drivers/gpio/adp5588-gpio.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(unsigned int irq)
 150 {
 151         struct adp5588_gpio *dev = get_irq_chip_data(irq);
 152         mutex_lock(&dev->irq_lock);
 153 }
 154
 155  /*
 156   * genirq core code can issue chip->mask/unmask from atomic context.
 157   * This doesn't work for slow busses where an access needs to sleep.
 158   * bus_sync_unlock() is therefore called outside the atomic context,
 159   * syncs the current irq mask state with the slow external controller
 160   * and unlocks the bus.
 161   */
 162
 163 static void adp5588_irq_bus_sync_unlock(unsigned int irq)
 164 {
 165         struct adp5588_gpio *dev = get_irq_chip_data(irq);
 166         int i;
 167
 168         for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
 169                 if (dev->int_en[i] ^ dev->irq_mask[i]) {
 170                         dev->int_en[i] = dev->irq_mask[i];
 171                         adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 172                                            dev->int_en[i]);
 173                 }
 174
 175         mutex_unlock(&dev->irq_lock);
 176 }
 177
 178 static void adp5588_irq_mask(unsigned int irq)
 179 {
 180         struct adp5588_gpio *dev = get_irq_chip_data(irq);
 181         unsigned gpio = irq - dev->irq_base;
 182
 183         dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
 184 }
 185
 186 static void adp5588_irq_unmask(unsigned int irq)
 187 {
 188         struct adp5588_gpio *dev = get_irq_chip_data(irq);
 189         unsigned gpio = irq - dev->irq_base;
 190
 191         dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
 192 }
 193
 194 static int adp5588_irq_set_type(unsigned int irq, unsigned int type)
 195 {
 196         struct adp5588_gpio *dev = get_irq_chip_data(irq);
 197         uint16_t gpio = irq - dev->irq_base;
 198         unsigned bank, bit;
 199
 200         if ((type & IRQ_TYPE_EDGE_BOTH)) {
 201                 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
 202                         irq, type);
 203                 return -EINVAL;
 204         }
 205
 206         bank = ADP5588_BANK(gpio);
 207         bit = ADP5588_BIT(gpio);
 208
 209         if (type & IRQ_TYPE_LEVEL_HIGH)
 210                 dev->int_lvl[bank] |= bit;
 211         else if (type & IRQ_TYPE_LEVEL_LOW)
 212                 dev->int_lvl[bank] &= ~bit;
 213         else
 214                 return -EINVAL;
 215
 216         adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
 217         adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
 218                            dev->int_lvl[bank]);
 219
 220         return 0;
 221 }
 222
 223 static struct irq_chip adp5588_irq_chip = {
 224         .name                   = "adp5588",
 225         .mask                   = adp5588_irq_mask,
 226         .unmask                 = adp5588_irq_unmask,
 227         .bus_lock               = adp5588_irq_bus_lock,
 228         .bus_sync_unlock        = adp5588_irq_bus_sync_unlock,
 229         .set_type               = adp5588_irq_set_type,
 230 };
 231
 232 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
 233 {
 234         int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
 235
 236         if (ret < 0)
 237                 dev_err(&client->dev, "Read INT_STAT Error\n");
 238
 239         return ret;
 240 }
 241
 242 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 243 {
 244         struct adp5588_gpio *dev = devid;
 245         unsigned status, bank, bit, pending;
 246         int ret;
 247         status = adp5588_gpio_read(dev->client, INT_STAT);
 248
 249         if (status & ADP5588_GPI_INT) {
 250                 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
 251                 if (ret < 0)
 252                         memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
 253
 254                 for (bank = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
 255                         bank++, bit = 0) {
 256                         pending = dev->irq_stat[bank] & dev->irq_mask[bank];
 257
 258                         while (pending) {
 259                                 if (pending & (1 << bit)) {
 260                                         handle_nested_irq(dev->irq_base +
 261                                                           (bank << 3) + bit);
 262                                         pending &= ~(1 << bit);
 263
 264                                 }
 265                                 bit++;
 266                         }
 267                 }
 268         }
 269
 270         adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
 271
 272         return IRQ_HANDLED;
 273 }
 274
 275 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 276 {
 277         struct i2c_client *client = dev->client;
 278         struct adp5588_gpio_platform_data *pdata = client->dev.platform_data;
 279         unsigned gpio;
 280         int ret;
 281
 282         adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 283         adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 284         adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
 285
 286         dev->irq_base = pdata->irq_base;
 287         mutex_init(&dev->irq_lock);
 288
 289         for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
 290                 int irq = gpio + dev->irq_base;
 291                 set_irq_chip_data(irq, dev);
 292                 set_irq_chip_and_handler(irq, &adp5588_irq_chip,
 293                                          handle_level_irq);
 294                 set_irq_nested_thread(irq, 1);
 295 #ifdef CONFIG_ARM
 296                 /*
 297                  * ARM needs us to explicitly flag the IRQ as VALID,
 298                  * once we do so, it will also set the noprobe.
