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/device.h>
  14 #include <linux/export.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/pm_runtime.h>
  19 #include <linux/regmap.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 unconditionally,
 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 || d->chip->use_ack)) {
 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_read && 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 || chip->use_ack)) {
 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         irq_set_noprobe(virq);
 310
 311         return 0;
 312 }
 313
 314 static const struct irq_domain_ops regmap_domain_ops = {
 315         .map    = regmap_irq_map,
 316         .xlate  = irq_domain_xlate_twocell,
 317 };
 318
 319 /**
 320  * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
 321  *
 322  * map:       The regmap for the device.
 323  * irq:       The IRQ the device uses to signal interrupts
 324  * irq_flags: The IRQF_ flags to use for the primary interrupt.
 325  * chip:      Configuration for the interrupt controller.
 326  * data:      Runtime data structure for the controller, allocated on success
 327  *
 328  * Returns 0 on success or an errno on failure.
 329  *
 330  * In order for this to be efficient the chip really should use a
 331  * register cache.  The chip driver is responsible for restoring the
 332  * register values used by the IRQ controller over suspend and resume.
 333  */
 334 int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 335                         int irq_base, const struct regmap_irq_chip *chip,
 336                         struct regmap_irq_chip_data **data)
 337 {
 338         struct regmap_irq_chip_data *d;
 339         int i;
 340         int ret = -ENOMEM;
 341         u32 reg;
 342
 343         if (chip->num_regs <= 0)
 344                 return -EINVAL;
 345
 346         for (i = 0; i < chip->num_irqs; i++) {
 347                 if (chip->irqs[i].reg_offset % map->reg_stride)
 348                         return -EINVAL;
 349                 if (chip->irqs[i].reg_offset / map->reg_stride >=
 350                     chip->num_regs)
 351                         return -EINVAL;
 352         }
 353
 354         if (irq_base) {
 355                 irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
 356                 if (irq_base < 0) {
 357                         dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
 358                                  irq_base);
 359                         return irq_base;
 360                 }
 361         }
 362
 363         d = kzalloc(sizeof(*d), GFP_KERNEL);
 364         if (!d)
 365                 return -ENOMEM;
 366
 367         d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 368                                 GFP_KERNEL);
 369         if (!d->status_buf)
 370                 goto err_alloc;
 371
 372         d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 373                               GFP_KERNEL);
 374         if (!d->mask_buf)
 375                 goto err_alloc;
 376
 377         d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
 378                                   GFP_KERNEL);
 379         if (!d->mask_buf_def)
 380                 goto err_alloc;
 381
 382         if (chip->wake_base) {
 383                 d->wake_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 384                                       GFP_KERNEL);
 385                 if (!d->wake_buf)
 386                         goto err_alloc;
 387         }
 388
 389         d->irq_chip = regmap_irq_chip;
 390         d->irq_chip.name = chip->name;
 391         d->irq = irq;
 392         d->map = map;
 393         d->chip = chip;
 394         d->irq_base = irq_base;
 395
 396         if (chip->irq_reg_stride)
 397                 d->irq_reg_stride = chip->irq_reg_stride;
 398         else
 399                 d->irq_reg_stride = 1;
 400
 401         if (!map->use_single_read && map->reg_stride == 1 &&
 402             d->irq_reg_stride == 1) {
 403                 d->status_reg_buf = kmalloc(map->format.val_bytes *
 404                                             chip->num_regs, GFP_KERNEL);
 405                 if (!d->status_reg_buf)
 406                         goto err_alloc;
 407         }
 408
 409         mutex_init(&d->lock);
 410
 411         for (i = 0; i < chip->num_irqs; i++)
 412                 d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
 413                         |= chip->irqs[i].mask;
 414
 415         /* Mask all the interrupts by default */
 416         for (i = 0; i < chip->num_regs; i++) {
 417                 d->mask_buf[i] = d->mask_buf_def[i];
 418                 reg = chip->mask_base +
 419                         (i * map->reg_stride * d->irq_reg_stride);
 420                 if (chip->mask_invert)
 421                         ret = regmap_update_bits(map, reg,
 422                                          d->mask_buf[i], ~d->mask_buf[i]);
 423                 else
 424                         ret = regmap_update_bits(map, reg,
 425                                          d->mask_buf[i], d->mask_buf[i]);
 426                 if (ret != 0) {
 427                         dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 428                                 reg, ret);
 429                         goto err_alloc;
 430                 }
 431
 432                 if (!chip->init_ack_masked)
 433                         continue;
 434
 435                 /* Ack masked but set interrupts */
 436                 reg = chip->status_base +
 437                         (i * map->reg_stride * d->irq_reg_stride);
 438                 ret = regmap_read(map, reg, &d->status_buf[i]);
 439                 if (ret != 0) {
 440                         dev_err(map->dev, "Failed to read IRQ status: %d\n",
