drivers/platform/mellanox/mlxreg-hotplug.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Mellanox hotplug driver
   4  *
   5  * Copyright (C) 2016-2020 Mellanox Technologies
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/device.h>
  10 #include <linux/hwmon.h>
  11 #include <linux/hwmon-sysfs.h>
  12 #include <linux/i2c.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/module.h>
  15 #include <linux/of_device.h>
  16 #include <linux/platform_data/mlxreg.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/string_helpers.h>
  20 #include <linux/regmap.h>
  21 #include <linux/workqueue.h>
  22
  23 /* Offset of event and mask registers from status register. */
  24 #define MLXREG_HOTPLUG_EVENT_OFF        1
  25 #define MLXREG_HOTPLUG_MASK_OFF         2
  26 #define MLXREG_HOTPLUG_AGGR_MASK_OFF    1
  27
  28 /* ASIC good health mask. */
  29 #define MLXREG_HOTPLUG_GOOD_HEALTH_MASK 0x02
  30
  31 #define MLXREG_HOTPLUG_ATTRS_MAX        128
  32 #define MLXREG_HOTPLUG_NOT_ASSERT       3
  33
  34 /**
  35  * struct mlxreg_hotplug_priv_data - platform private data:
  36  * @irq: platform device interrupt number;
  37  * @dev: basic device;
  38  * @pdev: platform device;
  39  * @plat: platform data;
  40  * @regmap: register map handle;
  41  * @dwork_irq: delayed work template;
  42  * @lock: spin lock;
  43  * @hwmon: hwmon device;
  44  * @mlxreg_hotplug_attr: sysfs attributes array;
  45  * @mlxreg_hotplug_dev_attr: sysfs sensor device attribute array;
  46  * @group: sysfs attribute group;
  47  * @groups: list of sysfs attribute group for hwmon registration;
  48  * @cell: location of top aggregation interrupt register;
  49  * @mask: top aggregation interrupt common mask;
  50  * @aggr_cache: last value of aggregation register status;
  51  * @after_probe: flag indication probing completion;
  52  * @not_asserted: number of entries in workqueue with no signal assertion;
  53  */
  54 struct mlxreg_hotplug_priv_data {
  55         int irq;
  56         struct device *dev;
  57         struct platform_device *pdev;
  58         struct mlxreg_hotplug_platform_data *plat;
  59         struct regmap *regmap;
  60         struct delayed_work dwork_irq;
  61         spinlock_t lock; /* sync with interrupt */
  62         struct device *hwmon;
  63         struct attribute *mlxreg_hotplug_attr[MLXREG_HOTPLUG_ATTRS_MAX + 1];
  64         struct sensor_device_attribute_2
  65                         mlxreg_hotplug_dev_attr[MLXREG_HOTPLUG_ATTRS_MAX];
  66         struct attribute_group group;
  67         const struct attribute_group *groups[2];
  68         u32 cell;
  69         u32 mask;
  70         u32 aggr_cache;
  71         bool after_probe;
  72         u8 not_asserted;
  73 };
  74
  75 /* Environment variables array for udev. */
  76 static char *mlxreg_hotplug_udev_envp[] = { NULL, NULL };
  77
  78 static int
  79 mlxreg_hotplug_udev_event_send(struct kobject *kobj,
  80                                struct mlxreg_core_data *data, bool action)
  81 {
  82         char event_str[MLXREG_CORE_LABEL_MAX_SIZE + 2];
  83         char label[MLXREG_CORE_LABEL_MAX_SIZE] = { 0 };
  84
  85         mlxreg_hotplug_udev_envp[0] = event_str;
  86         string_upper(label, data->label);
  87         snprintf(event_str, MLXREG_CORE_LABEL_MAX_SIZE, "%s=%d", label, !!action);
  88
  89         return kobject_uevent_env(kobj, KOBJ_CHANGE, mlxreg_hotplug_udev_envp);
  90 }
  91
  92 static void
  93 mlxreg_hotplug_pdata_export(void *pdata, void *regmap)
  94 {
  95         struct mlxreg_core_hotplug_platform_data *dev_pdata = pdata;
  96
  97         /* Export regmap to underlying device. */
  98         dev_pdata->regmap = regmap;
  99 }
 100
 101 static int mlxreg_hotplug_device_create(struct mlxreg_hotplug_priv_data *priv,
 102                                         struct mlxreg_core_data *data,
 103                                         enum mlxreg_hotplug_kind kind)
 104 {
 105         struct i2c_board_info *brdinfo = data->hpdev.brdinfo;
 106         struct mlxreg_core_hotplug_platform_data *pdata;
 107         struct i2c_client *client;
 108
 109         /* Notify user by sending hwmon uevent. */
 110         mlxreg_hotplug_udev_event_send(&priv->hwmon->kobj, data, true);
 111
 112         /*
 113          * Return if adapter number is negative. It could be in case hotplug
 114          * event is not associated with hotplug device.
