drivers/gpio/gpio-bcm-kona.c

   1 /*
   2  * Broadcom Kona GPIO Driver
   3  *
   4  * Author: Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>
   5  * Copyright (C) 2012-2014 Broadcom Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation version 2.
  10  *
  11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  12  * kind, whether express or implied; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/bitops.h>
  18 #include <linux/err.h>
  19 #include <linux/io.h>
  20 #include <linux/gpio.h>
  21 #include <linux/of_device.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/init.h>
  24 #include <linux/irqdomain.h>
  25 #include <linux/irqchip/chained_irq.h>
  26
  27 #define BCM_GPIO_PASSWD                         0x00a5a501
  28 #define GPIO_PER_BANK                           32
  29 #define GPIO_MAX_BANK_NUM                       8
  30
  31 #define GPIO_BANK(gpio)                         ((gpio) >> 5)
  32 #define GPIO_BIT(gpio)                          ((gpio) & (GPIO_PER_BANK - 1))
  33
  34 /* There is a GPIO control register for each GPIO */
  35 #define GPIO_CONTROL(gpio)                      (0x00000100 + ((gpio) << 2))
  36
  37 /* The remaining registers are per GPIO bank */
  38 #define GPIO_OUT_STATUS(bank)                   (0x00000000 + ((bank) << 2))
  39 #define GPIO_IN_STATUS(bank)                    (0x00000020 + ((bank) << 2))
  40 #define GPIO_OUT_SET(bank)                      (0x00000040 + ((bank) << 2))
  41 #define GPIO_OUT_CLEAR(bank)                    (0x00000060 + ((bank) << 2))
  42 #define GPIO_INT_STATUS(bank)                   (0x00000080 + ((bank) << 2))
  43 #define GPIO_INT_MASK(bank)                     (0x000000a0 + ((bank) << 2))
  44 #define GPIO_INT_MSKCLR(bank)                   (0x000000c0 + ((bank) << 2))
  45 #define GPIO_PWD_STATUS(bank)                   (0x00000500 + ((bank) << 2))
  46
  47 #define GPIO_GPPWR_OFFSET                       0x00000520
  48
  49 #define GPIO_GPCTR0_DBR_SHIFT                   5
  50 #define GPIO_GPCTR0_DBR_MASK                    0x000001e0
  51
  52 #define GPIO_GPCTR0_ITR_SHIFT                   3
  53 #define GPIO_GPCTR0_ITR_MASK                    0x00000018
  54 #define GPIO_GPCTR0_ITR_CMD_RISING_EDGE         0x00000001
  55 #define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE        0x00000002
  56 #define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE           0x00000003
  57
  58 #define GPIO_GPCTR0_IOTR_MASK                   0x00000001
  59 #define GPIO_GPCTR0_IOTR_CMD_0UTPUT             0x00000000
  60 #define GPIO_GPCTR0_IOTR_CMD_INPUT              0x00000001
  61
  62 #define GPIO_GPCTR0_DB_ENABLE_MASK              0x00000100
  63
  64 #define LOCK_CODE                               0xffffffff
  65 #define UNLOCK_CODE                             0x00000000
  66
  67 struct bcm_kona_gpio {
  68         void __iomem *reg_base;
  69         int num_bank;
  70         spinlock_t lock;
  71         struct gpio_chip gpio_chip;
  72         struct irq_domain *irq_domain;
  73         struct bcm_kona_gpio_bank *banks;
  74         struct platform_device *pdev;
  75 };
  76
  77 struct bcm_kona_gpio_bank {
  78         int id;
  79         int irq;
  80         /* Used in the interrupt handler */
  81         struct bcm_kona_gpio *kona_gpio;
  82 };
  83
  84 static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
  85                                                 int bank_id, u32 lockcode)
  86 {
  87         writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
  88         writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
  89 }
  90
  91 static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
  92                                         unsigned gpio)
  93 {
  94         u32 val;
  95         unsigned long flags;
  96         int bank_id = GPIO_BANK(gpio);
  97
  98         spin_lock_irqsave(&kona_gpio->lock, flags);
  99
 100         val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
 101         val |= BIT(gpio);
 102         bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
 103
