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