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 /*
  80  * To configure TWL4030 GPIO module registers
  81  */
  82 static inline int gpio_twl4030_write(u8 address, u8 data)
  83 {
  84         return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  85 }
  86
  87 /*----------------------------------------------------------------------*/
  88
  89 /*
  90  * LED register offsets from TWL_MODULE_LED base
  91  * PWMs A and B are dedicated to LEDs A and B, respectively.
  92  */
  93
  94 #define TWL4030_LED_LEDEN_REG   0x00
  95 #define TWL4030_PWMAON_REG      0x01
  96 #define TWL4030_PWMAOFF_REG     0x02
  97 #define TWL4030_PWMBON_REG      0x03
  98 #define TWL4030_PWMBOFF_REG     0x04
  99
 100 /* LEDEN bits */
 101 #define LEDEN_LEDAON            BIT(0)
 102 #define LEDEN_LEDBON            BIT(1)
 103 #define LEDEN_LEDAEXT           BIT(2)
 104 #define LEDEN_LEDBEXT           BIT(3)
 105 #define LEDEN_LEDAPWM           BIT(4)
 106 #define LEDEN_LEDBPWM           BIT(5)
 107 #define LEDEN_PWM_LENGTHA       BIT(6)
 108 #define LEDEN_PWM_LENGTHB       BIT(7)
 109
 110 #define PWMxON_LENGTH           BIT(7)
 111
 112 /*----------------------------------------------------------------------*/
 113
 114 /*
 115  * To read a TWL4030 GPIO module register
 116  */
 117 static inline int gpio_twl4030_read(u8 address)
 118 {
 119         u8 data;
 120         int ret = 0;
 121
 122         ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 123         return (ret < 0) ? ret : data;
 124 }
 125
 126 /*----------------------------------------------------------------------*/
 127
 128 static u8 cached_leden;
 129
 130 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 131  * external pullup is needed.  We could also expose the integrated PWM
 132  * as a LED brightness control; we initialize it as "always on".
 133  */
 134 static void twl4030_led_set_value(int led, int value)
 135 {
 136         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 137
 138         if (led)
 139                 mask <<= 1;
 140
 141         if (value)
 142                 cached_leden &= ~mask;
 143         else
 144                 cached_leden |= mask;
 145
 146         WARN_ON_ONCE(twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 147                                       TWL4030_LED_LEDEN_REG));
 148 }
 149
 150 static int twl4030_set_gpio_direction(int gpio, int is_input)
 151 {
 152         u8 d_bnk = gpio >> 3;
 153         u8 d_msk = BIT(gpio & 0x7);
 154         u8 reg = 0;
 155         u8 base = REG_GPIODATADIR1 + d_bnk;
 156         int ret = 0;
 157
 158         ret = gpio_twl4030_read(base);
 159         if (ret >= 0) {
 160                 if (is_input)
 161                         reg = ret & ~d_msk;
 162                 else
 163                         reg = ret | d_msk;
 164
 165                 ret = gpio_twl4030_write(base, reg);
 166         }
 167         return ret;
 168 }
 169
 170 static int twl4030_set_gpio_dataout(int gpio, int enable)
 171 {
 172         u8 d_bnk = gpio >> 3;
 173         u8 d_msk = BIT(gpio & 0x7);
 174         u8 base = 0;
 175
 176         if (enable)
 177                 base = REG_SETGPIODATAOUT1 + d_bnk;
 178         else
 179                 base = REG_CLEARGPIODATAOUT1 + d_bnk;
 180
 181         return gpio_twl4030_write(base, d_msk);
 182 }
 183
 184 static int twl4030_get_gpio_datain(int gpio)
 185 {
 186         u8 d_bnk = gpio >> 3;
 187         u8 d_off = gpio & 0x7;
 188         u8 base = 0;
 189         int ret = 0;
 190
 191         base = REG_GPIODATAIN1 + d_bnk;
 192         ret = gpio_twl4030_read(base);
 193         if (ret > 0)
 194                 ret = (ret >> d_off) & 0x1;
 195
 196         return ret;
 197 }
 198
 199 /*----------------------------------------------------------------------*/
 200
 201 static int twl_request(struct gpio_chip *chip, unsigned offset)
 202 {
 203         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 204         int status = 0;
 205
 206         mutex_lock(&priv->mutex);
 207
 208         /* Support the two LED outputs as output-only GPIOs. */
 209         if (offset >= TWL4030_GPIO_MAX) {
 210                 u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 211                                 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 212                 u8      reg = TWL4030_PWMAON_REG;
 213
 214                 offset -= TWL4030_GPIO_MAX;
 215                 if (offset) {
 216                         ledclr_mask <<= 1;
 217                         reg = TWL4030_PWMBON_REG;
 218                 }
 219
 220                 /* initialize PWM to always-drive */
 221                 /* Configure PWM OFF register first */
 222                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1);
 223                 if (status < 0)
 224                         goto done;
 225
 226                 /* Followed by PWM ON register */
 227                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg);
 228                 if (status < 0)
 229                         goto done;
 230
 231                 /* init LED to not-driven (high) */