 104         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 105 }
 106
 107 static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
 108                                         unsigned gpio)
 109 {
 110         u32 val;
 111         unsigned long flags;
 112         int bank_id = GPIO_BANK(gpio);
 113
 114         spin_lock_irqsave(&kona_gpio->lock, flags);
 115
 116         val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
 117         val &= ~BIT(gpio);
 118         bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
 119
 120         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 121 }
 122
 123 static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
 124 {
 125         struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
 126         void __iomem *reg_base = kona_gpio->reg_base;
 127         u32 val;
 128
 129         val = readl(reg_base + GPIO_CONTROL(gpio)) & GPIO_GPCTR0_IOTR_MASK;
 130         return val ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
 131 }
 132
 133 static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 134 {
 135         struct bcm_kona_gpio *kona_gpio;
 136         void __iomem *reg_base;
 137         int bank_id = GPIO_BANK(gpio);
 138         int bit = GPIO_BIT(gpio);
 139         u32 val, reg_offset;
 140         unsigned long flags;
 141
 142         kona_gpio = gpiochip_get_data(chip);
 143         reg_base = kona_gpio->reg_base;
 144         spin_lock_irqsave(&kona_gpio->lock, flags);
 145
 146         /* this function only applies to output pin */
 147         if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
 148                 goto out;
 149
 150         reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
 151
 152         val = readl(reg_base + reg_offset);
 153         val |= BIT(bit);
 154         writel(val, reg_base + reg_offset);
 155
 156 out:
 157         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 158 }
 159
 160 static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
 161 {
 162         struct bcm_kona_gpio *kona_gpio;
 163         void __iomem *reg_base;
 164         int bank_id = GPIO_BANK(gpio);
 165         int bit = GPIO_BIT(gpio);
 166         u32 val, reg_offset;
 167         unsigned long flags;
 168
 169         kona_gpio = gpiochip_get_data(chip);
 170         reg_base = kona_gpio->reg_base;
 171         spin_lock_irqsave(&kona_gpio->lock, flags);
 172
 173         if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
 174                 reg_offset = GPIO_IN_STATUS(bank_id);
 175         else
 176                 reg_offset = GPIO_OUT_STATUS(bank_id);
 177
 178         /* read the GPIO bank status */
 179         val = readl(reg_base + reg_offset);
 180
 181         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 182
 183         /* return the specified bit status */
 184         return !!(val & BIT(bit));
 185 }
 186
 187 static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
 188 {
 189         struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
 190
 191         bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
 192         return 0;
 193 }
 194
 195 static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
 196 {
 197         struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
 198
 199         bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
 200 }
 201
 202 static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 203 {
 204         struct bcm_kona_gpio *kona_gpio;
 205         void __iomem *reg_base;
 206         u32 val;
 207         unsigned long flags;
 208
 209         kona_gpio = gpiochip_get_data(chip);
 210         reg_base = kona_gpio->reg_base;
 211         spin_lock_irqsave(&kona_gpio->lock, flags);
 212
 213         val = readl(reg_base + GPIO_CONTROL(gpio));
 214         val &= ~GPIO_GPCTR0_IOTR_MASK;
 215         val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
 216         writel(val, reg_base + GPIO_CONTROL(gpio));
 217
 218         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 219
 220         return 0;
 221 }
 222
 223 static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