 441                                 ret);
 442                         goto err_alloc;
 443                 }
 444
 445                 if (d->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 446                         reg = chip->ack_base +
 447                                 (i * map->reg_stride * d->irq_reg_stride);
 448                         ret = regmap_write(map, reg,
 449                                         d->status_buf[i] & d->mask_buf[i]);
 450                         if (ret != 0) {
 451                                 dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 452                                         reg, ret);
 453                                 goto err_alloc;
 454                         }
 455                 }
 456         }
 457
 458         /* Wake is disabled by default */
 459         if (d->wake_buf) {
 460                 for (i = 0; i < chip->num_regs; i++) {
 461                         d->wake_buf[i] = d->mask_buf_def[i];
 462                         reg = chip->wake_base +
 463                                 (i * map->reg_stride * d->irq_reg_stride);
 464
 465                         if (chip->wake_invert)
 466                                 ret = regmap_update_bits(map, reg,
 467                                                          d->mask_buf_def[i],
 468                                                          0);
 469                         else
 470                                 ret = regmap_update_bits(map, reg,
 471                                                          d->mask_buf_def[i],
 472                                                          d->wake_buf[i]);
 473                         if (ret != 0) {
 474                                 dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 475                                         reg, ret);
 476                                 goto err_alloc;
 477                         }
 478                 }
 479         }
 480
 481         if (irq_base)
 482                 d->domain = irq_domain_add_legacy(map->dev->of_node,
 483                                                   chip->num_irqs, irq_base, 0,
 484                                                   &regmap_domain_ops, d);
 485         else
 486                 d->domain = irq_domain_add_linear(map->dev->of_node,
 487                                                   chip->num_irqs,
 488                                                   &regmap_domain_ops, d);
 489         if (!d->domain) {
 490                 dev_err(map->dev, "Failed to create IRQ domain\n");
 491                 ret = -ENOMEM;
 492                 goto err_alloc;
 493         }
 494
 495         ret = request_threaded_irq(irq, NULL, regmap_irq_thread,
 496                                    irq_flags | IRQF_ONESHOT,
 497                                    chip->name, d);
 498         if (ret != 0) {
 499                 dev_err(map->dev, "Failed to request IRQ %d for %s: %d\n",
 500                         irq, chip->name, ret);
 501                 goto err_domain;
 502         }
 503
 504         *data = d;
 505
 506         return 0;
 507
 508 err_domain:
 509         /* Should really dispose of the domain but... */
 510 err_alloc:
 511         kfree(d->wake_buf);
 512         kfree(d->mask_buf_def);
 513         kfree(d->mask_buf);
 514         kfree(d->status_buf);
 515         kfree(d->status_reg_buf);
 516         kfree(d);
 517         return ret;
 518 }
 519 EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
 520
 521 /**
 522  * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
 523  *
 524  * @irq: Primary IRQ for the device
 525  * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
 526  */
 527 void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
 528 {
 529         if (!d)
 530                 return;
 531
 532         free_irq(irq, d);
 533         irq_domain_remove(d->domain);
 534         kfree(d->wake_buf);
 535         kfree(d->mask_buf_def);
 536         kfree(d->mask_buf);
 537         kfree(d->status_reg_buf);
 538         kfree(d->status_buf);
 539         kfree(d);
 540 }
 541 EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
 542
 543 /**
 544  * regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
 545  *
 546  * Useful for drivers to request their own IRQs.
 547  *
 548  * @data: regmap_irq controller to operate on.
 549  */
 550 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
 551 {
 552         WARN_ON(!data->irq_base);
 553         return data->irq_base;
 554 }
 555 EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);
 556
 557 /**
 558  * regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
 559  *
 560  * Useful for drivers to request their own IRQs.
 561  *
 562  * @data: regmap_irq controller to operate on.
 563  * @irq: index of the interrupt requested in the chip IRQs
 564  */
 565 int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
 566 {
 567         /* Handle holes in the IRQ list */
 568         if (!data->chip->irqs[irq].mask)
 569                 return -EINVAL;
 570
 571         return irq_create_mapping(data->domain, irq);
 572 }
 573 EXPORT_SYMBOL_GPL(regmap_irq_get_virq);
 574
 575 /**
 576  * regmap_irq_get_domain(): Retrieve the irq_domain for the chip
 577  *
 578  * Useful for drivers to request their own IRQs and for integration
 579  * with subsystems.  For ease of integration NULL is accepted as a
 580  * domain, allowing devices to just call this even if no domain is
 581  * allocated.
 582  *
 583  * @data: regmap_irq controller to operate on.
 584  */
 585 struct irq_domain *regmap_irq_get_domain(struct regmap_irq_chip_data *data)
 586 {
 587         if (data)
 588                 return data->domain;
 589         else
 590                 return NULL;
 591 }
 592 EXPORT_SYMBOL_GPL(regmap_irq_get_domain);