drivers/platform/mellanox/mlxreg-hotplug.c

   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         u32 asserted, regval, bit;
 252         int ret;
 253
 254         /*
 255          * Validate if item related to received signal type is valid.
 256          * It should never happen, excepted the situation when some
 257          * piece of hardware is broken. In such situation just produce
 258          * error message and return. Caller must continue to handle the
 259          * signals from other devices if any.
 260          */
 261         if (unlikely(!item)) {
 262                 dev_err(priv->dev, "False signal: at offset:mask 0x%02x:0x%02x.\n",
 263                         item->reg, item->mask);
 264
 265                 return;
 266         }
 267
 268         /* Mask event. */
 269         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
 270                            0);
 271         if (ret)
 272                 goto out;
 273
 274         /* Read status. */
 275         ret = regmap_read(priv->regmap, item->reg, &regval);
 276         if (ret)
 277                 goto out;
 278
 279         /* Set asserted bits and save last status. */
 280         regval &= item->mask;
 281         asserted = item->cache ^ regval;
 282         item->cache = regval;
 283
 284         for_each_set_bit(bit, (unsigned long *)&asserted, 8) {
 285                 data = item->data + bit;
 286                 if (regval & BIT(bit)) {
 287                         if (item->inversed)
 288                                 mlxreg_hotplug_device_destroy(priv, data);
 289                         else
 290                                 mlxreg_hotplug_device_create(priv, data);
 291                 } else {
 292                         if (item->inversed)
 293                                 mlxreg_hotplug_device_create(priv, data);
 294                         else
 295                                 mlxreg_hotplug_device_destroy(priv, data);
 296                 }
 297         }
 298
 299         /* Acknowledge event. */
 300         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_EVENT_OFF,
 301                            0);
 302         if (ret)
 303                 goto out;
 304
 305         /* Unmask event. */
 306         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
 307                            item->mask);
 308
 309  out:
 310         if (ret)
 311                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 312 }
 313
 314 static void
 315 mlxreg_hotplug_health_work_helper(struct mlxreg_hotplug_priv_data *priv,
 316                                   struct mlxreg_core_item *item)
 317 {
 318         struct mlxreg_core_data *data = item->data;
 319         u32 regval;
 320         int i, ret = 0;
 321
 322         for (i = 0; i < item->count; i++, data++) {
 323                 /* Mask event. */
 324                 ret = regmap_write(priv->regmap, data->reg +
 325                                    MLXREG_HOTPLUG_MASK_OFF, 0);
 326                 if (ret)
 327                         goto out;
 328
 329                 /* Read status. */
 330                 ret = regmap_read(priv->regmap, data->reg, &regval);
 331                 if (ret)
 332                         goto out;
 333
 334                 regval &= data->mask;
 335
 336                 if (item->cache == regval)
 337                         goto ack_event;
 338
 339                 /*
 340                  * ASIC health indication is provided through two bits. Bits
 341                  * value 0x2 indicates that ASIC reached the good health, value
 342                  * 0x0 indicates ASIC the bad health or dormant state and value
 343                  * 0x3 indicates the booting state. During ASIC reset it should
 344                  * pass the following states: dormant -> booting -> good.
 345                  */
 346                 if (regval == MLXREG_HOTPLUG_GOOD_HEALTH_MASK) {
 347                         if (!data->attached) {
 348                                 /*
 349                                  * ASIC is in steady state. Connect associated
 350                                  * device, if configured.
 351                                  */
 352                                 mlxreg_hotplug_device_create(priv, data);
 353                                 data->attached = true;
 354                         }
 355                 } else {
 356                         if (data->attached) {
 357                                 /*
 358                                  * ASIC health is failed after ASIC has been
 359                                  * in steady state. Disconnect associated
 360                                  * device, if it has been connected.
