drivers/gpio/gpio-aspeed.c

   1 /*
   2  * Copyright 2015 IBM Corp.
   3  *
   4  * Joel Stanley <joel@jms.id.au>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <asm/div64.h>
  13 #include <linux/clk.h>
  14 #include <linux/gpio/driver.h>
  15 #include <linux/hashtable.h>
  16 #include <linux/init.h>
  17 #include <linux/io.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/pinctrl/consumer.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/string.h>
  24
  25 struct aspeed_bank_props {
  26         unsigned int bank;
  27         u32 input;
  28         u32 output;
  29 };
  30
  31 struct aspeed_gpio_config {
  32         unsigned int nr_gpios;
  33         const struct aspeed_bank_props *props;
  34 };
  35
  36 /*
  37  * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled
  38  * @timer_users: Tracks the number of users for each timer
  39  *
  40  * The @timer_users has four elements but the first element is unused. This is
  41  * to simplify accounting and indexing, as a zero value in @offset_timer
  42  * represents disabled debouncing for the GPIO. Any other value for an element
  43  * of @offset_timer is used as an index into @timer_users. This behaviour of
  44  * the zero value aligns with the behaviour of zero built from the timer
  45  * configuration registers (i.e. debouncing is disabled).
  46  */
  47 struct aspeed_gpio {
  48         struct gpio_chip chip;
  49         spinlock_t lock;
  50         void __iomem *base;
  51         int irq;
  52         const struct aspeed_gpio_config *config;
  53
  54         u8 *offset_timer;
  55         unsigned int timer_users[4];
  56         struct clk *clk;
  57 };
  58
  59 struct aspeed_gpio_bank {
  60         uint16_t        val_regs;
  61         uint16_t        irq_regs;
  62         uint16_t        debounce_regs;
  63         uint16_t        tolerance_regs;
  64         const char      names[4][3];
  65 };
  66
  67 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
  68
  69 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
  70         {
  71                 .val_regs = 0x0000,
  72                 .irq_regs = 0x0008,
  73                 .debounce_regs = 0x0040,
  74                 .tolerance_regs = 0x001c,
  75                 .names = { "A", "B", "C", "D" },
  76         },
  77         {
  78                 .val_regs = 0x0020,
  79                 .irq_regs = 0x0028,
  80                 .debounce_regs = 0x0048,
  81                 .tolerance_regs = 0x003c,
  82                 .names = { "E", "F", "G", "H" },
  83         },
  84         {
  85                 .val_regs = 0x0070,
  86                 .irq_regs = 0x0098,
  87                 .debounce_regs = 0x00b0,
  88                 .tolerance_regs = 0x00ac,
  89                 .names = { "I", "J", "K", "L" },
  90         },
  91         {
  92                 .val_regs = 0x0078,
  93                 .irq_regs = 0x00e8,
  94                 .debounce_regs = 0x0100,
  95                 .tolerance_regs = 0x00fc,
  96                 .names = { "M", "N", "O", "P" },
  97         },
  98         {
  99                 .val_regs = 0x0080,
 100                 .irq_regs = 0x0118,
 101                 .debounce_regs = 0x0130,
 102                 .tolerance_regs = 0x012c,
 103                 .names = { "Q", "R", "S", "T" },
 104         },
 105         {
 106                 .val_regs = 0x0088,
 107                 .irq_regs = 0x0148,
 108                 .debounce_regs = 0x0160,
 109                 .tolerance_regs = 0x015c,
 110                 .names = { "U", "V", "W", "X" },
 111         },
 112         {
 113                 .val_regs = 0x01E0,
 114                 .irq_regs = 0x0178,
 115                 .debounce_regs = 0x0190,
 116                 .tolerance_regs = 0x018c,
 117                 .names = { "Y", "Z", "AA", "AB" },
 118         },
 119         {
 120                 .val_regs = 0x01e8,
 121                 .irq_regs = 0x01a8,
 122                 .debounce_regs = 0x01c0,
 123                 .tolerance_regs = 0x01bc,
 124                 .names = { "AC", "", "", "" },
 125         },
 126 };
 127
 128 #define GPIO_BANK(x)    ((x) >> 5)
 129 #define GPIO_OFFSET(x)  ((x) & 0x1f)
 130 #define GPIO_BIT(x)     BIT(GPIO_OFFSET(x))
 131
 132 #define GPIO_DATA       0x00
 133 #define GPIO_DIR        0x04
 134
 135 #define GPIO_IRQ_ENABLE 0x00
 136 #define GPIO_IRQ_TYPE0  0x04
 137 #define GPIO_IRQ_TYPE1  0x08
