drivers/gpio/pca953x.c

   1 /*
   2  *  pca953x.c - 4/8/16 bit I/O ports
   3  *
   4  *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
   5  *  Copyright (C) 2007 Marvell International Ltd.
   6  *
   7  *  Derived from drivers/i2c/chips/pca9539.c
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; version 2 of the License.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/gpio.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/i2c.h>
  20 #include <linux/i2c/pca953x.h>
  21 #include <linux/slab.h>
  22 #ifdef CONFIG_OF_GPIO
  23 #include <linux/of_platform.h>
  24 #include <linux/of_gpio.h>
  25 #endif
  26
  27 #define PCA953X_INPUT          0
  28 #define PCA953X_OUTPUT         1
  29 #define PCA953X_INVERT         2
  30 #define PCA953X_DIRECTION      3
  31
  32 #define PCA953X_GPIOS          0x00FF
  33 #define PCA953X_INT            0x0100
  34
  35 static const struct i2c_device_id pca953x_id[] = {
  36         { "pca9534", 8  | PCA953X_INT, },
  37         { "pca9535", 16 | PCA953X_INT, },
  38         { "pca9536", 4, },
  39         { "pca9537", 4  | PCA953X_INT, },
  40         { "pca9538", 8  | PCA953X_INT, },
  41         { "pca9539", 16 | PCA953X_INT, },
  42         { "pca9554", 8  | PCA953X_INT, },
  43         { "pca9555", 16 | PCA953X_INT, },
  44         { "pca9556", 8, },
  45         { "pca9557", 8, },
  46
  47         { "max7310", 8, },
  48         { "max7312", 16 | PCA953X_INT, },
  49         { "max7313", 16 | PCA953X_INT, },
  50         { "max7315", 8  | PCA953X_INT, },
  51         { "pca6107", 8  | PCA953X_INT, },
  52         { "tca6408", 8  | PCA953X_INT, },
  53         { "tca6416", 16 | PCA953X_INT, },
  54         /* NYET:  { "tca6424", 24, }, */
  55         { }
  56 };
  57 MODULE_DEVICE_TABLE(i2c, pca953x_id);
  58
  59 struct pca953x_chip {
  60         unsigned gpio_start;
  61         uint16_t reg_output;
  62         uint16_t reg_direction;
  63         struct mutex i2c_lock;
  64
  65 #ifdef CONFIG_GPIO_PCA953X_IRQ
  66         struct mutex irq_lock;
  67         uint16_t irq_mask;
  68         uint16_t irq_stat;
  69         uint16_t irq_trig_raise;
  70         uint16_t irq_trig_fall;
  71         int      irq_base;
  72 #endif
  73
  74         struct i2c_client *client;
  75         struct pca953x_platform_data *dyn_pdata;
  76         struct gpio_chip gpio_chip;
  77         const char *const *names;
  78 };
  79
  80 static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
  81 {
  82         int ret;
  83
  84         if (chip->gpio_chip.ngpio <= 8)
  85                 ret = i2c_smbus_write_byte_data(chip->client, reg, val);
  86         else
  87                 ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
  88
  89         if (ret < 0) {
  90                 dev_err(&chip->client->dev, "failed writing register\n");
  91                 return ret;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
  98 {
  99         int ret;
 100
 101         if (chip->gpio_chip.ngpio <= 8)
 102                 ret = i2c_smbus_read_byte_data(chip->client, reg);
 103         else
 104                 ret = i2c_smbus_read_word_data(chip->client, reg << 1);
 105
 106         if (ret < 0) {
 107                 dev_err(&chip->client->dev, "failed reading register\n");
 108                 return ret;
 109         }
 110
 111         *val = (uint16_t)ret;
 112         return 0;
 113 }
 114
 115 static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
 116 {
 117         struct pca953x_chip *chip;
 118         uint16_t reg_val;
 119         int ret;
 120
 121         chip = container_of(gc, struct pca953x_chip, gpio_chip);
 122
 123         mutex_lock(&chip->i2c_lock);
 124         reg_val = chip->reg_direction | (1u << off);
 125         ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
 126         if (ret)
 127                 goto exit;
 128
 129         chip->reg_direction = reg_val;
 130         ret = 0;
 131 exit:
 132         mutex_unlock(&chip->i2c_lock);
 133         return ret;
 134 }
 135
 136 static int pca953x_gpio_direction_output(struct gpio_chip *gc,
 137                 unsigned off, int val)
