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 /*
  42  * The GPIO "subchip" supports 18 GPIOs which can be configured as
  43  * inputs or outputs, with pullups or pulldowns on each pin.  Each
  44  * GPIO can trigger interrupts on either or both edges.
  45  *
  46  * GPIO interrupts can be fed to either of two IRQ lines; this is
  47  * intended to support multiple hosts.
  48  *
  49  * There are also two LED pins used sometimes as output-only GPIOs.
  50  */
  51
  52
  53 static struct gpio_chip twl_gpiochip;
  54 static int twl4030_gpio_base;
  55 static int twl4030_gpio_irq_base;
  56
  57 /* genirq interfaces are not available to modules */
  58 #ifdef MODULE
  59 #define is_module()     true
  60 #else
  61 #define is_module()     false
  62 #endif
  63
  64 /* GPIO_CTRL Fields */
  65 #define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  66 #define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  67 #define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  68
  69 /* Mask for GPIO registers when aggregated into a 32-bit integer */
  70 #define GPIO_32_MASK                    0x0003ffff
  71
  72 /* Data structures */
  73 static DEFINE_MUTEX(gpio_lock);
  74
  75 /* store usage of each GPIO. - each bit represents one GPIO */
  76 static unsigned int gpio_usage_count;
  77
  78 /*----------------------------------------------------------------------*/
  79
  80 /*
  81  * To configure TWL4030 GPIO module registers
  82  */
  83 static inline int gpio_twl4030_write(u8 address, u8 data)
  84 {
  85         return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  86 }
  87
  88 /*----------------------------------------------------------------------*/
  89
  90 /*
  91  * LED register offsets from TWL_MODULE_LED base
  92  * PWMs A and B are dedicated to LEDs A and B, respectively.
  93  */
  94
  95 #define TWL4030_LED_LEDEN_REG   0x00
  96 #define TWL4030_PWMAON_REG      0x01
  97 #define TWL4030_PWMAOFF_REG     0x02
  98 #define TWL4030_PWMBON_REG      0x03
  99 #define TWL4030_PWMBOFF_REG     0x04
 100
 101 /* LEDEN bits */
 102 #define LEDEN_LEDAON            BIT(0)
 103 #define LEDEN_LEDBON            BIT(1)
 104 #define LEDEN_LEDAEXT           BIT(2)
 105 #define LEDEN_LEDBEXT           BIT(3)
 106 #define LEDEN_LEDAPWM           BIT(4)
 107 #define LEDEN_LEDBPWM           BIT(5)
 108 #define LEDEN_PWM_LENGTHA       BIT(6)
 109 #define LEDEN_PWM_LENGTHB       BIT(7)
 110
 111 #define PWMxON_LENGTH           BIT(7)
 112
 113 /*----------------------------------------------------------------------*/
 114
 115 /*
 116  * To read a TWL4030 GPIO module register
 117  */
 118 static inline int gpio_twl4030_read(u8 address)
 119 {
 120         u8 data;
 121         int ret = 0;
 122
 123         ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 124         return (ret < 0) ? ret : data;
 125 }
 126
 127 /*----------------------------------------------------------------------*/
 128
 129 static u8 cached_leden;         /* protected by gpio_lock */
 130
 131 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 132  * external pullup is needed.  We could also expose the integrated PWM
 133  * as a LED brightness control; we initialize it as "always on".
