drivers/gpio/ab8500-gpio.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2011
   3  *
   4  * Author: BIBEK BASU <bibek.basu@stericsson.com>
   5  * License terms: GNU General Public License (GPL) version 2
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/types.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/err.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <linux/gpio.h>
  20 #include <linux/irq.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/mfd/ab8500.h>
  23 #include <linux/mfd/abx500.h>
  24 #include <linux/mfd/ab8500/gpio.h>
  25
  26 /*
  27  * GPIO registers offset
  28  * Bank: 0x10
  29  */
  30 #define AB8500_GPIO_SEL1_REG    0x00
  31 #define AB8500_GPIO_SEL2_REG    0x01
  32 #define AB8500_GPIO_SEL3_REG    0x02
  33 #define AB8500_GPIO_SEL4_REG    0x03
  34 #define AB8500_GPIO_SEL5_REG    0x04
  35 #define AB8500_GPIO_SEL6_REG    0x05
  36
  37 #define AB8500_GPIO_DIR1_REG    0x10
  38 #define AB8500_GPIO_DIR2_REG    0x11
  39 #define AB8500_GPIO_DIR3_REG    0x12
  40 #define AB8500_GPIO_DIR4_REG    0x13
  41 #define AB8500_GPIO_DIR5_REG    0x14
  42 #define AB8500_GPIO_DIR6_REG    0x15
  43
  44 #define AB8500_GPIO_OUT1_REG    0x20
  45 #define AB8500_GPIO_OUT2_REG    0x21
  46 #define AB8500_GPIO_OUT3_REG    0x22
  47 #define AB8500_GPIO_OUT4_REG    0x23
  48 #define AB8500_GPIO_OUT5_REG    0x24
  49 #define AB8500_GPIO_OUT6_REG    0x25
  50
  51 #define AB8500_GPIO_PUD1_REG    0x30
  52 #define AB8500_GPIO_PUD2_REG    0x31
  53 #define AB8500_GPIO_PUD3_REG    0x32
  54 #define AB8500_GPIO_PUD4_REG    0x33
  55 #define AB8500_GPIO_PUD5_REG    0x34
  56 #define AB8500_GPIO_PUD6_REG    0x35
  57
  58 #define AB8500_GPIO_IN1_REG     0x40
  59 #define AB8500_GPIO_IN2_REG     0x41
  60 #define AB8500_GPIO_IN3_REG     0x42
  61 #define AB8500_GPIO_IN4_REG     0x43
  62 #define AB8500_GPIO_IN5_REG     0x44
  63 #define AB8500_GPIO_IN6_REG     0x45
  64 #define AB8500_GPIO_ALTFUN_REG  0x45
  65 #define ALTFUN_REG_INDEX        6
  66 #define AB8500_NUM_GPIO         42
  67 #define AB8500_NUM_VIR_GPIO_IRQ 16
  68
  69 enum ab8500_gpio_action {
  70         NONE,
  71         STARTUP,
  72         SHUTDOWN,
  73         MASK,
  74         UNMASK
  75 };
  76
  77 struct ab8500_gpio {
  78         struct gpio_chip chip;
  79         struct ab8500 *parent;
  80         struct device *dev;
  81         struct mutex lock;
  82         u32 irq_base;
  83         enum ab8500_gpio_action irq_action;
  84         u16 rising;
  85         u16 falling;
  86 };
  87 /**
  88  * to_ab8500_gpio() - get the pointer to ab8500_gpio
  89  * @chip:       Member of the structure ab8500_gpio
  90  */
  91 static inline struct ab8500_gpio *to_ab8500_gpio(struct gpio_chip *chip)
  92 {
  93         return container_of(chip, struct ab8500_gpio, chip);
  94 }
  95
  96 static int ab8500_gpio_set_bits(struct gpio_chip *chip, u8 reg,
  97                                         unsigned offset, int val)
  98 {
  99         struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 100         u8 pos = offset % 8;
 101         int ret;
 102
 103         reg = reg + (offset / 8);
 104         ret = abx500_mask_and_set_register_interruptible(ab8500_gpio->dev,
 105                                 AB8500_MISC, reg, 1 << pos, val << pos);
 106         if (ret < 0)
 107                 dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
 108         return ret;
 109 }
 110 /**
 111  * ab8500_gpio_get() - Get the particular GPIO value
 112  * @chip: Gpio device
 113  * @offset: GPIO number to read
 114  */
 115 static int ab8500_gpio_get(struct gpio_chip *chip, unsigned offset)
 116 {
 117         struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 118         u8 mask = 1 << (offset % 8);
 119         u8 reg = AB8500_GPIO_OUT1_REG + (offset / 8);
 120         int ret;
 121         u8 data;
 122         ret = abx500_get_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
