drivers/base/regmap/regmap-irq.c

   1 /*
   2  * regmap based irq_chip
   3  *
   4  * Copyright 2011 Wolfson Microelectronics plc
   5  *
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/export.h>
  14 #include <linux/device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/irq.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irqdomain.h>
  19 #include <linux/pm_runtime.h>
  20 #include <linux/slab.h>
  21
  22 #include "internal.h"
  23
  24 struct regmap_irq_chip_data {
  25         struct mutex lock;
  26         struct irq_chip irq_chip;
  27
  28         struct regmap *map;
  29         const struct regmap_irq_chip *chip;
  30
  31         int irq_base;
  32         struct irq_domain *domain;
  33
  34         int irq;
  35         int wake_count;
  36
  37         void *status_reg_buf;
  38         unsigned int *status_buf;
  39         unsigned int *mask_buf;
  40         unsigned int *mask_buf_def;
  41         unsigned int *wake_buf;
  42
  43         unsigned int irq_reg_stride;
  44 };
  45
  46 static inline const
  47 struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
  48                                      int irq)
  49 {
  50         return &data->chip->irqs[irq];
  51 }
  52
  53 static void regmap_irq_lock(struct irq_data *data)
  54 {
  55         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
  56
  57         mutex_lock(&d->lock);
  58 }
  59
  60 static void regmap_irq_sync_unlock(struct irq_data *data)
  61 {
  62         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
  63         struct regmap *map = d->map;
  64         int i, ret;
  65         u32 reg;
  66
  67         if (d->chip->runtime_pm) {
  68                 ret = pm_runtime_get_sync(map->dev);
  69                 if (ret < 0)
  70                         dev_err(map->dev, "IRQ sync failed to resume: %d\n",
  71                                 ret);
  72         }
  73
  74         /*
  75          * If there's been a change in the mask write it back to the
  76          * hardware.  We rely on the use of the regmap core cache to
  77          * suppress pointless writes.
  78          */
  79         for (i = 0; i < d->chip->num_regs; i++) {
  80                 reg = d->chip->mask_base +
  81                         (i * map->reg_stride * d->irq_reg_stride);
  82                 if (d->chip->mask_invert)
  83                         ret = regmap_update_bits(d->map, reg,
  84                                          d->mask_buf_def[i], ~d->mask_buf[i]);
  85                 else
  86                         ret = regmap_update_bits(d->map, reg,
  87                                          d->mask_buf_def[i], d->mask_buf[i]);
  88                 if (ret != 0)
  89                         dev_err(d->map->dev, "Failed to sync masks in %x\n",
  90                                 reg);
  91
  92                 reg = d->chip->wake_base +
  93                         (i * map->reg_stride * d->irq_reg_stride);
  94                 if (d->wake_buf) {
  95                         if (d->chip->wake_invert)
  96                                 ret = regmap_update_bits(d->map, reg,
  97                                                          d->mask_buf_def[i],
  98                                                          ~d->wake_buf[i]);
  99                         else
 100                                 ret = regmap_update_bits(d->map, reg,
 101                                                          d->mask_buf_def[i],
 102                                                          d->wake_buf[i]);
 103                         if (ret != 0)
 104                                 dev_err(d->map->dev,
 105                                         "Failed to sync wakes in %x: %d\n",
 106                                         reg, ret);
 107                 }
 108
 109                 if (!d->chip->init_ack_masked)
 110                         continue;
 111                 /*
 112                  * Ack all the masked interrupts uncondictionly,
 113                  * OR if there is masked interrupt which hasn't been Acked,
 114                  * it'll be ignored in irq handler, then may introduce irq storm
 115                  */
 116                 if (d->mask_buf[i] && d->chip->ack_base) {
 117                         reg = d->chip->ack_base +
 118                                 (i * map->reg_stride * d->irq_reg_stride);
 119                         ret = regmap_write(map, reg, d->mask_buf[i]);
 120                         if (ret != 0)
 121                                 dev_err(d->map->dev, "Failed to ack 0x%x: %d\n",
 122                                         reg, ret);
 123                 }
 124         }
 125
 126         if (d->chip->runtime_pm)
 127                 pm_runtime_put(map->dev);
 128
 129         /* If we've changed our wakeup count propagate it to the parent */
 130         if (d->wake_count < 0)
 131                 for (i = d->wake_count; i < 0; i++)
 132                         irq_set_irq_wake(d->irq, 0);
 133         else if (d->wake_count > 0)
 134                 for (i = 0; i < d->wake_count; i++)
 135                         irq_set_irq_wake(d->irq, 1);
 136
 137         d->wake_count = 0;
 138
 139         mutex_unlock(&d->lock);
 140 }
 141
 142 static void regmap_irq_enable(struct irq_data *data)
 143 {