 138 #define GPIO_IRQ_TYPE2  0x0c
 139 #define GPIO_IRQ_STATUS 0x10
 140
 141 #define GPIO_DEBOUNCE_SEL1 0x00
 142 #define GPIO_DEBOUNCE_SEL2 0x04
 143
 144 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
 145 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
 146 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
 147
 148 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
 149 {
 150         unsigned int bank = GPIO_BANK(offset);
 151
 152         WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
 153         return &aspeed_gpio_banks[bank];
 154 }
 155
 156 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
 157 {
 158         return !(props->input || props->output);
 159 }
 160
 161 static inline const struct aspeed_bank_props *find_bank_props(
 162                 struct aspeed_gpio *gpio, unsigned int offset)
 163 {
 164         const struct aspeed_bank_props *props = gpio->config->props;
 165
 166         while (!is_bank_props_sentinel(props)) {
 167                 if (props->bank == GPIO_BANK(offset))
 168                         return props;
 169                 props++;
 170         }
 171
 172         return NULL;
 173 }
 174
 175 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
 176 {
 177         const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
 178         const struct aspeed_gpio_bank *bank = to_bank(offset);
 179         unsigned int group = GPIO_OFFSET(offset) / 8;
 180
 181         return bank->names[group][0] != '\0' &&
 182                 (!props || ((props->input | props->output) & GPIO_BIT(offset)));
 183 }
 184
 185 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
 186 {
 187         const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
 188
 189         return !props || (props->input & GPIO_BIT(offset));
 190 }
 191
 192 #define have_irq(g, o) have_input((g), (o))
 193 #define have_debounce(g, o) have_input((g), (o))
 194
 195 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
 196 {
 197         const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
 198
 199         return !props || (props->output & GPIO_BIT(offset));
 200 }
 201
 202 static void __iomem *bank_val_reg(struct aspeed_gpio *gpio,
 203                 const struct aspeed_gpio_bank *bank,
 204                 unsigned int reg)
 205 {
 206         return gpio->base + bank->val_regs + reg;
 207 }
 208
 209 static void __iomem *bank_irq_reg(struct aspeed_gpio *gpio,
 210                 const struct aspeed_gpio_bank *bank,
 211                 unsigned int reg)
 212 {
 213         return gpio->base + bank->irq_regs + reg;
 214 }
 215
 216 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
 217 {
 218         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 219         const struct aspeed_gpio_bank *bank = to_bank(offset);
 220
 221         return !!(ioread32(bank_val_reg(gpio, bank, GPIO_DATA))
 222                         & GPIO_BIT(offset));
 223 }
 224
 225 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
 226                               int val)
 227 {
 228         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 229         const struct aspeed_gpio_bank *bank = to_bank(offset);
 230         void __iomem *addr;
 231         u32 reg;
 232
 233         addr = bank_val_reg(gpio, bank, GPIO_DATA);
 234         reg = ioread32(addr);
 235
 236         if (val)
 237                 reg |= GPIO_BIT(offset);
 238         else
 239                 reg &= ~GPIO_BIT(offset);
 240
 241         iowrite32(reg, addr);
 242 }
 243
 244 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
 245                             int val)
 246 {
 247         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 248         unsigned long flags;
 249
 250         spin_lock_irqsave(&gpio->lock, flags);
 251
 252         __aspeed_gpio_set(gc, offset, val);
 253
 254         spin_unlock_irqrestore(&gpio->lock, flags);
 255 }
 256
 257 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
 258 {
 259         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 260         const struct aspeed_gpio_bank *bank = to_bank(offset);
 261         unsigned long flags;
 262         u32 reg;
 263
 264         if (!have_input(gpio, offset))
 265                 return -ENOTSUPP;
 266
 267         spin_lock_irqsave(&gpio->lock, flags);
 268
 269         reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
 270         iowrite32(reg & ~GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