 138 {
 139         struct pca953x_chip *chip;
 140         uint16_t reg_val;
 141         int ret;
 142
 143         chip = container_of(gc, struct pca953x_chip, gpio_chip);
 144
 145         mutex_lock(&chip->i2c_lock);
 146         /* set output level */
 147         if (val)
 148                 reg_val = chip->reg_output | (1u << off);
 149         else
 150                 reg_val = chip->reg_output & ~(1u << off);
 151
 152         ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
 153         if (ret)
 154                 goto exit;
 155
 156         chip->reg_output = reg_val;
 157
 158         /* then direction */
 159         reg_val = chip->reg_direction & ~(1u << off);
 160         ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
 161         if (ret)
 162                 goto exit;
 163
 164         chip->reg_direction = reg_val;
 165         ret = 0;
 166 exit:
 167         mutex_unlock(&chip->i2c_lock);
 168         return ret;
 169 }
 170
 171 static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 172 {
 173         struct pca953x_chip *chip;
 174         uint16_t reg_val;
 175         int ret;
 176
 177         chip = container_of(gc, struct pca953x_chip, gpio_chip);
 178
 179         mutex_lock(&chip->i2c_lock);
 180         ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
 181         mutex_unlock(&chip->i2c_lock);
 182         if (ret < 0) {
 183                 /* NOTE:  diagnostic already emitted; that's all we should
 184                  * do unless gpio_*_value_cansleep() calls become different
 185                  * from their nonsleeping siblings (and report faults).
 186                  */
 187                 return 0;
 188         }
 189
 190         return (reg_val & (1u << off)) ? 1 : 0;
 191 }
 192
 193 static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
 194 {
 195         struct pca953x_chip *chip;
 196         uint16_t reg_val;
 197         int ret;
 198
 199         chip = container_of(gc, struct pca953x_chip, gpio_chip);
 200
 201         mutex_lock(&chip->i2c_lock);
 202         if (val)
 203                 reg_val = chip->reg_output | (1u << off);
 204         else
 205                 reg_val = chip->reg_output & ~(1u << off);
 206
 207         ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
 208         if (ret)
 209                 goto exit;
 210
 211         chip->reg_output = reg_val;
 212 exit:
 213         mutex_unlock(&chip->i2c_lock);
 214 }
 215
 216 static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
 217 {
 218         struct gpio_chip *gc;
 219
 220         gc = &chip->gpio_chip;
 221
 222         gc->direction_input  = pca953x_gpio_direction_input;
 223         gc->direction_output = pca953x_gpio_direction_output;
 224         gc->get = pca953x_gpio_get_value;
 225         gc->set = pca953x_gpio_set_value;
 226         gc->can_sleep = 1;
 227
 228         gc->base = chip->gpio_start;
 229         gc->ngpio = gpios;
 230         gc->label = chip->client->name;
 231         gc->dev = &chip->client->dev;
 232         gc->owner = THIS_MODULE;
 233         gc->names = chip->names;
 234 }
 235
 236 #ifdef CONFIG_GPIO_PCA953X_IRQ
 237 static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
 238 {
 239         struct pca953x_chip *chip;
 240
 241         chip = container_of(gc, struct pca953x_chip, gpio_chip);
 242         return chip->irq_base + off;
 243 }
 244
 245 static void pca953x_irq_mask(struct irq_data *d)
 246 {
 247         struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
 248
 249         chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
 250 }
 251
 252 static void pca953x_irq_unmask(struct irq_data *d)
 253 {
 254         struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
 255
 256         chip->irq_mask |= 1 << (d->irq - chip->irq_base);
 257 }
 258
 259 static void pca953x_irq_bus_lock(struct irq_data *d)
 260 {
 261         struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
 262
 263         mutex_lock(&chip->irq_lock);
 264 }
 265
 266 static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
 267 {