 144         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 145         struct regmap *map = d->map;
 146         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 147
 148         d->mask_buf[irq_data->reg_offset / map->reg_stride] &= ~irq_data->mask;
 149 }
 150
 151 static void regmap_irq_disable(struct irq_data *data)
 152 {
 153         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 154         struct regmap *map = d->map;
 155         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 156
 157         d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;
 158 }
 159
 160 static int regmap_irq_set_wake(struct irq_data *data, unsigned int on)
 161 {
 162         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 163         struct regmap *map = d->map;
 164         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 165
 166         if (on) {
 167                 if (d->wake_buf)
 168                         d->wake_buf[irq_data->reg_offset / map->reg_stride]
 169                                 &= ~irq_data->mask;
 170                 d->wake_count++;
 171         } else {
 172                 if (d->wake_buf)
 173                         d->wake_buf[irq_data->reg_offset / map->reg_stride]
 174                                 |= irq_data->mask;
 175                 d->wake_count--;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static const struct irq_chip regmap_irq_chip = {
 182         .irq_bus_lock           = regmap_irq_lock,
 183         .irq_bus_sync_unlock    = regmap_irq_sync_unlock,
 184         .irq_disable            = regmap_irq_disable,
 185         .irq_enable             = regmap_irq_enable,
 186         .irq_set_wake           = regmap_irq_set_wake,
 187 };
 188
 189 static irqreturn_t regmap_irq_thread(int irq, void *d)
 190 {
 191         struct regmap_irq_chip_data *data = d;
 192         const struct regmap_irq_chip *chip = data->chip;
 193         struct regmap *map = data->map;
 194         int ret, i;
 195         bool handled = false;
 196         u32 reg;
 197
 198         if (chip->runtime_pm) {
 199                 ret = pm_runtime_get_sync(map->dev);
 200                 if (ret < 0) {
 201                         dev_err(map->dev, "IRQ thread failed to resume: %d\n",
 202                                 ret);
 203                         pm_runtime_put(map->dev);
 204                         return IRQ_NONE;
 205                 }
 206         }
 207
 208         /*
 209          * Read in the statuses, using a single bulk read if possible
 210          * in order to reduce the I/O overheads.
 211          */
 212         if (!map->use_single_rw && map->reg_stride == 1 &&
 213             data->irq_reg_stride == 1) {
 214                 u8 *buf8 = data->status_reg_buf;
 215                 u16 *buf16 = data->status_reg_buf;
 216                 u32 *buf32 = data->status_reg_buf;
 217
 218                 BUG_ON(!data->status_reg_buf);
 219
 220                 ret = regmap_bulk_read(map, chip->status_base,
 221                                        data->status_reg_buf,
 222                                        chip->num_regs);
 223                 if (ret != 0) {
 224                         dev_err(map->dev, "Failed to read IRQ status: %d\n",
 225                                 ret);
 226                         return IRQ_NONE;
 227                 }
 228
 229                 for (i = 0; i < data->chip->num_regs; i++) {
 230                         switch (map->format.val_bytes) {
 231                         case 1:
 232                                 data->status_buf[i] = buf8[i];
 233                                 break;
 234                         case 2:
 235                                 data->status_buf[i] = buf16[i];
 236                                 break;
 237                         case 4:
 238                                 data->status_buf[i] = buf32[i];
 239                                 break;
 240                         default:
 241                                 BUG();
 242                                 return IRQ_NONE;
 243                         }
 244                 }
 245
 246         } else {
 247                 for (i = 0; i < data->chip->num_regs; i++) {
 248                         ret = regmap_read(map, chip->status_base +
 249                                           (i * map->reg_stride
 250                                            * data->irq_reg_stride),
 251                                           &data->status_buf[i]);
 252
 253                         if (ret != 0) {
 254                                 dev_err(map->dev,
 255                                         "Failed to read IRQ status: %d\n",
 256                                         ret);
 257                                 if (chip->runtime_pm)
 258                                         pm_runtime_put(map->dev);
 259                                 return IRQ_NONE;
 260                         }
 261                 }
 262         }
 263
 264         /*
 265          * Ignore masked IRQs and ack if we need to; we ack early so
 266          * there is no race between handling and acknowleding the
 267          * interrupt.  We assume that typically few of the interrupts
 268          * will fire simultaneously so don't worry about overhead from
 269          * doing a write per register.