 271
 272         spin_unlock_irqrestore(&gpio->lock, flags);
 273
 274         return 0;
 275 }
 276
 277 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
 278                                unsigned int offset, int val)
 279 {
 280         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 281         const struct aspeed_gpio_bank *bank = to_bank(offset);
 282         unsigned long flags;
 283         u32 reg;
 284
 285         if (!have_output(gpio, offset))
 286                 return -ENOTSUPP;
 287
 288         spin_lock_irqsave(&gpio->lock, flags);
 289
 290         reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
 291         iowrite32(reg | GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
 292
 293         __aspeed_gpio_set(gc, offset, val);
 294
 295         spin_unlock_irqrestore(&gpio->lock, flags);
 296
 297         return 0;
 298 }
 299
 300 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
 301 {
 302         struct aspeed_gpio *gpio = gpiochip_get_data(gc);
 303         const struct aspeed_gpio_bank *bank = to_bank(offset);
 304         unsigned long flags;
 305         u32 val;
 306
 307         if (!have_input(gpio, offset))
 308                 return 0;
 309
 310         if (!have_output(gpio, offset))
 311                 return 1;
 312
 313         spin_lock_irqsave(&gpio->lock, flags);
 314
 315         val = ioread32(bank_val_reg(gpio, bank, GPIO_DIR)) & GPIO_BIT(offset);
 316
 317         spin_unlock_irqrestore(&gpio->lock, flags);
 318
 319         return !val;
 320
 321 }
 322
 323 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
 324                 struct aspeed_gpio **gpio,
 325                 const struct aspeed_gpio_bank **bank,
 326                 u32 *bit)
 327 {
 328         int offset;
 329         struct aspeed_gpio *internal;
 330
 331         offset = irqd_to_hwirq(d);
 332
 333         internal = irq_data_get_irq_chip_data(d);
 334
 335         /* This might be a bit of a questionable place to check */
 336         if (!have_irq(internal, offset))
 337                 return -ENOTSUPP;
 338
 339         *gpio = internal;
 340         *bank = to_bank(offset);
 341         *bit = GPIO_BIT(offset);
 342
 343         return 0;
 344 }
 345
 346 static void aspeed_gpio_irq_ack(struct irq_data *d)
 347 {
 348         const struct aspeed_gpio_bank *bank;
 349         struct aspeed_gpio *gpio;
 350         unsigned long flags;
 351         void __iomem *status_addr;
 352         u32 bit;
 353         int rc;
 354
 355         rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
 356         if (rc)
 357                 return;
 358
 359         status_addr = bank_irq_reg(gpio, bank, GPIO_IRQ_STATUS);
 360
 361         spin_lock_irqsave(&gpio->lock, flags);
 362         iowrite32(bit, status_addr);
 363         spin_unlock_irqrestore(&gpio->lock, flags);
 364 }
 365
 366 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
 367 {
 368         const struct aspeed_gpio_bank *bank;
 369         struct aspeed_gpio *gpio;
 370         unsigned long flags;
 371         u32 reg, bit;
 372         void __iomem *addr;
 373         int rc;
 374
 375         rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
 376         if (rc)
 377                 return;
 378
 379         addr = bank_irq_reg(gpio, bank, GPIO_IRQ_ENABLE);
 380
 381         spin_lock_irqsave(&gpio->lock, flags);
 382
 383         reg = ioread32(addr);
 384         if (set)
 385                 reg |= bit;
 386         else
 387                 reg &= bit;
 388         iowrite32(reg, addr);
 389
 390         spin_unlock_irqrestore(&gpio->lock, flags);
 391 }
 392
 393 static void aspeed_gpio_irq_mask(struct irq_data *d)
 394 {
 395         aspeed_gpio_irq_set_mask(d, false);
 396 }
 397
 398 static void aspeed_gpio_irq_unmask(struct irq_data *d)
 399 {
 400         aspeed_gpio_irq_set_mask(d, true);
 401 }
 402
 403 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
 404 {
 405         u32 type0 = 0;
 406         u32 type1 = 0;
 407         u32 type2 = 0;
 408         u32 bit, reg;
 409         const struct aspeed_gpio_bank *bank;
 410         irq_flow_handler_t handler;
 411         struct aspeed_gpio *gpio;
 412         unsigned long flags;
 413         void __iomem *addr;
 414         int rc;
 415
 416         rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
 417         if (rc)
 418                 return -EINVAL;
 419