 299                  */
 300                 set_irq_flags(irq, IRQF_VALID);
 301 #else
 302                 set_irq_noprobe(irq);
 303 #endif
 304         }
 305
 306         ret = request_threaded_irq(client->irq,
 307                                    NULL,
 308                                    adp5588_irq_handler,
 309                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 310                                    dev_name(&client->dev), dev);
 311         if (ret) {
 312                 dev_err(&client->dev, "failed to request irq %d\n",
 313                         client->irq);
 314                 goto out;
 315         }
 316
 317         dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 318         adp5588_gpio_write(client, CFG,
 319                 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
 320
 321         return 0;
 322
 323 out:
 324         dev->irq_base = 0;
 325         return ret;
 326 }
 327
 328 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 329 {
 330         if (dev->irq_base)
 331                 free_irq(dev->client->irq, dev);
 332 }
 333
 334 #else
 335 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 336 {
 337         struct i2c_client *client = dev->client;
 338         dev_warn(&client->dev, "interrupt support not compiled in\n");
 339
 340         return 0;
 341 }
 342
 343 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 344 {
 345 }
 346 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 347
 348 static int __devinit adp5588_gpio_probe(struct i2c_client *client,
 349                                         const struct i2c_device_id *id)
 350 {
 351         struct adp5588_gpio_platform_data *pdata = client->dev.platform_data;
 352         struct adp5588_gpio *dev;
 353         struct gpio_chip *gc;
 354         int ret, i, revid;
 355
 356         if (pdata == NULL) {
 357                 dev_err(&client->dev, "missing platform data\n");
 358                 return -ENODEV;
 359         }
 360
 361         if (!i2c_check_functionality(client->adapter,
 362                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 363                 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 364                 return -EIO;
 365         }
 366
 367         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 368         if (dev == NULL) {
 369                 dev_err(&client->dev, "failed to alloc memory\n");
 370                 return -ENOMEM;
 371         }
 372
 373         dev->client = client;
 374
 375         gc = &dev->gpio_chip;
 376         gc->direction_input = adp5588_gpio_direction_input;
 377         gc->direction_output = adp5588_gpio_direction_output;
 378         gc->get = adp5588_gpio_get_value;
 379         gc->set = adp5588_gpio_set_value;
 380         gc->can_sleep = 1;
 381
 382         gc->base = pdata->gpio_start;
 383         gc->ngpio = ADP5588_MAXGPIO;
 384         gc->label = client->name;
 385         gc->owner = THIS_MODULE;
 386
 387         mutex_init(&dev->lock);
 388
 389         ret = adp5588_gpio_read(dev->client, DEV_ID);
 390         if (ret < 0)
 391                 goto err;
 392
 393         revid = ret & ADP5588_DEVICE_ID_MASK;
 394
 395         for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 396                 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 397                 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 398                 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 399                 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 400                                 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 401                 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 402                 if (ret)
 403                         goto err;
 404         }
 405
 406         if (pdata->irq_base) {
 407                 if (WA_DELAYED_READOUT_REVID(revid)) {
 408                         dev_warn(&client->dev, "GPIO int not supported\n");
 409                 } else {
 410                         ret = adp5588_irq_setup(dev);
 411                         if (ret)
 412                                 goto err;
 413                 }
 414         }
 415
 416         ret = gpiochip_add(&dev->gpio_chip);
 417         if (ret)
 418                 goto err_irq;
 419
 420         dev_info(&client->dev, "gpios %d..%d (IRQ Base %d) on a %s Rev. %d\n",
 421                         gc->base, gc->base + gc->ngpio - 1,
 422                         pdata->irq_base, client->name, revid);
 423
 424         if (pdata->setup) {
 425                 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 426                 if (ret < 0)
 427                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 428         }
 429
 430         i2c_set_clientdata(client, dev);
 431
 432         return 0;
 433
 434 err_irq:
 435         adp5588_irq_teardown(dev);
 436 err:
 437         kfree(dev);
 438         return ret;
 439 }
 440
 441 static int __devexit adp5588_gpio_remove(struct i2c_client *client)
 442 {
 443         struct adp5588_gpio_platform_data *pdata = client->dev.platform_data;
 444         struct adp5588_gpio *dev = i2c_get_clientdata(client);
 445         int ret;
 446
 447         if (pdata->teardown) {
 448                 ret = pdata->teardown(client,
 449                                       dev->gpio_chip.base, dev->gpio_chip.ngpio,
 450                                       pdata->context);
 451                 if (ret < 0) {
 452                         dev_err(&client->dev, "teardown failed %d\n", ret);
 453                         return ret;
 454                 }
 455         }
 456
 457         if (dev->irq_base)
 458                 free_irq(dev->client->irq, dev);
 459
 460         ret = gpiochip_remove(&dev->gpio_chip);
 461         if (ret) {
 462                 dev_err(&client->dev, "gpiochip_remove failed %d\n", ret);
 463                 return ret;
 464         }
 465
 466         kfree(dev);
 467         return 0;
 468 }
 469
 470 static const struct i2c_device_id adp5588_gpio_id[] = {
 471         {DRV_NAME, 0},
 472         {}
 473 };
 474
 475 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 476
 477 static struct i2c_driver adp5588_gpio_driver = {
 478         .driver = {
 479                    .name = DRV_NAME,
 480                    },
 481         .probe = adp5588_gpio_probe,
 482         .remove = __devexit_p(adp5588_gpio_remove),
 483         .id_table = adp5588_gpio_id,
 484 };
 485
 486 static int __init adp5588_gpio_init(void)
 487 {
 488         return i2c_add_driver(&adp5588_gpio_driver);
 489 }
 490
 491 module_init(adp5588_gpio_init);
 492
 493 static void __exit adp5588_gpio_exit(void)
 494 {
 495         i2c_del_driver(&adp5588_gpio_driver);
 496 }
 497
 498 module_exit(adp5588_gpio_exit);
 499
 500 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 501 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 502 MODULE_LICENSE("GPL");