drivers/gpio/gpio-adp5588.c

   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
  30 struct 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         uint8_t int_input_en[3];
  45         uint8_t int_lvl_cached[3];
  46 };
  47
  48 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
  49 {
  50         int ret = i2c_smbus_read_byte_data(client, reg);
  51
  52         if (ret < 0)
  53                 dev_err(&client->dev, "Read Error\n");
  54
  55         return ret;
  56 }
  57
  58 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
  59 {
  60         int ret = i2c_smbus_write_byte_data(client, reg, val);
  61
  62         if (ret < 0)
  63                 dev_err(&client->dev, "Write Error\n");
  64
  65         return ret;
  66 }
  67
  68 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
  69 {
  70         struct adp5588_gpio *dev =
  71             container_of(chip, struct adp5588_gpio, gpio_chip);
  72         unsigned bank = ADP5588_BANK(off);
  73         unsigned bit = ADP5588_BIT(off);
  74         int val;
  75
  76         mutex_lock(&dev->lock);
  77
  78         if (dev->dir[bank] & bit)
  79                 val = dev->dat_out[bank];
  80         else
  81                 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
  82
  83         mutex_unlock(&dev->lock);
  84
  85         return !!(val & bit);
  86 }
  87
  88 static void adp5588_gpio_set_value(struct gpio_chip *chip,
  89                                    unsigned off, int val)
  90 {
  91         unsigned bank, bit;
  92         struct adp5588_gpio *dev =
  93             container_of(chip, struct adp5588_gpio, gpio_chip);
  94
  95         bank = ADP5588_BANK(off);
  96         bit = ADP5588_BIT(off);
  97
  98         mutex_lock(&dev->lock);
  99         if (val)
 100                 dev->dat_out[bank] |= bit;
 101         else
 102                 dev->dat_out[bank] &= ~bit;
 103
 104         adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 105                            dev->dat_out[bank]);
 106         mutex_unlock(&dev->lock);
 107 }
 108
 109 static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
 110 {
 111         int ret;
 112         unsigned bank;
 113         struct adp5588_gpio *dev =
 114             container_of(chip, struct adp5588_gpio, gpio_chip);
 115
 116         bank = ADP5588_BANK(off);
 117
 118         mutex_lock(&dev->lock);
 119         dev->dir[bank] &= ~ADP5588_BIT(off);
 120         ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
 121         mutex_unlock(&dev->lock);
 122
 123         return ret;
 124 }
 125
 126 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
 127                                          unsigned off, int val)
 128 {
 129         int ret;
 130         unsigned bank, bit;
 131         struct adp5588_gpio *dev =
 132             container_of(chip, struct adp5588_gpio, gpio_chip);
 133
 134         bank = ADP5588_BANK(off);
 135         bit = ADP5588_BIT(off);
 136
 137         mutex_lock(&dev->lock);
 138         dev->dir[bank] |= bit;
 139
 140         if (val)
 141                 dev->dat_out[bank] |= bit;
 142         else
 143                 dev->dat_out[bank] &= ~bit;
 144
 145         ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 146                                  dev->dat_out[bank]);
 147         ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
 148                                  dev->dir[bank]);
 149         mutex_unlock(&dev->lock);
 150
 151         return ret;
 152 }
 153
 154 #ifdef CONFIG_GPIO_ADP5588_IRQ
 155 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
 156 {
 157         struct adp5588_gpio *dev =
 158                 container_of(chip, struct adp5588_gpio, gpio_chip);
 159         return dev->irq_base + off;
 160 }
 161
 162 static void adp5588_irq_bus_lock(struct irq_data *d)
 163 {
 164         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 165
 166         mutex_lock(&dev->irq_lock);
 167 }
 168
 169  /*
 170   * genirq core code can issue chip->mask/unmask from atomic context.
 171   * This doesn't work for slow busses where an access needs to sleep.
 172   * bus_sync_unlock() is therefore called outside the atomic context,
 173   * syncs the current irq mask state with the slow external controller
 174   * and unlocks the bus.