 123                                                 reg, &data);
 124         if (ret < 0) {
 125                 dev_err(ab8500_gpio->dev, "%s read failed\n", __func__);
 126                 return ret;
 127         }
 128         return (data & mask) >> (offset % 8);
 129 }
 130
 131 static void ab8500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 132 {
 133         struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 134         int ret;
 135         /* Write the data */
 136         ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, 1);
 137         if (ret < 0)
 138                 dev_err(ab8500_gpio->dev, "%s write failed\n", __func__);
 139 }
 140
 141 static int ab8500_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 142                                         int val)
 143 {
 144         int ret;
 145         /* set direction as output */
 146         ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 1);
 147         if (ret < 0)
 148                 return ret;
 149         /* disable pull down */
 150         ret = ab8500_gpio_set_bits(chip, AB8500_GPIO_PUD1_REG, offset, 1);
 151         if (ret < 0)
 152                 return ret;
 153         /* set the output as 1 or 0 */
 154         return ab8500_gpio_set_bits(chip, AB8500_GPIO_OUT1_REG, offset, val);
 155
 156 }
 157
 158 static int ab8500_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 159 {
 160         /* set the register as input */
 161         return ab8500_gpio_set_bits(chip, AB8500_GPIO_DIR1_REG, offset, 0);
 162 }
 163
 164 static int ab8500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 165 {
 166         /*
 167          * Only some GPIOs are interrupt capable, and they are
 168          * organized in discontiguous clusters:
 169          *
 170          *      GPIO6 to GPIO13
 171          *      GPIO24 and GPIO25
 172          *      GPIO36 to GPIO41
 173          */
 174         static struct ab8500_gpio_irq_cluster {
 175                 int start;
 176                 int end;
 177         } clusters[] = {
 178                 {.start = 6,  .end = 13},
 179                 {.start = 24, .end = 25},
 180                 {.start = 36, .end = 41},
 181         };
 182         struct ab8500_gpio *ab8500_gpio = to_ab8500_gpio(chip);
 183         int base = ab8500_gpio->irq_base;
 184         int i;
 185
 186         for (i = 0; i < ARRAY_SIZE(clusters); i++) {
 187                 struct ab8500_gpio_irq_cluster *cluster = &clusters[i];
 188
 189                 if (offset >= cluster->start && offset <= cluster->end)
 190                         return base + offset - cluster->start;
 191
 192                 /* Advance by the number of gpios in this cluster */
 193                 base += cluster->end - cluster->start + 1;
 194         }
 195
 196         return -EINVAL;
 197 }
 198
 199 static struct gpio_chip ab8500gpio_chip = {
 200         .label                  = "ab8500_gpio",
 201         .owner                  = THIS_MODULE,
 202         .direction_input        = ab8500_gpio_direction_input,
 203         .get                    = ab8500_gpio_get,
 204         .direction_output       = ab8500_gpio_direction_output,
 205         .set                    = ab8500_gpio_set,
 206         .to_irq                 = ab8500_gpio_to_irq,
 207 };
 208
 209 static unsigned int irq_to_rising(unsigned int irq)
 210 {
 211         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 212         int offset = irq - ab8500_gpio->irq_base;
 213         int new_irq = offset +  AB8500_INT_GPIO6R
 214                         + ab8500_gpio->parent->irq_base;
 215         return new_irq;
 216 }
 217
 218 static unsigned int irq_to_falling(unsigned int irq)
 219 {
 220         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 221         int offset = irq - ab8500_gpio->irq_base;
 222         int new_irq = offset +  AB8500_INT_GPIO6F
 223                         +  ab8500_gpio->parent->irq_base;
