linux/arch/mips/jz4740/gpio.c
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   1/*
   2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
   3 *  JZ4740 platform GPIO support
   4 *
   5 *  This program is free software; you can redistribute it and/or modify it
   6 *  under  the terms of the GNU General  Public License as published by the
   7 *  Free Software Foundation;  either version 2 of the License, or (at your
   8 *  option) any later version.
   9 *
  10 *  You should have received a copy of the GNU General Public License along
  11 *  with this program; if not, write to the Free Software Foundation, Inc.,
  12 *  675 Mass Ave, Cambridge, MA 02139, USA.
  13 *
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/init.h>
  19
  20#include <linux/spinlock.h>
  21#include <linux/syscore_ops.h>
  22#include <linux/io.h>
  23#include <linux/gpio.h>
  24#include <linux/delay.h>
  25#include <linux/interrupt.h>
  26#include <linux/bitops.h>
  27
  28#include <linux/debugfs.h>
  29#include <linux/seq_file.h>
  30
  31#include <asm/mach-jz4740/base.h>
  32
  33#define JZ4740_GPIO_BASE_A (32*0)
  34#define JZ4740_GPIO_BASE_B (32*1)
  35#define JZ4740_GPIO_BASE_C (32*2)
  36#define JZ4740_GPIO_BASE_D (32*3)
  37
  38#define JZ4740_GPIO_NUM_A 32
  39#define JZ4740_GPIO_NUM_B 32
  40#define JZ4740_GPIO_NUM_C 31
  41#define JZ4740_GPIO_NUM_D 32
  42
  43#define JZ4740_IRQ_GPIO_BASE_A (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_A)
  44#define JZ4740_IRQ_GPIO_BASE_B (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_B)
  45#define JZ4740_IRQ_GPIO_BASE_C (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_C)
  46#define JZ4740_IRQ_GPIO_BASE_D (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_D)
  47
  48#define JZ_REG_GPIO_PIN                 0x00
  49#define JZ_REG_GPIO_DATA                0x10
  50#define JZ_REG_GPIO_DATA_SET            0x14
  51#define JZ_REG_GPIO_DATA_CLEAR          0x18
  52#define JZ_REG_GPIO_MASK                0x20
  53#define JZ_REG_GPIO_MASK_SET            0x24
  54#define JZ_REG_GPIO_MASK_CLEAR          0x28
  55#define JZ_REG_GPIO_PULL                0x30
  56#define JZ_REG_GPIO_PULL_SET            0x34
  57#define JZ_REG_GPIO_PULL_CLEAR          0x38
  58#define JZ_REG_GPIO_FUNC                0x40
  59#define JZ_REG_GPIO_FUNC_SET            0x44
  60#define JZ_REG_GPIO_FUNC_CLEAR          0x48
  61#define JZ_REG_GPIO_SELECT              0x50
  62#define JZ_REG_GPIO_SELECT_SET          0x54
  63#define JZ_REG_GPIO_SELECT_CLEAR        0x58
  64#define JZ_REG_GPIO_DIRECTION           0x60
  65#define JZ_REG_GPIO_DIRECTION_SET       0x64
  66#define JZ_REG_GPIO_DIRECTION_CLEAR     0x68
  67#define JZ_REG_GPIO_TRIGGER             0x70
  68#define JZ_REG_GPIO_TRIGGER_SET         0x74
  69#define JZ_REG_GPIO_TRIGGER_CLEAR       0x78
  70#define JZ_REG_GPIO_FLAG                0x80
  71#define JZ_REG_GPIO_FLAG_CLEAR          0x14
  72
  73#define GPIO_TO_BIT(gpio) BIT(gpio & 0x1f)
  74#define GPIO_TO_REG(gpio, reg) (gpio_to_jz_gpio_chip(gpio)->base + (reg))
  75#define CHIP_TO_REG(chip, reg) (gpio_chip_to_jz_gpio_chip(chip)->base + (reg))
  76
  77struct jz_gpio_chip {
  78        unsigned int irq;
  79        unsigned int irq_base;
  80        uint32_t wakeup;
  81        uint32_t suspend_mask;
  82        uint32_t edge_trigger_both;
  83
  84        void __iomem *base;
  85
  86        spinlock_t lock;
  87
  88        struct gpio_chip gpio_chip;
  89};
  90
  91static struct jz_gpio_chip jz4740_gpio_chips[];
  92
  93static inline struct jz_gpio_chip *gpio_to_jz_gpio_chip(unsigned int gpio)
  94{
  95        return &jz4740_gpio_chips[gpio >> 5];
  96}
  97
  98static inline struct jz_gpio_chip *gpio_chip_to_jz_gpio_chip(struct gpio_chip *gpio_chip)
  99{
 100        return container_of(gpio_chip, struct jz_gpio_chip, gpio_chip);
 101}
 102
 103static inline struct jz_gpio_chip *irq_to_jz_gpio_chip(struct irq_data *data)
 104{
 105        return irq_data_get_irq_chip_data(data);
 106}
 107
 108static inline void jz_gpio_write_bit(unsigned int gpio, unsigned int reg)
 109{