 134  */
 135 static void twl4030_led_set_value(int led, int value)
 136 {
 137         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 138         int status;
 139
 140         if (led)
 141                 mask <<= 1;
 142
 143         mutex_lock(&gpio_lock);
 144         if (value)
 145                 cached_leden &= ~mask;
 146         else
 147                 cached_leden |= mask;
 148         status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 149                                   TWL4030_LED_LEDEN_REG);
 150         mutex_unlock(&gpio_lock);
 151 }
 152
 153 static int twl4030_set_gpio_direction(int gpio, int is_input)
 154 {
 155         u8 d_bnk = gpio >> 3;
 156         u8 d_msk = BIT(gpio & 0x7);
 157         u8 reg = 0;
 158         u8 base = REG_GPIODATADIR1 + d_bnk;
 159         int ret = 0;
 160
 161         mutex_lock(&gpio_lock);
 162         ret = gpio_twl4030_read(base);
 163         if (ret >= 0) {
 164                 if (is_input)
 165                         reg = ret & ~d_msk;
 166                 else
 167                         reg = ret | d_msk;
 168
 169                 ret = gpio_twl4030_write(base, reg);
 170         }
 171         mutex_unlock(&gpio_lock);
 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         if (unlikely((gpio >= TWL4030_GPIO_MAX)
 197                 || !(gpio_usage_count & BIT(gpio))))
 198                 return -EPERM;
 199
 200         base = REG_GPIODATAIN1 + d_bnk;
 201         ret = gpio_twl4030_read(base);
 202         if (ret > 0)
 203                 ret = (ret >> d_off) & 0x1;
 204
 205         return ret;
 206 }
 207
 208 /*----------------------------------------------------------------------*/
 209
 210 static int twl_request(struct gpio_chip *chip, unsigned offset)
 211 {
 212         int status = 0;
 213
 214         mutex_lock(&gpio_lock);
 215
 216         /* Support the two LED outputs as output-only GPIOs. */
 217         if (offset >= TWL4030_GPIO_MAX) {
 218                 u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 219                                 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 220                 u8      reg = TWL4030_PWMAON_REG;
 221
 222                 offset -= TWL4030_GPIO_MAX;
 223                 if (offset) {
 224                         ledclr_mask <<= 1;
 225                         reg = TWL4030_PWMBON_REG;
 226                 }
 227
 228                 /* initialize PWM to always-drive */
 229                 /* Configure PWM OFF register first */
 230                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1);
 231                 if (status < 0)
 232                         goto done;
 233
 234                 /* Followed by PWM ON register */
 235                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg);
 236                 if (status < 0)
 237                         goto done;
 238
 239                 /* init LED to not-driven (high) */
 240                 status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden,
 241                                          TWL4030_LED_LEDEN_REG);
 242                 if (status < 0)
 243                         goto done;
 244                 cached_leden &= ~ledclr_mask;
 245                 status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 246                                           TWL4030_LED_LEDEN_REG);
 247                 if (status < 0)
 248                         goto done;
 249
 250                 status = 0;
 251                 goto done;
 252         }
 253
 254         /* on first use, turn GPIO module "on" */
 255         if (!gpio_usage_count) {
 256                 struct twl4030_gpio_platform_data *pdata;
 257                 u8 value = MASK_GPIO_CTRL_GPIO_ON;
 258
 259                 /* optionally have the first two GPIOs switch vMMC1
 260                  * and vMMC2 power supplies based on card presence.
 261                  */
 262                 pdata = chip->dev->platform_data;
 263                 if (pdata)
 264                         value |= pdata->mmc_cd & 0x03;
 265
 266                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 267         }
 268
 269         if (!status)
 270                 gpio_usage_count |= (0x1 << offset);
 271
 272 done:
 273         mutex_unlock(&gpio_lock);
 274         return status;
 275 }
 276
 277 static void twl_free(struct gpio_chip *chip, unsigned offset)
 278 {
 279         if (offset >= TWL4030_GPIO_MAX) {
 280                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 281                 return;
 282         }
 283
 284         mutex_lock(&gpio_lock);
 285
 286         gpio_usage_count &= ~BIT(offset);
 287
 288         /* on last use, switch off GPIO module */
 289         if (!gpio_usage_count)
 290                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 291
 292         mutex_unlock(&gpio_lock);
 293 }
 294
 295 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 296 {
 297         return (offset < TWL4030_GPIO_MAX)
 298                 ? twl4030_set_gpio_direction(offset, 1)
 299                 : -EINVAL;
 300 }
 301
 302 static int twl_get(struct gpio_chip *chip, unsigned offset)
 303 {
 304         int status = 0;
 305
 306         if (offset < TWL4030_GPIO_MAX)
 307                 status = twl4030_get_gpio_datain(offset);
 308         else if (offset == TWL4030_GPIO_MAX)
 309                 status = cached_leden & LEDEN_LEDAON;
 310         else
 311                 status = cached_leden & LEDEN_LEDBON;
 312         return (status < 0) ? 0 : status;
 313 }
 314
 315 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 316 {
 317         if (offset < TWL4030_GPIO_MAX) {