 420         switch (type & IRQ_TYPE_SENSE_MASK) {
 421         case IRQ_TYPE_EDGE_BOTH:
 422                 type2 |= bit;
 423                 /* fall through */
 424         case IRQ_TYPE_EDGE_RISING:
 425                 type0 |= bit;
 426                 /* fall through */
 427         case IRQ_TYPE_EDGE_FALLING:
 428                 handler = handle_edge_irq;
 429                 break;
 430         case IRQ_TYPE_LEVEL_HIGH:
 431                 type0 |= bit;
 432                 /* fall through */
 433         case IRQ_TYPE_LEVEL_LOW:
 434                 type1 |= bit;
 435                 handler = handle_level_irq;
 436                 break;
 437         default:
 438                 return -EINVAL;
 439         }
 440
 441         spin_lock_irqsave(&gpio->lock, flags);
 442
 443         addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE0);
 444         reg = ioread32(addr);
 445         reg = (reg & ~bit) | type0;
 446         iowrite32(reg, addr);
 447
 448         addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE1);
 449         reg = ioread32(addr);
 450         reg = (reg & ~bit) | type1;
 451         iowrite32(reg, addr);
 452
 453         addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE2);
 454         reg = ioread32(addr);
 455         reg = (reg & ~bit) | type2;
 456         iowrite32(reg, addr);
 457
 458         spin_unlock_irqrestore(&gpio->lock, flags);
 459
 460         irq_set_handler_locked(d, handler);
 461
 462         return 0;
 463 }
 464
 465 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
 466 {
 467         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 468         struct irq_chip *ic = irq_desc_get_chip(desc);
 469         struct aspeed_gpio *data = gpiochip_get_data(gc);
 470         unsigned int i, p, girq;
 471         unsigned long reg;
 472
 473         chained_irq_enter(ic, desc);
 474
 475         for (i = 0; i < ARRAY_SIZE(aspeed_gpio_banks); i++) {
 476                 const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
 477
 478                 reg = ioread32(bank_irq_reg(data, bank, GPIO_IRQ_STATUS));
 479
 480                 for_each_set_bit(p, &reg, 32) {
 481                         girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
 482                         generic_handle_irq(girq);
 483                 }
 484
 485         }
 486
 487         chained_irq_exit(ic, desc);
 488 }
 489
 490 static struct irq_chip aspeed_gpio_irqchip = {
 491         .name           = "aspeed-gpio",
 492         .irq_ack        = aspeed_gpio_irq_ack,
 493         .irq_mask       = aspeed_gpio_irq_mask,
 494         .irq_unmask     = aspeed_gpio_irq_unmask,
 495         .irq_set_type   = aspeed_gpio_set_type,
 496 };
 497
 498 static void set_irq_valid_mask(struct aspeed_gpio *gpio)
 499 {
 500         const struct aspeed_bank_props *props = gpio->config->props;
 501
 502         while (!is_bank_props_sentinel(props)) {
 503                 unsigned int offset;
 504                 const unsigned long int input = props->input;
 505
 506                 /* Pretty crummy approach, but similar to GPIO core */
 507                 for_each_clear_bit(offset, &input, 32) {
 508                         unsigned int i = props->bank * 32 + offset;
 509
 510                         if (i >= gpio->config->nr_gpios)
 511                                 break;
 512
 513                         clear_bit(i, gpio->chip.irq.valid_mask);
 514                 }
 515
 516                 props++;
 517         }
 518 }
 519
 520 static int aspeed_gpio_setup_irqs(struct aspeed_gpio *gpio,
 521                 struct platform_device *pdev)
 522 {
 523         int rc;
 524
 525         rc = platform_get_irq(pdev, 0);
 526         if (rc < 0)
 527                 return rc;
 528
 529         gpio->irq = rc;
 530
 531         set_irq_valid_mask(gpio);
 532
 533         rc = gpiochip_irqchip_add(&gpio->chip, &aspeed_gpio_irqchip,
 534                         0, handle_bad_irq, IRQ_TYPE_NONE);
 535         if (rc) {
 536                 dev_info(&pdev->dev, "Could not add irqchip\n");
 537                 return rc;
 538         }
 539
 540         gpiochip_set_chained_irqchip(&gpio->chip, &aspeed_gpio_irqchip,
 541                                      gpio->irq, aspeed_gpio_irq_handler);
 542
 543         return 0;
 544 }
 545
 546 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
 547                                         unsigned int offset, bool enable)
