client);
239 		if (rc)
240 			return rc;
241 
242 		rc = 1;
243 		break;
244 	default:
245 		return -EINVAL;
246 	}
247 
248 	return rc;
249 }
250 
251 static const struct file_operations ibm_cffps_fops = {
252 	.llseek = noop_llseek,
253 	.read = ibm_cffps_debugfs_read,
254 	.write = ibm_cffps_debugfs_write,
255 	.open = simple_open,
256 };
257 
258 static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
259 				    int reg)
260 {
261 	int rc, mfr;
262 
263 	switch (reg) {
264 	case PMBUS_STATUS_VOUT:
265 	case PMBUS_STATUS_IOUT:
266 	case PMBUS_STATUS_TEMPERATURE:
267 	case PMBUS_STATUS_FAN_12:
268 		rc = pmbus_read_byte_data(client, page, reg);
269 		if (rc < 0)
270 			return rc;
271 
272 		mfr = pmbus_read_byte_data(client, page,
273 					   PMBUS_STATUS_MFR_SPECIFIC);
274 		if (mfr < 0)
275 			/*
276 			 * Return the status register instead of an error,
277 			 * since we successfully read status.
278 			 */
279 			return rc;
280 
281 		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
282 		if (reg == PMBUS_STATUS_FAN_12) {
283 			if (mfr & CFFPS_MFR_FAN_FAULT)
284 				rc |= PB_FAN_FAN1_FAULT;
285 		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
286 			if (mfr & CFFPS_MFR_THERMAL_FAULT)
287 				rc |= PB_TEMP_OT_FAULT;
288 		} else if (reg == PMBUS_STATUS_VOUT) {
289 			if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
290 				rc |= PB_VOLTAGE_OV_FAULT;
291 			if (mfr & CFFPS_MFR_UV_FAULT)
292 				rc |= PB_VOLTAGE_UV_FAULT;
293 		} else if (reg == PMBUS_STATUS_IOUT) {
294 			if (mfr & CFFPS_MFR_OC_FAULT)
295 				rc |= PB_IOUT_OC_FAULT;
296 			if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
297 				rc |= PB_CURRENT_SHARE_FAULT;
298 		}
299 		break;
300 	default:
301 		rc = -ENODATA;
302 		break;
303 	}
304 
305 	return rc;
306 }
307 
308 static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
309 				    int phase, int reg)
310 {
311 	int rc, mfr;
312 
313 	switch (reg) {
314 	case PMBUS_STATUS_WORD:
315 		rc = pmbus_read_word_data(client, page, phase, reg);
316 		if (rc < 0)
317 			return rc;
318 
319 		mfr = pmbus_read_byte_data(client, page,
320 					   PMBUS_STATUS_MFR_SPECIFIC);
321 		if (mfr < 0)
322 			/*
323 			 * Return the status register instead of an error,
324 			 * since we successfully read status.
325 			 */
326 			return rc;
327 
328 		if (mfr & CFFPS_MFR_PS_KILL)
329 			rc |= PB_STATUS_OFF;
330 		break;
331 	case PMBUS_VIRT_READ_VMON:
332 		rc = pmbus_read_word_data(client, page, phase,
333 					  CFFPS_12VCS_VOUT_CMD);
334 		break;
335 	default:
336 		rc = -ENODATA;
337 		break;
338 	}
339 
340 	return rc;
341 }
342 
343 static int ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
344 					enum led_brightness brightness)
345 {
346 	int rc;
347 	u8 next_led_state;
348 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
349 
350 	if (brightness == LED_OFF) {
351 		next_led_state = CFFPS_LED_OFF;
352 	} else {
353 		brightness = LED_FULL;
354 
355 		if (psu->led_state != CFFPS_LED_BLINK)
356 			next_led_state = CFFPS_LED_ON;
357 		else
358 			next_led_state = CFFPS_LED_BLINK;
359 	}
360 
361 	dev_dbg(&psu->client->dev, "LED brightness set: %d. Command: %d.\n",
362 		brightness, next_led_state);
363 
364 	rc = pmbus_lock_interruptible(psu->client);
365 	if (rc)
366 		return rc;
367 
368 	rc = pmbus_set_page(psu->client, 0, 0xff);
369 	if (rc) {
370 		pmbus_unlock(psu->client);
371 		return rc;
372 	}
373 
374 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
375 				       next_led_state);
376 	pmbus_unlock(psu->client);
377 	if (rc < 0)
378 		return rc;
379 
380 	psu->led_state = next_led_state;
381 	led_cdev->brightness = brightness;
