1 /*
2  * Copyright (c) 2016-2018 Mellanox Technologies. All rights reserved.
3  * Copyright (c) 2016-2018 Vadim Pasternak <vadimp@mellanox.com>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the names of the copyright holders nor the names of its
14  *    contributors may be used to endorse or promote products derived from
15  *    this software without specific prior written permission.
16  *
17  * Alternatively, this software may be distributed under the terms of the
18  * GNU General Public License ("GPL") version 2 as published by the Free
19  * Software Foundation.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <linux/bitops.h>
35 #include <linux/device.h>
36 #include <linux/hwmon.h>
37 #include <linux/hwmon-sysfs.h>
38 #include <linux/i2c.h>
39 #include <linux/interrupt.h>
40 #include <linux/module.h>
41 #include <linux/of_device.h>
42 #include <linux/platform_data/mlxreg.h>
43 #include <linux/platform_device.h>
44 #include <linux/spinlock.h>
45 #include <linux/regmap.h>
46 #include <linux/workqueue.h>
47 
48 /* Offset of event and mask registers from status register. */
49 #define MLXREG_HOTPLUG_EVENT_OFF	1
50 #define MLXREG_HOTPLUG_MASK_OFF		2
51 #define MLXREG_HOTPLUG_AGGR_MASK_OFF	1
52 
53 /* ASIC good health mask. */
54 #define MLXREG_HOTPLUG_GOOD_HEALTH_MASK	0x02
55 
56 #define MLXREG_HOTPLUG_ATTRS_MAX	24
57 #define MLXREG_HOTPLUG_NOT_ASSERT	3
58 
59 /**
60  * struct mlxreg_hotplug_priv_data - platform private data:
61  * @irq: platform device interrupt number;
62  * @dev: basic device;
63  * @pdev: platform device;
64  * @plat: platform data;
65  * @regmap: register map handle;
66  * @dwork_irq: delayed work template;
67  * @lock: spin lock;
68  * @hwmon: hwmon device;
69  * @mlxreg_hotplug_attr: sysfs attributes array;
70  * @mlxreg_hotplug_dev_attr: sysfs sensor device attribute array;
71  * @group: sysfs attribute group;
72  * @groups: list of sysfs attribute group for hwmon registration;
73  * @cell: location of top aggregation interrupt register;
74  * @mask: top aggregation interrupt common mask;
75  * @aggr_cache: last value of aggregation register status;
76  * @after_probe: flag indication probing completion;
77  * @not_asserted: number of entries in workqueue with no signal assertion;
78  */
79 struct mlxreg_hotplug_priv_data {
80 	int irq;
81 	struct device *dev;
82 	struct platform_device *pdev;
83 	struct mlxreg_hotplug_platform_data *plat;
84 	struct regmap *regmap;
85 	struct delayed_work dwork_irq;
86 	spinlock_t lock; /* sync with interrupt */
87 	struct device *hwmon;
88 	struct attribute *mlxreg_hotplug_attr[MLXREG_HOTPLUG_ATTRS_MAX + 1];
89 	struct sensor_device_attribute_2
90 			mlxreg_hotplug_dev_attr[MLXREG_HOTPLUG_ATTRS_MAX];
91 	struct attribute_group group;
92 	const struct attribute_group *groups[2];
93 	u32 cell;
94 	u32 mask;
95 	u32 aggr_cache;
96 	bool after_probe;
97 	u8 not_asserted;
98 };
99 
100 static int mlxreg_hotplug_device_create(struct mlxreg_hotplug_priv_data *priv,
101 					struct mlxreg_core_data *data)
102 {
103 	struct mlxreg_core_hotplug_platform_data *pdata;
104 
105 	/* Notify user by sending hwmon uevent. */
106 	kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE);
107 
108 	/*
109 	 * Return if adapter number is negative. It could be in case hotplug
110 	 * event is not associated with hotplug device.