 548 {
 549         struct aspeed_gpio *gpio = gpiochip_get_data(chip);
 550         const struct aspeed_gpio_bank *bank;
 551         unsigned long flags;
 552         u32 val;
 553
 554         bank = to_bank(offset);
 555
 556         spin_lock_irqsave(&gpio->lock, flags);
 557         val = readl(gpio->base + bank->tolerance_regs);
 558
 559         if (enable)
 560                 val |= GPIO_BIT(offset);
 561         else
 562                 val &= ~GPIO_BIT(offset);
 563
 564         writel(val, gpio->base + bank->tolerance_regs);
 565         spin_unlock_irqrestore(&gpio->lock, flags);
 566
 567         return 0;
 568 }
 569
 570 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
 571 {
 572         if (!have_gpio(gpiochip_get_data(chip), offset))
 573                 return -ENODEV;
 574
 575         return pinctrl_gpio_request(chip->base + offset);
 576 }
 577
 578 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
 579 {
 580         pinctrl_gpio_free(chip->base + offset);
 581 }
 582
 583 static inline void __iomem *bank_debounce_reg(struct aspeed_gpio *gpio,
 584                 const struct aspeed_gpio_bank *bank,
 585                 unsigned int reg)
 586 {
 587         return gpio->base + bank->debounce_regs + reg;
 588 }
 589
 590 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
 591                 u32 *cycles)
 592 {
 593         u64 rate;
 594         u64 n;
 595         u32 r;
 596
 597         rate = clk_get_rate(gpio->clk);
 598         if (!rate)
 599                 return -ENOTSUPP;
 600
 601         n = rate * usecs;
 602         r = do_div(n, 1000000);
 603
 604         if (n >= U32_MAX)
 605                 return -ERANGE;
 606
 607         /* At least as long as the requested time */
 608         *cycles = n + (!!r);
 609
 610         return 0;
 611 }
 612
 613 /* Call under gpio->lock */
 614 static int register_allocated_timer(struct aspeed_gpio *gpio,
 615                 unsigned int offset, unsigned int timer)
 616 {
 617         if (WARN(gpio->offset_timer[offset] != 0,
 618                                 "Offset %d already allocated timer %d\n",
 619                                 offset, gpio->offset_timer[offset]))
 620                 return -EINVAL;
 621
 622         if (WARN(gpio->timer_users[timer] == UINT_MAX,
 623                                 "Timer user count would overflow\n"))
 624                 return -EPERM;
 625
 626         gpio->offset_timer[offset] = timer;
 627         gpio->timer_users[timer]++;
 628
 629         return 0;
 630 }
 631
 632 /* Call under gpio->lock */
 633 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
 634                 unsigned int offset)
 635 {
 636         if (WARN(gpio->offset_timer[offset] == 0,
 637                                 "No timer allocated to offset %d\n", offset))
 638                 return -EINVAL;
 639
 640         if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
 641                                 "No users recorded for timer %d\n",
 642                                 gpio->offset_timer[offset]))
 643                 return -EINVAL;
 644
 645         gpio->timer_users[gpio->offset_timer[offset]]--;
 646         gpio->offset_timer[offset] = 0;
 647
 648         return 0;
 649 }
 650
 651 /* Call under gpio->lock */
 652 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
 653                 unsigned int offset)
 654 {
 655         return gpio->offset_timer[offset] > 0;
 656 }
 657
 658 /* Call under gpio->lock */
 659 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
 660                 unsigned int timer)
 661 {
 662         const struct aspeed_gpio_bank *bank = to_bank(offset);
 663         const u32 mask = GPIO_BIT(offset);
 664         void __iomem *addr;
 665         u32 val;
 666
 667         addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL1);
 668         val = ioread32(addr);
 669         iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
 670
 671         addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL2);
 672         val = ioread32(addr);
 673         iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
 674 }
 675
 676 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
 677                                     unsigned long usecs)
 678 {
 679         struct aspeed_gpio *gpio = gpiochip_get_data(chip);
 680         u32 requested_cycles;
 681         unsigned long flags;
