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