 232                 status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden,
 233                                          TWL4030_LED_LEDEN_REG);
 234                 if (status < 0)
 235                         goto done;
 236                 cached_leden &= ~ledclr_mask;
 237                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 238                                           TWL4030_LED_LEDEN_REG);
 239                 if (status < 0)
 240                         goto done;
 241
 242                 status = 0;
 243                 goto done;
 244         }
 245
 246         /* on first use, turn GPIO module "on" */
 247         if (!priv->usage_count) {
 248                 struct twl4030_gpio_platform_data *pdata;
 249                 u8 value = MASK_GPIO_CTRL_GPIO_ON;
 250
 251                 /* optionally have the first two GPIOs switch vMMC1
 252                  * and vMMC2 power supplies based on card presence.
 253                  */
 254                 pdata = dev_get_platdata(chip->parent);
 255                 if (pdata)
 256                         value |= pdata->mmc_cd & 0x03;
 257
 258                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 259         }
 260
 261 done:
 262         if (!status)
 263                 priv->usage_count |= BIT(offset);
 264
 265         mutex_unlock(&priv->mutex);
 266         return status;
 267 }
 268
 269 static void twl_free(struct gpio_chip *chip, unsigned offset)
 270 {
 271         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 272
 273         mutex_lock(&priv->mutex);
 274         if (offset >= TWL4030_GPIO_MAX) {
 275                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 276                 goto out;
 277         }
 278
 279         priv->usage_count &= ~BIT(offset);
 280
 281         /* on last use, switch off GPIO module */
 282         if (!priv->usage_count)
 283                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 284
 285 out:
 286         mutex_unlock(&priv->mutex);
 287 }
 288
 289 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 290 {
 291         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 292         int ret;
 293
 294         mutex_lock(&priv->mutex);
 295         if (offset < TWL4030_GPIO_MAX)
 296                 ret = twl4030_set_gpio_direction(offset, 1);
 297         else
 298                 ret = -EINVAL;  /* LED outputs can't be set as input */
 299
 300         if (!ret)
 301                 priv->direction &= ~BIT(offset);
 302
 303         mutex_unlock(&priv->mutex);
 304
 305         return ret;
 306 }
 307
 308 static int twl_get(struct gpio_chip *chip, unsigned offset)
 309 {
 310         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 311         int ret;
 312         int status = 0;
 313
 314         mutex_lock(&priv->mutex);
 315         if (!(priv->usage_count & BIT(offset))) {
 316                 ret = -EPERM;
 317                 goto out;
 318         }
 319
 320         if (priv->direction & BIT(offset))
 321                 status = priv->out_state & BIT(offset);
 322         else
 323                 status = twl4030_get_gpio_datain(offset);
 324
 325         ret = (status < 0) ? status : !!status;
 326 out:
 327         mutex_unlock(&priv->mutex);
 328         return ret;
 329 }
 330
 331 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 332 {
 333         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 334
 335         mutex_lock(&priv->mutex);
 336         if (offset < TWL4030_GPIO_MAX)
 337                 twl4030_set_gpio_dataout(offset, value);
 338         else
 339                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 340
 341         if (value)
 342                 priv->out_state |= BIT(offset);
 343         else
 344                 priv->out_state &= ~BIT(offset);
 345
 346         mutex_unlock(&priv->mutex);
 347 }
 348
 349 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 350 {
 351         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 352         int ret = 0;
 353
 354         mutex_lock(&priv->mutex);
 355         if (offset < TWL4030_GPIO_MAX) {
 356                 ret = twl4030_set_gpio_direction(offset, 0);
 357                 if (ret) {
 358                         mutex_unlock(&priv->mutex);
 359                         return ret;
 360                 }
 361         }
 362
 363         /*
 364          *  LED gpios i.e. offset >= TWL4030_GPIO_MAX are always output
 365          */
 366
 367         priv->direction |= BIT(offset);
 368         mutex_unlock(&priv->mutex);
 369
 370         twl_set(chip, offset, value);
 371
 372         return ret;
 373 }
 374
 375 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 376 {
 377         struct gpio_twl4030_priv *priv = gpiochip_get_data(chip);
 378
 379         return (priv->irq_base && (offset < TWL4030_GPIO_MAX))
 380                 ? (priv->irq_base + offset)
 381                 : -EINVAL;
 382 }
 383
 384 static struct gpio_chip template_chip = {
 385         .label                  = "twl4030",
 386         .owner                  = THIS_MODULE,
 387         .request                = twl_request,
