drivers/gpio/twl4030-gpio.c

   1 /*
   2  * twl4030_gpio.c -- 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
  36 #include <linux/i2c/twl.h>
  37
  38
  39 /*
  40  * The GPIO "subchip" supports 18 GPIOs which can be configured as
  41  * inputs or outputs, with pullups or pulldowns on each pin.  Each
  42  * GPIO can trigger interrupts on either or both edges.
  43  *
  44  * GPIO interrupts can be fed to either of two IRQ lines; this is
  45  * intended to support multiple hosts.
  46  *
  47  * There are also two LED pins used sometimes as output-only GPIOs.
  48  */
  49
  50
  51 static struct gpio_chip twl_gpiochip;
  52 static int twl4030_gpio_irq_base;
  53
  54 /* genirq interfaces are not available to modules */
  55 #ifdef MODULE
  56 #define is_module()     true
  57 #else
  58 #define is_module()     false
  59 #endif
  60
  61 /* GPIO_CTRL Fields */
  62 #define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  63 #define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  64 #define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  65
  66 /* Mask for GPIO registers when aggregated into a 32-bit integer */
  67 #define GPIO_32_MASK                    0x0003ffff
  68
  69 /* Data structures */
  70 static DEFINE_MUTEX(gpio_lock);
  71
  72 /* store usage of each GPIO. - each bit represents one GPIO */
  73 static unsigned int gpio_usage_count;
  74
  75 /*----------------------------------------------------------------------*/
  76
  77 /*
  78  * To configure TWL4030 GPIO module registers
  79  */
  80 static inline int gpio_twl4030_write(u8 address, u8 data)
  81 {
  82         return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  83 }
  84
  85 /*----------------------------------------------------------------------*/
  86
  87 /*
  88  * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
  89  * PWMs A and B are dedicated to LEDs A and B, respectively.
  90  */
  91
  92 #define TWL4030_LED_LEDEN       0x0
  93
  94 /* LEDEN bits */
  95 #define LEDEN_LEDAON            BIT(0)
  96 #define LEDEN_LEDBON            BIT(1)
  97 #define LEDEN_LEDAEXT           BIT(2)
  98 #define LEDEN_LEDBEXT           BIT(3)
  99 #define LEDEN_LEDAPWM           BIT(4)
 100 #define LEDEN_LEDBPWM           BIT(5)
 101 #define LEDEN_PWM_LENGTHA       BIT(6)
 102 #define LEDEN_PWM_LENGTHB       BIT(7)
 103
 104 #define TWL4030_PWMx_PWMxON     0x0
 105 #define TWL4030_PWMx_PWMxOFF    0x1
 106
 107 #define PWMxON_LENGTH           BIT(7)
 108
 109 /*----------------------------------------------------------------------*/
 110
 111 /*
 112  * To read a TWL4030 GPIO module register
 113  */
 114 static inline int gpio_twl4030_read(u8 address)
 115 {
 116         u8 data;
 117         int ret = 0;
 118
 119         ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 120         return (ret < 0) ? ret : data;
 121 }
 122
 123 /*----------------------------------------------------------------------*/
 124
 125 static u8 cached_leden;         /* protected by gpio_lock */
 126
 127 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 128  * external pullup is needed.  We could also expose the integrated PWM
 129  * as a LED brightness control; we initialize it as "always on".
 130  */
 131 static void twl4030_led_set_value(int led, int value)
 132 {
 133         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 134         int status;
 135
 136         if (led)
 137                 mask <<= 1;
 138
 139         mutex_lock(&gpio_lock);
 140         if (value)
 141                 cached_leden &= ~mask;
 142         else
 143                 cached_leden |= mask;
 144         status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 145                         TWL4030_LED_LEDEN);
 146         mutex_unlock(&gpio_lock);
 147 }
 148
 149 static int twl4030_set_gpio_direction(int gpio, int is_input)
 150 {
 151         u8 d_bnk = gpio >> 3;
 152         u8 d_msk = BIT(gpio & 0x7);
 153         u8 reg = 0;
 154         u8 base = REG_GPIODATADIR1 + d_bnk;
 155         int ret = 0;
 156
 157         mutex_lock(&gpio_lock);
 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         mutex_unlock(&gpio_lock);
 168         return ret;
 169 }
 170
 171 static int twl4030_set_gpio_dataout(int gpio, int enable)
 172 {
 173         u8 d_bnk = gpio >> 3;
 174         u8 d_msk = BIT(gpio & 0x7);
 175         u8 base = 0;
 176
 177         if (enable)
 178                 base = REG_SETGPIODATAOUT1 + d_bnk;
 179         else
 180                 base = REG_CLEARGPIODATAOUT1 + d_bnk;
 181
 182         return gpio_twl4030_write(base, d_msk);
 183 }
 184
 185 static int twl4030_get_gpio_datain(int gpio)
 186 {
 187         u8 d_bnk = gpio >> 3;
 188         u8 d_off = gpio & 0x7;
 189         u8 base = 0;
 190         int ret = 0;
 191
 192         if (unlikely((gpio >= TWL4030_GPIO_MAX)
 193                 || !(gpio_usage_count & BIT(gpio))))
 194                 return -EPERM;
 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         int status = 0;
 209
 210         mutex_lock(&gpio_lock);
 211
 212         /* Support the two LED outputs as output-only GPIOs. */
 213         if (offset >= TWL4030_GPIO_MAX) {
