linux/drivers/gpio/gpio-ab8500.c
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   1/*
   2 * Copyright (C) ST-Ericsson SA 2011
   3 *
   4 * Author: BIBEK BASU <bibek.basu@stericsson.com>
   5 * License terms: GNU General Public License (GPL) version 2
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11#include <linux/kernel.h>
  12#include <linux/types.h>
  13#include <linux/slab.h>
  14#include <linux/init.h>
  15#include <linux/module.h>
  16#include <linux/err.h>
  17#include <linux/platform_device.h>
  18#include <linux/gpio.h>
  19#include <linux/irq.h>
  20#include <linux/interrupt.h>
  21#include <linux/mfd/ab8500.h>
  22#include <linux/mfd/abx500.h>
  23#include <linux/mfd/ab8500/gpio.h>
  24
  25/*
  26 * GPIO registers offset
  27 * Bank: 0x10
  28 */
  29#define AB8500_GPIO_SEL1_REG    0x00
  30#define AB8500_GPIO_SEL2_REG    0x01
  31#define AB8500_GPIO_SEL3_REG    0x02
  32#define AB8500_GPIO_SEL4_REG    0x03
  33#define AB8500_GPIO_SEL5_REG    0x04
  34#define AB8500_GPIO_SEL6_REG    0x05
  35
  36#define AB8500_GPIO_DIR1_REG    0x10
  37#define AB8500_GPIO_DIR2_REG    0x11
  38#define AB8500_GPIO_DIR3_REG    0x12
  39#define AB8500_GPIO_DIR4_REG    0x13
  40#define AB8500_GPIO_DIR5_REG    0x14
  41#define AB8500_GPIO_DIR6_REG    0x15
  42
  43#define AB8500_GPIO_OUT1_REG    0x20
  44#define AB8500_GPIO_OUT2_REG    0x21
  45#define AB8500_GPIO_OUT3_REG    0x22
  46#define AB8500_GPIO_OUT4_REG    0x23
  47#define AB8500_GPIO_OUT5_REG    0x24
  48#define AB8500_GPIO_OUT6_REG    0x25
  49
  50#define AB8500_GPIO_PUD1_REG    0x30
  51#define AB8500_GPIO_PUD2_REG    0x31
  52#define AB8500_GPIO_PUD3_REG    0x32
  53#define AB8500_GPIO_PUD4_REG    0x33
  54#define AB8500_GPIO_PUD5_REG    0x34
  55#define AB8500_GPIO_PUD6_REG    0x35
  56
  57#define AB8500_GPIO_IN1_REG     0x40
  58#define AB8500_GPIO_IN2_REG     0x41
  59#define AB8500_GPIO_IN3_REG     0x42
  60#define AB8500_GPIO_IN4_REG     0x43
  61#define AB8500_GPIO_IN5_REG     0x44
  62#define AB8500_GPIO_IN6_REG     0x45
  63#define AB8500_GPIO_ALTFUN_REG  0x45
  64#define ALTFUN_REG_INDEX        6
  65#define AB8500_NUM_GPIO         42
  66#define AB8500_NUM_VIR_GPIO_IRQ 16
  67
  68enum ab8500_gpio_action {
  69        NONE,
  70        STARTUP,
  71        SHUTDOWN,
  72        MASK,
  73        UNMASK
  74};
  75
  76struct ab8500_gpio {
  77        struct gpio_chip chip;
  78        struct ab8500 *parent;
  79        struct device *dev;
  80        struct mutex lock;
  81        u32 irq_base;
  82        enum ab8500_gpio_action irq_action;
  83        u16 rising;
  84        u16 falling;
  85};
  86/**
  87 * to_ab8500_gpio() - get the pointer to ab8500_gpio
  88 * @chip:       Member of the structure ab8500_gpio
  89 */
  90static inline struct ab8500_gpio *to_ab8500_gpio(struct gpio_chip *chip)
  91{
  92        return container_of(chip, struct ab8500_gpio, chip);
  93}
  94
  95static int ab8500_gpio_set_bits(struct gpio_chip *chip, u8 reg,
  96                                        unsigned offset, int val)
  97{
  98        struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
  99        u8 pos = offset % 8;
 100        int ret;
 101
 102        reg = reg + (offset / 8);
 103        ret = abx500_mask_and_set_register_interruptible(ab8500_gpio->dev,
 104                                AB8500_MISC, reg, 1 << pos, val << pos);
 105        if (ret < 0)
 106                dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
 107        return ret;
 108}
 109/**
 110 * ab8500_gpio_get() - Get the particular GPIO value
 111 * @chip: Gpio device
 112 * @offset: GPIO number to read
 113 */
 114static int ab8500_gpio_get(struct gpio_chip *chip, unsigned offset)
 115{
 116        struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 117        u8 mask = 1 << (offset % 8);
 118        u8 reg = AB8500_GPIO_OUT1_REG + (offset / 8);
 119        int ret;