 270          */
 271         for (i = 0; i < data->chip->num_regs; i++) {
 272                 data->status_buf[i] &= ~data->mask_buf[i];
 273
 274                 if (data->status_buf[i] && chip->ack_base) {
 275                         reg = chip->ack_base +
 276                                 (i * map->reg_stride * data->irq_reg_stride);
 277                         ret = regmap_write(map, reg, data->status_buf[i]);
 278                         if (ret != 0)
 279                                 dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 280                                         reg, ret);
 281                 }
 282         }
 283
 284         for (i = 0; i < chip->num_irqs; i++) {
 285                 if (data->status_buf[chip->irqs[i].reg_offset /
 286                                      map->reg_stride] & chip->irqs[i].mask) {
 287                         handle_nested_irq(irq_find_mapping(data->domain, i));
 288                         handled = true;
 289                 }
 290         }
 291
 292         if (chip->runtime_pm)
 293                 pm_runtime_put(map->dev);
 294
 295         if (handled)
 296                 return IRQ_HANDLED;
 297         else
 298                 return IRQ_NONE;
 299 }
 300
 301 static int regmap_irq_map(struct irq_domain *h, unsigned int virq,
 302                           irq_hw_number_t hw)
 303 {
 304         struct regmap_irq_chip_data *data = h->host_data;
 305
 306         irq_set_chip_data(virq, data);
 307         irq_set_chip(virq, &data->irq_chip);
 308         irq_set_nested_thread(virq, 1);
 309
 310         /* ARM needs us to explicitly flag the IRQ as valid
 311          * and will set them noprobe when we do so. */
 312 #ifdef CONFIG_ARM
 313         set_irq_flags(virq, IRQF_VALID);
 314 #else
 315         irq_set_noprobe(virq);
 316 #endif
 317
 318         return 0;
 319 }
 320
 321 static struct irq_domain_ops regmap_domain_ops = {
 322         .map    = regmap_irq_map,
 323         .xlate  = irq_domain_xlate_twocell,
 324 };
 325
 326 /**
 327  * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
 328  *
 329  * map:       The regmap for the device.
 330  * irq:       The IRQ the device uses to signal interrupts
 331  * irq_flags: The IRQF_ flags to use for the primary interrupt.
 332  * chip:      Configuration for the interrupt controller.
 333  * data:      Runtime data structure for the controller, allocated on success
 334  *
 335  * Returns 0 on success or an errno on failure.
 336  *
 337  * In order for this to be efficient the chip really should use a
 338  * register cache.  The chip driver is responsible for restoring the
 339  * register values used by the IRQ controller over suspend and resume.