111 	 */
112 	if (data->hpdev.nr < 0)
113 		return 0;
114 
115 	pdata = dev_get_platdata(&priv->pdev->dev);
116 	data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr +
117 					      pdata->shift_nr);
118 	if (!data->hpdev.adapter) {
119 		dev_err(priv->dev, "Failed to get adapter for bus %d\n",
120 			data->hpdev.nr + pdata->shift_nr);
121 		return -EFAULT;
122 	}
123 
124 	data->hpdev.client = i2c_new_device(data->hpdev.adapter,
125 					    data->hpdev.brdinfo);
126 	if (!data->hpdev.client) {
127 		dev_err(priv->dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
128 			data->hpdev.brdinfo->type, data->hpdev.nr +
129 			pdata->shift_nr, data->hpdev.brdinfo->addr);
130 
131 		i2c_put_adapter(data->hpdev.adapter);
132 		data->hpdev.adapter = NULL;
133 		return -EFAULT;
134 	}
135 
136 	return 0;
137 }
138 
139 static void
140 mlxreg_hotplug_device_destroy(struct mlxreg_hotplug_priv_data *priv,
141 			      struct mlxreg_core_data *data)
142 {
143 	/* Notify user by sending hwmon uevent. */
144 	kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE);
145 
146 	if (data->hpdev.client) {
147 		i2c_unregister_device(data->hpdev.client);
148 		data->hpdev.client = NULL;
149 	}
150 
151 	if (data->hpdev.adapter) {
152 		i2c_put_adapter(data->hpdev.adapter);
153 		data->hpdev.adapter = NULL;
154 	}
155 }
156 
157 static ssize_t mlxreg_hotplug_attr_show(struct device *dev,
158 					struct device_attribute *attr,
159 					char *buf)
160 {
161 	struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(dev);
162 	struct mlxreg_core_hotplug_platform_data *pdata;
163 	int index = to_sensor_dev_attr_2(attr)->index;
164 	int nr = to_sensor_dev_attr_2(attr)->nr;
165 	struct mlxreg_core_item *item;
166 	struct mlxreg_core_data *data;
167 	u32 regval;
168 	int ret;
169 
170 	pdata = dev_get_platdata(&priv->pdev->dev);
171 	item = pdata->items + nr;
172 	data = item->data + index;
173 
174 	ret = regmap_read(priv->regmap, data->reg, &regval);
175 	if (ret)
176 		return ret;
177 
178 	if (item->health) {
179 		regval &= data->mask;
180 	} else {
181 		/* Bit = 0 : functional if item->inversed is true. */
182 		if (item->inversed)
183 			regval = !(regval & data->mask);
184 		else
185 			regval = !!(regval & data->mask);
186 	}
187 
188 	return sprintf(buf, "%u\n", regval);
189 }
190 
191 #define PRIV_ATTR(i) priv->mlxreg_hotplug_attr[i]
192 #define PRIV_DEV_ATTR(i) priv->mlxreg_hotplug_dev_attr[i]
193 
194 static int mlxreg_hotplug_attr_init(struct mlxreg_hotplug_priv_data *priv)
195 {
196 	struct mlxreg_core_hotplug_platform_data *pdata;
197 	struct mlxreg_core_item *item;
198 	struct mlxreg_core_data *data;
199 	int num_attrs = 0, id = 0, i, j;
200 
201 	pdata = dev_get_platdata(&priv->pdev->dev);
202 	item = pdata->items;
203 
204 	/* Go over all kinds of items - psu, pwr, fan. */
205 	for (i = 0; i < pdata->counter; i++, item++) {
206 		num_attrs += item->count;
207 		data = item->data;
208 		/* Go over all units within the item. */
209 		for (j = 0; j < item->count; j++, data++, id++) {
210 			PRIV_ATTR(id) = &PRIV_DEV_ATTR(id).dev_attr.attr;
211 			PRIV_ATTR(id)->name = devm_kasprintf(&priv->pdev->dev,
212 							     GFP_KERNEL,
213 							     data->label);
214 
215 			if (!PRIV_ATTR(id)->name) {
216 				dev_err(priv->dev, "Memory allocation failed for attr %d.\n",
217 					id);
218 				return -ENOMEM;
219 			}
220 
221 			PRIV_DEV_ATTR(id).dev_attr.attr.name =
222 							PRIV_ATTR(id)->name;
223 			PRIV_DEV_ATTR(id).dev_attr.attr.mode = 0444;
224 			PRIV_DEV_ATTR(id).dev_attr.show =
225 						mlxreg_hotplug_attr_show;
226 			PRIV_DEV_ATTR(id).nr = i;
227 			PRIV_DEV_ATTR(id).index = j;
228 			sysfs_attr_init(&PRIV_DEV_ATTR(id).dev_attr.attr);
229 		}
230 	}
231 
232 	priv->group.attrs = devm_kcalloc(&priv->pdev->dev,
233 					 num_attrs,
234 					 sizeof(struct attribute *),
235 					 GFP_KERNEL);
236 	if (!priv->group.attrs)
237 		return -ENOMEM;
238 
239 	priv->group.attrs = priv->mlxreg_hotplug_attr;
240 	priv->groups[0] = &priv->group;
241 	priv->groups[1] = NULL;
242 
243 	return 0;
244 }
245 
246 static void
247 mlxreg_hotplug_work_helper(struct mlxreg_hotplug_priv_data *priv,
248 			   struct mlxreg_core_item *item)
249 {
250 	struct mlxreg_core_data *data;
251 	unsigned long asserted;
252 	u32 regval, bit;
253 	int ret;
254 
255 	/*
256 	 * Validate if item related to received signal type is valid.
