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