 120        u8 data;
 121        ret = abx500_get_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
 122                                                reg, &data);
 123        if (ret < 0) {
 124                dev_err(ab8500_gpio->dev, "%s read failed\n", __func__);
 125                return ret;
 126        }
 127        return (data & mask) >> (offset % 8);
 128}
 129
 130static void ab8500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 131{
 132        struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 133        int ret;
 134        /* Write the data */
 135        ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, 1);
 136        if (ret < 0)
 137                dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
 138}
 139
 140static int ab8500_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 141                                        int val)
 142{
 143        int ret;
 144        /* set direction as output */
 145        ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 1);
 146        if (ret < 0)
 147                return ret;
 148        /* disable pull down */
 149        ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_PUD1_REG, offset, 1);
 150        if (ret < 0)
 151                return ret;
 152        /* set the output as 1 or 0 */
 153        return ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, val);
 154
 155}
 156
 157static int ab8500_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 158{
 159        /* set the register as input */
 160        return ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 0);
 161}
 162
 163static int ab8500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 164{
 165        /*
 166         * Only some GPIOs are interrupt capable, and they are
 167         * organized in discontiguous clusters:
 168         *
 169         *      GPIO6 to GPIO13
 170         *      GPIO24 and GPIO25
 171         *      GPIO36 to GPIO41
 172         */
 173        static struct ab8500_gpio_irq_cluster {
 174                int start;
 175                int end;
 176        } clusters[] = {
 177                {.start = 6,  .end = 13},
 178                {.start = 24, .end = 25},
 179                {.start = 36, .end = 41},
 180        };
 181        struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 182        int base = ab8500_gpio->irq_base;
 183        int i;
 184
 185        for (i = 0; i < ARRAY_SIZE(clusters); i++) {
 186                struct ab8500_gpio_irq_cluster *cluster = &clusters[i];
 187
 188                if (offset >= cluster->start && offset <= cluster->end)
 189                        return base + offset - cluster->start;
 190
 191                /* Advance by the number of gpios in this cluster */
 192                base += cluster->end - cluster->start + 1;
 193        }
 194
 195        return -EINVAL;
 196}
 197
 198static struct gpio_chip ab8500gpio_chip = {
 199        .label                  = "ab8500_gpio",
 200        .owner                  = THIS_MODULE,
 201        .direction_input        = ab8500_gpio_direction_input,
 202        .get                    = ab8500_gpio_get,
 203        .direction_output       = ab8500_gpio_direction_output,
 204        .set                    = ab8500_gpio_set,
 205        .to_irq                 = ab8500_gpio_to_irq,
 206};
 207
 208static unsigned int irq_to_rising(unsigned int irq)
 209{
 210        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 211        int offset = irq - ab8500_gpio->irq_base;
 212        int new_irq = offset +  AB8500_INT_GPIO6R
 213                        + ab8500_gpio->parent->irq_base;
 214        return new_irq;
 215}
 216
 217static unsigned int irq_to_falling(unsigned int irq)
 218{
 219        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 220        int offset = irq - ab8500_gpio->irq_base;
 221        int new_irq = offset +  AB8500_INT_GPIO6F