 224                                           unsigned gpio, int value)
 225 {
 226         struct bcm_kona_gpio *kona_gpio;
 227         void __iomem *reg_base;
 228         int bank_id = GPIO_BANK(gpio);
 229         int bit = GPIO_BIT(gpio);
 230         u32 val, reg_offset;
 231         unsigned long flags;
 232
 233         kona_gpio = gpiochip_get_data(chip);
 234         reg_base = kona_gpio->reg_base;
 235         spin_lock_irqsave(&kona_gpio->lock, flags);
 236
 237         val = readl(reg_base + GPIO_CONTROL(gpio));
 238         val &= ~GPIO_GPCTR0_IOTR_MASK;
 239         val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
 240         writel(val, reg_base + GPIO_CONTROL(gpio));
 241         reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
 242
 243         val = readl(reg_base + reg_offset);
 244         val |= BIT(bit);
 245         writel(val, reg_base + reg_offset);
 246
 247         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 248
 249         return 0;
 250 }
 251
 252 static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
 253 {
 254         struct bcm_kona_gpio *kona_gpio;
 255
 256         kona_gpio = gpiochip_get_data(chip);
 257         if (gpio >= kona_gpio->gpio_chip.ngpio)
 258                 return -ENXIO;
 259         return irq_create_mapping(kona_gpio->irq_domain, gpio);
 260 }
 261
 262 static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
 263                                       unsigned debounce)
 264 {
 265         struct bcm_kona_gpio *kona_gpio;
 266         void __iomem *reg_base;
 267         u32 val, res;
 268         unsigned long flags;
 269
 270         kona_gpio = gpiochip_get_data(chip);
 271         reg_base = kona_gpio->reg_base;
 272         /* debounce must be 1-128ms (or 0) */
 273         if ((debounce > 0 && debounce < 1000) || debounce > 128000) {
 274                 dev_err(chip->parent, "Debounce value %u not in range\n",
 275                         debounce);
 276                 return -EINVAL;
 277         }
 278
 279         /* calculate debounce bit value */
 280         if (debounce != 0) {
 281                 /* Convert to ms */
 282                 debounce /= 1000;
 283                 /* find the MSB */
 284                 res = fls(debounce) - 1;
 285                 /* Check if MSB-1 is set (round up or down) */
 286                 if (res > 0 && (debounce & BIT(res - 1)))
 287                         res++;
 288         }
 289
 290         /* spin lock for read-modify-write of the GPIO register */
 291         spin_lock_irqsave(&kona_gpio->lock, flags);
 292
 293         val = readl(reg_base + GPIO_CONTROL(gpio));
 294         val &= ~GPIO_GPCTR0_DBR_MASK;
 295
 296         if (debounce == 0) {
 297                 /* disable debounce */
 298                 val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
 299         } else {
 300                 val |= GPIO_GPCTR0_DB_ENABLE_MASK |
 301                     (res << GPIO_GPCTR0_DBR_SHIFT);
 302         }
 303
 304         writel(val, reg_base + GPIO_CONTROL(gpio));
 305
 306         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 307
 308         return 0;
 309 }
 310
 311 static const struct gpio_chip template_chip = {
 312         .label = "bcm-kona-gpio",
 313         .owner = THIS_MODULE,
 314         .request = bcm_kona_gpio_request,
 315         .free = bcm_kona_gpio_free,
 316         .get_direction = bcm_kona_gpio_get_dir,
 317         .direction_input = bcm_kona_gpio_direction_input,
 318         .get = bcm_kona_gpio_get,
 319         .direction_output = bcm_kona_gpio_direction_output,
 320         .set = bcm_kona_gpio_set,
 321         .set_debounce = bcm_kona_gpio_set_debounce,
 322         .to_irq = bcm_kona_gpio_to_irq,
 323         .base = 0,
 324 };
 325
 326 static void bcm_kona_gpio_irq_ack(struct irq_data *d)
 327 {
 328         struct bcm_kona_gpio *kona_gpio;
 329         void __iomem *reg_base;
 330         unsigned gpio = d->hwirq;
 331         int bank_id = GPIO_BANK(gpio);
 332         int bit = GPIO_BIT(gpio);
 333         u32 val;
 334         unsigned long flags;
