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/driver.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h>
  18
  19 #include <linux/platform_data/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 = gpiochip_get_data(chip);
  71         unsigned bank = ADP5588_BANK(off);
  72         unsigned bit = ADP5588_BIT(off);
  73         int val;
  74
  75         mutex_lock(&dev->lock);
  76
  77         if (dev->dir[bank] & bit)
  78                 val = dev->dat_out[bank];
  79         else
  80                 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
  81
  82         mutex_unlock(&dev->lock);
  83
  84         return !!(val & bit);
  85 }
  86
  87 static void adp5588_gpio_set_value(struct gpio_chip *chip,
  88                                    unsigned off, int val)
  89 {
  90         unsigned bank, bit;
  91         struct adp5588_gpio *dev = gpiochip_get_data(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 = gpiochip_get_data(chip);
 112
 113         bank = ADP5588_BANK(off);
 114
 115         mutex_lock(&dev->lock);
 116         dev->dir[bank] &= ~ADP5588_BIT(off);
 117         ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
 118         mutex_unlock(&dev->lock);
 119
 120         return ret;
 121 }
 122
 123 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
 124                                          unsigned off, int val)
 125 {
 126         int ret;
 127         unsigned bank, bit;
 128         struct adp5588_gpio *dev = gpiochip_get_data(chip);
 129
 130         bank = ADP5588_BANK(off);
 131         bit = ADP5588_BIT(off);
 132
 133         mutex_lock(&dev->lock);
 134         dev->dir[bank] |= bit;
 135
 136         if (val)
 137                 dev->dat_out[bank] |= bit;
 138         else
 139                 dev->dat_out[bank] &= ~bit;
 140
 141         ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 142                                  dev->dat_out[bank]);
 143         ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
 144                                  dev->dir[bank]);
 145         mutex_unlock(&dev->lock);
 146
 147         return ret;
 148 }
 149
 150 #ifdef CONFIG_GPIO_ADP5588_IRQ
 151 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
 152 {
 153         struct adp5588_gpio *dev = gpiochip_get_data(chip);
 154
 155         return dev->irq_base + off;
 156 }
 157
 158 static void adp5588_irq_bus_lock(struct irq_data *d)
 159 {
 160         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 161
 162         mutex_lock(&dev->irq_lock);
 163 }
 164
 165  /*
 166   * genirq core code can issue chip->mask/unmask from atomic context.
 167   * This doesn't work for slow busses where an access needs to sleep.
 168   * bus_sync_unlock() is therefore called outside the atomic context,
 169   * syncs the current irq mask state with the slow external controller
 170   * and unlocks the bus.
 171   */
 172
 173 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 174 {
 175         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 176         int i;
 177
 178         for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 179                 if (dev->int_input_en[i]) {
 180                         mutex_lock(&dev->lock);
 181                         dev->dir[i] &= ~dev->int_input_en[i];
 182                         dev->int_input_en[i] = 0;
 183                         adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
 184                                            dev->dir[i]);
 185                         mutex_unlock(&dev->lock);
 186                 }
 187
 188                 if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
 189                         dev->int_lvl_cached[i] = dev->int_lvl[i];
 190                         adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
 191                                            dev->int_lvl[i]);
 192                 }
 193
 194                 if (dev->int_en[i] ^ dev->irq_mask[i]) {
 195                         dev->int_en[i] = dev->irq_mask[i];
 196                         adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 197                                            dev->int_en[i]);
 198                 }
 199         }
 200
 201         mutex_unlock(&dev->irq_lock);
 202 }
 203
 204 static void adp5588_irq_mask(struct irq_data *d)
 205 {
 206         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 207         unsigned gpio = d->irq - dev->irq_base;
 208
 209         dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
 210 }
 211
 212 static void adp5588_irq_unmask(struct irq_data *d)
 213 {
 214         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 215         unsigned gpio = d->irq - dev->irq_base;
 216
 217         dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
 218 }
 219
 220 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 221 {
 222         struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 223         uint16_t gpio = d->irq - dev->irq_base;