 115          */
 116         if (data->hpdev.nr < 0)
 117                 return 0;
 118
 119         pdata = dev_get_platdata(&priv->pdev->dev);
 120         switch (data->hpdev.action) {
 121         case MLXREG_HOTPLUG_DEVICE_DEFAULT_ACTION:
 122                 data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr +
 123                                                       pdata->shift_nr);
 124                 if (!data->hpdev.adapter) {
 125                         dev_err(priv->dev, "Failed to get adapter for bus %d\n",
 126                                 data->hpdev.nr + pdata->shift_nr);
 127                         return -EFAULT;
 128                 }
 129
 130                 /* Export platform data to underlying device. */
 131                 if (brdinfo->platform_data)
 132                         mlxreg_hotplug_pdata_export(brdinfo->platform_data, pdata->regmap);
 133
 134                 client = i2c_new_client_device(data->hpdev.adapter,
 135                                                brdinfo);
 136                 if (IS_ERR(client)) {
 137                         dev_err(priv->dev, "Failed to create client %s at bus %d at addr 0x%02x\n",
 138                                 brdinfo->type, data->hpdev.nr +
 139                                 pdata->shift_nr, brdinfo->addr);
 140
 141                         i2c_put_adapter(data->hpdev.adapter);
 142                         data->hpdev.adapter = NULL;
 143                         return PTR_ERR(client);
 144                 }
 145
 146                 data->hpdev.client = client;
 147                 break;
 148         case MLXREG_HOTPLUG_DEVICE_PLATFORM_ACTION:
 149                 /* Export platform data to underlying device. */
 150                 if (data->hpdev.brdinfo && data->hpdev.brdinfo->platform_data)
 151                         mlxreg_hotplug_pdata_export(data->hpdev.brdinfo->platform_data,
 152                                                     pdata->regmap);
 153                 /* Pass parent hotplug device handle to underlying device. */
 154                 data->notifier = data->hpdev.notifier;
 155                 data->hpdev.pdev = platform_device_register_resndata(&priv->pdev->dev,
 156                                                                      brdinfo->type,
 157                                                                      data->hpdev.nr,
 158                                                                      NULL, 0, data,
 159                                                                      sizeof(*data));
 160                 if (IS_ERR(data->hpdev.pdev))
 161                         return PTR_ERR(data->hpdev.pdev);
 162
 163                 break;
 164         default:
 165                 break;
 166         }
 167
 168         if (data->hpdev.notifier && data->hpdev.notifier->user_handler)
 169                 return data->hpdev.notifier->user_handler(data->hpdev.notifier->handle, kind, 1);
 170
 171         return 0;
 172 }
 173
 174 static void
 175 mlxreg_hotplug_device_destroy(struct mlxreg_hotplug_priv_data *priv,
 176                               struct mlxreg_core_data *data,
 177                               enum mlxreg_hotplug_kind kind)
 178 {
 179         /* Notify user by sending hwmon uevent. */
 180         mlxreg_hotplug_udev_event_send(&priv->hwmon->kobj, data, false);
 181         if (data->hpdev.notifier && data->hpdev.notifier->user_handler)
 182                 data->hpdev.notifier->user_handler(data->hpdev.notifier->handle, kind, 0);
 183
 184         switch (data->hpdev.action) {
 185         case MLXREG_HOTPLUG_DEVICE_DEFAULT_ACTION:
 186                 if (data->hpdev.client) {
 187                         i2c_unregister_device(data->hpdev.client);
 188                         data->hpdev.client = NULL;
 189                 }
 190
 191                 if (data->hpdev.adapter) {
