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         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         int i, ret;
 500
 501         pdata = dev_get_platdata(&priv->pdev->dev);
 502         item = pdata->items;
 503
 504         for (i = 0; i < pdata->counter; i++, item++) {
 505                 /* Clear group presense event. */
 506                 ret = regmap_write(priv->regmap, item->reg +
 507                                    MLXREG_HOTPLUG_EVENT_OFF, 0);
 508                 if (ret)
 509                         goto out;
 510
 511                 /* Set group initial status as mask and unmask group event. */
 512                 if (item->inversed) {
 513                         item->cache = item->mask;
 514                         ret = regmap_write(priv->regmap, item->reg +
 515                                            MLXREG_HOTPLUG_MASK_OFF,
 516                                            item->mask);
 517                         if (ret)
 518                                 goto out;
 519                 }
 520         }
 521
 522         /* Keep aggregation initial status as zero and unmask events. */
 523         ret = regmap_write(priv->regmap, pdata->cell +
 524                            MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
 525         if (ret)
 526                 goto out;
 527
 528         /* Keep low aggregation initial status as zero and unmask events. */
 529         if (pdata->cell_low) {
 530                 ret = regmap_write(priv->regmap, pdata->cell_low +
 531                                    MLXREG_HOTPLUG_AGGR_MASK_OFF,
 532                                    pdata->mask_low);
 533                 if (ret)
 534                         goto out;
 535         }
 536
 537         /* Invoke work handler for initializing hot plug devices setting. */
 538         mlxreg_hotplug_work_handler(&priv->dwork_irq.work);
 539
 540  out:
 541         if (ret)
 542                 dev_err(priv->dev, "Failed to set interrupts.\n");
 543         enable_irq(priv->irq);
 544         return ret;
 545 }
 546
 547 static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
 548 {
 549         struct mlxreg_core_hotplug_platform_data *pdata;
 550         struct mlxreg_core_item *item;
 551         struct mlxreg_core_data *data;
 552         int count, i, j;
 553
 554         pdata = dev_get_platdata(&priv->pdev->dev);
 555         item = pdata->items;
 556         disable_irq(priv->irq);
 557         cancel_delayed_work_sync(&priv->dwork_irq);
 558
 559         /* Mask low aggregation event, if defined. */
 560         if (pdata->cell_low)
 561                 regmap_write(priv->regmap, pdata->cell_low +
 562                              MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
 563
 564         /* Mask aggregation event. */
 565         regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF,
 566                      0);
 567
 568         /* Clear topology configurations. */
 569         for (i = 0; i < pdata->counter; i++, item++) {
 570                 data = item->data;
 571                 /* Mask group presense event. */
 572                 regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF,
 573                              0);
 574                 /* Clear group presense event. */
 575                 regmap_write(priv->regmap, data->reg +
 576                              MLXREG_HOTPLUG_EVENT_OFF, 0);
 577
 578                 /* Remove all the attached devices in group. */
 579                 count = item->count;
 580                 for (j = 0; j < count; j++, data++)
 581                         mlxreg_hotplug_device_destroy(priv, data);
 582         }
 583 }
 584
 585 static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
 586 {
 587         struct mlxreg_hotplug_priv_data *priv;
 588
 589         priv = (struct mlxreg_hotplug_priv_data *)dev;
 590
 591         /* Schedule work task for immediate execution.*/
 592         schedule_delayed_work(&priv->dwork_irq, 0);
 593
 594         return IRQ_HANDLED;
 595 }
 596
 597 static int mlxreg_hotplug_probe(struct platform_device *pdev)
 598 {
 599         struct mlxreg_core_hotplug_platform_data *pdata;
 600         struct mlxreg_hotplug_priv_data *priv;
 601         struct i2c_adapter *deferred_adap;
 602         int err;
 603
 604         pdata = dev_get_platdata(&pdev->dev);
 605         if (!pdata) {
 606                 dev_err(&pdev->dev, "Failed to get platform data.\n");
 607                 return -EINVAL;
 608         }
 609
 610         /* Defer probing if the necessary adapter is not configured yet. */
 611         deferred_adap = i2c_get_adapter(pdata->deferred_nr);
 612         if (!deferred_adap)
 613                 return -EPROBE_DEFER;
 614         i2c_put_adapter(deferred_adap);
 615
 616         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 617         if (!priv)
 618                 return -ENOMEM;
 619
 620         if (pdata->irq) {
 621                 priv->irq = pdata->irq;
 622         } else {
 623                 priv->irq = platform_get_irq(pdev, 0);
 624                 if (priv->irq < 0) {
 625                         dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
 626                                 priv->irq);
 627                         return priv->irq;
 628                 }
 629         }
 630
 631         priv->regmap = pdata->regmap;
 632         priv->dev = pdev->dev.parent;
 633         priv->pdev = pdev;
 634
 635         err = devm_request_irq(&pdev->dev, priv->irq,
 636                                mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING
 637                                | IRQF_SHARED, "mlxreg-hotplug", priv);
 638         if (err) {
 639                 dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
 640                 return err;
 641         }
 642
 643         disable_irq(priv->irq);
 644         spin_lock_init(&priv->lock);
 645         INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler);
 646         dev_set_drvdata(&pdev->dev, priv);
 647
 648         err = mlxreg_hotplug_attr_init(priv);
 649         if (err) {
 650                 dev_err(&pdev->dev, "Failed to allocate attributes: %d\n",
 651                         err);
 652                 return err;
 653         }
 654
 655         priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
 656                                         "mlxreg_hotplug", priv, priv->groups);
 657         if (IS_ERR(priv->hwmon)) {
 658                 dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
 659                         PTR_ERR(priv->hwmon));
 660                 return PTR_ERR(priv->hwmon);
 661         }
 662
 663         /* Perform initial interrupts setup. */
 664         mlxreg_hotplug_set_irq(priv);
 665         priv->after_probe = true;
 666
 667         return 0;
 668 }
 669
 670 static int mlxreg_hotplug_remove(struct platform_device *pdev)
 671 {
 672         struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev);
 673
 674         /* Clean interrupts setup. */
 675         mlxreg_hotplug_unset_irq(priv);
 676         devm_free_irq(&pdev->dev, priv->irq, priv);
 677
 678         return 0;
 679 }
 680
 681 static struct platform_driver mlxreg_hotplug_driver = {
 682         .driver = {
 683                 .name = "mlxreg-hotplug",
 684         },
 685         .probe = mlxreg_hotplug_probe,
 686         .remove = mlxreg_hotplug_remove,
 687 };
 688
 689 module_platform_driver(mlxreg_hotplug_driver);
 690
 691 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 692 MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
 693 MODULE_LICENSE("Dual BSD/GPL");
 694 MODULE_ALIAS("platform:mlxreg-hotplug");