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