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         unsigned int *status_buf;
  38         unsigned int *mask_buf;
  39         unsigned int *mask_buf_def;
  40         unsigned int *wake_buf;
  41
  42         unsigned int irq_reg_stride;
  43 };
  44
  45 static inline const
  46 struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
  47                                      int irq)
  48 {
  49         return &data->chip->irqs[irq];
  50 }
  51
  52 static void regmap_irq_lock(struct irq_data *data)
  53 {
  54         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
  55
  56         mutex_lock(&d->lock);
  57 }
  58
  59 static void regmap_irq_sync_unlock(struct irq_data *data)
  60 {
  61         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
  62         struct regmap *map = d->map;
  63         int i, ret;
  64         u32 reg;
  65
  66         if (d->chip->runtime_pm) {
  67                 ret = pm_runtime_get_sync(map->dev);
  68                 if (ret < 0)
  69                         dev_err(map->dev, "IRQ sync failed to resume: %d\n",
  70                                 ret);
  71         }
  72
  73         /*
  74          * If there's been a change in the mask write it back to the
  75          * hardware.  We rely on the use of the regmap core cache to
  76          * suppress pointless writes.
  77          */
  78         for (i = 0; i < d->chip->num_regs; i++) {
  79                 reg = d->chip->mask_base +
  80                         (i * map->reg_stride * d->irq_reg_stride);
  81                 if (d->chip->mask_invert)
  82                         ret = regmap_update_bits(d->map, reg,
  83                                          d->mask_buf_def[i], ~d->mask_buf[i]);
  84                 else
  85                         ret = regmap_update_bits(d->map, reg,
  86                                          d->mask_buf_def[i], d->mask_buf[i]);
  87                 if (ret != 0)
  88                         dev_err(d->map->dev, "Failed to sync masks in %x\n",
  89                                 reg);
  90         }
  91
  92         if (d->chip->runtime_pm)
  93                 pm_runtime_put(map->dev);
  94
  95         /* If we've changed our wakeup count propagate it to the parent */
  96         if (d->wake_count < 0)
  97                 for (i = d->wake_count; i < 0; i++)
  98                         irq_set_irq_wake(d->irq, 0);
  99         else if (d->wake_count > 0)
 100                 for (i = 0; i < d->wake_count; i++)
 101                         irq_set_irq_wake(d->irq, 1);
 102
 103         d->wake_count = 0;
 104
 105         mutex_unlock(&d->lock);
 106 }
 107
 108 static void regmap_irq_enable(struct irq_data *data)
 109 {
 110         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 111         struct regmap *map = d->map;
 112         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 113
 114         d->mask_buf[irq_data->reg_offset / map->reg_stride] &= ~irq_data->mask;
 115 }
 116
 117 static void regmap_irq_disable(struct irq_data *data)
 118 {
 119         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 120         struct regmap *map = d->map;
 121         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 122
 123         d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;
 124 }
 125
 126 static int regmap_irq_set_wake(struct irq_data *data, unsigned int on)
 127 {
 128         struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 129         struct regmap *map = d->map;
 130         const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
 131
 132         if (!d->chip->wake_base)
 133                 return -EINVAL;
 134
 135         if (on) {
 136                 d->wake_buf[irq_data->reg_offset / map->reg_stride]
 137                         &= ~irq_data->mask;
 138                 d->wake_count++;
 139         } else {
 140                 d->wake_buf[irq_data->reg_offset / map->reg_stride]
 141                         |= irq_data->mask;
 142                 d->wake_count--;
 143         }
 144
 145         return 0;
 146 }
 147
 148 static const struct irq_chip regmap_irq_chip = {
 149         .irq_bus_lock           = regmap_irq_lock,
 150         .irq_bus_sync_unlock    = regmap_irq_sync_unlock,
 151         .irq_disable            = regmap_irq_disable,
 152         .irq_enable             = regmap_irq_enable,
 153         .irq_set_wake           = regmap_irq_set_wake,
 154 };
 155
 156 static irqreturn_t regmap_irq_thread(int irq, void *d)
 157 {
 158         struct regmap_irq_chip_data *data = d;
 159         const struct regmap_irq_chip *chip = data->chip;
 160         struct regmap *map = data->map;
 161         int ret, i;
 162         bool handled = false;
 163         u32 reg;
 164
 165         if (chip->runtime_pm) {
 166                 ret = pm_runtime_get_sync(map->dev);
 167                 if (ret < 0) {
 168                         dev_err(map->dev, "IRQ thread failed to resume: %d\n",
 169                                 ret);
 170                         return IRQ_NONE;
 171                 }
 172         }
 173
 174         /*
 175          * Ignore masked IRQs and ack if we need to; we ack early so
 176          * there is no race between handling and acknowleding the
 177          * interrupt.  We assume that typically few of the interrupts
 178          * will fire simultaneously so don't worry about overhead from
 179          * doing a write per register.