 110        writel(GPIO_TO_BIT(gpio), GPIO_TO_REG(gpio, reg));
 111}
 112
 113int jz_gpio_set_function(int gpio, enum jz_gpio_function function)
 114{
 115        if (function == JZ_GPIO_FUNC_NONE) {
 116                jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_CLEAR);
 117                jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
 118                jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
 119        } else {
 120                jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_SET);
 121                jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
 122                switch (function) {
 123                case JZ_GPIO_FUNC1:
 124                        jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
 125                        break;
 126                case JZ_GPIO_FUNC3:
 127                        jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_SET);
 128                case JZ_GPIO_FUNC2: /* Falltrough */
 129                        jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_SET);
 130                        break;
 131                default:
 132                        BUG();
 133                        break;
 134                }
 135        }
 136
 137        return 0;
 138}
 139EXPORT_SYMBOL_GPL(jz_gpio_set_function);
 140
 141int jz_gpio_bulk_request(const struct jz_gpio_bulk_request *request, size_t num)
 142{
 143        size_t i;
 144        int ret;
 145
 146        for (i = 0; i < num; ++i, ++request) {
 147                ret = gpio_request(request->gpio, request->name);
 148                if (ret)
 149                        goto err;
 150                jz_gpio_set_function(request->gpio, request->function);
 151        }
 152
 153        return 0;
 154
 155err:
 156        for (--request; i > 0; --i, --request) {
 157                gpio_free(request->gpio);
 158                jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 159        }
 160
 161        return ret;
 162}
 163EXPORT_SYMBOL_GPL(jz_gpio_bulk_request);
 164
 165void jz_gpio_bulk_free(const struct jz_gpio_bulk_request *request, size_t num)
 166{
 167        size_t i;
 168
 169        for (i = 0; i < num; ++i, ++request) {
 170                gpio_free(request->gpio);
 171                jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 172        }
 173
 174}
 175EXPORT_SYMBOL_GPL(jz_gpio_bulk_free);
 176
 177void jz_gpio_bulk_suspend(const struct jz_gpio_bulk_request *request, size_t num)
 178{
 179        size_t i;
 180
 181        for (i = 0; i < num; ++i, ++request) {
 182                jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 183                jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_DIRECTION_CLEAR);
 184                jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_PULL_SET);
 185        }
 186}
 187EXPORT_SYMBOL_GPL(jz_gpio_bulk_suspend);
 188
 189void jz_gpio_bulk_resume(const struct jz_gpio_bulk_request *request, size_t num)
 190{
 191        size_t i;
 192
 193        for (i = 0; i < num; ++i, ++request)
 194                jz_gpio_set_function(request->gpio, request->function);
 195}
 196EXPORT_SYMBOL_GPL(jz_gpio_bulk_resume);
 197
 198void jz_gpio_enable_pullup(unsigned gpio)
 199{
 200        jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_CLEAR);
 201}
 202EXPORT_SYMBOL_GPL(jz_gpio_enable_pullup);
 203
 204void jz_gpio_disable_pullup(unsigned gpio)
 205{
 206        jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_SET);
 207}
 208EXPORT_SYMBOL_GPL(jz_gpio_disable_pullup);
 209
 210static int jz_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 211{
 212        return !!(readl(CHIP_TO_REG(chip, JZ_REG_GPIO_PIN)) & BIT(gpio));
 213}
 214
 215static void jz_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
 216{
 217        uint32_t __iomem *reg = CHIP_TO_REG(chip, JZ_REG_GPIO_DATA_SET);
 218        reg += !value;
 219        writel(BIT(gpio), reg);
 220}
 221
 222static int jz_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 223        int value)
 224{
 225        writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_SET));