 224         return new_irq;
 225
 226 }
 227
 228 static unsigned int rising_to_irq(unsigned int irq, void *dev)
 229 {
 230         struct ab8500_gpio *ab8500_gpio = dev;
 231         int offset = irq - AB8500_INT_GPIO6R
 232                         - ab8500_gpio->parent->irq_base ;
 233         int new_irq = offset + ab8500_gpio->irq_base;
 234         return new_irq;
 235 }
 236
 237 static unsigned int falling_to_irq(unsigned int irq, void *dev)
 238 {
 239         struct ab8500_gpio *ab8500_gpio = dev;
 240         int offset = irq - AB8500_INT_GPIO6F
 241                         - ab8500_gpio->parent->irq_base ;
 242         int new_irq = offset + ab8500_gpio->irq_base;
 243         return new_irq;
 244
 245 }
 246
 247 /*
 248  * IRQ handler
 249  */
 250
 251 static irqreturn_t handle_rising(int irq, void *dev)
 252 {
 253
 254         handle_nested_irq(rising_to_irq(irq , dev));
 255         return IRQ_HANDLED;
 256 }
 257
 258 static irqreturn_t handle_falling(int irq, void *dev)
 259 {
 260
 261         handle_nested_irq(falling_to_irq(irq, dev));
 262         return IRQ_HANDLED;
 263 }
 264
 265 static void ab8500_gpio_irq_lock(unsigned int irq)
 266 {
 267         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 268         mutex_lock(&ab8500_gpio->lock);
 269 }
 270
 271 static void ab8500_gpio_irq_sync_unlock(unsigned int irq)
 272 {
 273         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 274         int offset = irq - ab8500_gpio->irq_base;
 275         bool rising = ab8500_gpio->rising & BIT(offset);
 276         bool falling = ab8500_gpio->falling & BIT(offset);
 277         int ret;
 278
 279         switch (ab8500_gpio->irq_action)        {
 280         case STARTUP:
 281                 if (rising)
 282                         ret = request_threaded_irq(irq_to_rising(irq),
 283                                         NULL, handle_rising,
 284                                         IRQF_TRIGGER_RISING,
 285                                         "ab8500-gpio-r", ab8500_gpio);
 286                 if (falling)
 287                         ret = request_threaded_irq(irq_to_falling(irq),
 288                                        NULL, handle_falling,
 289                                        IRQF_TRIGGER_FALLING,
 290                                        "ab8500-gpio-f", ab8500_gpio);
 291                 break;
 292         case SHUTDOWN:
 293                 if (rising)
 294                         free_irq(irq_to_rising(irq), ab8500_gpio);
 295                 if (falling)
 296                         free_irq(irq_to_falling(irq), ab8500_gpio);
 297                 break;
 298         case MASK:
 299                 if (rising)
 300                         disable_irq(irq_to_rising(irq));
 301                 if (falling)
 302                         disable_irq(irq_to_falling(irq));
 303                 break;
 304         case UNMASK:
 305                 if (rising)
 306                         enable_irq(irq_to_rising(irq));
 307                 if (falling)
 308                         enable_irq(irq_to_falling(irq));
 309                 break;
 310         case NONE:
 311                 break;
 312         }
 313         ab8500_gpio->irq_action = NONE;
 314         ab8500_gpio->rising &= ~(BIT(offset));
 315         ab8500_gpio->falling &= ~(BIT(offset));
 316         mutex_unlock(&ab8500_gpio->lock);
 317 }
 318
 319
 320 static void ab8500_gpio_irq_mask(unsigned int irq)
 321 {
 322         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 323         ab8500_gpio->irq_action = MASK;
 324 }
 325
 326 static void ab8500_gpio_irq_unmask(unsigned int irq)
 327 {
 328         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 329         ab8500_gpio->irq_action = UNMASK;
 330 }
 331
 332 static int ab8500_gpio_irq_set_type(unsigned int irq, unsigned int type)
 333 {
 334         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 335         int offset = irq - ab8500_gpio->irq_base;