 180          */
 181         for (i = 0; i < data->chip->num_regs; i++) {
 182                 ret = regmap_read(map, chip->status_base + (i * map->reg_stride
 183                                    * data->irq_reg_stride),
 184                                    &data->status_buf[i]);
 185
 186                 if (ret != 0) {
 187                         dev_err(map->dev, "Failed to read IRQ status: %d\n",
 188                                         ret);
 189                         if (chip->runtime_pm)
 190                                 pm_runtime_put(map->dev);
 191                         return IRQ_NONE;
 192                 }
 193
 194                 data->status_buf[i] &= ~data->mask_buf[i];
 195
 196                 if (data->status_buf[i] && chip->ack_base) {
 197                         reg = chip->ack_base +
 198                                 (i * map->reg_stride * data->irq_reg_stride);
 199                         ret = regmap_write(map, reg, data->status_buf[i]);
 200                         if (ret != 0)
 201                                 dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 202                                         reg, ret);
 203                 }
 204         }
 205
 206         for (i = 0; i < chip->num_irqs; i++) {
 207                 if (data->status_buf[chip->irqs[i].reg_offset /
 208                                      map->reg_stride] & chip->irqs[i].mask) {
 209                         handle_nested_irq(irq_find_mapping(data->domain, i));
 210                         handled = true;
 211                 }
 212         }
 213
 214         if (chip->runtime_pm)
 215                 pm_runtime_put(map->dev);
 216
 217         if (handled)
 218                 return IRQ_HANDLED;
 219         else
 220                 return IRQ_NONE;
 221 }
 222
 223 static int regmap_irq_map(struct irq_domain *h, unsigned int virq,
 224                           irq_hw_number_t hw)
 225 {
 226         struct regmap_irq_chip_data *data = h->host_data;
 227
 228         irq_set_chip_data(virq, data);
 229         irq_set_chip(virq, &data->irq_chip);
 230         irq_set_nested_thread(virq, 1);
 231
 232         /* ARM needs us to explicitly flag the IRQ as valid
 233          * and will set them noprobe when we do so. */
 234 #ifdef CONFIG_ARM
 235         set_irq_flags(virq, IRQF_VALID);
 236 #else
 237         irq_set_noprobe(virq);
 238 #endif
 239
 240         return 0;
 241 }
 242
 243 static struct irq_domain_ops regmap_domain_ops = {
 244         .map    = regmap_irq_map,
 245         .xlate  = irq_domain_xlate_twocell,
 246 };
 247
 248 /**
 249  * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
 250  *
 251  * map:       The regmap for the device.
 252  * irq:       The IRQ the device uses to signal interrupts
 253  * irq_flags: The IRQF_ flags to use for the primary interrupt.
 254  * chip:      Configuration for the interrupt controller.
 255  * data:      Runtime data structure for the controller, allocated on success
 256  *
 257  * Returns 0 on success or an errno on failure.
 258  *
 259  * In order for this to be efficient the chip really should use a
 260  * register cache.  The chip driver is responsible for restoring the
 261  * register values used by the IRQ controller over suspend and resume.
 262  */
 263 int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 264                         int irq_base, const struct regmap_irq_chip *chip,
 265                         struct regmap_irq_chip_data **data)
 266 {
 267         struct regmap_irq_chip_data *d;
 268         int i;
 269         int ret = -ENOMEM;
 270         u32 reg;
 271
 272         for (i = 0; i < chip->num_irqs; i++) {
 273                 if (chip->irqs[i].reg_offset % map->reg_stride)
 274                         return -EINVAL;
 275                 if (chip->irqs[i].reg_offset / map->reg_stride >=
 276                     chip->num_regs)
 277                         return -EINVAL;
 278         }
 279
 280         if (irq_base) {
 281                 irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
 282                 if (irq_base < 0) {
 283                         dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
 284                                  irq_base);
 285                         return irq_base;
 286                 }
 287         }
 288
 289         d = kzalloc(sizeof(*d), GFP_KERNEL);
 290         if (!d)
 291                 return -ENOMEM;
 292
 293         *data = d;
 294
 295         d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 296                                 GFP_KERNEL);
 297         if (!d->status_buf)
 298                 goto err_alloc;
 299
 300         d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 301                               GFP_KERNEL);
 302         if (!d->mask_buf)
 303                 goto err_alloc;
 304
 305         d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
 306                                   GFP_KERNEL);
 307         if (!d->mask_buf_def)
 308                 goto err_alloc;
 309
 310         if (chip->wake_base) {
 311                 d->wake_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 312                                       GFP_KERNEL);
 313                 if (!d->wake_buf)
 314                         goto err_alloc;
 315         }
 316
 317         d->irq_chip = regmap_irq_chip;
 318         d->irq_chip.name = chip->name;
 319         if (!chip->wake_base) {
 320                 d->irq_chip.irq_set_wake = NULL;
 321                 d->irq_chip.flags |= IRQCHIP_MASK_ON_SUSPEND |
 322                                      IRQCHIP_SKIP_SET_WAKE;
 323         }
 324         d->irq = irq;
 325         d->map = map;
 326         d->chip = chip;