 268         struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
 269         uint16_t new_irqs;
 270         uint16_t level;
 271
 272         /* Look for any newly setup interrupt */
 273         new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
 274         new_irqs &= ~chip->reg_direction;
 275
 276         while (new_irqs) {
 277                 level = __ffs(new_irqs);
 278                 pca953x_gpio_direction_input(&chip->gpio_chip, level);
 279                 new_irqs &= ~(1 << level);
 280         }
 281
 282         mutex_unlock(&chip->irq_lock);
 283 }
 284
 285 static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
 286 {
 287         struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
 288         uint16_t level = d->irq - chip->irq_base;
 289         uint16_t mask = 1 << level;
 290
 291         if (!(type & IRQ_TYPE_EDGE_BOTH)) {
 292                 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
 293                         d->irq, type);
 294                 return -EINVAL;
 295         }
 296
 297         if (type & IRQ_TYPE_EDGE_FALLING)
 298                 chip->irq_trig_fall |= mask;
 299         else
 300                 chip->irq_trig_fall &= ~mask;
 301
 302         if (type & IRQ_TYPE_EDGE_RISING)
 303                 chip->irq_trig_raise |= mask;
 304         else
 305                 chip->irq_trig_raise &= ~mask;
 306
 307         return 0;
 308 }
 309
 310 static struct irq_chip pca953x_irq_chip = {
 311         .name                   = "pca953x",
 312         .irq_mask               = pca953x_irq_mask,
 313         .irq_unmask             = pca953x_irq_unmask,
 314         .irq_bus_lock           = pca953x_irq_bus_lock,
 315         .irq_bus_sync_unlock    = pca953x_irq_bus_sync_unlock,
 316         .irq_set_type           = pca953x_irq_set_type,
 317 };
 318
 319 static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
 320 {
 321         uint16_t cur_stat;
 322         uint16_t old_stat;
 323         uint16_t pending;
 324         uint16_t trigger;
 325         int ret;
 326
 327         ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
 328         if (ret)
 329                 return 0;
 330
 331         /* Remove output pins from the equation */
 332         cur_stat &= chip->reg_direction;
 333
 334         old_stat = chip->irq_stat;
 335         trigger = (cur_stat ^ old_stat) & chip->irq_mask;
 336
 337         if (!trigger)
 338                 return 0;
 339
 340         chip->irq_stat = cur_stat;
 341
 342         pending = (old_stat & chip->irq_trig_fall) |
 343                   (cur_stat & chip->irq_trig_raise);
 344         pending &= trigger;
 345
 346         return pending;
 347 }
 348
 349 static irqreturn_t pca953x_irq_handler(int irq, void *devid)
 350 {
 351         struct pca953x_chip *chip = devid;
 352         uint16_t pending;
 353         uint16_t level;
 354
 355         pending = pca953x_irq_pending(chip);
 356
 357         if (!pending)
 358                 return IRQ_HANDLED;
 359
 360         do {
 361                 level = __ffs(pending);
 362                 generic_handle_irq(level + chip->irq_base);
 363
 364                 pending &= ~(1 << level);
 365         } while (pending);
 366
 367         return IRQ_HANDLED;
 368 }
 369
 370 static int pca953x_irq_setup(struct pca953x_chip *chip,
 371                              const struct i2c_device_id *id)
 372 {
 373         struct i2c_client *client = chip->client;
 374         struct pca953x_platform_data *pdata = client->dev.platform_data;
 375         int ret;
 376
 377         if (pdata->irq_base != -1
 378                         && (id->driver_data & PCA953X_INT)) {
 379                 int lvl;
 380
 381                 ret = pca953x_read_reg(chip, PCA953X_INPUT,
 382                                        &chip->irq_stat);
 383                 if (ret)
 384                         goto out_failed;
 385
 386                 /*
 387                  * There is no way to know which GPIO line generated the
 388                  * interrupt.  We have to rely on the previous read for
 389                  * this purpose.