 214                 u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 215                                 | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 216                 u8      module = TWL4030_MODULE_PWMA;
 217
 218                 offset -= TWL4030_GPIO_MAX;
 219                 if (offset) {
 220                         ledclr_mask <<= 1;
 221                         module = TWL4030_MODULE_PWMB;
 222                 }
 223
 224                 /* initialize PWM to always-drive */
 225                 status = twl_i2c_write_u8(module, 0x7f,
 226                                 TWL4030_PWMx_PWMxOFF);
 227                 if (status < 0)
 228                         goto done;
 229                 status = twl_i2c_write_u8(module, 0x7f,
 230                                 TWL4030_PWMx_PWMxON);
 231                 if (status < 0)
 232                         goto done;
 233
 234                 /* init LED to not-driven (high) */
 235                 module = TWL4030_MODULE_LED;
 236                 status = twl_i2c_read_u8(module, &cached_leden,
 237                                 TWL4030_LED_LEDEN);
 238                 if (status < 0)
 239                         goto done;
 240                 cached_leden &= ~ledclr_mask;
 241                 status = twl_i2c_write_u8(module, cached_leden,
 242                                 TWL4030_LED_LEDEN);
 243                 if (status < 0)
 244                         goto done;
 245
 246                 status = 0;
 247                 goto done;
 248         }
 249
 250         /* on first use, turn GPIO module "on" */
 251         if (!gpio_usage_count) {
 252                 struct twl4030_gpio_platform_data *pdata;
 253                 u8 value = MASK_GPIO_CTRL_GPIO_ON;
 254
 255                 /* optionally have the first two GPIOs switch vMMC1
 256                  * and vMMC2 power supplies based on card presence.
 257                  */
 258                 pdata = chip->dev->platform_data;
 259                 value |= pdata->mmc_cd & 0x03;
 260
 261                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 262         }
 263
 264         if (!status)
 265                 gpio_usage_count |= (0x1 << offset);
 266
 267 done:
 268         mutex_unlock(&gpio_lock);
 269         return status;
 270 }
 271
 272 static void twl_free(struct gpio_chip *chip, unsigned offset)
 273 {
 274         if (offset >= TWL4030_GPIO_MAX) {
 275                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 276                 return;
 277         }
 278
 279         mutex_lock(&gpio_lock);
 280
 281         gpio_usage_count &= ~BIT(offset);
 282
 283         /* on last use, switch off GPIO module */
 284         if (!gpio_usage_count)
 285                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 286
 287         mutex_unlock(&gpio_lock);
 288 }
 289
 290 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 291 {
 292         return (offset < TWL4030_GPIO_MAX)
 293                 ? twl4030_set_gpio_direction(offset, 1)
 294                 : -EINVAL;
 295 }
 296
 297 static int twl_get(struct gpio_chip *chip, unsigned offset)
 298 {
 299         int status = 0;
 300
 301         if (offset < TWL4030_GPIO_MAX)
 302                 status = twl4030_get_gpio_datain(offset);
 303         else if (offset == TWL4030_GPIO_MAX)
 304                 status = cached_leden & LEDEN_LEDAON;
 305         else
 306                 status = cached_leden & LEDEN_LEDBON;
 307         return (status < 0) ? 0 : status;
 308 }
 309
 310 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 311 {
 312         if (offset < TWL4030_GPIO_MAX) {
 313                 twl4030_set_gpio_dataout(offset, value);
 314                 return twl4030_set_gpio_direction(offset, 0);
 315         } else {
 316                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 317                 return 0;
 318         }
 319 }
 320
 321 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 322 {
 323         if (offset < TWL4030_GPIO_MAX)
 324                 twl4030_set_gpio_dataout(offset, value);
 325         else
 326                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 327 }
 328
 329 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 330 {
 331         return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
 332                 ? (twl4030_gpio_irq_base + offset)
 333                 : -EINVAL;
 334 }
 335
 336 static struct gpio_chip twl_gpiochip = {
 337         .label                  = "twl4030",
 338         .owner                  = THIS_MODULE,
 339         .request                = twl_request,
 340         .free                   = twl_free,
 341         .direction_input        = twl_direction_in,
 342         .get                    = twl_get,
 343         .direction_output       = twl_direction_out,
 344         .set                    = twl_set,
 345         .to_irq                 = twl_to_irq,
 346         .can_sleep              = 1,
 347 };
 348
 349 /*----------------------------------------------------------------------*/
 350
 351 static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
 352 {
 353         u8              message[6];
 354         unsigned        i, gpio_bit;
 355
 356         /* For most pins, a pulldown was enabled by default.