 226        jz_gpio_set_value(chip, gpio, value);
 227
 228        return 0;
 229}
 230
 231static int jz_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 232{
 233        writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_CLEAR));
 234
 235        return 0;
 236}
 237
 238int jz_gpio_port_direction_input(int port, uint32_t mask)
 239{
 240        writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_CLEAR));
 241
 242        return 0;
 243}
 244EXPORT_SYMBOL(jz_gpio_port_direction_input);
 245
 246int jz_gpio_port_direction_output(int port, uint32_t mask)
 247{
 248        writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_SET));
 249
 250        return 0;
 251}
 252EXPORT_SYMBOL(jz_gpio_port_direction_output);
 253
 254void jz_gpio_port_set_value(int port, uint32_t value, uint32_t mask)
 255{
 256        writel(~value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_CLEAR));
 257        writel(value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_SET));
 258}
 259EXPORT_SYMBOL(jz_gpio_port_set_value);
 260
 261uint32_t jz_gpio_port_get_value(int port, uint32_t mask)
 262{
 263        uint32_t value = readl(GPIO_TO_REG(port, JZ_REG_GPIO_PIN));
 264
 265        return value & mask;
 266}
 267EXPORT_SYMBOL(jz_gpio_port_get_value);
 268
 269int gpio_to_irq(unsigned gpio)
 270{
 271        return JZ4740_IRQ_GPIO(0) + gpio;
 272}
 273EXPORT_SYMBOL_GPL(gpio_to_irq);
 274
 275int irq_to_gpio(unsigned irq)
 276{
 277        return irq - JZ4740_IRQ_GPIO(0);
 278}
 279EXPORT_SYMBOL_GPL(irq_to_gpio);
 280
 281#define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)
 282
 283static void jz_gpio_check_trigger_both(struct jz_gpio_chip *chip, unsigned int irq)
 284{
 285        uint32_t value;
 286        void __iomem *reg;
 287        uint32_t mask = IRQ_TO_BIT(irq);
 288
 289        if (!(chip->edge_trigger_both & mask))
 290                return;
 291
 292        reg = chip->base;
 293
 294        value = readl(chip->base + JZ_REG_GPIO_PIN);
 295        if (value & mask)
 296                reg += JZ_REG_GPIO_DIRECTION_CLEAR;
 297        else
 298                reg += JZ_REG_GPIO_DIRECTION_SET;
 299
 300        writel(mask, reg);
 301}
 302
 303static void jz_gpio_irq_demux_handler(unsigned int irq, struct irq_desc *desc)
 304{
 305        uint32_t flag;
 306        unsigned int gpio_irq;
 307        unsigned int gpio_bank;
 308        struct jz_gpio_chip *chip = irq_desc_get_handler_data(desc);
 309
 310        gpio_bank = JZ4740_IRQ_GPIO0 - irq;
 311
 312        flag = readl(chip->base + JZ_REG_GPIO_FLAG);
 313
 314        if (!flag)
 315                return;
 316
 317        gpio_irq = __fls(flag);
 318
 319        jz_gpio_check_trigger_both(chip, irq);
 320
 321        gpio_irq += (gpio_bank << 5) + JZ4740_IRQ_GPIO(0);
 322
 323        generic_handle_irq(gpio_irq);
 324};
 325
 326static inline void jz_gpio_set_irq_bit(struct irq_data *data, unsigned int reg)
 327{
 328        struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
 329        writel(IRQ_TO_BIT(data->irq), chip->base + reg);
 330}
 331
 332static void jz_gpio_irq_mask(struct irq_data *data)
 333{
 334        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_MASK_SET);
 335};
 336
 337static void jz_gpio_irq_unmask(struct irq_data *data)
 338{
 339        struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
 340
 341        jz_gpio_check_trigger_both(chip, data->irq);
 342
 343        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_MASK_CLEAR);
 344};
 345
 346/* TODO: Check if function is gpio */
 347static unsigned int jz_gpio_irq_startup(struct irq_data *data)
 348{
 349        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_SELECT_SET);
 350        jz_gpio_irq_unmask(data);
 351        return 0;
 352}
 353
 354static void jz_gpio_irq_shutdown(struct irq_data *data)
 355{
 356        jz_gpio_irq_mask(data);
 357
 358        /* Set direction to input */
 359        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
 360        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_SELECT_CLEAR);