 318                 twl4030_set_gpio_dataout(offset, value);
 319                 return twl4030_set_gpio_direction(offset, 0);
 320         } else {
 321                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 322                 return 0;
 323         }
 324 }
 325
 326 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 327 {
 328         if (offset < TWL4030_GPIO_MAX)
 329                 twl4030_set_gpio_dataout(offset, value);
 330         else
 331                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 332 }
 333
 334 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 335 {
 336         return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
 337                 ? (twl4030_gpio_irq_base + offset)
 338                 : -EINVAL;
 339 }
 340
 341 static struct gpio_chip twl_gpiochip = {
 342         .label                  = "twl4030",
 343         .owner                  = THIS_MODULE,
 344         .request                = twl_request,
 345         .free                   = twl_free,
 346         .direction_input        = twl_direction_in,
 347         .get                    = twl_get,
 348         .direction_output       = twl_direction_out,
 349         .set                    = twl_set,
 350         .to_irq                 = twl_to_irq,
 351         .can_sleep              = 1,
 352 };
 353
 354 /*----------------------------------------------------------------------*/
 355
 356 static int gpio_twl4030_pulls(u32 ups, u32 downs)
 357 {
 358         u8              message[5];
 359         unsigned        i, gpio_bit;
 360
 361         /* For most pins, a pulldown was enabled by default.
 362          * We should have data that's specific to this board.
 363          */
 364         for (gpio_bit = 1, i = 0; i < 5; i++) {
 365                 u8              bit_mask;
 366                 unsigned        j;
 367
 368                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 369                         if (ups & gpio_bit)
 370                                 bit_mask |= 1 << (j + 1);
 371                         else if (downs & gpio_bit)
 372                                 bit_mask |= 1 << (j + 0);
 373                 }
 374                 message[i] = bit_mask;
 375         }
 376
 377         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 378                                 REG_GPIOPUPDCTR1, 5);
 379 }
 380
 381 static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 382 {
 383         u8              message[3];
 384
 385         /* 30 msec of debouncing is always used for MMC card detect,
 386          * and is optional for everything else.
 387          */
 388         message[0] = (debounce & 0xff) | (mmc_cd & 0x03);
 389         debounce >>= 8;
 390         message[1] = (debounce & 0xff);
 391         debounce >>= 8;
 392         message[2] = (debounce & 0x03);
 393
 394         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 395                                 REG_GPIO_DEBEN1, 3);
 396 }
 397
 398 static int gpio_twl4030_remove(struct platform_device *pdev);
 399
 400 static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev)
 401 {
 402         struct twl4030_gpio_platform_data *omap_twl_info;
 403
 404         omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 405         if (!omap_twl_info)
 406                 return NULL;
 407
 408         omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 409                         "ti,use-leds");
 410
 411         of_property_read_u32(dev->of_node, "ti,debounce",
 412                              &omap_twl_info->debounce);
 413         of_property_read_u32(dev->of_node, "ti,mmc-cd",
 414                              (u32 *)&omap_twl_info->mmc_cd);
 415         of_property_read_u32(dev->of_node, "ti,pullups",
 416                              &omap_twl_info->pullups);
 417         of_property_read_u32(dev->of_node, "ti,pulldowns",
 418                              &omap_twl_info->pulldowns);
 419
 420         return omap_twl_info;
 421 }
 422
 423 static int gpio_twl4030_probe(struct platform_device *pdev)
 424 {
 425         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 426         struct device_node *node = pdev->dev.of_node;
 427         int ret, irq_base;
 428
 429         /* maybe setup IRQs */
 430         if (is_module()) {
 431                 dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 432                 goto no_irqs;
 433         }
 434
 435         irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 436         if (irq_base < 0) {
 437                 dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 438                 return irq_base;
 439         }
 440
 441         irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 442                               &irq_domain_simple_ops, NULL);
 443
 444         ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 445         if (ret < 0)
 446                 return ret;
 447
 448         twl4030_gpio_irq_base = irq_base;
 449
 450 no_irqs:
 451         twl_gpiochip.base = -1;
 452         twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
 453         twl_gpiochip.dev = &pdev->dev;
 454
 455         if (node)
 456                 pdata = of_gpio_twl4030(&pdev->dev);
 457
 458         if (pdata == NULL) {
 459                 dev_err(&pdev->dev, "Platform data is missing\n");
 460                 return -ENXIO;
 461         }
 462
 463         /*
 464          * NOTE:  boards may waste power if they don't set pullups
 465          * and pulldowns correctly ... default for non-ULPI pins is
 466          * pulldown, and some other pins may have external pullups
 467          * or pulldowns.  Careful!