 222                        +  ab8500_gpio->parent->irq_base;
 223        return new_irq;
 224
 225}
 226
 227static unsigned int rising_to_irq(unsigned int irq, void *dev)
 228{
 229        struct ab8500_gpio *ab8500_gpio = dev;
 230        int offset = irq - AB8500_INT_GPIO6R
 231                        - ab8500_gpio->parent->irq_base ;
 232        int new_irq = offset + ab8500_gpio->irq_base;
 233        return new_irq;
 234}
 235
 236static unsigned int falling_to_irq(unsigned int irq, void *dev)
 237{
 238        struct ab8500_gpio *ab8500_gpio = dev;
 239        int offset = irq - AB8500_INT_GPIO6F
 240                        - ab8500_gpio->parent->irq_base ;
 241        int new_irq = offset + ab8500_gpio->irq_base;
 242        return new_irq;
 243
 244}
 245
 246/*
 247 * IRQ handler
 248 */
 249
 250static irqreturn_t handle_rising(int irq, void *dev)
 251{
 252
 253        handle_nested_irq(rising_to_irq(irq , dev));
 254        return IRQ_HANDLED;
 255}
 256
 257static irqreturn_t handle_falling(int irq, void *dev)
 258{
 259
 260        handle_nested_irq(falling_to_irq(irq, dev));
 261        return IRQ_HANDLED;
 262}
 263
 264static void ab8500_gpio_irq_lock(unsigned int irq)
 265{
 266        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 267        mutex_lock(&ab8500_gpio->lock);
 268}
 269
 270static void ab8500_gpio_irq_sync_unlock(unsigned int irq)
 271{
 272        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 273        int offset = irq - ab8500_gpio->irq_base;
 274        bool rising = ab8500_gpio->rising & BIT(offset);
 275        bool falling = ab8500_gpio->falling & BIT(offset);
 276        int ret;
 277
 278        switch (ab8500_gpio->irq_action)        {
 279        case STARTUP:
 280                if (rising)
 281                        ret = request_threaded_irq(irq_to_rising(irq),
 282                                        NULL, handle_rising,
 283                                        IRQF_TRIGGER_RISING,
 284                                        "ab8500-gpio-r", ab8500_gpio);
 285                if (falling)
 286                        ret = request_threaded_irq(irq_to_falling(irq),
 287                                       NULL, handle_falling,
 288                                       IRQF_TRIGGER_FALLING,
 289                                       "ab8500-gpio-f", ab8500_gpio);
 290                break;
 291        case SHUTDOWN:
 292                if (rising)
 293                        free_irq(irq_to_rising(irq), ab8500_gpio);
 294                if (falling)
 295                        free_irq(irq_to_falling(irq), ab8500_gpio);
 296                break;
 297        case MASK:
 298                if (rising)
 299                        disable_irq(irq_to_rising(irq));
 300                if (falling)
 301                        disable_irq(irq_to_falling(irq));
 302                break;
 303        case UNMASK:
 304                if (rising)
 305                        enable_irq(irq_to_rising(irq));
 306                if (falling)
 307                        enable_irq(irq_to_falling(irq));
 308                break;
 309        case NONE:
 310                break;
 311        }
 312        ab8500_gpio->irq_action = NONE;
 313        ab8500_gpio->rising &= ~(BIT(offset));
 314        ab8500_gpio->falling &= ~(BIT(offset));
 315        mutex_unlock(&ab8500_gpio->lock);
 316}
 317
 318
 319static void ab8500_gpio_irq_mask(unsigned int irq)
 320{
 321        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 322        ab8500_gpio->irq_action = MASK;
 323}
 324
 325static void ab8500_gpio_irq_unmask(unsigned int irq)
 326{
 327        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 328        ab8500_gpio->irq_action = UNMASK;
 329}
 330
 331static int ab8500_gpio_irq_set_type(unsigned int irq, unsigned int type)
 332{
