linux/drivers/gpio/gpio-adp5588.c
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   1/*
   2 * GPIO Chip driver for Analog Devices
   3 * ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
   4 *
   5 * Copyright 2009-2010 Analog Devices Inc.
   6 *
   7 * Licensed under the GPL-2 or later.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/kernel.h>
  12#include <linux/slab.h>
  13#include <linux/init.h>
  14#include <linux/i2c.h>
  15#include <linux/gpio.h>
  16#include <linux/interrupt.h>
  17#include <linux/irq.h>
  18
  19#include <linux/i2c/adp5588.h>
  20
  21#define DRV_NAME        "adp5588-gpio"
  22
  23/*
  24 * Early pre 4.0 Silicon required to delay readout by at least 25ms,
  25 * since the Event Counter Register updated 25ms after the interrupt
  26 * asserted.
  27 */
  28#define WA_DELAYED_READOUT_REVID(rev)   ((rev) < 4)
  29
  30struct adp5588_gpio {
  31        struct i2c_client *client;
  32        struct gpio_chip gpio_chip;
  33        struct mutex lock;      /* protect cached dir, dat_out */
  34        /* protect serialized access to the interrupt controller bus */
  35        struct mutex irq_lock;
  36        unsigned gpio_start;
  37        unsigned irq_base;
  38        uint8_t dat_out[3];
  39        uint8_t dir[3];
  40        uint8_t int_lvl[3];
  41        uint8_t int_en[3];
  42        uint8_t irq_mask[3];
  43        uint8_t irq_stat[3];
  44};
  45
  46static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
  47{
  48        int ret = i2c_smbus_read_byte_data(client, reg);
  49
  50        if (ret < 0)
  51                dev_err(&client->dev, "Read Error\n");
  52
  53        return ret;
  54}
  55
  56static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
  57{
  58        int ret = i2c_smbus_write_byte_data(client, reg, val);
  59
  60        if (ret < 0)
  61                dev_err(&client->dev, "Write Error\n");
  62
  63        return ret;
  64}
  65
  66static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
  67{
  68        struct adp5588_gpio *dev =
  69            container_of(chip, struct adp5588_gpio, gpio_chip);
  70
  71        return !!(adp5588_gpio_read(dev->client,
  72                  GPIO_DAT_STAT1 + ADP5588_BANK(off)) & ADP5588_BIT(off));
  73}
  74
  75static void adp5588_gpio_set_value(struct gpio_chip *chip,
  76                                   unsigned off, int val)
  77{
  78        unsigned bank, bit;
  79        struct adp5588_gpio *dev =
  80            container_of(chip, struct adp5588_gpio, gpio_chip);
  81
  82        bank = ADP5588_BANK(off);
  83        bit = ADP5588_BIT(off);
  84
  85        mutex_lock(&dev->lock);
  86        if (val)
  87                dev->dat_out[bank] |= bit;
  88        else
  89                dev->dat_out[bank] &= ~bit;
  90
  91        adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
  92                           dev->dat_out[bank]);
  93        mutex_unlock(&dev->lock);
  94}
  95
  96static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
  97{
  98        int ret;
  99        unsigned bank;
 100        struct adp5588_gpio *dev =
 101            container_of(chip, struct adp5588_gpio, gpio_chip);
 102
 103        bank = ADP5588_BANK(off);
 104
 105        mutex_lock(&dev->lock);
 106        dev->dir[bank] &= ~ADP5588_BIT(off);
 107        ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
 108        mutex_unlock(&dev->lock);
 109
 110        return ret;
 111}
 112
 113static int adp5588_gpio_direction_output(struct gpio_chip *chip,
 114                                         unsigned off, int val)
 115{
 116        int ret;
 117        unsigned bank, bit;
 118        struct adp5588_gpio *dev =
 119            container_of(chip, struct adp5588_gpio, gpio_chip);
 120
 121        bank = ADP5588_BANK(off);
 122        bit = ADP5588_BIT(off);
 123
 124        mutex_lock(&dev->lock);
 125        dev->dir[bank] |= bit;
 126
 127        if (val)
 128                dev->dat_out[bank] |= bit;
 129        else
 130                dev->dat_out[bank] &= ~bit;
 131
 132        ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 133                                 dev->dat_out[bank]);
 134        ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
 135                                 dev->dir[bank]);
 136        mutex_unlock(&dev->lock);
 137
 138        return ret;
 139}
 140
 141#ifdef CONFIG_GPIO_ADP5588_IRQ
 142static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
 143{
 144        struct adp5588_gpio *dev =
 145                container_of(chip, struct adp5588_gpio, gpio_chip);
 146        return dev->irq_base + off;
 147}
 148
 149static void adp5588_irq_bus_lock(struct irq_data *d)
 150{
 151        struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 152
 153        mutex_lock(&dev->irq_lock);
 154}
 155
 156 /*
 157  * genirq core code can issue chip->mask/unmask from atomic context.
 158  * This doesn't work for slow busses where an access needs to sleep.