 175   */
 176
 177 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 178 {
 179         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 180         int i;
 181
 182         for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 183                 if (dev->int_input_en[i]) {
 184                         mutex_lock(&dev->lock);
 185                         dev->dir[i] &= ~dev->int_input_en[i];
 186                         dev->int_input_en[i] = 0;
 187                         adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
 188                                            dev->dir[i]);
 189                         mutex_unlock(&dev->lock);
 190                 }
 191
 192                 if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
 193                         dev->int_lvl_cached[i] = dev->int_lvl[i];
 194                         adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
 195                                            dev->int_lvl[i]);
 196                 }
 197
 198                 if (dev->int_en[i] ^ dev->irq_mask[i]) {
 199                         dev->int_en[i] = dev->irq_mask[i];
 200                         adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 201                                            dev->int_en[i]);
 202                 }
 203         }
 204
 205         mutex_unlock(&dev->irq_lock);
 206 }
 207
 208 static void adp5588_irq_mask(struct irq_data *d)
 209 {
 210         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 211         unsigned gpio = d->irq - dev->irq_base;
 212
 213         dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
 214 }
 215
 216 static void adp5588_irq_unmask(struct irq_data *d)
 217 {
 218         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 219         unsigned gpio = d->irq - dev->irq_base;
 220
 221         dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
 222 }
 223
 224 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 225 {
 226         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 227         uint16_t gpio = d->irq - dev->irq_base;
 228         unsigned bank, bit;
 229
 230         if ((type & IRQ_TYPE_EDGE_BOTH)) {
 231                 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
 232                         d->irq, type);
 233                 return -EINVAL;
 234         }
 235
 236         bank = ADP5588_BANK(gpio);
 237         bit = ADP5588_BIT(gpio);
 238
 239         if (type & IRQ_TYPE_LEVEL_HIGH)
 240                 dev->int_lvl[bank] |= bit;
 241         else if (type & IRQ_TYPE_LEVEL_LOW)
 242                 dev->int_lvl[bank] &= ~bit;
 243         else
 244                 return -EINVAL;
 245
 246         dev->int_input_en[bank] |= bit;
 247
 248         return 0;
 249 }
 250
 251 static struct irq_chip adp5588_irq_chip = {
 252         .name                   = "adp5588",
 253         .irq_mask               = adp5588_irq_mask,
 254         .irq_unmask             = adp5588_irq_unmask,
 255         .irq_bus_lock           = adp5588_irq_bus_lock,
 256         .irq_bus_sync_unlock    = adp5588_irq_bus_sync_unlock,
 257         .irq_set_type           = adp5588_irq_set_type,
 258 };
 259
 260 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
 261 {
 262         int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
 263
 264         if (ret < 0)
 265                 dev_err(&client->dev, "Read INT_STAT Error\n");
 266
 267         return ret;
 268 }
 269
 270 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 271 {
 272         struct adp5588_gpio *dev = devid;
 273         unsigned status, bank, bit, pending;
 274         int ret;
 275         status = adp5588_gpio_read(dev->client, INT_STAT);
 276
 277         if (status & ADP5588_GPI_INT) {
 278                 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
 279                 if (ret < 0)
 280                         memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
 281
 282                 for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
 283                         bank++, bit = 0) {
 284                         pending = dev->irq_stat[bank] & dev->irq_mask[bank];
 285
 286                         while (pending) {
 287                                 if (pending & (1 << bit)) {
 288                                         handle_nested_irq(dev->irq_base +
 289                                                           (bank << 3) + bit);
 290                                         pending &= ~(1 << bit);
 291
 292                                 }
 293                                 bit++;
 294                         }
 295                 }
 296         }
 297
 298         adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
 299
 300         return IRQ_HANDLED;
 301 }
 302
 303 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 304 {
 305         struct i2c_client *client = dev->client;
 306         struct adp5588_gpio_platform_data *pdata =
 307                         dev_get_platdata(&client->dev);
 308         unsigned gpio;
 309         int ret;
 310
 311         adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 312         adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 313         adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
 314
 315         dev->irq_base = pdata->irq_base;
 316         mutex_init(&dev->irq_lock);
 317
 318         for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
 319                 int irq = gpio + dev->irq_base;
 320                 irq_set_chip_data(irq, dev);
 321                 irq_set_chip_and_handler(irq, &adp5588_irq_chip,
 322                                          handle_level_irq);
 323                 irq_set_nested_thread(irq, 1);
 324                 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
 325         }
 326
 327         ret = request_threaded_irq(client->irq,
 328                                    NULL,
 329                                    adp5588_irq_handler,