 361}
 362
 363static void jz_gpio_irq_ack(struct irq_data *data)
 364{
 365        jz_gpio_set_irq_bit(data, JZ_REG_GPIO_FLAG_CLEAR);
 366};
 367
 368static int jz_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
 369{
 370        struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
 371        unsigned int irq = data->irq;
 372
 373        if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 374                uint32_t value = readl(chip->base + JZ_REG_GPIO_PIN);
 375                if (value & IRQ_TO_BIT(irq))
 376                        flow_type = IRQ_TYPE_EDGE_FALLING;
 377                else
 378                        flow_type = IRQ_TYPE_EDGE_RISING;
 379                chip->edge_trigger_both |= IRQ_TO_BIT(irq);
 380        } else {
 381                chip->edge_trigger_both &= ~IRQ_TO_BIT(irq);
 382        }
 383
 384        switch (flow_type) {
 385        case IRQ_TYPE_EDGE_RISING:
 386                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_SET);
 387                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_SET);
 388                break;
 389        case IRQ_TYPE_EDGE_FALLING:
 390                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
 391                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_SET);
 392                break;
 393        case IRQ_TYPE_LEVEL_HIGH:
 394                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_SET);
 395                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_CLEAR);
 396                break;
 397        case IRQ_TYPE_LEVEL_LOW:
 398                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
 399                jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_CLEAR);
 400                break;
 401        default:
 402                return -EINVAL;
 403        }
 404
 405        return 0;
 406}
 407
 408static int jz_gpio_irq_set_wake(struct irq_data *data, unsigned int on)
 409{
 410        struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
 411        spin_lock(&chip->lock);
 412        if (on)
 413                chip->wakeup |= IRQ_TO_BIT(data->irq);
 414        else
 415                chip->wakeup &= ~IRQ_TO_BIT(data->irq);
 416        spin_unlock(&chip->lock);
 417
 418        irq_set_irq_wake(chip->irq, on);
 419        return 0;
 420}
 421
 422static struct irq_chip jz_gpio_irq_chip = {
 423        .name = "GPIO",
 424        .irq_mask = jz_gpio_irq_mask,
 425        .irq_unmask = jz_gpio_irq_unmask,
 426        .irq_ack = jz_gpio_irq_ack,
 427        .irq_startup = jz_gpio_irq_startup,
 428        .irq_shutdown = jz_gpio_irq_shutdown,
 429        .irq_set_type = jz_gpio_irq_set_type,
 430        .irq_set_wake = jz_gpio_irq_set_wake,
 431        .flags = IRQCHIP_SET_TYPE_MASKED,
 432};
 433
 434/*
 435 * This lock class tells lockdep that GPIO irqs are in a different
 436 * category than their parents, so it won't report false recursion.
 437 */
 438static struct lock_class_key gpio_lock_class;
 439
 440#define JZ4740_GPIO_CHIP(_bank) { \
 441        .irq_base = JZ4740_IRQ_GPIO_BASE_ ## _bank, \
 442        .gpio_chip = { \
 443                .label = "Bank " # _bank, \
 444                .owner = THIS_MODULE, \
 445                .set = jz_gpio_set_value, \
 446                .get = jz_gpio_get_value, \
 447                .direction_output = jz_gpio_direction_output, \
 448                .direction_input = jz_gpio_direction_input, \
 449                .base = JZ4740_GPIO_BASE_ ## _bank, \
 450                .ngpio = JZ4740_GPIO_NUM_ ## _bank, \
 451        }, \
 452}
 453
 454static struct jz_gpio_chip jz4740_gpio_chips[] = {
 455        JZ4740_GPIO_CHIP(A),
 456        JZ4740_GPIO_CHIP(B),
 457        JZ4740_GPIO_CHIP(C),
 458        JZ4740_GPIO_CHIP(D),
 459};
 460
 461static void jz4740_gpio_suspend_chip(struct jz_gpio_chip *chip)
 462{
 463        chip->suspend_mask = readl(chip->base + JZ_REG_GPIO_MASK);
 464        writel(~(chip->wakeup), chip->base + JZ_REG_GPIO_MASK_SET);
 465        writel(chip->wakeup, chip->base + JZ_REG_GPIO_MASK_CLEAR);