 192                         i2c_put_adapter(data->hpdev.adapter);
 193                         data->hpdev.adapter = NULL;
 194                 }
 195                 break;
 196         case MLXREG_HOTPLUG_DEVICE_PLATFORM_ACTION:
 197                 if (data->hpdev.pdev)
 198                         platform_device_unregister(data->hpdev.pdev);
 199                 break;
 200         default:
 201                 break;
 202         }
 203 }
 204
 205 static ssize_t mlxreg_hotplug_attr_show(struct device *dev,
 206                                         struct device_attribute *attr,
 207                                         char *buf)
 208 {
 209         struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(dev);
 210         struct mlxreg_core_hotplug_platform_data *pdata;
 211         int index = to_sensor_dev_attr_2(attr)->index;
 212         int nr = to_sensor_dev_attr_2(attr)->nr;
 213         struct mlxreg_core_item *item;
 214         struct mlxreg_core_data *data;
 215         u32 regval;
 216         int ret;
 217
 218         pdata = dev_get_platdata(&priv->pdev->dev);
 219         item = pdata->items + nr;
 220         data = item->data + index;
 221
 222         ret = regmap_read(priv->regmap, data->reg, &regval);
 223         if (ret)
 224                 return ret;
 225
 226         if (item->health) {
 227                 regval &= data->mask;
 228         } else {
 229                 /* Bit = 0 : functional if item->inversed is true. */
 230                 if (item->inversed)
 231                         regval = !(regval & data->mask);
 232                 else
 233                         regval = !!(regval & data->mask);
 234         }
 235
 236         return sprintf(buf, "%u\n", regval);
 237 }
 238
 239 #define PRIV_ATTR(i) priv->mlxreg_hotplug_attr[i]
 240 #define PRIV_DEV_ATTR(i) priv->mlxreg_hotplug_dev_attr[i]
 241
 242 static int mlxreg_hotplug_item_label_index_get(u32 mask, u32 bit)
 243 {
 244         int i, j;
 245
 246         for (i = 0, j = -1; i <= bit; i++) {
 247                 if (mask & BIT(i))
 248                         j++;
 249         }
 250         return j;
 251 }
 252
 253 static int mlxreg_hotplug_attr_init(struct mlxreg_hotplug_priv_data *priv)
 254 {
 255         struct mlxreg_core_hotplug_platform_data *pdata;
 256         struct mlxreg_core_item *item;
 257         struct mlxreg_core_data *data;
 258         unsigned long mask;
 259         u32 regval;
 260         int num_attrs = 0, id = 0, i, j, k, count, ret;
 261
 262         pdata = dev_get_platdata(&priv->pdev->dev);
 263         item = pdata->items;
 264
 265         /* Go over all kinds of items - psu, pwr, fan. */
 266         for (i = 0; i < pdata->counter; i++, item++) {
 267                 if (item->capability) {
 268                         /*
 269                          * Read group capability register to get actual number
 270                          * of interrupt capable components and set group mask
 271                          * accordingly.
 272                          */
 273                         ret = regmap_read(priv->regmap, item->capability,
 274                                           &regval);
 275                         if (ret)
 276                                 return ret;
 277
 278                         item->mask = GENMASK((regval & item->mask) - 1, 0);
 279                 }
 280
 281                 data = item->data;
 282
 283                 /* Go over all unmasked units within item. */
 284                 mask = item->mask;
 285                 k = 0;
 286                 count = item->ind ? item->ind : item->count;
 287                 for_each_set_bit(j, &mask, count) {
 288                         if (data->capability) {
 289                                 /*
 290                                  * Read capability register and skip non
 291                                  * relevant attributes.
