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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 health parameters. */
54#define MLXREG_HOTPLUG_HEALTH_MASK 0x02
55#define MLXREG_HOTPLUG_RST_CNTR 3
56
57#define MLXREG_HOTPLUG_ATTRS_MAX 24
58
59/**
60 * struct mlxreg_hotplug_priv_data - platform private data:
61 * @irq: platform device interrupt number;
62 * @pdev: platform device;
63 * @plat: platform data;
64 * @dwork: delayed work template;
65 * @lock: spin lock;
66 * @hwmon: hwmon device;
67 * @mlxreg_hotplug_attr: sysfs attributes array;
68 * @mlxreg_hotplug_dev_attr: sysfs sensor device attribute array;
69 * @group: sysfs attribute group;
70 * @groups: list of sysfs attribute group for hwmon registration;
71 * @cell: location of top aggregation interrupt register;
72 * @mask: top aggregation interrupt common mask;
73 * @aggr_cache: last value of aggregation register status;
74 */
75struct mlxreg_hotplug_priv_data {
76 int irq;
77 struct device *dev;
78 struct platform_device *pdev;
79 struct mlxreg_hotplug_platform_data *plat;
80 struct regmap *regmap;
81 struct delayed_work dwork_irq;
82 struct delayed_work dwork;
83 spinlock_t lock; /* sync with interrupt */
84 struct device *hwmon;
85 struct attribute *mlxreg_hotplug_attr[MLXREG_HOTPLUG_ATTRS_MAX + 1];
86 struct sensor_device_attribute_2
87 mlxreg_hotplug_dev_attr[MLXREG_HOTPLUG_ATTRS_MAX];
88 struct attribute_group group;
89 const struct attribute_group *groups[2];
90 u32 cell;
91 u32 mask;
92 u32 aggr_cache;
93 bool after_probe;
94};
95
96static int mlxreg_hotplug_device_create(struct mlxreg_hotplug_priv_data *priv,
97 struct mlxreg_core_data *data)
98{
99 struct mlxreg_core_hotplug_platform_data *pdata;
100
101 /*
102 * Return if adapter number is negative. It could be in case hotplug
103 * event is not associated with hotplug device.
104 */
105 if (data->hpdev.nr < 0)
106 return 0;
107
108 pdata = dev_get_platdata(&priv->pdev->dev);
109 data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr +
110 pdata->shift_nr);
111 if (!data->hpdev.adapter) {
112 dev_err(priv->dev, "Failed to get adapter for bus %d\n",
113 data->hpdev.nr + pdata->shift_nr);
114 return -EFAULT;
115 }
116
117 data->hpdev.client = i2c_new_device(data->hpdev.adapter,
118 data->hpdev.brdinfo);
119 if (!data->hpdev.client) {
120 dev_err(priv->dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
121 data->hpdev.brdinfo->type, data->hpdev.nr +
122 pdata->shift_nr, data->hpdev.brdinfo->addr);
123
124 i2c_put_adapter(data->hpdev.adapter);
125 data->hpdev.adapter = NULL;
126 return -EFAULT;
127 }
128
129 return 0;
130}
131
132static void mlxreg_hotplug_device_destroy(struct mlxreg_core_data *data)
133{
134 if (data->hpdev.client) {
135 i2c_unregister_device(data->hpdev.client);
136 data->hpdev.client = NULL;
137 }
138
139 if (data->hpdev.adapter) {
140 i2c_put_adapter(data->hpdev.adapter);
141 data->hpdev.adapter = NULL;
142 }
143}
144
145static ssize_t mlxreg_hotplug_attr_show(struct device *dev,
