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_irq_base;
  55
  56 /* genirq interfaces are not available to modules */
  57 #ifdef MODULE
  58 #define is_module()     true
  59 #else
  60 #define is_module()     false
  61 #endif
  62
  63 /* GPIO_CTRL Fields */
  64 #define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  65 #define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  66 #define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  67
  68 /* Mask for GPIO registers when aggregated into a 32-bit integer */
  69 #define GPIO_32_MASK                    0x0003ffff
  70
  71 /* Data structures */
  72 static DEFINE_MUTEX(gpio_lock);
  73
  74 /* store usage of each GPIO. - each bit represents one GPIO */
  75 static unsigned int gpio_usage_count;
  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 (use TWL4030_MODULE_{LED,PWMA,PWMB}))
  91  * PWMs A and B are dedicated to LEDs A and B, respectively.
  92  */
  93
  94 #define TWL4030_LED_LEDEN       0x0
  95
  96 /* LEDEN bits */
  97 #define LEDEN_LEDAON            BIT(0)
  98 #define LEDEN_LEDBON            BIT(1)
  99 #define LEDEN_LEDAEXT           BIT(2)
 100 #define LEDEN_LEDBEXT           BIT(3)
 101 #define LEDEN_LEDAPWM           BIT(4)
 102 #define LEDEN_LEDBPWM           BIT(5)
 103 #define LEDEN_PWM_LENGTHA       BIT(6)
 104 #define LEDEN_PWM_LENGTHB       BIT(7)
 105
 106 #define TWL4030_PWMx_PWMxON     0x0
 107 #define TWL4030_PWMx_PWMxOFF    0x1
 108
 109 #define PWMxON_LENGTH           BIT(7)
 110
 111 /*----------------------------------------------------------------------*/
 112
 113 /*
 114  * To read a TWL4030 GPIO module register
 115  */
 116 static inline int gpio_twl4030_read(u8 address)
 117 {
 118         u8 data;
 119         int ret = 0;
 120
 121         ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 122         return (ret < 0) ? ret : data;
 123 }
 124
 125 /*----------------------------------------------------------------------*/
 126
 127 static u8 cached_leden;         /* protected by gpio_lock */
 128
 129 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 130  * external pullup is needed.  We could also expose the integrated PWM
 131  * as a LED brightness control; we initialize it as "always on".
 132  */
 133 static void twl4030_led_set_value(int led, int value)
 134 {
 135         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 136         int status;
 137
 138         if (led)
 139                 mask <<= 1;
 140
 141         mutex_lock(&gpio_lock);
 142         if (value)
 143                 cached_leden &= ~mask;
 144         else
 145                 cached_leden |= mask;
 146         status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 147                         TWL4030_LED_LEDEN);
 148         mutex_unlock(&gpio_lock);
 149 }
 150
 151 static int twl4030_set_gpio_direction(int gpio, int is_input)
 152 {
 153         u8 d_bnk = gpio >> 3;
 154         u8 d_msk = BIT(gpio & 0x7);
 155         u8 reg = 0;
 156         u8 base = REG_GPIODATADIR1 + d_bnk;
 157         int ret = 0;
 158
 159         mutex_lock(&gpio_lock);
 160         ret = gpio_twl4030_read(base);
 161         if (ret >= 0) {
 162                 if (is_input)
 163                         reg = ret & ~d_msk;
 164                 else
 165                         reg = ret | d_msk;
 166
 167                 ret = gpio_twl4030_write(base, reg);
 168         }
 169         mutex_unlock(&gpio_lock);
 170         return ret;
 171 }
 172
 173 static int twl4030_set_gpio_dataout(int gpio, int enable)
 174 {
 175         u8 d_bnk = gpio >> 3;
 176         u8 d_msk = BIT(gpio & 0x7);
 177         u8 base = 0;
 178
 179         if (enable)
 180                 base = REG_SETGPIODATAOUT1 + d_bnk;
 181         else
 182                 base = REG_CLEARGPIODATAOUT1 + d_bnk;
 183
 184         return gpio_twl4030_write(base, d_msk);
 185 }
 186
 187 static int twl4030_get_gpio_datain(int gpio)
 188 {
 189         u8 d_bnk = gpio >> 3;
 190         u8 d_off = gpio & 0x7;
 191         u8 base = 0;
 192         int ret = 0;
 193
 194         if (unlikely((gpio >= TWL4030_GPIO_MAX)
 195                 || !(gpio_usage_count & BIT(gpio))))
 196                 return -EPERM;
 197
 198         base = REG_GPIODATAIN1 + d_bnk;
 199         ret = gpio_twl4030_read(base);
 200         if (ret > 0)
 201                 ret = (ret >> d_off) & 0x1;
 202
 203         return ret;
 204 }
 205
 206 /*----------------------------------------------------------------------*/
 207
 208 static int twl_request(struct gpio_chip *chip, unsigned offset)
 209 {
 210         int status = 0;
 211
 212         mutex_lock(&gpio_lock);
 213
 214         /* Support the two LED outputs as output-only GPIOs. */
 215         if (offset >= TWL4030_GPIO_MAX) {
 216                 u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 217                                 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 218                 u8      module = TWL4030_MODULE_PWMA;
 219
 220                 offset -= TWL4030_GPIO_MAX;
 221                 if (offset) {