 682         int rc;
 683         int i;
 684
 685         if (!gpio->clk)
 686                 return -EINVAL;
 687
 688         rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
 689         if (rc < 0) {
 690                 dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
 691                                 usecs, clk_get_rate(gpio->clk), rc);
 692                 return rc;
 693         }
 694
 695         spin_lock_irqsave(&gpio->lock, flags);
 696
 697         if (timer_allocation_registered(gpio, offset)) {
 698                 rc = unregister_allocated_timer(gpio, offset);
 699                 if (rc < 0)
 700                         goto out;
 701         }
 702
 703         /* Try to find a timer already configured for the debounce period */
 704         for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
 705                 u32 cycles;
 706
 707                 cycles = ioread32(gpio->base + debounce_timers[i]);
 708                 if (requested_cycles == cycles)
 709                         break;
 710         }
 711
 712         if (i == ARRAY_SIZE(debounce_timers)) {
 713                 int j;
 714
 715                 /*
 716                  * As there are no timers configured for the requested debounce
 717                  * period, find an unused timer instead
 718                  */
 719                 for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
 720                         if (gpio->timer_users[j] == 0)
 721                                 break;
 722                 }
 723
 724                 if (j == ARRAY_SIZE(gpio->timer_users)) {
 725                         dev_warn(chip->parent,
 726                                         "Debounce timers exhausted, cannot debounce for period %luus\n",
 727                                         usecs);
 728
 729                         rc = -EPERM;
 730
 731                         /*
 732                          * We already adjusted the accounting to remove @offset
 733                          * as a user of its previous timer, so also configure
 734                          * the hardware so @offset has timers disabled for
 735                          * consistency.
 736                          */
 737                         configure_timer(gpio, offset, 0);
 738                         goto out;
 739                 }
 740
 741                 i = j;
 742
 743                 iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
 744         }
 745
 746         if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
 747                 rc = -EINVAL;
 748                 goto out;
 749         }
 750
 751         register_allocated_timer(gpio, offset, i);
 752         configure_timer(gpio, offset, i);
 753
 754 out:
 755         spin_unlock_irqrestore(&gpio->lock, flags);
 756
 757         return rc;
 758 }
 759
 760 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
 761 {
 762         struct aspeed_gpio *gpio = gpiochip_get_data(chip);
 763         unsigned long flags;
 764         int rc;
 765
 766         spin_lock_irqsave(&gpio->lock, flags);
 767
 768         rc = unregister_allocated_timer(gpio, offset);
 769         if (!rc)
 770                 configure_timer(gpio, offset, 0);
 771
 772         spin_unlock_irqrestore(&gpio->lock, flags);
 773
 774         return rc;
 775 }
 776
 777 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
 778                                     unsigned long usecs)
 779 {
 780         struct aspeed_gpio *gpio = gpiochip_get_data(chip);
 781
 782         if (!have_debounce(gpio, offset))
 783                 return -ENOTSUPP;
 784
 785         if (usecs)
 786                 return enable_debounce(chip, offset, usecs);
 787
 788         return disable_debounce(chip, offset);
 789 }
 790
 791 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 792                                   unsigned long config)
 793 {
 794         unsigned long param = pinconf_to_config_param(config);
 795         u32 arg = pinconf_to_config_argument(config);
 796
 797         if (param == PIN_CONFIG_INPUT_DEBOUNCE)
 798                 return set_debounce(chip, offset, arg);
 799         else if (param == PIN_CONFIG_BIAS_DISABLE ||
 800                         param == PIN_CONFIG_BIAS_PULL_DOWN ||
 801                         param == PIN_CONFIG_DRIVE_STRENGTH)
 802                 return pinctrl_gpio_set_config(offset, config);