382 
383 	return 0;
384 }
385 
386 static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
387 				   unsigned long *delay_on,
388 				   unsigned long *delay_off)
389 {
390 	int rc;
391 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
392 
393 	dev_dbg(&psu->client->dev, "LED blink set.\n");
394 
395 	rc = pmbus_lock_interruptible(psu->client);
396 	if (rc)
397 		return rc;
398 
399 	rc = pmbus_set_page(psu->client, 0, 0xff);
400 	if (rc) {
401 		pmbus_unlock(psu->client);
402 		return rc;
403 	}
404 
405 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
406 				       CFFPS_LED_BLINK);
407 	pmbus_unlock(psu->client);
408 	if (rc < 0)
409 		return rc;
410 
411 	psu->led_state = CFFPS_LED_BLINK;
412 	led_cdev->brightness = LED_FULL;
413 	*delay_on = CFFPS_BLINK_RATE_MS;
414 	*delay_off = CFFPS_BLINK_RATE_MS;
415 
416 	return 0;
417 }
418 
419 static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
420 {
421 	int rc;
422 	struct i2c_client *client = psu->client;
423 	struct device *dev = &client->dev;
424 
425 	snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
426 		 client->addr);
427 	psu->led.name = psu->led_name;
428 	psu->led.max_brightness = LED_FULL;
429 	psu->led.brightness_set_blocking = ibm_cffps_led_brightness_set;
430 	psu->led.blink_set = ibm_cffps_led_blink_set;
431 
432 	rc = devm_led_classdev_register(dev, &psu->led);
433 	if (rc)
434 		dev_warn(dev, "failed to register led class: %d\n", rc);
435 	else
436 		i2c_smbus_write_byte_data(client, CFFPS_SYS_CONFIG_CMD,
437 					  CFFPS_LED_OFF);
438 }
439 
440 static struct pmbus_driver_info ibm_cffps_info[] = {
441 	[cffps1] = {
442 		.pages = 1,
443 		.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
444 			PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
445 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
446 			PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
447 			PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
448 			PMBUS_HAVE_STATUS_FAN12,
449 		.read_byte_data = ibm_cffps_read_byte_data,
450 		.read_word_data = ibm_cffps_read_word_data,
451 	},
452 	[cffps2] = {
453 		.pages = 2,
454 		.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
455 			PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
456 			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
457 			PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
458 			PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
459 			PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_VMON,
460 		.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
461 			PMBUS_HAVE_PIN | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
462 			PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
463 			PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
464 			PMBUS_HAVE_STATUS_TEMP,
465 		.read_byte_data = ibm_cffps_read_byte_data,
466 		.read_word_data = ibm_cffps_read_word_data,
467 	},
468 };
469 
470 static struct pmbus_platform_data ibm_cffps_pdata = {
471 	.flags = PMBUS_SKIP_STATUS_CHECK | PMBUS_NO_CAPABILITY,
472 };
473 
474 static const struct i2c_device_id ibm_cffps_id[] = {
475 	{ "ibm_cffps1", cffps1 },
476 	{ "ibm_cffps2", cffps2 },
477 	{ "ibm_cffps", cffps_unknown },
478 	{}
479 };
480 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
481 
482 static int ibm_cffps_probe(struct i2c_client *client)
483 {
484 	int i, rc;
485 	enum versions vs = cffps_unknown;
486 	struct dentry *debugfs;
487 	struct ibm_cffps *psu;
488 	const void *md = of_device_get_match_data(&client->dev);
489 	const struct i2c_device_id *id;
490 
491 	if (md) {
492 		vs = (uintptr_t)md;
493 	} else {