 335
 336         kona_gpio = irq_data_get_irq_chip_data(d);
 337         reg_base = kona_gpio->reg_base;
 338         spin_lock_irqsave(&kona_gpio->lock, flags);
 339
 340         val = readl(reg_base + GPIO_INT_STATUS(bank_id));
 341         val |= BIT(bit);
 342         writel(val, reg_base + GPIO_INT_STATUS(bank_id));
 343
 344         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 345 }
 346
 347 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
 348 {
 349         struct bcm_kona_gpio *kona_gpio;
 350         void __iomem *reg_base;
 351         unsigned gpio = d->hwirq;
 352         int bank_id = GPIO_BANK(gpio);
 353         int bit = GPIO_BIT(gpio);
 354         u32 val;
 355         unsigned long flags;
 356
 357         kona_gpio = irq_data_get_irq_chip_data(d);
 358         reg_base = kona_gpio->reg_base;
 359         spin_lock_irqsave(&kona_gpio->lock, flags);
 360
 361         val = readl(reg_base + GPIO_INT_MASK(bank_id));
 362         val |= BIT(bit);
 363         writel(val, reg_base + GPIO_INT_MASK(bank_id));
 364
 365         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 366 }
 367
 368 static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
 369 {
 370         struct bcm_kona_gpio *kona_gpio;
 371         void __iomem *reg_base;
 372         unsigned gpio = d->hwirq;
 373         int bank_id = GPIO_BANK(gpio);
 374         int bit = GPIO_BIT(gpio);
 375         u32 val;
 376         unsigned long flags;
 377
 378         kona_gpio = irq_data_get_irq_chip_data(d);
 379         reg_base = kona_gpio->reg_base;
 380         spin_lock_irqsave(&kona_gpio->lock, flags);
 381
 382         val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
 383         val |= BIT(bit);
 384         writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
 385
 386         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 387 }
 388
 389 static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 390 {
 391         struct bcm_kona_gpio *kona_gpio;
 392         void __iomem *reg_base;
 393         unsigned gpio = d->hwirq;
 394         u32 lvl_type;
 395         u32 val;
 396         unsigned long flags;
 397
 398         kona_gpio = irq_data_get_irq_chip_data(d);
 399         reg_base = kona_gpio->reg_base;
 400         switch (type & IRQ_TYPE_SENSE_MASK) {
 401         case IRQ_TYPE_EDGE_RISING:
 402                 lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
 403                 break;
 404
 405         case IRQ_TYPE_EDGE_FALLING:
 406                 lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
 407                 break;
 408
 409         case IRQ_TYPE_EDGE_BOTH:
 410                 lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
 411                 break;
 412
 413         case IRQ_TYPE_LEVEL_HIGH:
 414         case IRQ_TYPE_LEVEL_LOW:
 415                 /* BCM GPIO doesn't support level triggering */
 416         default:
 417                 dev_err(kona_gpio->gpio_chip.parent,
 418                         "Invalid BCM GPIO irq type 0x%x\n", type);
 419                 return -EINVAL;
 420         }
 421
 422         spin_lock_irqsave(&kona_gpio->lock, flags);
 423
 424         val = readl(reg_base + GPIO_CONTROL(gpio));
 425         val &= ~GPIO_GPCTR0_ITR_MASK;
 426         val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
 427         writel(val, reg_base + GPIO_CONTROL(gpio));
 428
 429         spin_unlock_irqrestore(&kona_gpio->lock, flags);
 430
 431         return 0;
 432 }
 433
 434 static void bcm_kona_gpio_irq_handler(struct irq_desc *desc)
 435 {
 436         void __iomem *reg_base;
 437         int bit, bank_id;
 438         unsigned long sta;
 439         struct bcm_kona_gpio_bank *bank = irq_desc_get_handler_data(desc);
 440         struct irq_chip *chip = irq_desc_get_chip(desc);
 441
 442         chained_irq_enter(chip, desc);
 443
 444         /*
 445          * For bank interrupts, we can't use chip_data to store the kona_gpio
 446          * pointer, since GIC needs it for its own purposes. Therefore, we get
 447          * our pointer from the bank structure.