146 struct device_attribute *attr,
147 char *buf)
148{
149 struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(dev);
150 struct mlxreg_core_hotplug_platform_data *pdata;
151 int index = to_sensor_dev_attr_2(attr)->index;
152 int nr = to_sensor_dev_attr_2(attr)->nr;
153 struct mlxreg_core_item *item;
154 struct mlxreg_core_data *data;
155 u32 regval;
156 int ret;
157
158 pdata = dev_get_platdata(&priv->pdev->dev);
159 item = pdata->items + nr;
160 data = item->data + index;
161
162 ret = regmap_read(priv->regmap, data->reg, ®val);
163 if (ret)
164 return ret;
165
166 if (item->health) {
167 regval &= data->mask;
168 } else {
169 /* Bit = 0 : functional if item->inversed is true. */
170 if (item->inversed)
171 regval = !(regval & data->mask);
172 else
173 regval = !!(regval & data->mask);
174 }
175
176 return sprintf(buf, "%u\n", regval);
177}
178
179#define PRIV_ATTR(i) priv->mlxreg_hotplug_attr[i]
180#define PRIV_DEV_ATTR(i) priv->mlxreg_hotplug_dev_attr[i]
181
182static int mlxreg_hotplug_attr_init(struct mlxreg_hotplug_priv_data *priv)
183{
184 struct mlxreg_core_hotplug_platform_data *pdata;
185 struct mlxreg_core_item *item;
186 struct mlxreg_core_data *data;
187 int num_attrs = 0, id = 0, i, j;
188
189 pdata = dev_get_platdata(&priv->pdev->dev);
190 item = pdata->items;
191
192 /* Go over all kinds of items - psu, pwr, fan. */
193 for (i = 0; i < pdata->counter; i++, item++) {
194 num_attrs += item->count;
195 data = item->data;
196 /* Go over all units within the item. */
197 for (j = 0; j < item->count; j++, data++, id++) {
198 PRIV_ATTR(id) = &PRIV_DEV_ATTR(id).dev_attr.attr;
199 PRIV_ATTR(id)->name = devm_kasprintf(&priv->pdev->dev,
200 GFP_KERNEL,
201 data->label);
202
203 if (!PRIV_ATTR(id)->name) {
204 dev_err(priv->dev, "Memory allocation failed for attr %d.\n",
205 id);
206 return -ENOMEM;
207 }
208
209 PRIV_DEV_ATTR(id).dev_attr.attr.name =
210 PRIV_ATTR(id)->name;
211 PRIV_DEV_ATTR(id).dev_attr.attr.mode = 0444;
212 PRIV_DEV_ATTR(id).dev_attr.show =
213 mlxreg_hotplug_attr_show;
214 PRIV_DEV_ATTR(id).nr = i;
215 PRIV_DEV_ATTR(id).index = j;
216 sysfs_attr_init(&PRIV_DEV_ATTR(id).dev_attr.attr);
217 }
218 }
219
220 priv->group.attrs = devm_kzalloc(&priv->pdev->dev, num_attrs *
221 sizeof(struct attribute *),
222 GFP_KERNEL);
223 if (!priv->group.attrs)
224 return -ENOMEM;
225
226 priv->group.attrs = priv->mlxreg_hotplug_attr;
227 priv->groups[0] = &priv->group;
228 priv->groups[1] = NULL;
229
230 return 0;
231}
232
233static void
234mlxreg_hotplug_work_helper(struct mlxreg_hotplug_priv_data *priv,
235 struct mlxreg_core_item *item)
236{
237 struct mlxreg_core_data *data;
238 u32 asserted, regval, bit;
239 int ret;
240
241 /*
242 * Validate if item related to received signal type is valid.
243 * It should never happen, excepted the situation when some
244 * piece of hardware is broken. In such situation just produce
245 * error message and return. Caller must continue to handle the
246 * signals from other devices if any.
