drivers/gpio/gpio-twl4030.c

   1 /*
   2  * Access to GPIOs on TWL4030/TPS659x0 chips
   3  *
   4  * Copyright (C) 2006-2007 Texas Instruments, Inc.
   5  * Copyright (C) 2006 MontaVista Software, Inc.
   6  *
   7  * Code re-arranged and cleaned up by:
   8  *      Syed Mohammed Khasim <x0khasim@ti.com>
   9  *
  10  * Initial Code:
  11  *      Andy Lowe / Nishanth Menon
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/kthread.h>
  32 #include <linux/irq.h>
  33 #include <linux/gpio.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/of.h>
  36 #include <linux/irqdomain.h>
  37
  38 #include <linux/i2c/twl.h>
  39
  40 /*
  41  * The GPIO "subchip" supports 18 GPIOs which can be configured as
  42  * inputs or outputs, with pullups or pulldowns on each pin.  Each
  43  * GPIO can trigger interrupts on either or both edges.
  44  *
  45  * GPIO interrupts can be fed to either of two IRQ lines; this is
  46  * intended to support multiple hosts.
  47  *
  48  * There are also two LED pins used sometimes as output-only GPIOs.
  49  */
  50
  51 /* genirq interfaces are not available to modules */
  52 #ifdef MODULE
  53 #define is_module()     true
  54 #else
  55 #define is_module()     false
  56 #endif
  57
  58 /* GPIO_CTRL Fields */
  59 #define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  60 #define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  61 #define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  62
  63 /* Mask for GPIO registers when aggregated into a 32-bit integer */
  64 #define GPIO_32_MASK                    0x0003ffff
  65
  66 struct gpio_twl4030_priv {
  67         struct gpio_chip gpio_chip;
  68         struct mutex mutex;
  69         int irq_base;
  70
  71         /* Bitfields for state caching */
  72         unsigned int usage_count;
  73         unsigned int direction;
  74         unsigned int out_state;
  75 };
  76
  77 /*----------------------------------------------------------------------*/
  78
  79 static inline struct gpio_twl4030_priv *to_gpio_twl4030(struct gpio_chip *chip)
  80 {
  81         return container_of(chip, struct gpio_twl4030_priv, gpio_chip);
  82 }
  83
  84 /*
  85  * To configure TWL4030 GPIO module registers
  86  */
  87 static inline int gpio_twl4030_write(u8 address, u8 data)
  88 {
  89         return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  90 }
  91
  92 /*----------------------------------------------------------------------*/
  93
  94 /*
  95  * LED register offsets from TWL_MODULE_LED base
  96  * PWMs A and B are dedicated to LEDs A and B, respectively.
  97  */
  98
  99 #define TWL4030_LED_LEDEN_REG   0x00
 100 #define TWL4030_PWMAON_REG      0x01
 101 #define TWL4030_PWMAOFF_REG     0x02
 102 #define TWL4030_PWMBON_REG      0x03
 103 #define TWL4030_PWMBOFF_REG     0x04
 104
 105 /* LEDEN bits */
 106 #define LEDEN_LEDAON            BIT(0)
 107 #define LEDEN_LEDBON            BIT(1)
 108 #define LEDEN_LEDAEXT           BIT(2)
 109 #define LEDEN_LEDBEXT           BIT(3)
 110 #define LEDEN_LEDAPWM           BIT(4)
 111 #define LEDEN_LEDBPWM           BIT(5)
 112 #define LEDEN_PWM_LENGTHA       BIT(6)
 113 #define LEDEN_PWM_LENGTHB       BIT(7)
 114
 115 #define PWMxON_LENGTH           BIT(7)
 116
 117 /*----------------------------------------------------------------------*/
 118
 119 /*
 120  * To read a TWL4030 GPIO module register
 121  */
 122 static inline int gpio_twl4030_read(u8 address)
 123 {
 124         u8 data;
 125         int ret = 0;
 126
 127         ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 128         return (ret < 0) ? ret : data;
 129 }
 130
 131 /*----------------------------------------------------------------------*/
 132
 133 static u8 cached_leden;
 134
 135 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 136  * external pullup is needed.  We could also expose the integrated PWM
 137  * as a LED brightness control; we initialize it as "always on".