 340  */
 341 int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 342                         int irq_base, const struct regmap_irq_chip *chip,
 343                         struct regmap_irq_chip_data **data)
 344 {
 345         struct regmap_irq_chip_data *d;
 346         int i;
 347         int ret = -ENOMEM;
 348         u32 reg;
 349
 350         for (i = 0; i < chip->num_irqs; i++) {
 351                 if (chip->irqs[i].reg_offset % map->reg_stride)
 352                         return -EINVAL;
 353                 if (chip->irqs[i].reg_offset / map->reg_stride >=
 354                     chip->num_regs)
 355                         return -EINVAL;
 356         }
 357
 358         if (irq_base) {
 359                 irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
 360                 if (irq_base < 0) {
 361                         dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
 362                                  irq_base);
 363                         return irq_base;
 364                 }
 365         }
 366
 367         d = kzalloc(sizeof(*d), GFP_KERNEL);
 368         if (!d)
 369                 return -ENOMEM;
 370
 371         *data = d;
 372
 373         d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 374                                 GFP_KERNEL);
 375         if (!d->status_buf)
 376                 goto err_alloc;
 377
 378         d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 379                               GFP_KERNEL);
 380         if (!d->mask_buf)
 381                 goto err_alloc;
 382
 383         d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
 384                                   GFP_KERNEL);
 385         if (!d->mask_buf_def)
 386                 goto err_alloc;
 387
 388         if (chip->wake_base) {
 389                 d->wake_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 390                                       GFP_KERNEL);
 391                 if (!d->wake_buf)
 392                         goto err_alloc;
 393         }
 394
 395         d->irq_chip = regmap_irq_chip;
 396         d->irq_chip.name = chip->name;
 397         d->irq = irq;
 398         d->map = map;
 399         d->chip = chip;
 400         d->irq_base = irq_base;
 401
 402         if (chip->irq_reg_stride)
 403                 d->irq_reg_stride = chip->irq_reg_stride;
 404         else
 405                 d->irq_reg_stride = 1;
 406
 407         if (!map->use_single_rw && map->reg_stride == 1 &&
 408             d->irq_reg_stride == 1) {
 409                 d->status_reg_buf = kmalloc(map->format.val_bytes *
 410                                             chip->num_regs, GFP_KERNEL);
 411                 if (!d->status_reg_buf)
 412                         goto err_alloc;
 413         }
 414
 415         mutex_init(&d->lock);
 416
 417         for (i = 0; i < chip->num_irqs; i++)
 418                 d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
 419                         |= chip->irqs[i].mask;
 420
 421         /* Mask all the interrupts by default */
 422         for (i = 0; i < chip->num_regs; i++) {
 423                 d->mask_buf[i] = d->mask_buf_def[i];
 424                 reg = chip->mask_base +
 425                         (i * map->reg_stride * d->irq_reg_stride);
 426                 if (chip->mask_invert)
 427                         ret = regmap_update_bits(map, reg,
 428                                          d->mask_buf[i], ~d->mask_buf[i]);
 429                 else
 430                         ret = regmap_update_bits(map, reg,
 431                                          d->mask_buf[i], d->mask_buf[i]);
 432                 if (ret != 0) {
 433                         dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 434                                 reg, ret);
 435                         goto err_alloc;
 436                 }
 437
 438                 if (!chip->init_ack_masked)
 439                         continue;
 440
 441                 /* Ack masked but set interrupts */
 442                 reg = chip->status_base +
 443                         (i * map->reg_stride * d->irq_reg_stride);
 444                 ret = regmap_read(map, reg, &d->status_buf[i]);
 445                 if (ret != 0) {
 446                         dev_err(map->dev, "Failed to read IRQ status: %d\n",
 447                                 ret);
 448                         goto err_alloc;
 449                 }
 450
 451                 if (d->status_buf[i] && chip->ack_base) {
 452                         reg = chip->ack_base +
 453                                 (i * map->reg_stride * d->irq_reg_stride);
 454                         ret = regmap_write(map, reg,
 455                                         d->status_buf[i] & d->mask_buf[i]);
 456                         if (ret != 0) {
 457                                 dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 458                                         reg, ret);
 459                                 goto err_alloc;