 803         else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
 804                         param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
 805                 /* Return -ENOTSUPP to trigger emulation, as per datasheet */
 806                 return -ENOTSUPP;
 807         else if (param == PIN_CONFIG_PERSIST_STATE)
 808                 return aspeed_gpio_reset_tolerance(chip, offset, arg);
 809
 810         return -ENOTSUPP;
 811 }
 812
 813 /*
 814  * Any banks not specified in a struct aspeed_bank_props array are assumed to
 815  * have the properties:
 816  *
 817  *     { .input = 0xffffffff, .output = 0xffffffff }
 818  */
 819
 820 static const struct aspeed_bank_props ast2400_bank_props[] = {
 821         /*     input      output   */
 822         { 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
 823         { 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
 824         { },
 825 };
 826
 827 static const struct aspeed_gpio_config ast2400_config =
 828         /* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
 829         { .nr_gpios = 220, .props = ast2400_bank_props, };
 830
 831 static const struct aspeed_bank_props ast2500_bank_props[] = {
 832         /*     input      output   */
 833         { 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
 834         { 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
 835         { 7, 0x000000ff, 0x000000ff }, /* AC */
 836         { },
 837 };
 838
 839 static const struct aspeed_gpio_config ast2500_config =
 840         /* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
 841         { .nr_gpios = 232, .props = ast2500_bank_props, };
 842
 843 static const struct of_device_id aspeed_gpio_of_table[] = {
 844         { .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
 845         { .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
 846         {}
 847 };
 848 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
 849
 850 static int __init aspeed_gpio_probe(struct platform_device *pdev)
 851 {
 852         const struct of_device_id *gpio_id;
 853         struct aspeed_gpio *gpio;
 854         struct resource *res;
 855         int rc;
 856
 857         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 858         if (!gpio)
 859                 return -ENOMEM;
 860
 861         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 862         gpio->base = devm_ioremap_resource(&pdev->dev, res);
 863         if (IS_ERR(gpio->base))
 864                 return PTR_ERR(gpio->base);
 865
 866         spin_lock_init(&gpio->lock);
 867
 868         gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
 869         if (!gpio_id)
 870                 return -EINVAL;
 871
 872         gpio->clk = of_clk_get(pdev->dev.of_node, 0);
 873         if (IS_ERR(gpio->clk)) {
 874                 dev_warn(&pdev->dev,
 875                                 "Failed to get clock from devicetree, debouncing disabled\n");
 876                 gpio->clk = NULL;
 877         }
 878
 879         gpio->config = gpio_id->data;
 880
 881         gpio->chip.parent = &pdev->dev;
 882         gpio->chip.ngpio = gpio->config->nr_gpios;
 883         gpio->chip.parent = &pdev->dev;
 884         gpio->chip.direction_input = aspeed_gpio_dir_in;
 885         gpio->chip.direction_output = aspeed_gpio_dir_out;
 886         gpio->chip.get_direction = aspeed_gpio_get_direction;
 887         gpio->chip.request = aspeed_gpio_request;
 888         gpio->chip.free = aspeed_gpio_free;
 889         gpio->chip.get = aspeed_gpio_get;
 890         gpio->chip.set = aspeed_gpio_set;
 891         gpio->chip.set_config = aspeed_gpio_set_config;
 892         gpio->chip.label = dev_name(&pdev->dev);
 893         gpio->chip.base = -1;
 894         gpio->chip.irq.need_valid_mask = true;
 895
 896         rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
 897         if (rc < 0)
 898                 return rc;
 899
 900         gpio->offset_timer =
 901                 devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
 902
 903         return aspeed_gpio_setup_irqs(gpio, pdev);
 904 }
 905
 906 static struct platform_driver aspeed_gpio_driver = {
 907         .driver = {
 908                 .name = KBUILD_MODNAME,
 909                 .of_match_table = aspeed_gpio_of_table,
 910         },
 911 };
 912
 913 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
 914
 915 MODULE_DESCRIPTION("Aspeed GPIO Driver");
 916 MODULE_LICENSE("GPL");