 224         unsigned bank, bit;
 225
 226         if ((type & IRQ_TYPE_EDGE_BOTH)) {
 227                 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
 228                         d->irq, type);
 229                 return -EINVAL;
 230         }
 231
 232         bank = ADP5588_BANK(gpio);
 233         bit = ADP5588_BIT(gpio);
 234
 235         if (type & IRQ_TYPE_LEVEL_HIGH)
 236                 dev->int_lvl[bank] |= bit;
 237         else if (type & IRQ_TYPE_LEVEL_LOW)
 238                 dev->int_lvl[bank] &= ~bit;
 239         else
 240                 return -EINVAL;
 241
 242         dev->int_input_en[bank] |= bit;
 243
 244         return 0;
 245 }
 246
 247 static struct irq_chip adp5588_irq_chip = {
 248         .name                   = "adp5588",
 249         .irq_mask               = adp5588_irq_mask,
 250         .irq_unmask             = adp5588_irq_unmask,
 251         .irq_bus_lock           = adp5588_irq_bus_lock,
 252         .irq_bus_sync_unlock    = adp5588_irq_bus_sync_unlock,
 253         .irq_set_type           = adp5588_irq_set_type,
 254 };
 255
 256 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
 257 {
 258         int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
 259
 260         if (ret < 0)
 261                 dev_err(&client->dev, "Read INT_STAT Error\n");
 262
 263         return ret;
 264 }
 265
 266 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 267 {
 268         struct adp5588_gpio *dev = devid;
 269         unsigned status, bank, bit, pending;
 270         int ret;
 271         status = adp5588_gpio_read(dev->client, INT_STAT);
 272
 273         if (status & ADP5588_GPI_INT) {
 274                 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
 275                 if (ret < 0)
 276                         memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
 277
 278                 for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
 279                         bank++, bit = 0) {
 280                         pending = dev->irq_stat[bank] & dev->irq_mask[bank];
 281
 282                         while (pending) {
 283                                 if (pending & (1 << bit)) {
 284                                         handle_nested_irq(dev->irq_base +
 285                                                           (bank << 3) + bit);
 286                                         pending &= ~(1 << bit);
 287
 288                                 }
 289                                 bit++;
 290                         }
 291                 }
 292         }
 293
 294         adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
 295
 296         return IRQ_HANDLED;
 297 }
 298
 299 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 300 {
 301         struct i2c_client *client = dev->client;
 302         struct adp5588_gpio_platform_data *pdata =
 303                         dev_get_platdata(&client->dev);
 304         unsigned gpio;
 305         int ret;
 306
 307         adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 308         adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 309         adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
 310
 311         dev->irq_base = pdata->irq_base;
 312         mutex_init(&dev->irq_lock);
 313
 314         for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
 315                 int irq = gpio + dev->irq_base;
 316                 irq_set_chip_data(irq, dev);
 317                 irq_set_chip_and_handler(irq, &adp5588_irq_chip,
 318                                          handle_level_irq);
 319                 irq_set_nested_thread(irq, 1);
 320                 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
 321         }
 322
 323         ret = request_threaded_irq(client->irq,
 324                                    NULL,
 325                                    adp5588_irq_handler,
 326                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 327                                    dev_name(&client->dev), dev);
 328         if (ret) {
 329                 dev_err(&client->dev, "failed to request irq %d\n",
 330                         client->irq);
 331                 goto out;
 332         }
 333
 334         dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 335         adp5588_gpio_write(client, CFG,
 336                 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
 337
 338         return 0;
 339
 340 out:
 341         dev->irq_base = 0;
 342         return ret;
 343 }
 344
 345 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 346 {
 347         if (dev->irq_base)
 348                 free_irq(dev->client->irq, dev);
 349 }
 350
 351 #else
 352 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 353 {
 354         struct i2c_client *client = dev->client;
 355         dev_warn(&client->dev, "interrupt support not compiled in\n");
 356
 357         return 0;
 358 }
 359