 330                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 331                                    dev_name(&client->dev), dev);
 332         if (ret) {
 333                 dev_err(&client->dev, "failed to request irq %d\n",
 334                         client->irq);
 335                 goto out;
 336         }
 337
 338         dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 339         adp5588_gpio_write(client, CFG,
 340                 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
 341
 342         return 0;
 343
 344 out:
 345         dev->irq_base = 0;
 346         return ret;
 347 }
 348
 349 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 350 {
 351         if (dev->irq_base)
 352                 free_irq(dev->client->irq, dev);
 353 }
 354
 355 #else
 356 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 357 {
 358         struct i2c_client *client = dev->client;
 359         dev_warn(&client->dev, "interrupt support not compiled in\n");
 360
 361         return 0;
 362 }
 363
 364 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 365 {
 366 }
 367 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 368
 369 static int adp5588_gpio_probe(struct i2c_client *client,
 370                                         const struct i2c_device_id *id)
 371 {
 372         struct adp5588_gpio_platform_data *pdata =
 373                         dev_get_platdata(&client->dev);
 374         struct adp5588_gpio *dev;
 375         struct gpio_chip *gc;
 376         int ret, i, revid;
 377
 378         if (!pdata) {
 379                 dev_err(&client->dev, "missing platform data\n");
 380                 return -ENODEV;
 381         }
 382
 383         if (!i2c_check_functionality(client->adapter,
 384                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 385                 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 386                 return -EIO;
 387         }
 388
 389         dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
 390         if (!dev)
 391                 return -ENOMEM;
 392
 393         dev->client = client;
 394
 395         gc = &dev->gpio_chip;
 396         gc->direction_input = adp5588_gpio_direction_input;
 397         gc->direction_output = adp5588_gpio_direction_output;
 398         gc->get = adp5588_gpio_get_value;
 399         gc->set = adp5588_gpio_set_value;
 400         gc->can_sleep = true;
 401
 402         gc->base = pdata->gpio_start;
 403         gc->ngpio = ADP5588_MAXGPIO;
 404         gc->label = client->name;
 405         gc->owner = THIS_MODULE;
 406         gc->names = pdata->names;
 407
 408         mutex_init(&dev->lock);
 409
 410         ret = adp5588_gpio_read(dev->client, DEV_ID);
 411         if (ret < 0)
 412                 goto err;
 413
 414         revid = ret & ADP5588_DEVICE_ID_MASK;
 415
 416         for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 417                 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 418                 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 419                 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 420                 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 421                                 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 422                 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 423                 if (ret)
 424                         goto err;
 425         }
 426
 427         if (pdata->irq_base) {
 428                 if (WA_DELAYED_READOUT_REVID(revid)) {
 429                         dev_warn(&client->dev, "GPIO int not supported\n");
 430                 } else {
 431                         ret = adp5588_irq_setup(dev);
 432                         if (ret)
 433                                 goto err;
 434                 }
 435         }
 436
 437         ret = gpiochip_add(&dev->gpio_chip);
 438         if (ret)
 439                 goto err_irq;
 440
 441         dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
 442                         pdata->irq_base, revid);
 443
 444         if (pdata->setup) {
 445                 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 446                 if (ret < 0)
 447                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 448         }
 449
 450         i2c_set_clientdata(client, dev);
 451
 452         return 0;
 453
 454 err_irq:
 455         adp5588_irq_teardown(dev);
 456 err:
 457         return ret;
 458 }
 459
 460 static int adp5588_gpio_remove(struct i2c_client *client)
 461 {
 462         struct adp5588_gpio_platform_data *pdata =
 463                         dev_get_platdata(&client->dev);
 464         struct adp5588_gpio *dev = i2c_get_clientdata(client);
 465         int ret;
 466
 467         if (pdata->teardown) {
 468                 ret = pdata->teardown(client,
 469                                       dev->gpio_chip.base, dev->gpio_chip.ngpio,
 470                                       pdata->context);
 471                 if (ret < 0) {
 472                         dev_err(&client->dev, "teardown failed %d\n", ret);
 473                         return ret;
 474                 }
 475         }
 476
 477         if (dev->irq_base)
 478                 free_irq(dev->client->irq, dev);
 479
 480         gpiochip_remove(&dev->gpio_chip);
 481
 482         return 0;
 483 }
 484
 485 static const struct i2c_device_id adp5588_gpio_id[] = {
 486         {DRV_NAME, 0},
 487         {}
 488 };
 489
 490 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 491
 492 static struct i2c_driver adp5588_gpio_driver = {
 493         .driver = {
 494                    .name = DRV_NAME,
 495                    },
 496         .probe = adp5588_gpio_probe,
 497         .remove = adp5588_gpio_remove,
 498         .id_table = adp5588_gpio_id,
 499 };
 500
 501 module_i2c_driver(adp5588_gpio_driver);
 502
 503 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 504 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 505 MODULE_LICENSE("GPL");