 388         .free                   = twl_free,
 389         .direction_input        = twl_direction_in,
 390         .get                    = twl_get,
 391         .direction_output       = twl_direction_out,
 392         .set                    = twl_set,
 393         .to_irq                 = twl_to_irq,
 394         .can_sleep              = true,
 395 };
 396
 397 /*----------------------------------------------------------------------*/
 398
 399 static int gpio_twl4030_pulls(u32 ups, u32 downs)
 400 {
 401         u8              message[5];
 402         unsigned        i, gpio_bit;
 403
 404         /* For most pins, a pulldown was enabled by default.
 405          * We should have data that's specific to this board.
 406          */
 407         for (gpio_bit = 1, i = 0; i < 5; i++) {
 408                 u8              bit_mask;
 409                 unsigned        j;
 410
 411                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 412                         if (ups & gpio_bit)
 413                                 bit_mask |= 1 << (j + 1);
 414                         else if (downs & gpio_bit)
 415                                 bit_mask |= 1 << (j + 0);
 416                 }
 417                 message[i] = bit_mask;
 418         }
 419
 420         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 421                                 REG_GPIOPUPDCTR1, 5);
 422 }
 423
 424 static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 425 {
 426         u8              message[3];
 427
 428         /* 30 msec of debouncing is always used for MMC card detect,
 429          * and is optional for everything else.
 430          */
 431         message[0] = (debounce & 0xff) | (mmc_cd & 0x03);
 432         debounce >>= 8;
 433         message[1] = (debounce & 0xff);
 434         debounce >>= 8;
 435         message[2] = (debounce & 0x03);
 436
 437         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 438                                 REG_GPIO_DEBEN1, 3);
 439 }
 440
 441 static int gpio_twl4030_remove(struct platform_device *pdev);
 442
 443 static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev,
 444                                 struct twl4030_gpio_platform_data *pdata)
 445 {
 446         struct twl4030_gpio_platform_data *omap_twl_info;
 447
 448         omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 449         if (!omap_twl_info)
 450                 return NULL;
 451
 452         if (pdata)
 453                 *omap_twl_info = *pdata;
 454
 455         omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 456                         "ti,use-leds");
 457
 458         of_property_read_u32(dev->of_node, "ti,debounce",
 459                              &omap_twl_info->debounce);
 460         of_property_read_u32(dev->of_node, "ti,mmc-cd",
 461                              (u32 *)&omap_twl_info->mmc_cd);
 462         of_property_read_u32(dev->of_node, "ti,pullups",
 463                              &omap_twl_info->pullups);
 464         of_property_read_u32(dev->of_node, "ti,pulldowns",
 465                              &omap_twl_info->pulldowns);
 466
 467         return omap_twl_info;
 468 }
 469
 470 static int gpio_twl4030_probe(struct platform_device *pdev)
 471 {
 472         struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 473         struct device_node *node = pdev->dev.of_node;
 474         struct gpio_twl4030_priv *priv;
 475         int ret, irq_base;
 476
 477         priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv),
 478                             GFP_KERNEL);
 479         if (!priv)
 480                 return -ENOMEM;
 481
 482         /* maybe setup IRQs */
 483         if (is_module()) {
 484                 dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 485                 goto no_irqs;
 486         }
 487
 488         irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 489         if (irq_base < 0) {
 490                 dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 491                 return irq_base;
 492         }
 493
 494         irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 495                               &irq_domain_simple_ops, NULL);
 496
 497         ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 498         if (ret < 0)
 499                 return ret;
 500
 501         priv->irq_base = irq_base;
 502
 503 no_irqs:
 504         priv->gpio_chip = template_chip;
 505         priv->gpio_chip.base = -1;
 506         priv->gpio_chip.ngpio = TWL4030_GPIO_MAX;
 507         priv->gpio_chip.parent = &pdev->dev;
 508
 509         mutex_init(&priv->mutex);
 510
 511         if (node)
 512                 pdata = of_gpio_twl4030(&pdev->dev, pdata);
 513
 514         if (pdata == NULL) {
 515                 dev_err(&pdev->dev, "Platform data is missing\n");
 516                 return -ENXIO;
 517         }
 518
 519         /*
 520          * NOTE:  boards may waste power if they don't set pullups
 521          * and pulldowns correctly ... default for non-ULPI pins is
 522          * pulldown, and some other pins may have external pullups
 523          * or pulldowns.  Careful!