 390                  */
 391                 chip->irq_stat &= chip->reg_direction;
 392                 chip->irq_base = pdata->irq_base;
 393                 mutex_init(&chip->irq_lock);
 394
 395                 for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
 396                         int irq = lvl + chip->irq_base;
 397
 398                         set_irq_chip_data(irq, chip);
 399                         set_irq_chip_and_handler(irq, &pca953x_irq_chip,
 400                                                  handle_edge_irq);
 401 #ifdef CONFIG_ARM
 402                         set_irq_flags(irq, IRQF_VALID);
 403 #else
 404                         set_irq_noprobe(irq);
 405 #endif
 406                 }
 407
 408                 ret = request_threaded_irq(client->irq,
 409                                            NULL,
 410                                            pca953x_irq_handler,
 411                                            IRQF_TRIGGER_RISING |
 412                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 413                                            dev_name(&client->dev), chip);
 414                 if (ret) {
 415                         dev_err(&client->dev, "failed to request irq %d\n",
 416                                 client->irq);
 417                         goto out_failed;
 418                 }
 419
 420                 chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
 421         }
 422
 423         return 0;
 424
 425 out_failed:
 426         chip->irq_base = -1;
 427         return ret;
 428 }
 429
 430 static void pca953x_irq_teardown(struct pca953x_chip *chip)
 431 {
 432         if (chip->irq_base != -1)
 433                 free_irq(chip->client->irq, chip);
 434 }
 435 #else /* CONFIG_GPIO_PCA953X_IRQ */
 436 static int pca953x_irq_setup(struct pca953x_chip *chip,
 437                              const struct i2c_device_id *id)
 438 {
 439         struct i2c_client *client = chip->client;
 440         struct pca953x_platform_data *pdata = client->dev.platform_data;
 441
 442         if (pdata->irq_base != -1 && (id->driver_data & PCA953X_INT))
 443                 dev_warn(&client->dev, "interrupt support not compiled in\n");
 444
 445         return 0;
 446 }
 447
 448 static void pca953x_irq_teardown(struct pca953x_chip *chip)
 449 {
 450 }
 451 #endif
 452
 453 /*
 454  * Handlers for alternative sources of platform_data
 455  */
 456 #ifdef CONFIG_OF_GPIO
 457 /*
 458  * Translate OpenFirmware node properties into platform_data
 459  */
 460 static struct pca953x_platform_data *
 461 pca953x_get_alt_pdata(struct i2c_client *client)
 462 {
 463         struct pca953x_platform_data *pdata;
 464         struct device_node *node;
 465         const uint16_t *val;
 466
 467         node = client->dev.of_node;
 468         if (node == NULL)
 469                 return NULL;
 470
 471         pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
 472         if (pdata == NULL) {
 473                 dev_err(&client->dev, "Unable to allocate platform_data\n");
 474                 return NULL;
 475         }
 476
 477         pdata->gpio_base = -1;
 478         val = of_get_property(node, "linux,gpio-base", NULL);
 479         if (val) {
 480                 if (*val < 0)
 481                         dev_warn(&client->dev,
 482                                  "invalid gpio-base in device tree\n");
 483                 else
 484                         pdata->gpio_base = *val;
 485         }
 486
 487         val = of_get_property(node, "polarity", NULL);
 488         if (val)
 489                 pdata->invert = *val;
 490
 491         return pdata;
 492 }
 493 #else
 494 static struct pca953x_platform_data *
 495 pca953x_get_alt_pdata(struct i2c_client *client)
 496 {
 497         return NULL;
 498 }
 499 #endif
 500
 501 static int __devinit pca953x_probe(struct i2c_client *client,
 502                                    const struct i2c_device_id *id)
 503 {
 504         struct pca953x_platform_data *pdata;
 505         struct pca953x_chip *chip;
 506         int ret;
 507
 508         chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
 509         if (chip == NULL)
 510                 return -ENOMEM;
 511
 512         pdata = client->dev.platform_data;
 513         if (pdata == NULL) {
 514                 pdata = pca953x_get_alt_pdata(client);
 515                 /*
 516                  * Unlike normal platform_data, this is allocated
 517                  * dynamically and must be freed in the driver
 518                  */
 519                 chip->dyn_pdata = pdata;
 520         }
 521
 522         if (pdata == NULL) {
 523                 dev_dbg(&client->dev, "no platform data\n");
 524                 ret = -EINVAL;
 525                 goto out_failed;
 526         }
 527
 528         chip->client = client;
 529
 530         chip->gpio_start = pdata->gpio_base;
 531
 532         chip->names = pdata->names;
 533
 534         mutex_init(&chip->i2c_lock);
 535
 536         /* initialize cached registers from their original values.