 336
 337         if (type == IRQ_TYPE_EDGE_BOTH) {
 338                 ab8500_gpio->rising =  BIT(offset);
 339                 ab8500_gpio->falling = BIT(offset);
 340         } else if (type == IRQ_TYPE_EDGE_RISING) {
 341                 ab8500_gpio->rising =  BIT(offset);
 342         } else  {
 343                 ab8500_gpio->falling = BIT(offset);
 344         }
 345         return 0;
 346 }
 347
 348 unsigned int ab8500_gpio_irq_startup(unsigned int irq)
 349 {
 350         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 351         ab8500_gpio->irq_action = STARTUP;
 352         return 0;
 353 }
 354
 355 void ab8500_gpio_irq_shutdown(unsigned int irq)
 356 {
 357         struct ab8500_gpio *ab8500_gpio = get_irq_chip_data(irq);
 358         ab8500_gpio->irq_action = SHUTDOWN;
 359 }
 360
 361 static struct irq_chip ab8500_gpio_irq_chip = {
 362         .name                   = "ab8500-gpio",
 363         .startup                = ab8500_gpio_irq_startup,
 364         .shutdown               = ab8500_gpio_irq_shutdown,
 365         .bus_lock               = ab8500_gpio_irq_lock,
 366         .bus_sync_unlock        = ab8500_gpio_irq_sync_unlock,
 367         .mask                   = ab8500_gpio_irq_mask,
 368         .unmask                 = ab8500_gpio_irq_unmask,
 369         .set_type               = ab8500_gpio_irq_set_type,
 370 };
 371
 372 static int ab8500_gpio_irq_init(struct ab8500_gpio *ab8500_gpio)
 373 {
 374         u32 base = ab8500_gpio->irq_base;
 375         int irq;
 376
 377         for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ ; irq++) {
 378                 set_irq_chip_data(irq, ab8500_gpio);
 379                 set_irq_chip_and_handler(irq, &ab8500_gpio_irq_chip,
 380                                 handle_simple_irq);
 381                 set_irq_nested_thread(irq, 1);
 382 #ifdef CONFIG_ARM
 383                 set_irq_flags(irq, IRQF_VALID);
 384 #else
 385                 set_irq_noprobe(irq);
 386 #endif
 387         }
 388
 389         return 0;
 390 }
 391
 392 static void ab8500_gpio_irq_remove(struct ab8500_gpio *ab8500_gpio)
 393 {
 394         int base = ab8500_gpio->irq_base;
 395         int irq;
 396
 397         for (irq = base; irq < base + AB8500_NUM_VIR_GPIO_IRQ; irq++) {
 398 #ifdef CONFIG_ARM
 399                 set_irq_flags(irq, 0);
 400 #endif
 401                 set_irq_chip_and_handler(irq, NULL, NULL);
 402                 set_irq_chip_data(irq, NULL);
 403         }
 404 }
 405
 406 static int __devinit ab8500_gpio_probe(struct platform_device *pdev)
 407 {
 408         struct ab8500_platform_data *ab8500_pdata =
 409                                 dev_get_platdata(pdev->dev.parent);
 410         struct ab8500_gpio_platform_data *pdata;
 411         struct ab8500_gpio *ab8500_gpio;
 412         int ret;
 413         int i;
 414
 415         pdata = ab8500_pdata->gpio;
 416         if (!pdata)     {
 417                 dev_err(&pdev->dev, "gpio platform data missing\n");
 418                 return -ENODEV;
 419         }
 420
 421         ab8500_gpio = kzalloc(sizeof(struct ab8500_gpio), GFP_KERNEL);
 422         if (ab8500_gpio == NULL) {
 423                 dev_err(&pdev->dev, "failed to allocate memory\n");
 424                 return -ENOMEM;
 425         }
 426         ab8500_gpio->dev = &pdev->dev;
 427         ab8500_gpio->parent = dev_get_drvdata(pdev->dev.parent);
 428         ab8500_gpio->chip = ab8500gpio_chip;
 429         ab8500_gpio->chip.ngpio = AB8500_NUM_GPIO;
 430         ab8500_gpio->chip.dev = &pdev->dev;
 431         ab8500_gpio->chip.base = pdata->gpio_base;
 432         ab8500_gpio->irq_base = pdata->irq_base;
 433         /* initialize the lock */
 434         mutex_init(&ab8500_gpio->lock);
 435         /*
 436          * AB8500 core will handle and clear the IRQ
 437          * configre GPIO based on config-reg value.