 333        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 334        int offset = irq - ab8500_gpio->irq_base;
 335
 336        if (type == IRQ_TYPE_EDGE_BOTH) {
 337                ab8500_gpio->rising =  BIT(offset);
 338                ab8500_gpio->falling = BIT(offset);
 339        } else if (type == IRQ_TYPE_EDGE_RISING) {
 340                ab8500_gpio->rising =  BIT(offset);
 341        } else  {
 342                ab8500_gpio->falling = BIT(offset);
 343        }
 344        return 0;
 345}
 346
 347unsigned int ab8500_gpio_irq_startup(unsigned int irq)
 348{
 349        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 350        ab8500_gpio->irq_action = STARTUP;
 351        return 0;
 352}
 353
 354void ab8500_gpio_irq_shutdown(unsigned int irq)
 355{
 356        struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 357        ab8500_gpio->irq_action = SHUTDOWN;
 358}
 359
 360static struct irq_chip ab8500_gpio_irq_chip = {
 361        .name                   = "ab8500-gpio",
 362        .startup                = ab8500_gpio_irq_startup,
 363        .shutdown               = ab8500_gpio_irq_shutdown,
 364        .bus_lock               = ab8500_gpio_irq_lock,
 365        .bus_sync_unlock        = ab8500_gpio_irq_sync_unlock,
 366        .mask                   = ab8500_gpio_irq_mask,
 367        .unmask                 = ab8500_gpio_irq_unmask,
 368        .set_type               = ab8500_gpio_irq_set_type,
 369};
 370
 371static int ab8500_gpio_irq_init(struct ab8500_gpio *ab8500_gpio)
 372{
 373        u32 base = ab8500_gpio->irq_base;
 374        int irq;
 375
 376        for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ ; irq++) {
 377                set_irq_chip_data(irq, ab8500_gpio);
 378                set_irq_chip_and_handler(irq, &ab8500_gpio_irq_chip,
 379                                handle_simple_irq);
 380                set_irq_nested_thread(irq, 1);
 381#ifdef CONFIG_ARM
 382                set_irq_flags(irq, IRQF_VALID);
 383#else
 384                set_irq_noprobe(irq);
 385#endif
 386        }
 387
 388        return 0;
 389}
 390
 391static void ab8500_gpio_irq_remove(struct ab8500_gpio *ab8500_gpio)
 392{
 393        int base = ab8500_gpio->irq_base;
 394        int irq;
 395
 396        for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ; irq++) {
 397#ifdef CONFIG_ARM
 398                set_irq_flags(irq, 0);
 399#endif
 400                set_irq_chip_and_handler(irq, NULL, NULL);
 401                set_irq_chip_data(irq, NULL);
 402        }
 403}
 404
 405static int __devinit ab8500_gpio_probe(struct platform_device *pdev)
 406{
 407        struct ab8500_platform_data *ab8500_pdata =
 408                                dev_get_platdata(pdev->dev.parent);
 409        struct ab8500_gpio_platform_data *pdata;
 410        struct ab8500_gpio *ab8500_gpio;
 411        int ret;
 412        int i;
 413
 414        pdata = ab8500_pdata->gpio;
 415        if (!pdata)     {
 416                dev_err(&pdev->dev, "gpio platform data missing\n");
 417                return -ENODEV;
 418        }
 419
 420        ab8500_gpio = kzalloc(sizeof(struct ab8500_gpio), GFP_KERNEL);
 421        if (ab8500_gpio == NULL) {
 422                dev_err(&pdev->dev, "failed to allocate memory\n");
 423                return -ENOMEM;
 424        }
 425        ab8500_gpio->dev = &pdev->dev;
 426        ab8500_gpio->parent = dev_get_drvdata(pdev->dev.parent);
 427        ab8500_gpio->chip = ab8500gpio_chip;
 428        ab8500_gpio->chip.ngpio = AB8500_NUM_GPIO;
 429        ab8500_gpio->chip.dev = &pdev->dev;
 430        ab8500_gpio->chip.base = pdata->gpio_base;
 431        ab8500_gpio->irq_base = pdata->irq_base;
 432        /* initialize the lock */
 433        mutex_init(&ab8500_gpio->lock);
 434        /*
 435         * AB8500 core will handle and clear the IRQ
 436         * configre GPIO based on config-reg value.