257 	 * It should never happen, excepted the situation when some
258 	 * piece of hardware is broken. In such situation just produce
259 	 * error message and return. Caller must continue to handle the
260 	 * signals from other devices if any.
261 	 */
262 	if (unlikely(!item)) {
263 		dev_err(priv->dev, "False signal: at offset:mask 0x%02x:0x%02x.\n",
264 			item->reg, item->mask);
265 
266 		return;
267 	}
268 
269 	/* Mask event. */
270 	ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
271 			   0);
272 	if (ret)
273 		goto out;
274 
275 	/* Read status. */
276 	ret = regmap_read(priv->regmap, item->reg, &regval);
277 	if (ret)
278 		goto out;
279 
280 	/* Set asserted bits and save last status. */
281 	regval &= item->mask;
282 	asserted = item->cache ^ regval;
283 	item->cache = regval;
284 
285 	for_each_set_bit(bit, &asserted, 8) {
286 		data = item->data + bit;
287 		if (regval & BIT(bit)) {
288 			if (item->inversed)
289 				mlxreg_hotplug_device_destroy(priv, data);
290 			else
291 				mlxreg_hotplug_device_create(priv, data);
292 		} else {
293 			if (item->inversed)
294 				mlxreg_hotplug_device_create(priv, data);
295 			else
296 				mlxreg_hotplug_device_destroy(priv, data);
297 		}
298 	}
299 
300 	/* Acknowledge event. */
301 	ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_EVENT_OFF,
302 			   0);
303 	if (ret)
304 		goto out;
305 
306 	/* Unmask event. */
307 	ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
308 			   item->mask);
309 
310  out:
311 	if (ret)
312 		dev_err(priv->dev, "Failed to complete workqueue.\n");
313 }
314 
315 static void
316 mlxreg_hotplug_health_work_helper(struct mlxreg_hotplug_priv_data *priv,
317 				  struct mlxreg_core_item *item)
318 {
319 	struct mlxreg_core_data *data = item->data;
320 	u32 regval;
321 	int i, ret = 0;
322 
323 	for (i = 0; i < item->count; i++, data++) {
324 		/* Mask event. */
325 		ret = regmap_write(priv->regmap, data->reg +
326 				   MLXREG_HOTPLUG_MASK_OFF, 0);
327 		if (ret)
328 			goto out;
329 
330 		/* Read status. */
331 		ret = regmap_read(priv->regmap, data->reg, &regval);
332 		if (ret)
333 			goto out;
334 
335 		regval &= data->mask;
336 
337 		if (item->cache == regval)
338 			goto ack_event;
339 
340 		/*
341 		 * ASIC health indication is provided through two bits. Bits
342 		 * value 0x2 indicates that ASIC reached the good health, value
343 		 * 0x0 indicates ASIC the bad health or dormant state and value
344 		 * 0x3 indicates the booting state. During ASIC reset it should
345 		 * pass the following states: dormant -> booting -> good.
346 		 */
347 		if (regval == MLXREG_HOTPLUG_GOOD_HEALTH_MASK) {
348 			if (!data->attached) {
349 				/*
350 				 * ASIC is in steady state. Connect associated
351 				 * device, if configured.