 524          */
 525         ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 526         if (ret)
 527                 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 528                         pdata->pullups, pdata->pulldowns, ret);
 529
 530         ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 531         if (ret)
 532                 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 533                         pdata->debounce, pdata->mmc_cd, ret);
 534
 535         /*
 536          * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 537          * is (still) clear if use_leds is set.
 538          */
 539         if (pdata->use_leds)
 540                 priv->gpio_chip.ngpio += 2;
 541
 542         ret = gpiochip_add_data(&priv->gpio_chip, priv);
 543         if (ret < 0) {
 544                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 545                 priv->gpio_chip.ngpio = 0;
 546                 gpio_twl4030_remove(pdev);
 547                 goto out;
 548         }
 549
 550         platform_set_drvdata(pdev, priv);
 551
 552         if (pdata->setup) {
 553                 int status;
 554
 555                 status = pdata->setup(&pdev->dev, priv->gpio_chip.base,
 556                                       TWL4030_GPIO_MAX);
 557                 if (status)
 558                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 559         }
 560
 561 out:
 562         return ret;
 563 }
 564
 565 /* Cannot use as gpio_twl4030_probe() calls us */
 566 static int gpio_twl4030_remove(struct platform_device *pdev)
 567 {
 568         struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 569         struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev);
 570         int status;
 571
 572         if (pdata && pdata->teardown) {
 573                 status = pdata->teardown(&pdev->dev, priv->gpio_chip.base,
 574                                          TWL4030_GPIO_MAX);
 575                 if (status) {
 576                         dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 577                         return status;
 578                 }
 579         }
 580
 581         gpiochip_remove(&priv->gpio_chip);
 582
 583         if (is_module())
 584                 return 0;
 585
 586         /* REVISIT no support yet for deregistering all the IRQs */
 587         WARN_ON(1);
 588         return -EIO;
 589 }
 590
 591 static const struct of_device_id twl_gpio_match[] = {
 592         { .compatible = "ti,twl4030-gpio", },
 593         { },
 594 };
 595 MODULE_DEVICE_TABLE(of, twl_gpio_match);
 596
 597 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 598 MODULE_ALIAS("platform:twl4030_gpio");
 599
 600 static struct platform_driver gpio_twl4030_driver = {
 601         .driver = {
 602                 .name   = "twl4030_gpio",
 603                 .of_match_table = twl_gpio_match,
 604         },
 605         .probe          = gpio_twl4030_probe,
 606         .remove         = gpio_twl4030_remove,
 607 };
 608
 609 static int __init gpio_twl4030_init(void)
 610 {
 611         return platform_driver_register(&gpio_twl4030_driver);
 612 }
 613 subsys_initcall(gpio_twl4030_init);
 614
 615 static void __exit gpio_twl4030_exit(void)
 616 {
 617         platform_driver_unregister(&gpio_twl4030_driver);
 618 }
 619 module_exit(gpio_twl4030_exit);
 620
 621 MODULE_AUTHOR("Texas Instruments, Inc.");
 622 MODULE_DESCRIPTION("GPIO interface for TWL4030");
 623 MODULE_LICENSE("GPL");