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 #ifdef CONFIG_ARM
 309                 /*
 310                  * ARM needs us to explicitly flag the IRQ as VALID,
 311                  * once we do so, it will also set the noprobe.
 312                  */
 313                 set_irq_flags(irq, IRQF_VALID);
 314 #else
 315                 irq_set_noprobe(irq);
 316 #endif
 317         }
 318
 319         ret = request_threaded_irq(client->irq,
 320                                    NULL,
 321                                    adp5588_irq_handler,
 322                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 323                                    dev_name(&client->dev), dev);
 324         if (ret) {
 325                 dev_err(&client->dev, "failed to request irq %d\n",
 326                         client->irq);
 327                 goto out;
 328         }
 329
 330         dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 331         adp5588_gpio_write(client, CFG,
 332                 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
 333
 334         return 0;
 335
 336 out:
 337         dev->irq_base = 0;
 338         return ret;
 339 }
 340
 341 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 342 {
 343         if (dev->irq_base)
 344                 free_irq(dev->client->irq, dev);
 345 }
 346
 347 #else
 348 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 349 {
 350         struct i2c_client *client = dev->client;
 351         dev_warn(&client->dev, "interrupt support not compiled in\n");
 352
 353         return 0;
 354 }
 355
 356 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 357 {
 358 }
 359 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 360
 361 static int adp5588_gpio_probe(struct i2c_client *client,
 362                                         const struct i2c_device_id *id)
 363 {
 364         struct adp5588_gpio_platform_data *pdata =
 365                         dev_get_platdata(&client->dev);
 366         struct adp5588_gpio *dev;
 367         struct gpio_chip *gc;
 368         int ret, i, revid;
 369
 370         if (pdata == NULL) {
 371                 dev_err(&client->dev, "missing platform data\n");
 372                 return -ENODEV;
 373         }
 374
 375         if (!i2c_check_functionality(client->adapter,
 376                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 377                 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 378                 return -EIO;
 379         }
 380
 381         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 382         if (dev == NULL) {
 383                 dev_err(&client->dev, "failed to alloc memory\n");
 384                 return -ENOMEM;
 385         }
 386
 387         dev->client = client;
 388
 389         gc = &dev->gpio_chip;
 390         gc->direction_input = adp5588_gpio_direction_input;
 391         gc->direction_output = adp5588_gpio_direction_output;
 392         gc->get = adp5588_gpio_get_value;
 393         gc->set = adp5588_gpio_set_value;
 394         gc->can_sleep = true;
 395
 396         gc->base = pdata->gpio_start;
 397         gc->ngpio = ADP5588_MAXGPIO;
 398         gc->label = client->name;
 399         gc->owner = THIS_MODULE;
 400         gc->names = pdata->names;
 401
 402         mutex_init(&dev->lock);
 403
 404         ret = adp5588_gpio_read(dev->client, DEV_ID);
 405         if (ret < 0)
 406                 goto err;
 407
 408         revid = ret & ADP5588_DEVICE_ID_MASK;
 409
 410         for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 411                 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 412                 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 413                 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 414                 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 415                                 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 416                 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 417                 if (ret)
 418                         goto err;
 419         }
 420
 421         if (pdata->irq_base) {
 422                 if (WA_DELAYED_READOUT_REVID(revid)) {
 423                         dev_warn(&client->dev, "GPIO int not supported\n");
 424                 } else {
 425                         ret = adp5588_irq_setup(dev);
 426                         if (ret)
 427                                 goto err;
 428                 }
 429         }
 430
 431         ret = gpiochip_add(&dev->gpio_chip);
 432         if (ret)
 433                 goto err_irq;
 434
 435         dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
 436                         pdata->irq_base, revid);
 437
 438         if (pdata->setup) {
 439                 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 440                 if (ret < 0)
 441                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 442         }
 443
 444         i2c_set_clientdata(client, dev);
 445
 446         return 0;
 447
 448 err_irq:
 449         adp5588_irq_teardown(dev);
 450 err:
 451         kfree(dev);
 452         return ret;
 453 }
 454
 455 static int adp5588_gpio_remove(struct i2c_client *client)
 456 {
 457         struct adp5588_gpio_platform_data *pdata =
 458                         dev_get_platdata(&client->dev);
 459         struct adp5588_gpio *dev = i2c_get_clientdata(client);
 460         int ret;
 461
 462         if (pdata->teardown) {
 463                 ret = pdata->teardown(client,
 464                                       dev->gpio_chip.base, dev->gpio_chip.ngpio,
 465                                       pdata->context);
 466                 if (ret < 0) {
 467                         dev_err(&client->dev, "teardown failed %d\n", ret);
 468                         return ret;
 469                 }
 470         }
 471
 472         if (dev->irq_base)
 473                 free_irq(dev->client->irq, dev);
 474
 475         ret = gpiochip_remove(&dev->gpio_chip);
 476         if (ret) {
 477                 dev_err(&client->dev, "gpiochip_remove failed %d\n", ret);
 478                 return ret;
 479         }
 480
 481         kfree(dev);
 482         return 0;
 483 }
 484
 485 static const struct i2c_device_id adp5588_gpio_id[] = {
 486         {DRV_NAME, 0},
 487         {}
 488 };
 489
 490 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 491
 492 static struct i2c_driver adp5588_gpio_driver = {
 493         .driver = {
 494                    .name = DRV_NAME,
 495                    },
 496         .probe = adp5588_gpio_probe,
 497         .remove = adp5588_gpio_remove,
 498         .id_table = adp5588_gpio_id,
 499 };
 500
 501 module_i2c_driver(adp5588_gpio_driver);
 502
 503 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 504 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 505 MODULE_LICENSE("GPL");