352 				 */
353 				mlxreg_hotplug_device_create(priv, data);
354 				data->attached = true;
355 			}
356 		} else {
357 			if (data->attached) {
358 				/*
359 				 * ASIC health is failed after ASIC has been
360 				 * in steady state. Disconnect associated
361 				 * device, if it has been connected.
362 				 */
363 				mlxreg_hotplug_device_destroy(priv, data);
364 				data->attached = false;
365 				data->health_cntr = 0;
366 			}
367 		}
368 		item->cache = regval;
369 ack_event:
370 		/* Acknowledge event. */
371 		ret = regmap_write(priv->regmap, data->reg +
372 				   MLXREG_HOTPLUG_EVENT_OFF, 0);
373 		if (ret)
374 			goto out;
375 
376 		/* Unmask event. */
377 		ret = regmap_write(priv->regmap, data->reg +
378 				   MLXREG_HOTPLUG_MASK_OFF, data->mask);
379 		if (ret)
380 			goto out;
381 	}
382 
383  out:
384 	if (ret)
385 		dev_err(priv->dev, "Failed to complete workqueue.\n");
386 }
387 
388 /*
389  * mlxreg_hotplug_work_handler - performs traversing of device interrupt
390  * registers according to the below hierarchy schema:
391  *
392  *				Aggregation registers (status/mask)
393  * PSU registers:		*---*
394  * *-----------------*		|   |
395  * |status/event/mask|----->    | * |
396  * *-----------------*		|   |
397  * Power registers:		|   |
398  * *-----------------*		|   |
399  * |status/event/mask|----->    | * |
400  * *-----------------*		|   |
401  * FAN registers:		|   |--> CPU
402  * *-----------------*		|   |
403  * |status/event/mask|----->    | * |
404  * *-----------------*		|   |
405  * ASIC registers:		|   |
406  * *-----------------*		|   |
407  * |status/event/mask|----->    | * |
408  * *-----------------*		|   |
409  *				*---*
410  *
411  * In case some system changed are detected: FAN in/out, PSU in/out, power
412  * cable attached/detached, ASIC health good/bad, relevant device is created
413  * or destroyed.
414  */
415 static void mlxreg_hotplug_work_handler(struct work_struct *work)
416 {
417 	struct mlxreg_core_hotplug_platform_data *pdata;
418 	struct mlxreg_hotplug_priv_data *priv;
419 	struct mlxreg_core_item *item;
420 	u32 regval, aggr_asserted;
421 	unsigned long flags;
422 	int i, ret;
423 
424 	priv = container_of(work, struct mlxreg_hotplug_priv_data,
425 			    dwork_irq.work);
426 	pdata = dev_get_platdata(&priv->pdev->dev);
427 	item = pdata->items;
428 
429 	/* Mask aggregation event. */
430 	ret = regmap_write(priv->regmap, pdata->cell +
431 			   MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
432 	if (ret < 0)
433 		goto out;
434 
435 	/* Read aggregation status. */
436 	ret = regmap_read(priv->regmap, pdata->cell, &regval);
437 	if (ret)
438 		goto out;
439 
440 	regval &= pdata->mask;
441 	aggr_asserted = priv->aggr_cache ^ regval;
442 	priv->aggr_cache = regval;
443 
444 	/*
445 	 * Handler is invoked, but no assertion is detected at top aggregation
446 	 * status level. Set aggr_asserted to mask value to allow handler extra
447 	 * run over all relevant signals to recover any missed signal.
448 	 */
449 	if (priv->not_asserted == MLXREG_HOTPLUG_NOT_ASSERT) {
450 		priv->not_asserted = 0;
451 		aggr_asserted = pdata->mask;
452 	}
453 	if (!aggr_asserted)
454 		goto unmask_event;
455 
456 	/* Handle topology and health configuration changes. */
457 	for (i = 0; i < pdata->counter; i++, item++) {
458 		if (aggr_asserted & item->aggr_mask) {
459 			if (item->health)
460 				mlxreg_hotplug_health_work_helper(priv, item);
461 			else
462 				mlxreg_hotplug_work_helper(priv, item);
463 		}
464 	}
465 
466 	spin_lock_irqsave(&priv->lock, flags);
467 
468 	/*
469 	 * It is possible, that some signals have been inserted, while
470 	 * interrupt has been masked by mlxreg_hotplug_work_handler. In this
471 	 * case such signals will be missed. In order to handle these signals
472 	 * delayed work is canceled and work task re-scheduled for immediate
473 	 * execution. It allows to handle missed signals, if any. In other case
474 	 * work handler just validates that no new signals have been received
475 	 * during masking.