 448          */
 449         reg_base = bank->kona_gpio->reg_base;
 450         bank_id = bank->id;
 451
 452         while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
 453                     (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
 454                 for_each_set_bit(bit, &sta, 32) {
 455                         int hwirq = GPIO_PER_BANK * bank_id + bit;
 456                         int child_irq =
 457                                 irq_find_mapping(bank->kona_gpio->irq_domain,
 458                                                  hwirq);
 459                         /*
 460                          * Clear interrupt before handler is called so we don't
 461                          * miss any interrupt occurred during executing them.
 462                          */
 463                         writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
 464                                BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
 465                         /* Invoke interrupt handler */
 466                         generic_handle_irq(child_irq);
 467                 }
 468         }
 469
 470         chained_irq_exit(chip, desc);
 471 }
 472
 473 static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
 474 {
 475         struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
 476
 477         if (gpiochip_lock_as_irq(&kona_gpio->gpio_chip, d->hwirq)) {
 478                 dev_err(kona_gpio->gpio_chip.parent,
 479                         "unable to lock HW IRQ %lu for IRQ\n",
 480                         d->hwirq);
 481                 return -EINVAL;
 482         }
 483         return 0;
 484 }
 485
 486 static void bcm_kona_gpio_irq_relres(struct irq_data *d)
 487 {
 488         struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
 489
 490         gpiochip_unlock_as_irq(&kona_gpio->gpio_chip, d->hwirq);
 491 }
 492
 493 static struct irq_chip bcm_gpio_irq_chip = {
 494         .name = "bcm-kona-gpio",
 495         .irq_ack = bcm_kona_gpio_irq_ack,
 496         .irq_mask = bcm_kona_gpio_irq_mask,
 497         .irq_unmask = bcm_kona_gpio_irq_unmask,
 498         .irq_set_type = bcm_kona_gpio_irq_set_type,
 499         .irq_request_resources = bcm_kona_gpio_irq_reqres,
 500         .irq_release_resources = bcm_kona_gpio_irq_relres,
 501 };
 502
 503 static struct of_device_id const bcm_kona_gpio_of_match[] = {
 504         { .compatible = "brcm,kona-gpio" },
 505         {}
 506 };
 507
 508 /*
 509  * This lock class tells lockdep that GPIO irqs are in a different
 510  * category than their parents, so it won't report false recursion.
 511  */
 512 static struct lock_class_key gpio_lock_class;
 513
 514 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
 515                                  irq_hw_number_t hwirq)
 516 {
 517         int ret;
 518
 519         ret = irq_set_chip_data(irq, d->host_data);
 520         if (ret < 0)
 521                 return ret;
 522         irq_set_lockdep_class(irq, &gpio_lock_class);
 523         irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
 524         irq_set_noprobe(irq);
 525
 526         return 0;
 527 }
 528
 529 static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 530 {
 531         irq_set_chip_and_handler(irq, NULL, NULL);
 532         irq_set_chip_data(irq, NULL);
 533 }
 534
 535 static const struct irq_domain_ops bcm_kona_irq_ops = {
 536         .map = bcm_kona_gpio_irq_map,
 537         .unmap = bcm_kona_gpio_irq_unmap,
 538         .xlate = irq_domain_xlate_twocell,
 539 };
 540
 541 static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
 542 {
 543         void __iomem *reg_base;
 544         int i;
 545
 546         reg_base = kona_gpio->reg_base;
 547         /* disable interrupts and clear status */
 548         for (i = 0; i < kona_gpio->num_bank; i++) {
 549                 /* Unlock the entire bank first */
 550                 bcm_kona_gpio_write_lock_regs(reg_base, i, UNLOCK_CODE);
 551                 writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
 552                 writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
 553                 /* Now re-lock the bank */
 554                 bcm_kona_gpio_write_lock_regs(reg_base, i, LOCK_CODE);