 159  * bus_sync_unlock() is therefore called outside the atomic context,
 160  * syncs the current irq mask state with the slow external controller
 161  * and unlocks the bus.
 162  */
 163
 164static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 165{
 166        struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 167        int i;
 168
 169        for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
 170                if (dev->int_en[i] ^ dev->irq_mask[i]) {
 171                        dev->int_en[i] = dev->irq_mask[i];
 172                        adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 173                                           dev->int_en[i]);
 174                }
 175
 176        mutex_unlock(&dev->irq_lock);
 177}
 178
 179static void adp5588_irq_mask(struct irq_data *d)
 180{
 181        struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 182        unsigned gpio = d->irq - dev->irq_base;
 183
 184        dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
 185}
 186
 187static void adp5588_irq_unmask(struct irq_data *d)
 188{
 189        struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 190        unsigned gpio = d->irq - dev->irq_base;
 191
 192        dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
 193}
 194
 195static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 196{
 197        struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 198        uint16_t gpio = d->irq - dev->irq_base;
 199        unsigned bank, bit;
 200
 201        if ((type & IRQ_TYPE_EDGE_BOTH)) {
 202                dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
 203                        d->irq, type);
 204                return -EINVAL;
 205        }
 206
 207        bank = ADP5588_BANK(gpio);
 208        bit = ADP5588_BIT(gpio);
 209
 210        if (type & IRQ_TYPE_LEVEL_HIGH)
 211                dev->int_lvl[bank] |= bit;
 212        else if (type & IRQ_TYPE_LEVEL_LOW)
 213                dev->int_lvl[bank] &= ~bit;
 214        else
 215                return -EINVAL;
 216
 217        adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
 218        adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
 219                           dev->int_lvl[bank]);
 220
 221        return 0;
 222}
 223
 224static struct irq_chip adp5588_irq_chip = {
 225        .name                   = "adp5588",
 226        .irq_mask               = adp5588_irq_mask,
 227        .irq_unmask             = adp5588_irq_unmask,
 228        .irq_bus_lock           = adp5588_irq_bus_lock,
 229        .irq_bus_sync_unlock    = adp5588_irq_bus_sync_unlock,
 230        .irq_set_type           = adp5588_irq_set_type,
 231};
 232
 233static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
 234{
 235        int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
 236
 237        if (ret < 0)
 238                dev_err(&client->dev, "Read INT_STAT Error\n");
 239
 240        return ret;
 241}
 242
 243static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 244{
 245        struct adp5588_gpio *dev = devid;
 246        unsigned status, bank, bit, pending;
 247        int ret;
 248        status = adp5588_gpio_read(dev->client, INT_STAT);
 249
 250        if (status & ADP5588_GPI_INT) {
 251                ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
 252                if (ret < 0)
 253                        memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
 254
 255                for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
 256                        bank++, bit = 0) {
 257                        pending = dev->irq_stat[bank] & dev->irq_mask[bank];
 258
 259                        while (pending) {
 260                                if (pending & (1 << bit)) {
 261                                        handle_nested_irq(dev->irq_base +
 262                                                          (bank << 3) + bit);
 263                                        pending &= ~(1 << bit);
 264
 265                                }
 266                                bit++;
 267                        }
 268                }
 269        }
 270
 271        adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
 272
 273        return IRQ_HANDLED;
 274}
 275
 276static int adp5588_irq_setup(struct adp5588_gpio *dev)
 277{
 278        struct i2c_client *client = dev->client;
 279        struct adp5588_gpio_platform_data *pdata =
 280                        dev_get_platdata(&client->dev);
 281        unsigned gpio;
 282        int ret;
 283
 284        adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 285        adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 286        adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
 287
 288        dev->irq_base = pdata->irq_base;
 289        mutex_init(&dev->irq_lock);
 290
 291        for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
 292                int irq = gpio + dev->irq_base;
 293                irq_set_chip_data(irq, dev);
 294                irq_set_chip_and_handler(irq, &adp5588_irq_chip,
 295                                         handle_level_irq);
 296                irq_set_nested_thread(irq, 1);
 297#ifdef CONFIG_ARM
 298                /*
 299                 * ARM needs us to explicitly flag the IRQ as VALID,
 300                 * once we do so, it will also set the noprobe.