476 	 */
477 	cancel_delayed_work(&priv->dwork_irq);
478 	schedule_delayed_work(&priv->dwork_irq, 0);
479 
480 	spin_unlock_irqrestore(&priv->lock, flags);
481 
482 	return;
483 
484 unmask_event:
485 	priv->not_asserted++;
486 	/* Unmask aggregation event (no need acknowledge). */
487 	ret = regmap_write(priv->regmap, pdata->cell +
488 			   MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
489 
490  out:
491 	if (ret)
492 		dev_err(priv->dev, "Failed to complete workqueue.\n");
493 }
494 
495 static int mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv)
496 {
497 	struct mlxreg_core_hotplug_platform_data *pdata;
498 	struct mlxreg_core_item *item;
499 	struct mlxreg_core_data *data;
500 	u32 regval;
501 	int i, j, ret;
502 
503 	pdata = dev_get_platdata(&priv->pdev->dev);
504 	item = pdata->items;
505 
506 	for (i = 0; i < pdata->counter; i++, item++) {
507 		/* Clear group presense event. */
508 		ret = regmap_write(priv->regmap, item->reg +
509 				   MLXREG_HOTPLUG_EVENT_OFF, 0);
510 		if (ret)
511 			goto out;
512 
513 		/*
514 		 * Verify if hardware configuration requires to disable
515 		 * interrupt capability for some of components.
516 		 */
517 		data = item->data;
518 		for (j = 0; j < item->count; j++, data++) {
519 			/* Verify if the attribute has capability register. */
520 			if (data->capability) {
521 				/* Read capability register. */
522 				ret = regmap_read(priv->regmap,
523 						  data->capability, &regval);
524 				if (ret)
525 					goto out;
526 
527 				if (!(regval & data->bit))
528 					item->mask &= ~BIT(j);
529 			}
530 		}
531 
532 		/* Set group initial status as mask and unmask group event. */
533 		if (item->inversed) {
534 			item->cache = item->mask;
535 			ret = regmap_write(priv->regmap, item->reg +
536 					   MLXREG_HOTPLUG_MASK_OFF,
537 					   item->mask);
538 			if (ret)
539 				goto out;
540 		}
541 	}
542 
543 	/* Keep aggregation initial status as zero and unmask events. */
544 	ret = regmap_write(priv->regmap, pdata->cell +
545 			   MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
546 	if (ret)
547 		goto out;
548 
549 	/* Keep low aggregation initial status as zero and unmask events. */
550 	if (pdata->cell_low) {
551 		ret = regmap_write(priv->regmap, pdata->cell_low +
552 				   MLXREG_HOTPLUG_AGGR_MASK_OFF,
553 				   pdata->mask_low);
554 		if (ret)
555 			goto out;
556 	}
557 
558 	/* Invoke work handler for initializing hot plug devices setting. */
559 	mlxreg_hotplug_work_handler(&priv->dwork_irq.work);
560 
561  out:
562 	if (ret)
563 		dev_err(priv->dev, "Failed to set interrupts.\n");
564 	enable_irq(priv->irq);
565 	return ret;
566 }
567 
568 static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
569 {
570 	struct mlxreg_core_hotplug_platform_data *pdata;
571 	struct mlxreg_core_item *item;
572 	struct mlxreg_core_data *data;
573 	int count, i, j;
574 
575 	pdata = dev_get_platdata(&priv->pdev->dev);
576 	item = pdata->items;
577 	disable_irq(priv->irq);
578 	cancel_delayed_work_sync(&priv->dwork_irq);
579 
580 	/* Mask low aggregation event, if defined. */
581 	if (pdata->cell_low)
582 		regmap_write(priv->regmap, pdata->cell_low +
583 			     MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
584 
585 	/* Mask aggregation event. */
586 	regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF,
587 		     0);
588 
589 	/* Clear topology configurations. */
590 	for (i = 0; i < pdata->counter; i++, item++) {
591 		data = item->data;
592 		/* Mask group presense event. */