 361                                  */
 362                                 mlxreg_hotplug_device_destroy(priv, data);
 363                                 data->attached = false;
 364                                 data->health_cntr = 0;
 365                         }
 366                 }
 367                 item->cache = regval;
 368 ack_event:
 369                 /* Acknowledge event. */
 370                 ret = regmap_write(priv->regmap, data->reg +
 371                                    MLXREG_HOTPLUG_EVENT_OFF, 0);
 372                 if (ret)
 373                         goto out;
 374
 375                 /* Unmask event. */
 376                 ret = regmap_write(priv->regmap, data->reg +
 377                                    MLXREG_HOTPLUG_MASK_OFF, data->mask);
 378                 if (ret)
 379                         goto out;
 380         }
 381
 382  out:
 383         if (ret)
 384                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 385 }
 386
 387 /*
 388  * mlxreg_hotplug_work_handler - performs traversing of device interrupt
 389  * registers according to the below hierarchy schema:
 390  *
 391  *                              Aggregation registers (status/mask)
 392  * PSU registers:               *---*
 393  * *-----------------*          |   |
 394  * |status/event/mask|----->    | * |
 395  * *-----------------*          |   |
 396  * Power registers:             |   |
 397  * *-----------------*          |   |
 398  * |status/event/mask|----->    | * |
 399  * *-----------------*          |   |
 400  * FAN registers:               |   |--> CPU
 401  * *-----------------*          |   |
 402  * |status/event/mask|----->    | * |
 403  * *-----------------*          |   |
 404  * ASIC registers:              |   |
 405  * *-----------------*          |   |
 406  * |status/event/mask|----->    | * |
 407  * *-----------------*          |   |
 408  *                              *---*
 409  *
 410  * In case some system changed are detected: FAN in/out, PSU in/out, power
 411  * cable attached/detached, ASIC health good/bad, relevant device is created
 412  * or destroyed.
 413  */
 414 static void mlxreg_hotplug_work_handler(struct work_struct *work)
 415 {
 416         struct mlxreg_core_hotplug_platform_data *pdata;
 417         struct mlxreg_hotplug_priv_data *priv;
 418         struct mlxreg_core_item *item;
 419         u32 regval, aggr_asserted;
 420         unsigned long flags;
 421         int i, ret;
 422
 423         priv = container_of(work, struct mlxreg_hotplug_priv_data,
 424                             dwork_irq.work);
 425         pdata = dev_get_platdata(&priv->pdev->dev);
 426         item = pdata->items;
 427
 428         /* Mask aggregation event. */
 429         ret = regmap_write(priv->regmap, pdata->cell +
 430                            MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
 431         if (ret < 0)
 432                 goto out;
 433
 434         /* Read aggregation status. */
 435         ret = regmap_read(priv->regmap, pdata->cell, &regval);
 436         if (ret)
 437                 goto out;
 438
 439         regval &= pdata->mask;
 440         aggr_asserted = priv->aggr_cache ^ regval;
 441         priv->aggr_cache = regval;
 442
 443         /*
 444          * Handler is invoked, but no assertion is detected at top aggregation
 445          * status level. Set aggr_asserted to mask value to allow handler extra
 446          * run over all relevant signals to recover any missed signal.
 447          */
 448         if (priv->not_asserted == MLXREG_HOTPLUG_NOT_ASSERT) {
 449                 priv->not_asserted = 0;
 450                 aggr_asserted = pdata->mask;
 451         }
 452         if (!aggr_asserted)
 453                 goto unmask_event;
 454
 455         /* Handle topology and health configuration changes. */
 456         for (i = 0; i < pdata->counter; i++, item++) {
 457                 if (aggr_asserted & item->aggr_mask) {
 458                         if (item->health)
 459                                 mlxreg_hotplug_health_work_helper(priv, item);
 460                         else
 461                                 mlxreg_hotplug_work_helper(priv, item);
 462                 }
 463         }
 464
 465         spin_lock_irqsave(&priv->lock, flags);
 466
 467         /*
 468          * It is possible, that some signals have been inserted, while
 469          * interrupt has been masked by mlxreg_hotplug_work_handler. In this
 470          * case such signals will be missed. In order to handle these signals
 471          * delayed work is canceled and work task re-scheduled for immediate
 472          * execution. It allows to handle missed signals, if any. In other case
 473          * work handler just validates that no new signals have been received
 474          * during masking.