247 */
248 if (unlikely(!item)) {
249 dev_err(priv->dev, "False signal: at offset:mask 0x%02x:0x%02x.\n",
250 item->reg, item->mask);
251
252 return;
253 }
254
255 /* Mask event. */
256 ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
257 0);
258 if (ret)
259 goto out;
260
261 /* Read status. */
262 ret = regmap_read(priv->regmap, item->reg, ®val);
263 if (ret)
264 goto out;
265
266 /* Set asserted bits and save last status. */
267 regval &= item->mask;
268 asserted = item->cache ^ regval;
269 item->cache = regval;
270
271 for_each_set_bit(bit, (unsigned long *)&asserted, 8) {
272 data = item->data + bit;
273 if (regval & BIT(bit)) {
274 if (item->inversed)
275 mlxreg_hotplug_device_destroy(data);
276 else
277 mlxreg_hotplug_device_create(priv, data);
278 } else {
279 if (item->inversed)
280 mlxreg_hotplug_device_create(priv, data);
281 else
282 mlxreg_hotplug_device_destroy(data);
283 }
284 }
285
286 /* Acknowledge event. */
287 ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_EVENT_OFF,
288 0);
289 if (ret)
290 goto out;
291
292 /* Unmask event. */
293 ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
294 item->mask);
295
296 out:
297 if (ret)
298 dev_err(priv->dev, "Failed to complete workqueue.\n");
299}
300
301static void
302mlxreg_hotplug_health_work_helper(struct mlxreg_hotplug_priv_data *priv,
303 struct mlxreg_core_item *item)
304{
305 struct mlxreg_core_data *data = item->data;
306 u32 regval;
307 int i, ret = 0;
308
309 for (i = 0; i < item->count; i++, data++) {
310 /* Mask event. */
311 ret = regmap_write(priv->regmap, data->reg +
312 MLXREG_HOTPLUG_MASK_OFF, 0);
313 if (ret)
314 goto out;
315
316 /* Read status. */
317 ret = regmap_read(priv->regmap, data->reg, ®val);
318 if (ret)
319 goto out;
320
321 regval &= data->mask;
322 item->cache = regval;
323 if (regval == MLXREG_HOTPLUG_HEALTH_MASK) {
324 if ((data->health_cntr++ == MLXREG_HOTPLUG_RST_CNTR) ||
325 !priv->after_probe) {
326 mlxreg_hotplug_device_create(priv, data);
327 data->attached = true;
328 }
329 } else {
330 if (data->attached) {
331 mlxreg_hotplug_device_destroy(data);
332 data->attached = false;
333 data->health_cntr = 0;
334 }
335 }
336
337 /* Acknowledge event. */
338 ret = regmap_write(priv->regmap, data->reg +
339 MLXREG_HOTPLUG_EVENT_OFF, 0);
340 if (ret)
341 goto out;
342
343 /* Unmask event. */
344 ret = regmap_write(priv->regmap, data->reg +
345 MLXREG_HOTPLUG_MASK_OFF, data->mask);
346 if (ret)
347 goto out;
348 }
349
350 out:
351 if (ret)
352 dev_err(priv->dev, "Failed to complete workqueue.\n");
353}
354
355/*
356 * mlxreg_hotplug_work_handler - performs traversing of device interrupt
357 * registers according to the below hierarchy schema:
358 *
359 * Aggregation registers (status/mask)
360 * PSU registers: *---*
361 * *-----------------* | |
362 * |status/event/mask|-----> | * |
363 * *-----------------* | |
364 * Power registers: | |
365 * *-----------------* | |
366 * |status/event/mask|-----> | * |
367 * *-----------------* | |
368 * FAN registers: | |--> CPU
369 * *-----------------* | |
370 * |status/event/mask|-----> | * |
371 * *-----------------* | |
372 * ASIC registers: | |
373 * *-----------------* | |
374 * |status/event/mask|-----> | * |
375 * *-----------------* | |
376 * *---*
377 *
378 * In case some system changed are detected: FAN in/out, PSU in/out, power
379 * cable attached/detached, ASIC health good/bad, relevant device is created
380 * or destroyed.