593 		regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF,
594 			     0);
595 		/* Clear group presense event. */
596 		regmap_write(priv->regmap, data->reg +
597 			     MLXREG_HOTPLUG_EVENT_OFF, 0);
598 
599 		/* Remove all the attached devices in group. */
600 		count = item->count;
601 		for (j = 0; j < count; j++, data++)
602 			mlxreg_hotplug_device_destroy(priv, data);
603 	}
604 }
605 
606 static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
607 {
608 	struct mlxreg_hotplug_priv_data *priv;
609 
610 	priv = (struct mlxreg_hotplug_priv_data *)dev;
611 
612 	/* Schedule work task for immediate execution.*/
613 	schedule_delayed_work(&priv->dwork_irq, 0);
614 
615 	return IRQ_HANDLED;
616 }
617 
618 static int mlxreg_hotplug_probe(struct platform_device *pdev)
619 {
620 	struct mlxreg_core_hotplug_platform_data *pdata;
621 	struct mlxreg_hotplug_priv_data *priv;
622 	struct i2c_adapter *deferred_adap;
623 	int err;
624 
625 	pdata = dev_get_platdata(&pdev->dev);
626 	if (!pdata) {
627 		dev_err(&pdev->dev, "Failed to get platform data.\n");
628 		return -EINVAL;
629 	}
630 
631 	/* Defer probing if the necessary adapter is not configured yet. */
632 	deferred_adap = i2c_get_adapter(pdata->deferred_nr);
633 	if (!deferred_adap)
634 		return -EPROBE_DEFER;
635 	i2c_put_adapter(deferred_adap);
636 
637 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
638 	if (!priv)
639 		return -ENOMEM;
640 
641 	if (pdata->irq) {
642 		priv->irq = pdata->irq;
643 	} else {
644 		priv->irq = platform_get_irq(pdev, 0);
645 		if (priv->irq < 0)
646 			return priv->irq;
647 	}
648 
649 	priv->regmap = pdata->regmap;
650 	priv->dev = pdev->dev.parent;
651 	priv->pdev = pdev;
652 
653 	err = devm_request_irq(&pdev->dev, priv->irq,
654 			       mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING
655 			       | IRQF_SHARED, "mlxreg-hotplug", priv);
656 	if (err) {
657 		dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
658 		return err;
659 	}
660 
661 	disable_irq(priv->irq);
662 	spin_lock_init(&priv->lock);
663 	INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler);
664 	dev_set_drvdata(&pdev->dev, priv);
665 
666 	err = mlxreg_hotplug_attr_init(priv);
667 	if (err) {
668 		dev_err(&pdev->dev, "Failed to allocate attributes: %d\n",
669 			err);
670 		return err;
671 	}
672 
673 	priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
674 					"mlxreg_hotplug", priv, priv->groups);
675 	if (IS_ERR(priv->hwmon)) {
676 		dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
677 			PTR_ERR(priv->hwmon));
678 		return PTR_ERR(priv->hwmon);
679 	}
680 
681 	/* Perform initial interrupts setup. */
682 	mlxreg_hotplug_set_irq(priv);
683 	priv->after_probe = true;
684 
685 	return 0;
686 }
687 
688 static int mlxreg_hotplug_remove(struct platform_device *pdev)
689 {
690 	struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev);
691 
692 	/* Clean interrupts setup. */
693 	mlxreg_hotplug_unset_irq(priv);
694 	devm_free_irq(&pdev->dev, priv->irq, priv);
695 
696 	return 0;
697 }
698 
699 static struct platform_driver mlxreg_hotplug_driver = {
700 	.driver = {
701 		.name = "mlxreg-hotplug",
702 	},
703 	.probe = mlxreg_hotplug_probe,
704 	.remove = mlxreg_hotplug_remove,
705 };
706 
707 module_platform_driver(mlxreg_hotplug_driver);
708 
709 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
710 MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
711 MODULE_LICENSE("Dual BSD/GPL");
712 MODULE_ALIAS("platform:mlxreg-hotplug");
713