 292                                  */
 293                                 ret = regmap_read(priv->regmap,
 294                                                   data->capability, &regval);
 295                                 if (ret)
 296                                         return ret;
 297
 298                                 if (!(regval & data->bit)) {
 299                                         data++;
 300                                         continue;
 301                                 }
 302                         }
 303
 304                         PRIV_ATTR(id) = &PRIV_DEV_ATTR(id).dev_attr.attr;
 305                         PRIV_ATTR(id)->name = devm_kasprintf(&priv->pdev->dev,
 306                                                              GFP_KERNEL,
 307                                                              data->label);
 308                         if (!PRIV_ATTR(id)->name) {
 309                                 dev_err(priv->dev, "Memory allocation failed for attr %d.\n",
 310                                         id);
 311                                 return -ENOMEM;
 312                         }
 313
 314                         PRIV_DEV_ATTR(id).dev_attr.attr.name =
 315                                                         PRIV_ATTR(id)->name;
 316                         PRIV_DEV_ATTR(id).dev_attr.attr.mode = 0444;
 317                         PRIV_DEV_ATTR(id).dev_attr.show =
 318                                                 mlxreg_hotplug_attr_show;
 319                         PRIV_DEV_ATTR(id).nr = i;
 320                         PRIV_DEV_ATTR(id).index = k;
 321                         sysfs_attr_init(&PRIV_DEV_ATTR(id).dev_attr.attr);
 322                         data++;
 323                         id++;
 324                         k++;
 325                 }
 326                 num_attrs += k;
 327         }
 328
 329         priv->group.attrs = devm_kcalloc(&priv->pdev->dev,
 330                                          num_attrs,
 331                                          sizeof(struct attribute *),
 332                                          GFP_KERNEL);
 333         if (!priv->group.attrs)
 334                 return -ENOMEM;
 335
 336         priv->group.attrs = priv->mlxreg_hotplug_attr;
 337         priv->groups[0] = &priv->group;
 338         priv->groups[1] = NULL;
 339
 340         return 0;
 341 }
 342
 343 static void
 344 mlxreg_hotplug_work_helper(struct mlxreg_hotplug_priv_data *priv,
 345                            struct mlxreg_core_item *item)
 346 {
 347         struct mlxreg_core_data *data;
 348         unsigned long asserted;
 349         u32 regval, bit;
 350         int ret;
 351
 352         /*
 353          * Validate if item related to received signal type is valid.
 354          * It should never happen, excepted the situation when some
 355          * piece of hardware is broken. In such situation just produce
 356          * error message and return. Caller must continue to handle the
 357          * signals from other devices if any.
 358          */
 359         if (unlikely(!item)) {
 360                 dev_err(priv->dev, "False signal: at offset:mask 0x%02x:0x%02x.\n",
 361                         item->reg, item->mask);
 362
 363                 return;
 364         }
 365
 366         /* Mask event. */
 367         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
 368                            0);
 369         if (ret)
 370                 goto out;
 371
 372         /* Read status. */
 373         ret = regmap_read(priv->regmap, item->reg, &regval);
 374         if (ret)
 375                 goto out;
 376
 377         /* Set asserted bits and save last status. */
 378         regval &= item->mask;
 379         asserted = item->cache ^ regval;
 380         item->cache = regval;
 381         for_each_set_bit(bit, &asserted, 8) {
 382                 int pos;
 383
 384                 pos = mlxreg_hotplug_item_label_index_get(item->mask, bit);
 385                 if (pos < 0)
 386                         goto out;
 387
 388                 data = item->data + pos;
 389                 if (regval & BIT(bit)) {
 390                         if (item->inversed)
 391                                 mlxreg_hotplug_device_destroy(priv, data, item->kind);
 392                         else
 393                                 mlxreg_hotplug_device_create(priv, data, item->kind);
 394                 } else {
 395                         if (item->inversed)
 396                                 mlxreg_hotplug_device_create(priv, data, item->kind);
 397                         else
 398                                 mlxreg_hotplug_device_destroy(priv, data, item->kind);
 399                 }
 400         }
 401
 402         /* Acknowledge event. */