 438          * These values are for selecting the PINs as
 439          * GPIO or alternate function
 440          */
 441         for (i = AB8500_GPIO_SEL1_REG; i <= AB8500_GPIO_SEL6_REG; i++)  {
 442                 ret = abx500_set_register_interruptible(ab8500_gpio->dev,
 443                                 AB8500_MISC, i,
 444                                 pdata->config_reg[i]);
 445                 if (ret < 0)
 446                         goto out_free;
 447         }
 448         ret = abx500_set_register_interruptible(ab8500_gpio->dev, AB8500_MISC,
 449                                 AB8500_GPIO_ALTFUN_REG,
 450                                 pdata->config_reg[ALTFUN_REG_INDEX]);
 451         if (ret < 0)
 452                 goto out_free;
 453
 454         ret = ab8500_gpio_irq_init(ab8500_gpio);
 455         if (ret)
 456                 goto out_free;
 457         ret = gpiochip_add(&ab8500_gpio->chip);
 458         if (ret) {
 459                 dev_err(&pdev->dev, "unable to add gpiochip: %d\n",
 460                                 ret);
 461                 goto out_rem_irq;
 462         }
 463         platform_set_drvdata(pdev, ab8500_gpio);
 464         return 0;
 465
 466 out_rem_irq:
 467         ab8500_gpio_irq_remove(ab8500_gpio);
 468 out_free:
 469         mutex_destroy(&ab8500_gpio->lock);
 470         kfree(ab8500_gpio);
 471         return ret;
 472 }
 473
 474 /*
 475  * ab8500_gpio_remove() - remove Ab8500-gpio driver
 476  * @pdev :      Platform device registered
 477  */
 478 static int __devexit ab8500_gpio_remove(struct platform_device *pdev)
 479 {
 480         struct ab8500_gpio *ab8500_gpio = platform_get_drvdata(pdev);
 481         int ret;
 482
 483         ret = gpiochip_remove(&ab8500_gpio->chip);
 484         if (ret < 0) {
 485                 dev_err(ab8500_gpio->dev, "unable to remove gpiochip:\
 486                                 %d\n", ret);
 487                 return ret;
 488         }
 489
 490         platform_set_drvdata(pdev, NULL);
 491         mutex_destroy(&ab8500_gpio->lock);
 492         kfree(ab8500_gpio);
 493
 494         return 0;
 495 }
 496
 497 static struct platform_driver ab8500_gpio_driver = {
 498         .driver = {
 499                 .name = "ab8500-gpio",
 500                 .owner = THIS_MODULE,
 501         },
 502         .probe = ab8500_gpio_probe,
 503         .remove = __devexit_p(ab8500_gpio_remove),
 504 };
 505
 506 static int __init ab8500_gpio_init(void)
 507 {
 508         return platform_driver_register(&ab8500_gpio_driver);
 509 }
 510 arch_initcall(ab8500_gpio_init);
 511
 512 static void __exit ab8500_gpio_exit(void)
 513 {
 514         platform_driver_unregister(&ab8500_gpio_driver);
 515 }
 516 module_exit(ab8500_gpio_exit);
 517
 518 MODULE_AUTHOR("BIBEK BASU <bibek.basu@stericsson.com>");
 519 MODULE_DESCRIPTION("Driver allows to use AB8500 unused pins\
 520                         to be used as GPIO");
 521 MODULE_ALIAS("AB8500 GPIO driver");
 522 MODULE_LICENSE("GPL v2");