 460                         }
 461                 }
 462         }
 463
 464         /* Wake is disabled by default */
 465         if (d->wake_buf) {
 466                 for (i = 0; i < chip->num_regs; i++) {
 467                         d->wake_buf[i] = d->mask_buf_def[i];
 468                         reg = chip->wake_base +
 469                                 (i * map->reg_stride * d->irq_reg_stride);
 470
 471                         if (chip->wake_invert)
 472                                 ret = regmap_update_bits(map, reg,
 473                                                          d->mask_buf_def[i],
 474                                                          0);
 475                         else
 476                                 ret = regmap_update_bits(map, reg,
 477                                                          d->mask_buf_def[i],
 478                                                          d->wake_buf[i]);
 479                         if (ret != 0) {
 480                                 dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 481                                         reg, ret);
 482                                 goto err_alloc;
 483                         }
 484                 }
 485         }
 486
 487         if (irq_base)
 488                 d->domain = irq_domain_add_legacy(map->dev->of_node,
 489                                                   chip->num_irqs, irq_base, 0,
 490                                                   &regmap_domain_ops, d);
 491         else
 492                 d->domain = irq_domain_add_linear(map->dev->of_node,
 493                                                   chip->num_irqs,
 494                                                   &regmap_domain_ops, d);
 495         if (!d->domain) {
 496                 dev_err(map->dev, "Failed to create IRQ domain\n");
 497                 ret = -ENOMEM;
 498                 goto err_alloc;
 499         }
 500
 501         ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags,
 502                                    chip->name, d);
 503         if (ret != 0) {
 504                 dev_err(map->dev, "Failed to request IRQ %d for %s: %d\n",
 505                         irq, chip->name, ret);
 506                 goto err_domain;
 507         }
 508
 509         return 0;
 510
 511 err_domain:
 512         /* Should really dispose of the domain but... */
 513 err_alloc:
 514         kfree(d->wake_buf);
 515         kfree(d->mask_buf_def);
 516         kfree(d->mask_buf);
 517         kfree(d->status_buf);
 518         kfree(d->status_reg_buf);
 519         kfree(d);
 520         return ret;
 521 }
 522 EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
 523
 524 /**
 525  * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
 526  *
 527  * @irq: Primary IRQ for the device
 528  * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
 529  */
 530 void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
 531 {
 532         if (!d)
 533                 return;
 534
 535         free_irq(irq, d);
 536         /* We should unmap the domain but... */
 537         kfree(d->wake_buf);
 538         kfree(d->mask_buf_def);
 539         kfree(d->mask_buf);
 540         kfree(d->status_reg_buf);
 541         kfree(d->status_buf);
 542         kfree(d);
 543 }
 544 EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
 545
 546 /**
 547  * regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
 548  *
 549  * Useful for drivers to request their own IRQs.
 550  *
 551  * @data: regmap_irq controller to operate on.
 552  */
 553 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
 554 {
 555         WARN_ON(!data->irq_base);
 556         return data->irq_base;
 557 }
 558 EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);
 559
 560 /**
 561  * regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
 562  *
 563  * Useful for drivers to request their own IRQs.
 564  *
 565  * @data: regmap_irq controller to operate on.
 566  * @irq: index of the interrupt requested in the chip IRQs
 567  */
 568 int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
 569 {
 570         /* Handle holes in the IRQ list */
 571         if (!data->chip->irqs[irq].mask)
 572                 return -EINVAL;
 573
 574         return irq_create_mapping(data->domain, irq);
 575 }
 576 EXPORT_SYMBOL_GPL(regmap_irq_get_virq);
 577
 578 /**
 579  * regmap_irq_get_domain(): Retrieve the irq_domain for the chip
 580  *
 581  * Useful for drivers to request their own IRQs and for integration
 582  * with subsystems.  For ease of integration NULL is accepted as a
 583  * domain, allowing devices to just call this even if no domain is
 584  * allocated.
 585  *
 586  * @data: regmap_irq controller to operate on.
 587  */
 588 struct irq_domain *regmap_irq_get_domain(struct regmap_irq_chip_data *data)
 589 {
 590         if (data)
 591                 return data->domain;
 592         else
 593                 return NULL;
 594 }
 595 EXPORT_SYMBOL_GPL(regmap_irq_get_domain);