 403         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_EVENT_OFF,
 404                            0);
 405         if (ret)
 406                 goto out;
 407
 408         /* Unmask event. */
 409         ret = regmap_write(priv->regmap, item->reg + MLXREG_HOTPLUG_MASK_OFF,
 410                            item->mask);
 411
 412  out:
 413         if (ret)
 414                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 415 }
 416
 417 static void
 418 mlxreg_hotplug_health_work_helper(struct mlxreg_hotplug_priv_data *priv,
 419                                   struct mlxreg_core_item *item)
 420 {
 421         struct mlxreg_core_data *data = item->data;
 422         u32 regval;
 423         int i, ret = 0;
 424
 425         for (i = 0; i < item->count; i++, data++) {
 426                 /* Mask event. */
 427                 ret = regmap_write(priv->regmap, data->reg +
 428                                    MLXREG_HOTPLUG_MASK_OFF, 0);
 429                 if (ret)
 430                         goto out;
 431
 432                 /* Read status. */
 433                 ret = regmap_read(priv->regmap, data->reg, &regval);
 434                 if (ret)
 435                         goto out;
 436
 437                 regval &= data->mask;
 438
 439                 if (item->cache == regval)
 440                         goto ack_event;
 441
 442                 /*
 443                  * ASIC health indication is provided through two bits. Bits
 444                  * value 0x2 indicates that ASIC reached the good health, value
 445                  * 0x0 indicates ASIC the bad health or dormant state and value
 446                  * 0x3 indicates the booting state. During ASIC reset it should
 447                  * pass the following states: dormant -> booting -> good.
 448                  */
 449                 if (regval == MLXREG_HOTPLUG_GOOD_HEALTH_MASK) {
 450                         if (!data->attached) {
 451                                 /*
 452                                  * ASIC is in steady state. Connect associated
 453                                  * device, if configured.
 454                                  */
 455                                 mlxreg_hotplug_device_create(priv, data, item->kind);
 456                                 data->attached = true;
 457                         }
 458                 } else {
 459                         if (data->attached) {
 460                                 /*
 461                                  * ASIC health is failed after ASIC has been
 462                                  * in steady state. Disconnect associated
 463                                  * device, if it has been connected.
 464                                  */
 465                                 mlxreg_hotplug_device_destroy(priv, data, item->kind);
 466                                 data->attached = false;
 467                                 data->health_cntr = 0;
 468                         }
 469                 }
 470                 item->cache = regval;
 471 ack_event:
 472                 /* Acknowledge event. */
 473                 ret = regmap_write(priv->regmap, data->reg +
 474                                    MLXREG_HOTPLUG_EVENT_OFF, 0);
 475                 if (ret)
 476                         goto out;
 477
 478                 /* Unmask event. */
 479                 ret = regmap_write(priv->regmap, data->reg +
 480                                    MLXREG_HOTPLUG_MASK_OFF, data->mask);
 481                 if (ret)
 482                         goto out;
 483         }
 484
 485  out:
 486         if (ret)
 487                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 488 }
 489
 490 /*
 491  * mlxreg_hotplug_work_handler - performs traversing of device interrupt
 492  * registers according to the below hierarchy schema:
 493  *
 494  *                              Aggregation registers (status/mask)
 495  * PSU registers:               *---*
 496  * *-----------------*          |   |
 497  * |status/event/mask|----->    | * |
 498  * *-----------------*          |   |
 499  * Power registers:             |   |
 500  * *-----------------*          |   |
 501  * |status/event/mask|----->    | * |
 502  * *-----------------*          |   |
 503  * FAN registers:               |   |--> CPU
 504  * *-----------------*          |   |
 505  * |status/event/mask|----->    | * |
 506  * *-----------------*          |   |
 507  * ASIC registers:              |   |
 508  * *-----------------*          |   |
 509  * |status/event/mask|----->    | * |
 510  * *-----------------*          |   |
 511  *                              *---*
 512  *
 513  * In case some system changed are detected: FAN in/out, PSU in/out, power
 514  * cable attached/detached, ASIC health good/bad, relevant device is created
 515  * or destroyed.