 357          * We should have data that's specific to this board.
 358          */
 359         for (gpio_bit = 1, i = 1; i < 6; i++) {
 360                 u8              bit_mask;
 361                 unsigned        j;
 362
 363                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 364                         if (ups & gpio_bit)
 365                                 bit_mask |= 1 << (j + 1);
 366                         else if (downs & gpio_bit)
 367                                 bit_mask |= 1 << (j + 0);
 368                 }
 369                 message[i] = bit_mask;
 370         }
 371
 372         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 373                                 REG_GPIOPUPDCTR1, 5);
 374 }
 375
 376 static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 377 {
 378         u8              message[4];
 379
 380         /* 30 msec of debouncing is always used for MMC card detect,
 381          * and is optional for everything else.
 382          */
 383         message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
 384         debounce >>= 8;
 385         message[2] = (debounce & 0xff);
 386         debounce >>= 8;
 387         message[3] = (debounce & 0x03);
 388
 389         return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 390                                 REG_GPIO_DEBEN1, 3);
 391 }
 392
 393 static int gpio_twl4030_remove(struct platform_device *pdev);
 394
 395 static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
 396 {
 397         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 398         int ret;
 399
 400         /* maybe setup IRQs */
 401         if (pdata->irq_base) {
 402                 if (is_module()) {
 403                         dev_err(&pdev->dev,
 404                                 "can't dispatch IRQs from modules\n");
 405                         goto no_irqs;
 406                 }
 407                 ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
 408                 if (ret < 0)
 409                         return ret;
 410                 WARN_ON(ret != pdata->irq_base);
 411                 twl4030_gpio_irq_base = ret;
 412         }
 413
 414 no_irqs:
 415         /*
 416          * NOTE:  boards may waste power if they don't set pullups
 417          * and pulldowns correctly ... default for non-ULPI pins is
 418          * pulldown, and some other pins may have external pullups
 419          * or pulldowns.  Careful!
 420          */
 421         ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 422         if (ret)
 423                 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 424                                 pdata->pullups, pdata->pulldowns,
 425                                 ret);
 426
 427         ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 428         if (ret)
 429                 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 430                                 pdata->debounce, pdata->mmc_cd,
 431                                 ret);
 432
 433         twl_gpiochip.base = pdata->gpio_base;
 434         twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
 435         twl_gpiochip.dev = &pdev->dev;
 436
 437         /* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 438          * is (still) clear if use_leds is set.
 439          */
 440         if (pdata->use_leds)
 441                 twl_gpiochip.ngpio += 2;
 442
 443         ret = gpiochip_add(&twl_gpiochip);
 444         if (ret < 0) {
 445                 dev_err(&pdev->dev,
 446                                 "could not register gpiochip, %d\n",
 447                                 ret);
 448                 twl_gpiochip.ngpio = 0;
 449                 gpio_twl4030_remove(pdev);
 450         } else if (pdata->setup) {
 451                 int status;
 452
 453                 status = pdata->setup(&pdev->dev,
 454                                 pdata->gpio_base, TWL4030_GPIO_MAX);
 455                 if (status)
 456                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 457         }
 458
 459         return ret;
 460 }
 461
 462 /* Cannot use __devexit as gpio_twl4030_probe() calls us */
 463 static int gpio_twl4030_remove(struct platform_device *pdev)
 464 {
 465         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 466         int status;
 467
 468         if (pdata->teardown) {
 469                 status = pdata->teardown(&pdev->dev,
 470                                 pdata->gpio_base, TWL4030_GPIO_MAX);
 471                 if (status) {
 472                         dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 473                         return status;
 474                 }
 475         }
 476
 477         status = gpiochip_remove(&twl_gpiochip);
 478         if (status < 0)
 479                 return status;
 480
 481         if (is_module())
 482                 return 0;
 483
 484         /* REVISIT no support yet for deregistering all the IRQs */
 485         WARN_ON(1);
 486         return -EIO;
 487 }
 488
 489 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 490 MODULE_ALIAS("platform:twl4030_gpio");
 491
 492 static struct platform_driver gpio_twl4030_driver = {
 493         .driver.name    = "twl4030_gpio",
 494         .driver.owner   = THIS_MODULE,
 495         .probe          = gpio_twl4030_probe,
 496         .remove         = gpio_twl4030_remove,
 497 };
 498
 499 static int __init gpio_twl4030_init(void)
 500 {
 501         return platform_driver_register(&gpio_twl4030_driver);
 502 }
 503 subsys_initcall(gpio_twl4030_init);
 504
 505 static void __exit gpio_twl4030_exit(void)
 506 {
 507         platform_driver_unregister(&gpio_twl4030_driver);
 508 }
 509 module_exit(gpio_twl4030_exit);
 510
 511 MODULE_AUTHOR("Texas Instruments, Inc.");
 512 MODULE_DESCRIPTION("GPIO interface for TWL4030");
 513 MODULE_LICENSE("GPL");