 475          */
 476         cancel_delayed_work(&priv->dwork_irq);
 477         schedule_delayed_work(&priv->dwork_irq, 0);
 478
 479         spin_unlock_irqrestore(&priv->lock, flags);
 480
 481         return;
 482
 483 unmask_event:
 484         priv->not_asserted++;
 485         /* Unmask aggregation event (no need acknowledge). */
 486         ret = regmap_write(priv->regmap, pdata->cell +
 487                            MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
 488
 489  out:
 490         if (ret)
 491                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 492 }
 493
 494 static int mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv)
 495 {
 496         struct mlxreg_core_hotplug_platform_data *pdata;
 497         struct mlxreg_core_item *item;
 498         int i, ret;
 499
 500         pdata = dev_get_platdata(&priv->pdev->dev);
 501         item = pdata->items;
 502
 503         for (i = 0; i < pdata->counter; i++, item++) {
 504                 /* Clear group presense event. */
 505                 ret = regmap_write(priv->regmap, item->reg +
 506                                    MLXREG_HOTPLUG_EVENT_OFF, 0);
 507                 if (ret)
 508                         goto out;
 509
 510                 /* Set group initial status as mask and unmask group event. */
 511                 if (item->inversed) {
 512                         item->cache = item->mask;
 513                         ret = regmap_write(priv->regmap, item->reg +
 514                                            MLXREG_HOTPLUG_MASK_OFF,
 515                                            item->mask);
 516                         if (ret)
 517                                 goto out;
 518                 }
 519         }
 520
 521         /* Keep aggregation initial status as zero and unmask events. */
 522         ret = regmap_write(priv->regmap, pdata->cell +
 523                            MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
 524         if (ret)
 525                 goto out;
 526
 527         /* Keep low aggregation initial status as zero and unmask events. */
 528         if (pdata->cell_low) {
 529                 ret = regmap_write(priv->regmap, pdata->cell_low +
 530                                    MLXREG_HOTPLUG_AGGR_MASK_OFF,
 531                                    pdata->mask_low);
 532                 if (ret)
 533                         goto out;
 534         }
 535
 536         /* Invoke work handler for initializing hot plug devices setting. */
 537         mlxreg_hotplug_work_handler(&priv->dwork_irq.work);
 538
 539  out:
 540         if (ret)
 541                 dev_err(priv->dev, "Failed to set interrupts.\n");
 542         enable_irq(priv->irq);
 543         return ret;
 544 }
 545
 546 static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
 547 {
 548         struct mlxreg_core_hotplug_platform_data *pdata;
 549         struct mlxreg_core_item *item;
 550         struct mlxreg_core_data *data;
 551         int count, i, j;
 552
 553         pdata = dev_get_platdata(&priv->pdev->dev);
 554         item = pdata->items;
 555         disable_irq(priv->irq);
 556         cancel_delayed_work_sync(&priv->dwork_irq);
 557
 558         /* Mask low aggregation event, if defined. */
 559         if (pdata->cell_low)
 560                 regmap_write(priv->regmap, pdata->cell_low +
 561                              MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
 562
 563         /* Mask aggregation event. */
 564         regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF,
 565                      0);
 566
 567         /* Clear topology configurations. */
 568         for (i = 0; i < pdata->counter; i++, item++) {
 569                 data = item->data;
 570                 /* Mask group presense event. */
 571                 regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF,
 572                              0);
 573                 /* Clear group presense event. */
 574                 regmap_write(priv->regmap, data->reg +
 575                              MLXREG_HOTPLUG_EVENT_OFF, 0);
 576
 577                 /* Remove all the attached devices in group. */