 327         d->irq_base = irq_base;
 328
 329         if (chip->irq_reg_stride)
 330                 d->irq_reg_stride = chip->irq_reg_stride;
 331         else
 332                 d->irq_reg_stride = 1;
 333
 334         mutex_init(&d->lock);
 335
 336         for (i = 0; i < chip->num_irqs; i++)
 337                 d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
 338                         |= chip->irqs[i].mask;
 339
 340         /* Mask all the interrupts by default */
 341         for (i = 0; i < chip->num_regs; i++) {
 342                 d->mask_buf[i] = d->mask_buf_def[i];
 343                 reg = chip->mask_base +
 344                         (i * map->reg_stride * d->irq_reg_stride);
 345                 if (chip->mask_invert)
 346                         ret = regmap_update_bits(map, reg,
 347                                          d->mask_buf[i], ~d->mask_buf[i]);
 348                 else
 349                         ret = regmap_update_bits(map, reg,
 350                                          d->mask_buf[i], d->mask_buf[i]);
 351                 if (ret != 0) {
 352                         dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 353                                 reg, ret);
 354                         goto err_alloc;
 355                 }
 356         }
 357
 358         /* Wake is disabled by default */
 359         if (d->wake_buf) {
 360                 for (i = 0; i < chip->num_regs; i++) {
 361                         d->wake_buf[i] = d->mask_buf_def[i];
 362                         reg = chip->wake_base +
 363                                 (i * map->reg_stride * d->irq_reg_stride);
 364                         ret = regmap_update_bits(map, reg, d->wake_buf[i],
 365                                                  d->wake_buf[i]);
 366                         if (ret != 0) {
 367                                 dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 368                                         reg, ret);
 369                                 goto err_alloc;
 370                         }
 371                 }
 372         }
 373
 374         if (irq_base)
 375                 d->domain = irq_domain_add_legacy(map->dev->of_node,
 376                                                   chip->num_irqs, irq_base, 0,
 377                                                   &regmap_domain_ops, d);
 378         else
 379                 d->domain = irq_domain_add_linear(map->dev->of_node,
 380                                                   chip->num_irqs,
 381                                                   &regmap_domain_ops, d);
 382         if (!d->domain) {
 383                 dev_err(map->dev, "Failed to create IRQ domain\n");
 384                 ret = -ENOMEM;
 385                 goto err_alloc;
 386         }
 387
 388         ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags,
 389                                    chip->name, d);
 390         if (ret != 0) {
 391                 dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret);
 392                 goto err_domain;
 393         }
 394
 395         return 0;
 396
 397 err_domain:
 398         /* Should really dispose of the domain but... */
 399 err_alloc:
 400         kfree(d->wake_buf);
 401         kfree(d->mask_buf_def);
 402         kfree(d->mask_buf);
 403         kfree(d->status_buf);
 404         kfree(d);
 405         return ret;
 406 }
 407 EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
 408
 409 /**
 410  * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
 411  *
 412  * @irq: Primary IRQ for the device
 413  * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
 414  */
 415 void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
 416 {
 417         if (!d)
 418                 return;
 419
 420         free_irq(irq, d);
 421         /* We should unmap the domain but... */
 422         kfree(d->wake_buf);
 423         kfree(d->mask_buf_def);
 424         kfree(d->mask_buf);
 425         kfree(d->status_buf);
 426         kfree(d);
 427 }
 428 EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
 429
 430 /**
 431  * regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
 432  *
 433  * Useful for drivers to request their own IRQs.
 434  *
 435  * @data: regmap_irq controller to operate on.
 436  */
 437 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
 438 {
 439         WARN_ON(!data->irq_base);
 440         return data->irq_base;
 441 }
 442 EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);
 443
 444 /**
 445  * regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
 446  *
 447  * Useful for drivers to request their own IRQs.
 448  *
 449  * @data: regmap_irq controller to operate on.
 450  * @irq: index of the interrupt requested in the chip IRQs
 451  */
 452 int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
 453 {
 454         /* Handle holes in the IRQ list */
 455         if (!data->chip->irqs[irq].mask)
 456                 return -EINVAL;
 457
 458         return irq_create_mapping(data->domain, irq);
 459 }
 460 EXPORT_SYMBOL_GPL(regmap_irq_get_virq);
 461
 462 /**
 463  * regmap_irq_get_domain(): Retrieve the irq_domain for the chip
 464  *
 465  * Useful for drivers to request their own IRQs and for integration
 466  * with subsystems.  For ease of integration NULL is accepted as a
 467  * domain, allowing devices to just call this even if no domain is
 468  * allocated.
 469  *
 470  * @data: regmap_irq controller to operate on.
 471  */
 472 struct irq_domain *regmap_irq_get_domain(struct regmap_irq_chip_data *data)
 473 {
 474         if (data)
 475                 return data->domain;
 476         else
 477                 return NULL;
 478 }
 479 EXPORT_SYMBOL_GPL(regmap_irq_get_domain);