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 };
  45
  46 static 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
  56 static 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
  66 static 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
  75 static 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
  96 static 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
 113 static 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
 142 static 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
 149 static 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
 164 static 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
 179 static 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
 187 static 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
 195 static 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
 224 static 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
 233 static 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
 243 static 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
 276 static 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
 325 out:
 326         dev->irq_base = 0;
 327         return ret;
 328 }
 329
 330 static 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
 337 static 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
 345 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 346 {
 347 }
 348 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 349
 350 static 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
 436 err_irq:
 437         adp5588_irq_teardown(dev);
 438 err:
 439         kfree(dev);
 440         return ret;
 441 }
 442
 443 static 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
 473 static const struct i2c_device_id adp5588_gpio_id[] = {
 474         {DRV_NAME, 0},
 475         {}
 476 };
 477
 478 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 479
 480 static 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
 489 module_i2c_driver(adp5588_gpio_driver);
 490
 491 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 492 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 493 MODULE_LICENSE("GPL");