 578                 count = item->count;
 579                 for (j = 0; j < count; j++, data++)
 580                         mlxreg_hotplug_device_destroy(priv, data);
 581         }
 582 }
 583
 584 static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
 585 {
 586         struct mlxreg_hotplug_priv_data *priv;
 587
 588         priv = (struct mlxreg_hotplug_priv_data *)dev;
 589
 590         /* Schedule work task for immediate execution.*/
 591         schedule_delayed_work(&priv->dwork_irq, 0);
 592
 593         return IRQ_HANDLED;
 594 }
 595
 596 static int mlxreg_hotplug_probe(struct platform_device *pdev)
 597 {
 598         struct mlxreg_core_hotplug_platform_data *pdata;
 599         struct mlxreg_hotplug_priv_data *priv;
 600         struct i2c_adapter *deferred_adap;
 601         int err;
 602
 603         pdata = dev_get_platdata(&pdev->dev);
 604         if (!pdata) {
 605                 dev_err(&pdev->dev, "Failed to get platform data.\n");
 606                 return -EINVAL;
 607         }
 608
 609         /* Defer probing if the necessary adapter is not configured yet. */
 610         deferred_adap = i2c_get_adapter(pdata->deferred_nr);
 611         if (!deferred_adap)
 612                 return -EPROBE_DEFER;
 613         i2c_put_adapter(deferred_adap);
 614
 615         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 616         if (!priv)
 617                 return -ENOMEM;
 618
 619         if (pdata->irq) {
 620                 priv->irq = pdata->irq;
 621         } else {
 622                 priv->irq = platform_get_irq(pdev, 0);
 623                 if (priv->irq < 0) {
 624                         dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
 625                                 priv->irq);
 626                         return priv->irq;
 627                 }
 628         }
 629
 630         priv->regmap = pdata->regmap;
 631         priv->dev = pdev->dev.parent;
 632         priv->pdev = pdev;
 633
 634         err = devm_request_irq(&pdev->dev, priv->irq,
 635                                mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING
 636                                | IRQF_SHARED, "mlxreg-hotplug", priv);
 637         if (err) {
 638                 dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
 639                 return err;
 640         }
 641
 642         disable_irq(priv->irq);
 643         spin_lock_init(&priv->lock);
 644         INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler);
 645         dev_set_drvdata(&pdev->dev, priv);
 646
 647         err = mlxreg_hotplug_attr_init(priv);
 648         if (err) {
 649                 dev_err(&pdev->dev, "Failed to allocate attributes: %d\n",
 650                         err);
 651                 return err;
 652         }
 653
 654         priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
 655                                         "mlxreg_hotplug", priv, priv->groups);
 656         if (IS_ERR(priv->hwmon)) {
 657                 dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
 658                         PTR_ERR(priv->hwmon));
 659                 return PTR_ERR(priv->hwmon);
 660         }
 661
 662         /* Perform initial interrupts setup. */
 663         mlxreg_hotplug_set_irq(priv);
 664         priv->after_probe = true;
 665
 666         return 0;
 667 }
 668
 669 static int mlxreg_hotplug_remove(struct platform_device *pdev)
 670 {
 671         struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev);
 672
 673         /* Clean interrupts setup. */
 674         mlxreg_hotplug_unset_irq(priv);
 675
 676         return 0;
 677 }
 678
 679 static struct platform_driver mlxreg_hotplug_driver = {
 680         .driver = {
 681                 .name = "mlxreg-hotplug",
 682         },
 683         .probe = mlxreg_hotplug_probe,
 684         .remove = mlxreg_hotplug_remove,
 685 };
 686
 687 module_platform_driver(mlxreg_hotplug_driver);
 688
 689 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 690 MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
 691 MODULE_LICENSE("Dual BSD/GPL");
 692 MODULE_ALIAS("platform:mlxreg-hotplug");