 468          */
 469         ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 470         if (ret)
 471                 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 472                         pdata->pullups, pdata->pulldowns, ret);
 473
 474         ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 475         if (ret)
 476                 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 477                         pdata->debounce, pdata->mmc_cd, ret);
 478
 479         /*
 480          * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 481          * is (still) clear if use_leds is set.
 482          */
 483         if (pdata->use_leds)
 484                 twl_gpiochip.ngpio += 2;
 485
 486         ret = gpiochip_add(&twl_gpiochip);
 487         if (ret < 0) {
 488                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 489                 twl_gpiochip.ngpio = 0;
 490                 gpio_twl4030_remove(pdev);
 491                 goto out;
 492         }
 493
 494         twl4030_gpio_base = twl_gpiochip.base;
 495
 496         if (pdata && pdata->setup) {
 497                 int status;
 498
 499                 status = pdata->setup(&pdev->dev,
 500                                 twl4030_gpio_base, TWL4030_GPIO_MAX);
 501                 if (status)
 502                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 503         }
 504
 505 out:
 506         return ret;
 507 }
 508
 509 /* Cannot use as gpio_twl4030_probe() calls us */
 510 static int gpio_twl4030_remove(struct platform_device *pdev)
 511 {
 512         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 513         int status;
 514
 515         if (pdata && pdata->teardown) {
 516                 status = pdata->teardown(&pdev->dev,
 517                                 twl4030_gpio_base, TWL4030_GPIO_MAX);
 518                 if (status) {
 519                         dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 520                         return status;
 521                 }
 522         }
 523
 524         status = gpiochip_remove(&twl_gpiochip);
 525         if (status < 0)
 526                 return status;
 527
 528         if (is_module())
 529                 return 0;
 530
 531         /* REVISIT no support yet for deregistering all the IRQs */
 532         WARN_ON(1);
 533         return -EIO;
 534 }
 535
 536 static const struct of_device_id twl_gpio_match[] = {
 537         { .compatible = "ti,twl4030-gpio", },
 538         { },
 539 };
 540 MODULE_DEVICE_TABLE(of, twl_gpio_match);
 541
 542 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 543 MODULE_ALIAS("platform:twl4030_gpio");
 544
 545 static struct platform_driver gpio_twl4030_driver = {
 546         .driver = {
 547                 .name   = "twl4030_gpio",
 548                 .owner  = THIS_MODULE,
 549                 .of_match_table = of_match_ptr(twl_gpio_match),
 550         },
 551         .probe          = gpio_twl4030_probe,
 552         .remove         = gpio_twl4030_remove,
 553 };
 554
 555 static int __init gpio_twl4030_init(void)
 556 {
 557         return platform_driver_register(&gpio_twl4030_driver);
 558 }
 559 subsys_initcall(gpio_twl4030_init);
 560
 561 static void __exit gpio_twl4030_exit(void)
 562 {
 563         platform_driver_unregister(&gpio_twl4030_driver);
 564 }
 565 module_exit(gpio_twl4030_exit);
 566
 567 MODULE_AUTHOR("Texas Instruments, Inc.");
 568 MODULE_DESCRIPTION("GPIO interface for TWL4030");
 569 MODULE_LICENSE("GPL");