 537          * we can't share this chip with another i2c master.
 538          */
 539         pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);
 540
 541         ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
 542         if (ret)
 543                 goto out_failed;
 544
 545         ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
 546         if (ret)
 547                 goto out_failed;
 548
 549         /* set platform specific polarity inversion */
 550         ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
 551         if (ret)
 552                 goto out_failed;
 553
 554         ret = pca953x_irq_setup(chip, id);
 555         if (ret)
 556                 goto out_failed;
 557
 558         ret = gpiochip_add(&chip->gpio_chip);
 559         if (ret)
 560                 goto out_failed;
 561
 562         if (pdata->setup) {
 563                 ret = pdata->setup(client, chip->gpio_chip.base,
 564                                 chip->gpio_chip.ngpio, pdata->context);
 565                 if (ret < 0)
 566                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 567         }
 568
 569         i2c_set_clientdata(client, chip);
 570         return 0;
 571
 572 out_failed:
 573         pca953x_irq_teardown(chip);
 574         kfree(chip->dyn_pdata);
 575         kfree(chip);
 576         return ret;
 577 }
 578
 579 static int pca953x_remove(struct i2c_client *client)
 580 {
 581         struct pca953x_platform_data *pdata = client->dev.platform_data;
 582         struct pca953x_chip *chip = i2c_get_clientdata(client);
 583         int ret = 0;
 584
 585         if (pdata->teardown) {
 586                 ret = pdata->teardown(client, chip->gpio_chip.base,
 587                                 chip->gpio_chip.ngpio, pdata->context);
 588                 if (ret < 0) {
 589                         dev_err(&client->dev, "%s failed, %d\n",
 590                                         "teardown", ret);
 591                         return ret;
 592                 }
 593         }
 594
 595         ret = gpiochip_remove(&chip->gpio_chip);
 596         if (ret) {
 597                 dev_err(&client->dev, "%s failed, %d\n",
 598                                 "gpiochip_remove()", ret);
 599                 return ret;
 600         }
 601
 602         pca953x_irq_teardown(chip);
 603         kfree(chip->dyn_pdata);
 604         kfree(chip);
 605         return 0;
 606 }
 607
 608 static struct i2c_driver pca953x_driver = {
 609         .driver = {
 610                 .name   = "pca953x",
 611         },
 612         .probe          = pca953x_probe,
 613         .remove         = pca953x_remove,
 614         .id_table       = pca953x_id,
 615 };
 616
 617 static int __init pca953x_init(void)
 618 {
 619         return i2c_add_driver(&pca953x_driver);
 620 }
 621 /* register after i2c postcore initcall and before
 622  * subsys initcalls that may rely on these GPIOs
 623  */
 624 subsys_initcall(pca953x_init);
 625
 626 static void __exit pca953x_exit(void)
 627 {
 628         i2c_del_driver(&pca953x_driver);
 629 }
 630 module_exit(pca953x_exit);
 631
 632 MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
 633 MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
 634 MODULE_LICENSE("GPL");