381 */
382static void mlxreg_hotplug_work_handler(struct work_struct *work)
383{
384 struct mlxreg_core_hotplug_platform_data *pdata;
385 struct mlxreg_hotplug_priv_data *priv;
386 struct mlxreg_core_item *item;
387 u32 regval, aggr_asserted;
388 unsigned long flags;
389 int i, ret;
390
391 priv = container_of(work, struct mlxreg_hotplug_priv_data,
392 dwork_irq.work);
393 pdata = dev_get_platdata(&priv->pdev->dev);
394 item = pdata->items;
395
396 /* Mask aggregation event. */
397 ret = regmap_write(priv->regmap, pdata->cell +
398 MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
399 if (ret < 0)
400 goto out;
401
402 /* Read aggregation status. */
403 ret = regmap_read(priv->regmap, pdata->cell, ®val);
404 if (ret)
405 goto out;
406
407 regval &= pdata->mask;
408 aggr_asserted = priv->aggr_cache ^ regval;
409 priv->aggr_cache = regval;
410
411 /* Handle topology and health configuration changes. */
412 for (i = 0; i < pdata->counter; i++, item++) {
413 if (aggr_asserted & item->aggr_mask) {
414 if (item->health)
415 mlxreg_hotplug_health_work_helper(priv, item);
416 else
417 mlxreg_hotplug_work_helper(priv, item);
418 }
419 }
420
421 if (aggr_asserted) {
422 spin_lock_irqsave(&priv->lock, flags);
423
424 /*
425 * It is possible, that some signals have been inserted, while
426 * interrupt has been masked by mlxreg_hotplug_work_handler.
427 * In this case such signals will be missed. In order to handle
428 * these signals delayed work is canceled and work task
429 * re-scheduled for immediate execution. It allows to handle
430 * missed signals, if any. In other case work handler just
431 * validates that no new signals have been received during
432 * masking.
433 */
434 cancel_delayed_work(&priv->dwork_irq);
435 schedule_delayed_work(&priv->dwork_irq, 0);
436
437 spin_unlock_irqrestore(&priv->lock, flags);
438
439 return;
440 }
441
442 /* Unmask aggregation event (no need acknowledge). */
443 ret = regmap_write(priv->regmap, pdata->cell +
444 MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
445
446 out:
447 if (ret)
448 dev_err(priv->dev, "Failed to complete workqueue.\n");
449}
450
451static int mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv)
452{
453 struct mlxreg_core_hotplug_platform_data *pdata;
454 struct mlxreg_core_item *item;
455 int i, ret;
456
457 pdata = dev_get_platdata(&priv->pdev->dev);
458 item = pdata->items;
459
460 for (i = 0; i < pdata->counter; i++, item++) {
461 /* Clear group presense event. */
462 ret = regmap_write(priv->regmap, item->reg +
463 MLXREG_HOTPLUG_EVENT_OFF, 0);
464 if (ret)
465 goto out;
466
467 /* Set group initial status as mask and unmask group event. */
468 if (item->inversed) {
469 item->cache = item->mask;
470 ret = regmap_write(priv->regmap, item->reg +
471 MLXREG_HOTPLUG_MASK_OFF,
472 item->mask);
473 if (ret)
474 goto out;
475 }
476 }
477
478 /* Keep aggregation initial status as zero and unmask events. */
479 ret = regmap_write(priv->regmap, pdata->cell +
480 MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
481 if (ret)
482 goto out;
483
484 /* Keep low aggregation initial status as zero and unmask events. */
485 if (pdata->cell_low) {
486 ret = regmap_write(priv->regmap, pdata->cell_low +
487 MLXREG_HOTPLUG_AGGR_MASK_OFF,
488 pdata->mask_low);
489 if (ret)
490 goto out;
491 }
492
493 /* Invoke work handler for initializing hot plug devices setting. */
494 mlxreg_hotplug_work_handler(&priv->dwork_irq.work);
495
496 out:
497 if (ret)
498 dev_err(priv->dev, "Failed to set interrupts.\n");
499 enable_irq(priv->irq);
500 return ret;
501}
502
503static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
504{
505 struct mlxreg_core_hotplug_platform_data *pdata;
506 struct mlxreg_core_item *item;
507 struct mlxreg_core_data *data;
508 int count, i, j;
509
510 pdata = dev_get_platdata(&priv->pdev->dev);
511 item = pdata->items;