 516  */
 517 static void mlxreg_hotplug_work_handler(struct work_struct *work)
 518 {
 519         struct mlxreg_core_hotplug_platform_data *pdata;
 520         struct mlxreg_hotplug_priv_data *priv;
 521         struct mlxreg_core_item *item;
 522         u32 regval, aggr_asserted;
 523         unsigned long flags;
 524         int i, ret;
 525
 526         priv = container_of(work, struct mlxreg_hotplug_priv_data,
 527                             dwork_irq.work);
 528         pdata = dev_get_platdata(&priv->pdev->dev);
 529         item = pdata->items;
 530
 531         /* Mask aggregation event. */
 532         ret = regmap_write(priv->regmap, pdata->cell +
 533                            MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
 534         if (ret < 0)
 535                 goto out;
 536
 537         /* Read aggregation status. */
 538         ret = regmap_read(priv->regmap, pdata->cell, &regval);
 539         if (ret)
 540                 goto out;
 541
 542         regval &= pdata->mask;
 543         aggr_asserted = priv->aggr_cache ^ regval;
 544         priv->aggr_cache = regval;
 545
 546         /*
 547          * Handler is invoked, but no assertion is detected at top aggregation
 548          * status level. Set aggr_asserted to mask value to allow handler extra
 549          * run over all relevant signals to recover any missed signal.
 550          */
 551         if (priv->not_asserted == MLXREG_HOTPLUG_NOT_ASSERT) {
 552                 priv->not_asserted = 0;
 553                 aggr_asserted = pdata->mask;
 554         }
 555         if (!aggr_asserted)
 556                 goto unmask_event;
 557
 558         /* Handle topology and health configuration changes. */
 559         for (i = 0; i < pdata->counter; i++, item++) {
 560                 if (aggr_asserted & item->aggr_mask) {
 561                         if (item->health)
 562                                 mlxreg_hotplug_health_work_helper(priv, item);
 563                         else
 564                                 mlxreg_hotplug_work_helper(priv, item);
 565                 }
 566         }
 567
 568         spin_lock_irqsave(&priv->lock, flags);
 569
 570         /*
 571          * It is possible, that some signals have been inserted, while
 572          * interrupt has been masked by mlxreg_hotplug_work_handler. In this
 573          * case such signals will be missed. In order to handle these signals
 574          * delayed work is canceled and work task re-scheduled for immediate
 575          * execution. It allows to handle missed signals, if any. In other case
 576          * work handler just validates that no new signals have been received
 577          * during masking.
 578          */
 579         cancel_delayed_work(&priv->dwork_irq);
 580         schedule_delayed_work(&priv->dwork_irq, 0);
 581
 582         spin_unlock_irqrestore(&priv->lock, flags);
 583
 584         return;
 585
 586 unmask_event:
 587         priv->not_asserted++;
 588         /* Unmask aggregation event (no need acknowledge). */
 589         ret = regmap_write(priv->regmap, pdata->cell +
 590                            MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
 591
 592  out:
 593         if (ret)
 594                 dev_err(priv->dev, "Failed to complete workqueue.\n");
 595 }
 596
 597 static int mlxreg_hotplug_set_irq(struct mlxreg_hotplug_priv_data *priv)
 598 {
 599         struct mlxreg_core_hotplug_platform_data *pdata;
 600         struct mlxreg_core_item *item;
 601         struct mlxreg_core_data *data;
 602         u32 regval;
 603         int i, j, ret;
 604
 605         pdata = dev_get_platdata(&priv->pdev->dev);
 606         item = pdata->items;
 607
 608         for (i = 0; i < pdata->counter; i++, item++) {
 609                 /* Clear group presense event. */
 610                 ret = regmap_write(priv->regmap, item->reg +
 611                                    MLXREG_HOTPLUG_EVENT_OFF, 0);
 612                 if (ret)
 613                         goto out;
 614
 615                 /*
 616                  * Verify if hardware configuration requires to disable
 617                  * interrupt capability for some of components.