 466}
 467
 468static int jz4740_gpio_suspend(void)
 469{
 470        int i;
 471
 472        for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); i++)
 473                jz4740_gpio_suspend_chip(&jz4740_gpio_chips[i]);
 474
 475        return 0;
 476}
 477
 478static void jz4740_gpio_resume_chip(struct jz_gpio_chip *chip)
 479{
 480        uint32_t mask = chip->suspend_mask;
 481
 482        writel(~mask, chip->base + JZ_REG_GPIO_MASK_CLEAR);
 483        writel(mask, chip->base + JZ_REG_GPIO_MASK_SET);
 484}
 485
 486static void jz4740_gpio_resume(void)
 487{
 488        int i;
 489
 490        for (i = ARRAY_SIZE(jz4740_gpio_chips) - 1; i >= 0 ; i--)
 491                jz4740_gpio_resume_chip(&jz4740_gpio_chips[i]);
 492}
 493
 494static struct syscore_ops jz4740_gpio_syscore_ops = {
 495        .suspend = jz4740_gpio_suspend,
 496        .resume = jz4740_gpio_resume,
 497};
 498
 499static void jz4740_gpio_chip_init(struct jz_gpio_chip *chip, unsigned int id)
 500{
 501        int irq;
 502
 503        spin_lock_init(&chip->lock);
 504
 505        chip->base = ioremap(JZ4740_GPIO_BASE_ADDR + (id * 0x100), 0x100);
 506
 507        gpiochip_add(&chip->gpio_chip);
 508
 509        chip->irq = JZ4740_IRQ_INTC_GPIO(id);
 510        irq_set_handler_data(chip->irq, chip);
 511        irq_set_chained_handler(chip->irq, jz_gpio_irq_demux_handler);
 512
 513        for (irq = chip->irq_base; irq < chip->irq_base + chip->gpio_chip.ngpio; ++irq) {
 514                irq_set_lockdep_class(irq, &gpio_lock_class);
 515                irq_set_chip_data(irq, chip);
 516                irq_set_chip_and_handler(irq, &jz_gpio_irq_chip,
 517                                         handle_level_irq);
 518        }
 519}
 520
 521static int __init jz4740_gpio_init(void)
 522{
 523        unsigned int i;
 524
 525        for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i)
 526                jz4740_gpio_chip_init(&jz4740_gpio_chips[i], i);
 527
 528        register_syscore_ops(&jz4740_gpio_syscore_ops);
 529
 530        printk(KERN_INFO "JZ4740 GPIO initialized\n");
 531
 532        return 0;
 533}
 534arch_initcall(jz4740_gpio_init);
 535
 536#ifdef CONFIG_DEBUG_FS
 537
 538static inline void gpio_seq_reg(struct seq_file *s, struct jz_gpio_chip *chip,
 539        const char *name, unsigned int reg)
 540{
 541        seq_printf(s, "\t%s: %08x\n", name, readl(chip->base + reg));
 542}
 543
 544static int gpio_regs_show(struct seq_file *s, void *unused)
 545{
 546        struct jz_gpio_chip *chip = jz4740_gpio_chips;
 547        int i;
 548
 549        for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i, ++chip) {
 550                seq_printf(s, "==GPIO %d==\n", i);
 551                gpio_seq_reg(s, chip, "Pin", JZ_REG_GPIO_PIN);
 552                gpio_seq_reg(s, chip, "Data", JZ_REG_GPIO_DATA);
 553                gpio_seq_reg(s, chip, "Mask", JZ_REG_GPIO_MASK);
 554                gpio_seq_reg(s, chip, "Pull", JZ_REG_GPIO_PULL);
 555                gpio_seq_reg(s, chip, "Func", JZ_REG_GPIO_FUNC);
 556                gpio_seq_reg(s, chip, "Select", JZ_REG_GPIO_SELECT);
 557                gpio_seq_reg(s, chip, "Direction", JZ_REG_GPIO_DIRECTION);
 558                gpio_seq_reg(s, chip, "Trigger", JZ_REG_GPIO_TRIGGER);
 559                gpio_seq_reg(s, chip, "Flag", JZ_REG_GPIO_FLAG);
 560        }
 561
 562        return 0;
 563}
 564
 565static int gpio_regs_open(struct inode *inode, struct file *file)
 566{
 567        return single_open(file, gpio_regs_show, NULL);
 568}
 569
 570static const struct file_operations gpio_regs_operations = {
 571        .open           = gpio_regs_open,
 572        .read           = seq_read,
 573        .llseek         = seq_lseek,
 574        .release        = single_release,
 575};
 576
 577static int __init gpio_debugfs_init(void)
 578{
 579        (void) debugfs_create_file("jz_regs_gpio", S_IFREG | S_IRUGO,
 580                                NULL, NULL, &gpio_regs_operations);
 581        return 0;
 582}
 583subsys_initcall(gpio_debugfs_init);
 584
 585#endif
 586