 138  */
 139 static void twl4030_led_set_value(int led, int value)
 140 {
 141         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 142         int status;
 143
 144         if (led)
 145                 mask <<= 1;
 146
 147         if (value)
 148                 cached_leden &= ~mask;
 149         else
 150                 cached_leden |= mask;
 151         status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 152                                   TWL4030_LED_LEDEN_REG);
 153 }
 154
 155 static int twl4030_set_gpio_direction(int gpio, int is_input)
 156 {
 157         u8 d_bnk = gpio >> 3;
 158         u8 d_msk = BIT(gpio & 0x7);
 159         u8 reg = 0;
 160         u8 base = REG_GPIODATADIR1 + d_bnk;
 161         int ret = 0;
 162
 163         ret = gpio_twl4030_read(base);
 164         if (ret >= 0) {
 165                 if (is_input)
 166                         reg = ret & ~d_msk;
 167                 else
 168                         reg = ret | d_msk;
 169
 170                 ret = gpio_twl4030_write(base, reg);
 171         }
 172         return ret;
 173 }
 174
 175 static int twl4030_set_gpio_dataout(int gpio, int enable)
 176 {
 177         u8 d_bnk = gpio >> 3;
 178         u8 d_msk = BIT(gpio & 0x7);
 179         u8 base = 0;
 180
 181         if (enable)
 182                 base = REG_SETGPIODATAOUT1 + d_bnk;
 183         else
 184                 base = REG_CLEARGPIODATAOUT1 + d_bnk;
 185
 186         return gpio_twl4030_write(base, d_msk);
 187 }
 188
 189 static int twl4030_get_gpio_datain(int gpio)
 190 {
 191         u8 d_bnk = gpio >> 3;
 192         u8 d_off = gpio & 0x7;
 193         u8 base = 0;
 194         int ret = 0;
 195
 196         base = REG_GPIODATAIN1 + d_bnk;
 197         ret = gpio_twl4030_read(base);
 198         if (ret > 0)
 199                 ret = (ret >> d_off) & 0x1;
 200
 201         return ret;
 202 }
 203
 204 /*----------------------------------------------------------------------*/
 205
 206 static int twl_request(struct gpio_chip *chip, unsigned offset)
 207 {
 208         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 209         int status = 0;
 210
 211         mutex_lock(&priv->mutex);
 212
 213         /* Support the two LED outputs as output-only GPIOs. */
 214         if (offset >= TWL4030_GPIO_MAX) {
 215                 u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 216                                 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 217                 u8      reg = TWL4030_PWMAON_REG;
 218
 219                 offset -= TWL4030_GPIO_MAX;
 220                 if (offset) {
 221                         ledclr_mask <<= 1;
 222                         reg = TWL4030_PWMBON_REG;
 223                 }
 224
 225                 /* initialize PWM to always-drive */
 226                 /* Configure PWM OFF register first */
 227                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1);
 228                 if (status < 0)
 229                         goto done;
 230
 231                 /* Followed by PWM ON register */
 232                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg);
 233                 if (status < 0)
 234                         goto done;
 235
 236                 /* init LED to not-driven (high) */
 237                 status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden,
 238                                          TWL4030_LED_LEDEN_REG);
 239                 if (status < 0)
 240                         goto done;
 241                 cached_leden &= ~ledclr_mask;
 242                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 243                                           TWL4030_LED_LEDEN_REG);
 244                 if (status < 0)
 245                         goto done;
 246
 247                 status = 0;
 248                 goto done;
 249         }
 250
 251         /* on first use, turn GPIO module "on" */
 252         if (!priv->usage_count) {
 253                 struct twl4030_gpio_platform_data *pdata;
 254                 u8 value = MASK_GPIO_CTRL_GPIO_ON;
 255
 256                 /* optionally have the first two GPIOs switch vMMC1
 257                  * and vMMC2 power supplies based on card presence.