512 disable_irq(priv->irq);
513 cancel_delayed_work_sync(&priv->dwork_irq);
514
515 /* Mask low aggregation event, if defined. */
516 if (pdata->cell_low)
517 regmap_write(priv->regmap, pdata->cell_low +
518 MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
519
520 /* Mask aggregation event. */
521 regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF,
522 0);
523
524 /* Clear topology configurations. */
525 for (i = 0; i < pdata->counter; i++, item++) {
526 data = item->data;
527 /* Mask group presense event. */
528 regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF,
529 0);
530 /* Clear group presense event. */
531 regmap_write(priv->regmap, data->reg +
532 MLXREG_HOTPLUG_EVENT_OFF, 0);
533
534 /* Remove all the attached devices in group. */
535 count = item->count;
536 for (j = 0; j < count; j++, data++)
537 mlxreg_hotplug_device_destroy(data);
538 }
539}
540
541static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
542{
543 struct mlxreg_hotplug_priv_data *priv;
544
545 priv = (struct mlxreg_hotplug_priv_data *)dev;
546
547 /* Schedule work task for immediate execution.*/
548 schedule_delayed_work(&priv->dwork_irq, 0);
549
550 return IRQ_HANDLED;
551}
552
553static int mlxreg_hotplug_probe(struct platform_device *pdev)
554{
555 struct mlxreg_core_hotplug_platform_data *pdata;
556 struct mlxreg_hotplug_priv_data *priv;
557 struct i2c_adapter *deferred_adap;
558 int err;
559
560 pdata = dev_get_platdata(&pdev->dev);
561 if (!pdata) {
562 dev_err(&pdev->dev, "Failed to get platform data.\n");
563 return -EINVAL;
564 }
565
566 /* Defer probing if the necessary adapter is not configured yet. */
567 deferred_adap = i2c_get_adapter(pdata->deferred_nr);
568 if (!deferred_adap)
569 return -EPROBE_DEFER;
570 i2c_put_adapter(deferred_adap);
571
572 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
573 if (!priv)
574 return -ENOMEM;
575
576 if (pdata->irq) {
577 priv->irq = pdata->irq;
578 } else {
579 priv->irq = platform_get_irq(pdev, 0);
580 if (priv->irq < 0) {
581 dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
582 priv->irq);
583 return priv->irq;
584 }
585 }
586
587 priv->regmap = pdata->regmap;
588 priv->dev = pdev->dev.parent;
589 priv->pdev = pdev;
590
591 err = devm_request_irq(&pdev->dev, priv->irq,
592 mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING
593 | IRQF_SHARED, "mlxreg-hotplug", priv);
594 if (err) {
595 dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
596 return err;
597 }
598
599 disable_irq(priv->irq);
600 spin_lock_init(&priv->lock);
601 INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler);
602 /* Perform initial interrupts setup. */
603 mlxreg_hotplug_set_irq(priv);
604
605 priv->after_probe = true;
606 dev_set_drvdata(&pdev->dev, priv);
607
608 err = mlxreg_hotplug_attr_init(priv);
609 if (err) {
610 dev_err(&pdev->dev, "Failed to allocate attributes: %d\n",
611 err);
612 return err;
613 }
614
615 priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
616 "mlxreg_hotplug", priv, priv->groups);
617 if (IS_ERR(priv->hwmon)) {
618 dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
619 PTR_ERR(priv->hwmon));
620 return PTR_ERR(priv->hwmon);
621 }
622
623 return 0;
624}
625
626static int mlxreg_hotplug_remove(struct platform_device *pdev)
627{
628 struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev);
629
630 /* Clean interrupts setup. */
631 mlxreg_hotplug_unset_irq(priv);
632
633 return 0;
634}
635
636static struct platform_driver mlxreg_hotplug_driver = {
637 .driver = {
638 .name = "mlxreg-hotplug",
639 },
640 .probe = mlxreg_hotplug_probe,
641 .remove = mlxreg_hotplug_remove,
642};
643
644module_platform_driver(mlxreg_hotplug_driver);
645
646MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
647MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
648MODULE_LICENSE("Dual BSD/GPL");
649MODULE_ALIAS("platform:mlxreg-hotplug");