 222                         ledclr_mask <<= 1;
 223                         module = TWL4030_MODULE_PWMB;
 224                 }
 225
 226                 /* initialize PWM to always-drive */
 227                 status = twl_i2c_write_u8(module, 0x7f,
 228                                 TWL4030_PWMx_PWMxOFF);
 229                 if (status < 0)
 230                         goto done;
 231                 status = twl_i2c_write_u8(module, 0x7f,
 232                                 TWL4030_PWMx_PWMxON);
 233                 if (status < 0)
 234                         goto done;
 235
 236                 /* init LED to not-driven (high) */
 237                 module = TWL4030_MODULE_LED;
 238                 status = twl_i2c_read_u8(module, &cached_leden,
 239                                 TWL4030_LED_LEDEN);
 240                 if (status < 0)
 241                         goto done;
 242                 cached_leden &= ~ledclr_mask;
 243                 status = twl_i2c_write_u8(module, cached_leden,
 244                                 TWL4030_LED_LEDEN);
 245                 if (status < 0)
 246                         goto done;
 247
 248                 status = 0;
 249                 goto done;
 250         }
 251
 252         /* on first use, turn GPIO module "on" */
 253         if (!gpio_usage_count) {
 254                 struct twl4030_gpio_platform_data *pdata;
 255                 u8 value = MASK_GPIO_CTRL_GPIO_ON;
 256
 257                 /* optionally have the first two GPIOs switch vMMC1
 258                  * and vMMC2 power supplies based on card presence.
 259                  */
 260                 pdata = chip->dev->platform_data;
 261                 if (pdata)
 262                         value |= pdata->mmc_cd & 0x03;
 263
 264                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 265         }
 266
 267         if (!status)
 268                 gpio_usage_count |= (0x1 << offset);
 269
 270 done:
 271         mutex_unlock(&gpio_lock);
 272         return status;
 273 }
 274
 275 static void twl_free(struct gpio_chip *chip, unsigned offset)
 276 {
 277         if (offset >= TWL4030_GPIO_MAX) {
 278                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 279                 return;
 280         }
 281
 282         mutex_lock(&gpio_lock);
 283
 284         gpio_usage_count &= ~BIT(offset);
 285
 286         /* on last use, switch off GPIO module */
 287         if (!gpio_usage_count)
 288                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 289
 290         mutex_unlock(&gpio_lock);
 291 }
 292
 293 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 294 {
 295         return (offset < TWL4030_GPIO_MAX)
 296                 ? twl4030_set_gpio_direction(offset, 1)
 297                 : -EINVAL;
 298 }
 299
 300 static int twl_get(struct gpio_chip *chip, unsigned offset)
 301 {
 302         int status = 0;
 303
 304         if (offset < TWL4030_GPIO_MAX)
 305                 status = twl4030_get_gpio_datain(offset);
 306         else if (offset == TWL4030_GPIO_MAX)
 307                 status = cached_leden & LEDEN_LEDAON;
 308         else
 309                 status = cached_leden & LEDEN_LEDBON;
 310         return (status < 0) ? 0 : status;
 311 }
 312
 313 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 314 {
 315         if (offset < TWL4030_GPIO_MAX) {
 316                 twl4030_set_gpio_dataout(offset, value);
 317                 return twl4030_set_gpio_direction(offset, 0);
 318         } else {
 319                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 320                 return 0;
 321         }
 322 }
 323
 324 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 325 {
 326         if (offset < TWL4030_GPIO_MAX)
 327                 twl4030_set_gpio_dataout(offset, value);
 328         else
 329                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 330 }
 331
 332 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 333 {
 334         return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
 335                 ? (twl4030_gpio_irq_base + offset)
 336                 : -EINVAL;
 337 }
 338
 339 static struct gpio_chip twl_gpiochip = {
 340         .label                  = "twl4030",
 341         .owner                  = THIS_MODULE,
 342         .request                = twl_request,
 343         .free                   = twl_free,
 344         .direction_input        = twl_direction_in,
 345         .get                    = twl_get,
 346         .direction_output       = twl_direction_out,
 347         .set                    = twl_set,
 348         .to_irq                 = twl_to_irq,
 349         .can_sleep              = 1,
 350 };
 351
 352 /*----------------------------------------------------------------------*/
 353
 354 static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
 355 {
 356         u8              message[6];
 357         unsigned        i, gpio_bit;
 358
 359         /* For most pins, a pulldown was enabled by default.
 360          * We should have data that's specific to this board.