 555         }
 556 }
 557
 558 static int bcm_kona_gpio_probe(struct platform_device *pdev)
 559 {
 560         struct device *dev = &pdev->dev;
 561         const struct of_device_id *match;
 562         struct resource *res;
 563         struct bcm_kona_gpio_bank *bank;
 564         struct bcm_kona_gpio *kona_gpio;
 565         struct gpio_chip *chip;
 566         int ret;
 567         int i;
 568
 569         match = of_match_device(bcm_kona_gpio_of_match, dev);
 570         if (!match) {
 571                 dev_err(dev, "Failed to find gpio controller\n");
 572                 return -ENODEV;
 573         }
 574
 575         kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
 576         if (!kona_gpio)
 577                 return -ENOMEM;
 578
 579         kona_gpio->gpio_chip = template_chip;
 580         chip = &kona_gpio->gpio_chip;
 581         kona_gpio->num_bank = of_irq_count(dev->of_node);
 582         if (kona_gpio->num_bank == 0) {
 583                 dev_err(dev, "Couldn't determine # GPIO banks\n");
 584                 return -ENOENT;
 585         }
 586         if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
 587                 dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
 588                         GPIO_MAX_BANK_NUM);
 589                 return -ENXIO;
 590         }
 591         kona_gpio->banks = devm_kzalloc(dev,
 592                                         kona_gpio->num_bank *
 593                                         sizeof(*kona_gpio->banks), GFP_KERNEL);
 594         if (!kona_gpio->banks)
 595                 return -ENOMEM;
 596
 597         kona_gpio->pdev = pdev;
 598         platform_set_drvdata(pdev, kona_gpio);
 599         chip->of_node = dev->of_node;
 600         chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
 601
 602         kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
 603                                                       chip->ngpio,
 604                                                       &bcm_kona_irq_ops,
 605                                                       kona_gpio);
 606         if (!kona_gpio->irq_domain) {
 607                 dev_err(dev, "Couldn't allocate IRQ domain\n");
 608                 return -ENXIO;
 609         }
 610
 611         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 612         kona_gpio->reg_base = devm_ioremap_resource(dev, res);
 613         if (IS_ERR(kona_gpio->reg_base)) {
 614                 ret = -ENXIO;
 615                 goto err_irq_domain;
 616         }
 617
 618         for (i = 0; i < kona_gpio->num_bank; i++) {
 619                 bank = &kona_gpio->banks[i];
 620                 bank->id = i;
 621                 bank->irq = platform_get_irq(pdev, i);
 622                 bank->kona_gpio = kona_gpio;
 623                 if (bank->irq < 0) {
 624                         dev_err(dev, "Couldn't get IRQ for bank %d", i);
 625                         ret = -ENOENT;
 626                         goto err_irq_domain;
 627                 }
 628         }
 629
 630         dev_info(&pdev->dev, "Setting up Kona GPIO\n");
 631
 632         bcm_kona_gpio_reset(kona_gpio);
 633
 634         ret = devm_gpiochip_add_data(dev, chip, kona_gpio);
 635         if (ret < 0) {
 636                 dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
 637                 goto err_irq_domain;
 638         }
 639         for (i = 0; i < kona_gpio->num_bank; i++) {
 640                 bank = &kona_gpio->banks[i];
 641                 irq_set_chained_handler_and_data(bank->irq,
 642                                                  bcm_kona_gpio_irq_handler,
 643                                                  bank);
 644         }
 645
 646         spin_lock_init(&kona_gpio->lock);
 647
 648         return 0;
 649
 650 err_irq_domain:
 651         irq_domain_remove(kona_gpio->irq_domain);
 652
 653         return ret;
 654 }
 655
 656 static struct platform_driver bcm_kona_gpio_driver = {
 657         .driver = {
 658                         .name = "bcm-kona-gpio",
 659                         .of_match_table = bcm_kona_gpio_of_match,
 660         },
 661         .probe = bcm_kona_gpio_probe,
 662 };
 663 builtin_platform_driver(bcm_kona_gpio_driver);