 360 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 361 {
 362 }
 363 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 364
 365 static int adp5588_gpio_probe(struct i2c_client *client,
 366                                         const struct i2c_device_id *id)
 367 {
 368         struct adp5588_gpio_platform_data *pdata =
 369                         dev_get_platdata(&client->dev);
 370         struct adp5588_gpio *dev;
 371         struct gpio_chip *gc;
 372         int ret, i, revid;
 373
 374         if (!pdata) {
 375                 dev_err(&client->dev, "missing platform data\n");
 376                 return -ENODEV;
 377         }
 378
 379         if (!i2c_check_functionality(client->adapter,
 380                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 381                 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 382                 return -EIO;
 383         }
 384
 385         dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
 386         if (!dev)
 387                 return -ENOMEM;
 388
 389         dev->client = client;
 390
 391         gc = &dev->gpio_chip;
 392         gc->direction_input = adp5588_gpio_direction_input;
 393         gc->direction_output = adp5588_gpio_direction_output;
 394         gc->get = adp5588_gpio_get_value;
 395         gc->set = adp5588_gpio_set_value;
 396         gc->can_sleep = true;
 397
 398         gc->base = pdata->gpio_start;
 399         gc->ngpio = ADP5588_MAXGPIO;
 400         gc->label = client->name;
 401         gc->owner = THIS_MODULE;
 402         gc->names = pdata->names;
 403
 404         mutex_init(&dev->lock);
 405
 406         ret = adp5588_gpio_read(dev->client, DEV_ID);
 407         if (ret < 0)
 408                 goto err;
 409
 410         revid = ret & ADP5588_DEVICE_ID_MASK;
 411
 412         for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 413                 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 414                 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 415                 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 416                 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 417                                 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 418                 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 419                 if (ret)
 420                         goto err;
 421         }
 422
 423         if (pdata->irq_base) {
 424                 if (WA_DELAYED_READOUT_REVID(revid)) {
 425                         dev_warn(&client->dev, "GPIO int not supported\n");
 426                 } else {
 427                         ret = adp5588_irq_setup(dev);
 428                         if (ret)
 429                                 goto err;
 430                 }
 431         }
 432
 433         ret = devm_gpiochip_add_data(&client->dev, &dev->gpio_chip, dev);
 434         if (ret)
 435                 goto err_irq;
 436
 437         dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
 438                         pdata->irq_base, revid);
 439
 440         if (pdata->setup) {
 441                 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 442                 if (ret < 0)
 443                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 444         }
 445
 446         i2c_set_clientdata(client, dev);
 447
 448         return 0;
 449
 450 err_irq:
 451         adp5588_irq_teardown(dev);
 452 err:
 453         return ret;
 454 }
 455
 456 static int adp5588_gpio_remove(struct i2c_client *client)
 457 {
 458         struct adp5588_gpio_platform_data *pdata =
 459                         dev_get_platdata(&client->dev);
 460         struct adp5588_gpio *dev = i2c_get_clientdata(client);
 461         int ret;
 462
 463         if (pdata->teardown) {
 464                 ret = pdata->teardown(client,
 465                                       dev->gpio_chip.base, dev->gpio_chip.ngpio,
 466                                       pdata->context);
 467                 if (ret < 0) {
 468                         dev_err(&client->dev, "teardown failed %d\n", ret);
 469                         return ret;
 470                 }
 471         }
 472
 473         if (dev->irq_base)
 474                 free_irq(dev->client->irq, dev);
 475
 476         return 0;
 477 }
 478
 479 static const struct i2c_device_id adp5588_gpio_id[] = {
 480         {DRV_NAME, 0},
 481         {}
 482 };
 483
 484 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 485
 486 static struct i2c_driver adp5588_gpio_driver = {
 487         .driver = {
 488                    .name = DRV_NAME,
 489                    },
 490         .probe = adp5588_gpio_probe,
 491         .remove = adp5588_gpio_remove,
 492         .id_table = adp5588_gpio_id,
 493 };
 494
 495 module_i2c_driver(adp5588_gpio_driver);
 496
 497 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 498 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 499 MODULE_LICENSE("GPL");