 258                  */
 259                 pdata = chip->dev->platform_data;
 260                 if (pdata)
 261                         value |= pdata->mmc_cd & 0x03;
 262
 263                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 264         }
 265
 266 done:
 267         if (!status)
 268                 priv->usage_count |= BIT(offset);
 269
 270         mutex_unlock(&priv->mutex);
 271         return status;
 272 }
 273
 274 static void twl_free(struct gpio_chip *chip, unsigned offset)
 275 {
 276         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 277
 278         mutex_lock(&priv->mutex);
 279         if (offset >= TWL4030_GPIO_MAX) {
 280                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 281                 goto out;
 282         }
 283
 284         priv->usage_count &= ~BIT(offset);
 285
 286         /* on last use, switch off GPIO module */
 287         if (!priv->usage_count)
 288                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 289
 290 out:
 291         mutex_unlock(&priv->mutex);
 292 }
 293
 294 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 295 {
 296         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 297         int ret;
 298
 299         mutex_lock(&priv->mutex);
 300         if (offset < TWL4030_GPIO_MAX)
 301                 ret = twl4030_set_gpio_direction(offset, 1);
 302         else
 303                 ret = -EINVAL;
 304
 305         if (!ret)
 306                 priv->direction &= ~BIT(offset);
 307
 308         mutex_unlock(&priv->mutex);
 309
 310         return ret;
 311 }
 312
 313 static int twl_get(struct gpio_chip *chip, unsigned offset)
 314 {
 315         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 316         int ret;
 317         int status = 0;
 318
 319         mutex_lock(&priv->mutex);
 320         if (!(priv->usage_count & BIT(offset))) {
 321                 ret = -EPERM;
 322                 goto out;
 323         }
 324
 325         if (priv->direction & BIT(offset))
 326                 status = priv->out_state & BIT(offset);
 327         else
 328                 status = twl4030_get_gpio_datain(offset);
 329
 330         ret = (status <= 0) ? 0 : 1;
 331 out:
 332         mutex_unlock(&priv->mutex);
 333         return ret;
 334 }
 335
 336 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 337 {
 338         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 339
 340         mutex_lock(&priv->mutex);
 341         if (offset < TWL4030_GPIO_MAX)
 342                 twl4030_set_gpio_dataout(offset, value);
 343         else
 344                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 345
 346         if (value)
 347                 priv->out_state |= BIT(offset);
 348         else
 349                 priv->out_state &= ~BIT(offset);
 350
 351         mutex_unlock(&priv->mutex);
 352 }
 353
 354 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 355 {
 356         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 357
 358         mutex_lock(&priv->mutex);
 359         if (offset < TWL4030_GPIO_MAX)
 360                 twl4030_set_gpio_dataout(offset, value);
 361
 362         priv->direction |= BIT(offset);
 363         mutex_unlock(&priv->mutex);
 364
 365         twl_set(chip, offset, value);
 366
 367         return 0;
 368 }
 369
 370 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 371 {
 372         struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 373
 374         return (priv->irq_base && (offset < TWL4030_GPIO_MAX))
 375                 ? (priv->irq_base + offset)
 376                 : -EINVAL;
 377 }
 378
 379 static struct gpio_chip template_chip = {
 380         .label                  = "twl4030",
 381         .owner                  = THIS_MODULE,
 382         .request                = twl_request,
 383         .free                   = twl_free,
 384         .direction_input        = twl_direction_in,
 385         .get                    = twl_get,
 386         .direction_output       = twl_direction_out,
 387         .set                    = twl_set,
 388         .to_irq                 = twl_to_irq,
 389         .can_sleep              = 1,
 390 };
 391
 392 /*----------------------------------------------------------------------*/
 393
 394 static int gpio_twl4030_pulls(u32 ups, u32 downs)
 395 {
 396         u8              message[5];
 397         unsigned        i, gpio_bit;
 398
 399         /* For most pins, a pulldown was enabled by default.
 400          * We should have data that's specific to this board.
 401          */
 402         for (gpio_bit = 1, i = 0; i < 5; i++) {
 403                 u8              bit_mask;
 404                 unsigned        j;
 405
 406                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 407                         if (ups & gpio_bit)
 408                                 bit_mask |= 1 << (j + 1);
 409                         else if (downs & gpio_bit)
 410                                 bit_mask |= 1 << (j + 0);
 411                 }
 412                 message[i] = bit_mask;
 413         }
 414
 415         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 416                                 REG_GPIOPUPDCTR1, 5);
 417 }
 418
 419 static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 420 {
 421         u8              message[3];
 422
 423         /* 30 msec of debouncing is always used for MMC card detect,
 424          * and is optional for everything else.