 301                 */
 302                set_irq_flags(irq, IRQF_VALID);
 303#else
 304                irq_set_noprobe(irq);
 305#endif
 306        }
 307
 308        ret = request_threaded_irq(client->irq,
 309                                   NULL,
 310                                   adp5588_irq_handler,
 311                                   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 312                                   dev_name(&client->dev), dev);
 313        if (ret) {
 314                dev_err(&client->dev, "failed to request irq %d\n",
 315                        client->irq);
 316                goto out;
 317        }
 318
 319        dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 320        adp5588_gpio_write(client, CFG,
 321                ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
 322
 323        return 0;
 324
 325out:
 326        dev->irq_base = 0;
 327        return ret;
 328}
 329
 330static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 331{
 332        if (dev->irq_base)
 333                free_irq(dev->client->irq, dev);
 334}
 335
 336#else
 337static int adp5588_irq_setup(struct adp5588_gpio *dev)
 338{
 339        struct i2c_client *client = dev->client;
 340        dev_warn(&client->dev, "interrupt support not compiled in\n");
 341
 342        return 0;
 343}
 344
 345static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 346{
 347}
 348#endif /* CONFIG_GPIO_ADP5588_IRQ */
 349
 350static int adp5588_gpio_probe(struct i2c_client *client,
 351                                        const struct i2c_device_id *id)
 352{
 353        struct adp5588_gpio_platform_data *pdata =
 354                        dev_get_platdata(&client->dev);
 355        struct adp5588_gpio *dev;
 356        struct gpio_chip *gc;
 357        int ret, i, revid;
 358
 359        if (pdata == NULL) {
 360                dev_err(&client->dev, "missing platform data\n");
 361                return -ENODEV;
 362        }
 363
 364        if (!i2c_check_functionality(client->adapter,
 365                                        I2C_FUNC_SMBUS_BYTE_DATA)) {
 366                dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 367                return -EIO;
 368        }
 369
 370        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 371        if (dev == NULL) {
 372                dev_err(&client->dev, "failed to alloc memory\n");
 373                return -ENOMEM;
 374        }
 375
 376        dev->client = client;
 377
 378        gc = &dev->gpio_chip;
 379        gc->direction_input = adp5588_gpio_direction_input;
 380        gc->direction_output = adp5588_gpio_direction_output;
 381        gc->get = adp5588_gpio_get_value;
 382        gc->set = adp5588_gpio_set_value;
 383        gc->can_sleep = 1;
 384
 385        gc->base = pdata->gpio_start;
 386        gc->ngpio = ADP5588_MAXGPIO;
 387        gc->label = client->name;
 388        gc->owner = THIS_MODULE;
 389
 390        mutex_init(&dev->lock);
 391
 392        ret = adp5588_gpio_read(dev->client, DEV_ID);
 393        if (ret < 0)
 394                goto err;
 395
 396        revid = ret & ADP5588_DEVICE_ID_MASK;
 397
 398        for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 399                dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 400                dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 401                ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 402                ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 403                                (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 404                ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 405                if (ret)
 406                        goto err;
 407        }
 408
 409        if (pdata->irq_base) {
 410                if (WA_DELAYED_READOUT_REVID(revid)) {
 411                        dev_warn(&client->dev, "GPIO int not supported\n");
 412                } else {
 413                        ret = adp5588_irq_setup(dev);
 414                        if (ret)
 415                                goto err;
 416                }
 417        }
 418
 419        ret = gpiochip_add(&dev->gpio_chip);
 420        if (ret)
 421                goto err_irq;
 422
 423        dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
 424                        pdata->irq_base, revid);
 425
 426        if (pdata->setup) {
 427                ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 428                if (ret < 0)
 429                        dev_warn(&client->dev, "setup failed, %d\n", ret);
 430        }
 431
 432        i2c_set_clientdata(client, dev);
 433
 434        return 0;
 435
 436err_irq:
 437        adp5588_irq_teardown(dev);
 438err:
 439        kfree(dev);
 440        return ret;
 441}
 442
 443static int adp5588_gpio_remove(struct i2c_client *client)
 444{
 445        struct adp5588_gpio_platform_data *pdata =
 446                        dev_get_platdata(&client->dev);
 447        struct adp5588_gpio *dev = i2c_get_clientdata(client);
 448        int ret;
 449
 450        if (pdata->teardown) {
 451                ret = pdata->teardown(client,
 452                                      dev->gpio_chip.base, dev->gpio_chip.ngpio,
 453                                      pdata->context);
 454                if (ret < 0) {
 455                        dev_err(&client->dev, "teardown failed %d\n", ret);
 456                        return ret;
 457                }
 458        }
 459
 460        if (dev->irq_base)
 461                free_irq(dev->client->irq, dev);
 462
 463        ret = gpiochip_remove(&dev->gpio_chip);
 464        if (ret) {
 465                dev_err(&client->dev, "gpiochip_remove failed %d\n", ret);
 466                return ret;
 467        }
 468
 469        kfree(dev);
 470        return 0;
 471}
 472
 473static const struct i2c_device_id adp5588_gpio_id[] = {
 474        {DRV_NAME, 0},
 475        {}
 476};
 477
 478MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 479
 480static struct i2c_driver adp5588_gpio_driver = {
 481        .driver = {
 482                   .name = DRV_NAME,
 483                   },
 484        .probe = adp5588_gpio_probe,
 485        .remove = adp5588_gpio_remove,
 486        .id_table = adp5588_gpio_id,
 487};
 488
 489module_i2c_driver(adp5588_gpio_driver);
 490
 491MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 492MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 493MODULE_LICENSE("GPL");
 494
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