 361          */
 362         for (gpio_bit = 1, i = 1; i < 6; i++) {
 363                 u8              bit_mask;
 364                 unsigned        j;
 365
 366                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 367                         if (ups & gpio_bit)
 368                                 bit_mask |= 1 << (j + 1);
 369                         else if (downs & gpio_bit)
 370                                 bit_mask |= 1 << (j + 0);
 371                 }
 372                 message[i] = bit_mask;
 373         }
 374
 375         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 376                                 REG_GPIOPUPDCTR1, 5);
 377 }
 378
 379 static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 380 {
 381         u8              message[4];
 382
 383         /* 30 msec of debouncing is always used for MMC card detect,
 384          * and is optional for everything else.
 385          */
 386         message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
 387         debounce >>= 8;
 388         message[2] = (debounce & 0xff);
 389         debounce >>= 8;
 390         message[3] = (debounce & 0x03);
 391
 392         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 393                                 REG_GPIO_DEBEN1, 3);
 394 }
 395
 396 static int gpio_twl4030_remove(struct platform_device *pdev);
 397
 398 static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
 399 {
 400         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 401         struct device_node *node = pdev->dev.of_node;
 402         int ret, irq_base;
 403
 404         /* maybe setup IRQs */
 405         if (is_module()) {
 406                 dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 407                 goto no_irqs;
 408         }
 409
 410         irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 411         if (irq_base < 0) {
 412                 dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 413                 return irq_base;
 414         }
 415
 416         irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 417                               &irq_domain_simple_ops, NULL);
 418
 419         ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 420         if (ret < 0)
 421                 return ret;
 422
 423         twl4030_gpio_irq_base = irq_base;
 424
 425 no_irqs:
 426         twl_gpiochip.base = -1;
 427         twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
 428         twl_gpiochip.dev = &pdev->dev;
 429
 430         if (pdata) {
 431                 twl_gpiochip.base = pdata->gpio_base;
 432
 433                 /*
 434                  * NOTE:  boards may waste power if they don't set pullups
 435                  * and pulldowns correctly ... default for non-ULPI pins is
 436                  * pulldown, and some other pins may have external pullups
 437                  * or pulldowns.  Careful!
 438                  */
 439                 ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 440                 if (ret)
 441                         dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 442                                         pdata->pullups, pdata->pulldowns,
 443                                         ret);
 444
 445                 ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 446                 if (ret)
 447                         dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 448                                         pdata->debounce, pdata->mmc_cd,
 449                                         ret);
 450
 451                 /*
 452                  * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 453                  * is (still) clear if use_leds is set.
 454                  */
 455                 if (pdata->use_leds)
 456                         twl_gpiochip.ngpio += 2;
 457         }
 458
 459         ret = gpiochip_add(&twl_gpiochip);
 460         if (ret < 0) {
 461                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 462                 twl_gpiochip.ngpio = 0;
 463                 gpio_twl4030_remove(pdev);
 464         } else if (pdata && pdata->setup) {
 465                 int status;
 466
 467                 status = pdata->setup(&pdev->dev,
 468                                 pdata->gpio_base, TWL4030_GPIO_MAX);
 469                 if (status)
 470                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 471         }
 472
 473         return ret;
 474 }
 475
 476 /* Cannot use __devexit as gpio_twl4030_probe() calls us */
 477 static int gpio_twl4030_remove(struct platform_device *pdev)
 478 {
 479         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 480         int status;
 481
 482         if (pdata && pdata->teardown) {
 483                 status = pdata->teardown(&pdev->dev,
 484                                 pdata->gpio_base, TWL4030_GPIO_MAX);
 485                 if (status) {
 486                         dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 487                         return status;
 488                 }
 489         }
 490
 491         status = gpiochip_remove(&twl_gpiochip);
 492         if (status < 0)
 493                 return status;
 494
 495         if (is_module())
 496                 return 0;
 497
 498         /* REVISIT no support yet for deregistering all the IRQs */
 499         WARN_ON(1);
 500         return -EIO;
 501 }
 502
 503 static const struct of_device_id twl_gpio_match[] = {
 504         { .compatible = "ti,twl4030-gpio", },
 505         { },
 506 };
 507 MODULE_DEVICE_TABLE(of, twl_gpio_match);
 508
 509 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 510 MODULE_ALIAS("platform:twl4030_gpio");
 511
 512 static struct platform_driver gpio_twl4030_driver = {
 513         .driver = {
 514                 .name   = "twl4030_gpio",
 515                 .owner  = THIS_MODULE,
 516                 .of_match_table = of_match_ptr(twl_gpio_match),
 517         },
 518         .probe          = gpio_twl4030_probe,
 519         .remove         = gpio_twl4030_remove,
 520 };
 521
 522 static int __init gpio_twl4030_init(void)
 523 {
 524         return platform_driver_register(&gpio_twl4030_driver);
 525 }
 526 subsys_initcall(gpio_twl4030_init);
 527
 528 static void __exit gpio_twl4030_exit(void)
 529 {
 530         platform_driver_unregister(&gpio_twl4030_driver);
 531 }
 532 module_exit(gpio_twl4030_exit);
 533
 534 MODULE_AUTHOR("Texas Instruments, Inc.");
 535 MODULE_DESCRIPTION("GPIO interface for TWL4030");
 536 MODULE_LICENSE("GPL");