 425          */
 426         message[0] = (debounce & 0xff) | (mmc_cd & 0x03);
 427         debounce >>= 8;
 428         message[1] = (debounce & 0xff);
 429         debounce >>= 8;
 430         message[2] = (debounce & 0x03);
 431
 432         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 433                                 REG_GPIO_DEBEN1, 3);
 434 }
 435
 436 static int gpio_twl4030_remove(struct platform_device *pdev);
 437
 438 static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev)
 439 {
 440         struct twl4030_gpio_platform_data *omap_twl_info;
 441
 442         omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 443         if (!omap_twl_info)
 444                 return NULL;
 445
 446         omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 447                         "ti,use-leds");
 448
 449         of_property_read_u32(dev->of_node, "ti,debounce",
 450                              &omap_twl_info->debounce);
 451         of_property_read_u32(dev->of_node, "ti,mmc-cd",
 452                              (u32 *)&omap_twl_info->mmc_cd);
 453         of_property_read_u32(dev->of_node, "ti,pullups",
 454                              &omap_twl_info->pullups);
 455         of_property_read_u32(dev->of_node, "ti,pulldowns",
 456                              &omap_twl_info->pulldowns);
 457
 458         return omap_twl_info;
 459 }
 460
 461 static int gpio_twl4030_probe(struct platform_device *pdev)
 462 {
 463         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 464         struct device_node *node = pdev->dev.of_node;
 465         struct gpio_twl4030_priv *priv;
 466         int ret, irq_base;
 467
 468         priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv),
 469                             GFP_KERNEL);
 470         if (!priv)
 471                 return -ENOMEM;
 472
 473         /* maybe setup IRQs */
 474         if (is_module()) {
 475                 dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 476                 goto no_irqs;
 477         }
 478
 479         irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 480         if (irq_base < 0) {
 481                 dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 482                 return irq_base;
 483         }
 484
 485         irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 486                               &irq_domain_simple_ops, NULL);
 487
 488         ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 489         if (ret < 0)
 490                 return ret;
 491
 492         priv->irq_base = irq_base;
 493
 494 no_irqs:
 495         priv->gpio_chip = template_chip;
 496         priv->gpio_chip.base = -1;
 497         priv->gpio_chip.ngpio = TWL4030_GPIO_MAX;
 498         priv->gpio_chip.dev = &pdev->dev;
 499
 500         mutex_init(&priv->mutex);
 501
 502         if (node)
 503                 pdata = of_gpio_twl4030(&pdev->dev);
 504
 505         if (pdata == NULL) {
 506                 dev_err(&pdev->dev, "Platform data is missing\n");
 507                 return -ENXIO;
 508         }
 509
 510         /*
 511          * NOTE:  boards may waste power if they don't set pullups
 512          * and pulldowns correctly ... default for non-ULPI pins is
 513          * pulldown, and some other pins may have external pullups
 514          * or pulldowns.  Careful!
 515          */
 516         ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 517         if (ret)
 518                 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 519                         pdata->pullups, pdata->pulldowns, ret);
 520
 521         ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 522         if (ret)
 523                 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 524                         pdata->debounce, pdata->mmc_cd, ret);
 525
 526         /*
 527          * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 528          * is (still) clear if use_leds is set.
 529          */
 530         if (pdata->use_leds)
 531                 priv->gpio_chip.ngpio += 2;
 532
 533         ret = gpiochip_add(&priv->gpio_chip);
 534         if (ret < 0) {
 535                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 536                 priv->gpio_chip.ngpio = 0;
 537                 gpio_twl4030_remove(pdev);
 538                 goto out;
 539         }
 540
 541         platform_set_drvdata(pdev, priv);
 542
 543         if (pdata && pdata->setup) {
 544                 int status;
 545
 546                 status = pdata->setup(&pdev->dev, priv->gpio_chip.base,
 547                                       TWL4030_GPIO_MAX);
 548                 if (status)
 549                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 550         }
 551
 552 out:
 553         return ret;
 554 }
 555
 556 /* Cannot use as gpio_twl4030_probe() calls us */
 557 static int gpio_twl4030_remove(struct platform_device *pdev)
 558 {
 559         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 560         struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev);
 561         int status;
 562
 563         if (pdata && pdata->teardown) {
 564                 status = pdata->teardown(&pdev->dev, priv->gpio_chip.base,
 565                                          TWL4030_GPIO_MAX);
 566                 if (status) {
 567                         dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 568                         return status;
 569                 }
 570         }
 571
 572         status = gpiochip_remove(&priv->gpio_chip);
 573         if (status < 0)
 574                 return status;
 575
 576         if (is_module())
 577                 return 0;
 578
 579         /* REVISIT no support yet for deregistering all the IRQs */
 580         WARN_ON(1);
 581         return -EIO;
 582 }
 583
 584 static const struct of_device_id twl_gpio_match[] = {
 585         { .compatible = "ti,twl4030-gpio", },
 586         { },
 587 };
 588 MODULE_DEVICE_TABLE(of, twl_gpio_match);
 589
 590 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 591 MODULE_ALIAS("platform:twl4030_gpio");
 592
 593 static struct platform_driver gpio_twl4030_driver = {
 594         .driver = {
 595                 .name   = "twl4030_gpio",
 596                 .owner  = THIS_MODULE,
 597                 .of_match_table = of_match_ptr(twl_gpio_match),
 598         },
 599         .probe          = gpio_twl4030_probe,
 600         .remove         = gpio_twl4030_remove,
 601 };
 602
 603 static int __init gpio_twl4030_init(void)
 604 {
 605         return platform_driver_register(&gpio_twl4030_driver);
 606 }
 607 subsys_initcall(gpio_twl4030_init);
 608
 609 static void __exit gpio_twl4030_exit(void)
 610 {
 611         platform_driver_unregister(&gpio_twl4030_driver);
 612 }
 613 module_exit(gpio_twl4030_exit);
 614
 615 MODULE_AUTHOR("Texas Instruments, Inc.");
 616 MODULE_DESCRIPTION("GPIO interface for TWL4030");
 617 MODULE_LICENSE("GPL");