 437         * These values are for selecting the PINs as
 438         * GPIO or alternate function
 439         */
 440        for (i = AB8500_GPIO_SEL1_REG; i <= AB8500_GPIO_SEL6_REG; i++)  {
 441                ret = abx500_set_register_interruptible(ab8500_gpio->dev,
 442                                AB8500_MISC, i,
 443                                pdata->config_reg[i]);
 444                if (ret < 0)
 445                        goto out_free;
 446        }
 447        ret = abx500_set_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
 448                                AB8500_GPIO_ALTFUN_REG,
 449                                pdata->config_reg[ALTFUN_REG_INDEX]);
 450        if (ret < 0)
 451                goto out_free;
 452
 453        ret = ab8500_gpio_irq_init(ab8500_gpio);
 454        if (ret)
 455                goto out_free;
 456        ret = gpiochip_add(&ab8500_gpio->chip);
 457        if (ret) {
 458                dev_err(&pdev->dev, "unable to add gpiochip: %d\n",
 459                                ret);
 460                goto out_rem_irq;
 461        }
 462        platform_set_drvdata(pdev, ab8500_gpio);
 463        return 0;
 464
 465out_rem_irq:
 466        ab8500_gpio_irq_remove(ab8500_gpio);
 467out_free:
 468        mutex_destroy(&ab8500_gpio->lock);
 469        kfree(ab8500_gpio);
 470        return ret;
 471}
 472
 473/*
 474 * ab8500_gpio_remove() - remove Ab8500-gpio driver
 475 * @pdev :      Platform device registered
 476 */
 477static int __devexit ab8500_gpio_remove(struct platform_device *pdev)
 478{
 479        struct ab8500_gpio *ab8500_gpio = platform_get_drvdata(pdev);
 480        int ret;
 481
 482        ret = gpiochip_remove(&ab8500_gpio->chip);
 483        if (ret < 0) {
 484                dev_err(ab8500_gpio->dev, "unable to remove gpiochip: %d\n",
 485                        ret);
 486                return ret;
 487        }
 488
 489        platform_set_drvdata(pdev, NULL);
 490        mutex_destroy(&ab8500_gpio->lock);
 491        kfree(ab8500_gpio);
 492
 493        return 0;
 494}
 495
 496static struct platform_driver ab8500_gpio_driver = {
 497        .driver = {
 498                .name = "ab8500-gpio",
 499                .owner = THIS_MODULE,
 500        },
 501        .probe = ab8500_gpio_probe,
 502        .remove = __devexit_p(ab8500_gpio_remove),
 503};
 504
 505static int __init ab8500_gpio_init(void)
 506{
 507        return platform_driver_register(&ab8500_gpio_driver);
 508}
 509arch_initcall(ab8500_gpio_init);
 510
 511static void __exit ab8500_gpio_exit(void)
 512{
 513        platform_driver_unregister(&ab8500_gpio_driver);
 514}
 515module_exit(ab8500_gpio_exit);
 516
 517MODULE_AUTHOR("BIBEK BASU <bibek.basu@stericsson.com>");
 518MODULE_DESCRIPTION("Driver allows to use AB8500 unused pins to be used as GPIO");
 519MODULE_ALIAS("platform:ab8500-gpio");
 520MODULE_LICENSE("GPL v2");
 521
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