494 		id = i2c_match_id(ibm_cffps_id, client);
495 		if (id)
496 			vs = (enum versions)id->driver_data;
497 	}
498 
499 	if (vs == cffps_unknown) {
500 		u16 ccin_revision = 0;
501 		u16 ccin_version = CFFPS_CCIN_VERSION_1;
502 		int ccin = i2c_smbus_read_word_swapped(client, CFFPS_CCIN_CMD);
503 		char mfg_id[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
504 
505 		if (ccin > 0) {
506 			ccin_revision = FIELD_GET(CFFPS_CCIN_REVISION, ccin);
507 			ccin_version = FIELD_GET(CFFPS_CCIN_VERSION, ccin);
508 		}
509 
510 		rc = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, mfg_id);
511 		if (rc < 0) {
512 			dev_err(&client->dev, "Failed to read Manufacturer ID\n");
513 			return rc;
514 		}
515 
516 		switch (ccin_version) {
517 		default:
518 		case CFFPS_CCIN_VERSION_1:
519 			if ((strncmp(mfg_id, "ACBE", 4) == 0) ||
520 				     (strncmp(mfg_id, "ARTE", 4) == 0))
521 				vs = cffps1;
522 			else
523 				vs = cffps2;
524 			break;
525 		case CFFPS_CCIN_VERSION_2:
526 			vs = cffps2;
527 			break;
528 		case CFFPS_CCIN_VERSION_3:
529 			if (ccin_revision == CFFPS_CCIN_REVISION_LEGACY)
530 				vs = cffps1;
531 			else
532 				vs = cffps2;
533 			break;
534 		}
535 
536 		/* Set the client name to include the version number. */
537 		snprintf(client->name, I2C_NAME_SIZE, "cffps%d", vs + 1);
538 	}
539 
540 	client->dev.platform_data = &ibm_cffps_pdata;
541 	rc = pmbus_do_probe(client, &ibm_cffps_info[vs]);
542 	if (rc)
543 		return rc;
544 
545 	/*
546 	 * Don't fail the probe if there isn't enough memory for leds and
547 	 * debugfs.
548 	 */
549 	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
550 	if (!psu)
551 		return 0;
552 
553 	psu->version = vs;
554 	psu->client = client;
555 
556 	ibm_cffps_create_led_class(psu);
557 
558 	/* Don't fail the probe if we can't create debugfs */
559 	debugfs = pmbus_get_debugfs_dir(client);
560 	if (!debugfs)
561 		return 0;
562 
563 	for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
564 		psu->debugfs_entries[i] = i;
565 
566 	debugfs_create_file("input_history", 0444, debugfs, psu, &ibm_cffps_input_history_fops);
567 	debugfs_create_file("max_power_out", 0444, debugfs,
568 			    &psu->debugfs_entries[CFFPS_DEBUGFS_MAX_POWER_OUT],
569 			    &ibm_cffps_fops);
570 	debugfs_create_file("ccin", 0444, debugfs,
571 			    &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
572 			    &ibm_cffps_fops);
573 	debugfs_create_file("fw_version", 0444, debugfs,
574 			    &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
575 			    &ibm_cffps_fops);
576 	debugfs_create_file("on_off_config", 0644, debugfs,
577 			    &psu->debugfs_entries[CFFPS_DEBUGFS_ON_OFF_CONFIG],
578 			    &ibm_cffps_fops);
579 
580 	/* For compatibility with users of the old naming scheme. */
581 	debugfs_create_symlink(client->name, debugfs, ".");
582 
583 	return 0;
584 }
585 
586 static const struct of_device_id ibm_cffps_of_match[] = {
587 	{
588 		.compatible = "ibm,cffps1",
589 		.data = (void *)cffps1
590 	},
591 	{
592 		.compatible = "ibm,cffps2",
593 		.data = (void *)cffps2
594 	},
595 	{
596 		.compatible = "ibm,cffps",
597 		.data = (void *)cffps_unknown
598 	},
599 	{}
600 };
601 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
602 
603 static struct i2c_driver ibm_cffps_driver = {
604 	.driver = {
605 		.name = "ibm-cffps",
606 		.of_match_table = ibm_cffps_of_match,
607 	},
608 	.probe = ibm_cffps_probe,
609 	.id_table = ibm_cffps_id,
610 };
611 
612 module_i2c_driver(ibm_cffps_driver);
613 
614 MODULE_AUTHOR("Eddie James");
615 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
616 MODULE_LICENSE("GPL");
617 MODULE_IMPORT_NS(PMBUS);
618