 618                  */
 619                 data = item->data;
 620                 for (j = 0; j < item->count; j++, data++) {
 621                         /* Verify if the attribute has capability register. */
 622                         if (data->capability) {
 623                                 /* Read capability register. */
 624                                 ret = regmap_read(priv->regmap,
 625                                                   data->capability, &regval);
 626                                 if (ret)
 627                                         goto out;
 628
 629                                 if (!(regval & data->bit))
 630                                         item->mask &= ~BIT(j);
 631                         }
 632                 }
 633
 634                 /* Set group initial status as mask and unmask group event. */
 635                 if (item->inversed) {
 636                         item->cache = item->mask;
 637                         ret = regmap_write(priv->regmap, item->reg +
 638                                            MLXREG_HOTPLUG_MASK_OFF,
 639                                            item->mask);
 640                         if (ret)
 641                                 goto out;
 642                 }
 643         }
 644
 645         /* Keep aggregation initial status as zero and unmask events. */
 646         ret = regmap_write(priv->regmap, pdata->cell +
 647                            MLXREG_HOTPLUG_AGGR_MASK_OFF, pdata->mask);
 648         if (ret)
 649                 goto out;
 650
 651         /* Keep low aggregation initial status as zero and unmask events. */
 652         if (pdata->cell_low) {
 653                 ret = regmap_write(priv->regmap, pdata->cell_low +
 654                                    MLXREG_HOTPLUG_AGGR_MASK_OFF,
 655                                    pdata->mask_low);
 656                 if (ret)
 657                         goto out;
 658         }
 659
 660         /* Invoke work handler for initializing hot plug devices setting. */
 661         mlxreg_hotplug_work_handler(&priv->dwork_irq.work);
 662
 663  out:
 664         if (ret)
 665                 dev_err(priv->dev, "Failed to set interrupts.\n");
 666         enable_irq(priv->irq);
 667         return ret;
 668 }
 669
 670 static void mlxreg_hotplug_unset_irq(struct mlxreg_hotplug_priv_data *priv)
 671 {
 672         struct mlxreg_core_hotplug_platform_data *pdata;
 673         struct mlxreg_core_item *item;
 674         struct mlxreg_core_data *data;
 675         int count, i, j;
 676
 677         pdata = dev_get_platdata(&priv->pdev->dev);
 678         item = pdata->items;
 679         disable_irq(priv->irq);
 680         cancel_delayed_work_sync(&priv->dwork_irq);
 681
 682         /* Mask low aggregation event, if defined. */
 683         if (pdata->cell_low)
 684                 regmap_write(priv->regmap, pdata->cell_low +
 685                              MLXREG_HOTPLUG_AGGR_MASK_OFF, 0);
 686
 687         /* Mask aggregation event. */
 688         regmap_write(priv->regmap, pdata->cell + MLXREG_HOTPLUG_AGGR_MASK_OFF,
 689                      0);
 690
 691         /* Clear topology configurations. */
 692         for (i = 0; i < pdata->counter; i++, item++) {
 693                 data = item->data;
 694                 /* Mask group presense event. */
 695                 regmap_write(priv->regmap, data->reg + MLXREG_HOTPLUG_MASK_OFF,
 696                              0);
 697                 /* Clear group presense event. */
 698                 regmap_write(priv->regmap, data->reg +
 699                              MLXREG_HOTPLUG_EVENT_OFF, 0);
 700
 701                 /* Remove all the attached devices in group. */
 702                 count = item->count;
 703                 for (j = 0; j < count; j++, data++)
 704                         mlxreg_hotplug_device_destroy(priv, data, item->kind);
 705         }
 706 }
 707
 708 static irqreturn_t mlxreg_hotplug_irq_handler(int irq, void *dev)
 709 {
 710         struct mlxreg_hotplug_priv_data *priv;
 711
 712         priv = (struct mlxreg_hotplug_priv_data *)dev;
 713
 714         /* Schedule work task for immediate execution.*/
 715         schedule_delayed_work(&priv->dwork_irq, 0);
 716
 717         return IRQ_HANDLED;
 718 }
 719
 720 static int mlxreg_hotplug_probe(struct platform_device *pdev)
 721 {
 722         struct mlxreg_core_hotplug_platform_data *pdata;
 723         struct mlxreg_hotplug_priv_data *priv;
 724         struct i2c_adapter *deferred_adap;
 725         int err;
 726
 727         pdata = dev_get_platdata(&pdev->dev);
 728         if (!pdata) {
 729                 dev_err(&pdev->dev, "Failed to get platform data.\n");
 730                 return -EINVAL;
 731         }
 732
 733         /* Defer probing if the necessary adapter is not configured yet. */
 734         deferred_adap = i2c_get_adapter(pdata->deferred_nr);
 735         if (!deferred_adap)
 736                 return -EPROBE_DEFER;
 737         i2c_put_adapter(deferred_adap);
 738
 739         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 740         if (!priv)
 741                 return -ENOMEM;
 742
 743         if (pdata->irq) {
 744                 priv->irq = pdata->irq;
 745         } else {
 746                 priv->irq = platform_get_irq(pdev, 0);
 747                 if (priv->irq < 0)
 748                         return priv->irq;
 749         }
 750
 751         priv->regmap = pdata->regmap;
 752         priv->dev = pdev->dev.parent;
 753         priv->pdev = pdev;
 754
 755         err = devm_request_irq(&pdev->dev, priv->irq,
 756                                mlxreg_hotplug_irq_handler, IRQF_TRIGGER_FALLING
 757                                | IRQF_SHARED, "mlxreg-hotplug", priv);
 758         if (err) {
 759                 dev_err(&pdev->dev, "Failed to request irq: %d\n", err);
 760                 return err;
 761         }
 762
 763         disable_irq(priv->irq);
 764         spin_lock_init(&priv->lock);
 765         INIT_DELAYED_WORK(&priv->dwork_irq, mlxreg_hotplug_work_handler);
 766         dev_set_drvdata(&pdev->dev, priv);
 767
 768         err = mlxreg_hotplug_attr_init(priv);
 769         if (err) {
 770                 dev_err(&pdev->dev, "Failed to allocate attributes: %d\n",
 771                         err);
 772                 return err;
 773         }
 774
 775         priv->hwmon = devm_hwmon_device_register_with_groups(&pdev->dev,
 776                                         "mlxreg_hotplug", priv, priv->groups);
 777         if (IS_ERR(priv->hwmon)) {
 778                 dev_err(&pdev->dev, "Failed to register hwmon device %ld\n",
 779                         PTR_ERR(priv->hwmon));
 780                 return PTR_ERR(priv->hwmon);
 781         }
 782
 783         /* Perform initial interrupts setup. */
 784         mlxreg_hotplug_set_irq(priv);
 785         priv->after_probe = true;
 786
 787         return 0;
 788 }
 789
 790 static int mlxreg_hotplug_remove(struct platform_device *pdev)
 791 {
 792         struct mlxreg_hotplug_priv_data *priv = dev_get_drvdata(&pdev->dev);
 793
 794         /* Clean interrupts setup. */
 795         mlxreg_hotplug_unset_irq(priv);
 796         devm_free_irq(&pdev->dev, priv->irq, priv);
 797
 798         return 0;
 799 }
 800
 801 static struct platform_driver mlxreg_hotplug_driver = {
 802         .driver = {
 803                 .name = "mlxreg-hotplug",
 804         },
 805         .probe = mlxreg_hotplug_probe,
 806         .remove = mlxreg_hotplug_remove,
 807 };
 808
 809 module_platform_driver(mlxreg_hotplug_driver);
 810
 811 MODULE_AUTHOR("Vadim Pasternak <[email protected]>");
 812 MODULE_DESCRIPTION("Mellanox regmap hotplug platform driver");
 813 MODULE_LICENSE("Dual BSD/GPL");
 814 MODULE_ALIAS("platform:mlxreg-hotplug");