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 #include <linux/slab.h>
  36
  37 #include <linux/i2c/twl4030.h>
  38
  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
  52 static struct gpio_chip twl_gpiochip;
  53 static int twl4030_gpio_irq_base;
  54
  55 /* genirq interfaces are not available to modules */
  56 #ifdef MODULE
  57 #define is_module()     true
  58 #else
  59 #define is_module()     false
  60 #endif
  61
  62 /* GPIO_CTRL Fields */
  63 #define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  64 #define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  65 #define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  66
  67 /* Mask for GPIO registers when aggregated into a 32-bit integer */
  68 #define GPIO_32_MASK                    0x0003ffff
  69
  70 /* Data structures */
  71 static DEFINE_MUTEX(gpio_lock);
  72
  73 /* store usage of each GPIO. - each bit represents one GPIO */
  74 static unsigned int gpio_usage_count;
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 /*
  79  * To configure TWL4030 GPIO module registers
  80  */
  81 static inline int gpio_twl4030_write(u8 address, u8 data)
  82 {
  83         return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  84 }
  85
  86 /*----------------------------------------------------------------------*/
  87
  88 /*
  89  * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
  90  * PWMs A and B are dedicated to LEDs A and B, respectively.
  91  */
  92
  93 #define TWL4030_LED_LEDEN       0x0
  94
  95 /* LEDEN bits */
  96 #define LEDEN_LEDAON            BIT(0)
  97 #define LEDEN_LEDBON            BIT(1)
  98 #define LEDEN_LEDAEXT           BIT(2)
  99 #define LEDEN_LEDBEXT           BIT(3)
 100 #define LEDEN_LEDAPWM           BIT(4)
 101 #define LEDEN_LEDBPWM           BIT(5)
 102 #define LEDEN_PWM_LENGTHA       BIT(6)
 103 #define LEDEN_PWM_LENGTHB       BIT(7)
 104
 105 #define TWL4030_PWMx_PWMxON     0x0
 106 #define TWL4030_PWMx_PWMxOFF    0x1
 107
 108 #define PWMxON_LENGTH           BIT(7)
 109
 110 /*----------------------------------------------------------------------*/
 111
 112 /*
 113  * To read a TWL4030 GPIO module register
 114  */
 115 static inline int gpio_twl4030_read(u8 address)
 116 {
 117         u8 data;
 118         int ret = 0;
 119
 120         ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 121         return (ret < 0) ? ret : data;
 122 }
 123
 124 /*----------------------------------------------------------------------*/
 125
 126 static u8 cached_leden;         /* protected by gpio_lock */
 127
 128 /* The LED lines are open drain outputs ... a FET pulls to GND, so an
 129  * external pullup is needed.  We could also expose the integrated PWM
 130  * as a LED brightness control; we initialize it as "always on".
 131  */
 132 static void twl4030_led_set_value(int led, int value)
 133 {
 134         u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 135         int status;
 136
 137         if (led)
 138                 mask <<= 1;
 139
 140         mutex_lock(&gpio_lock);
 141         if (value)
 142                 cached_leden &= ~mask;
 143         else
 144                 cached_leden |= mask;
 145         status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 146                         TWL4030_LED_LEDEN);
 147         mutex_unlock(&gpio_lock);
 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         mutex_lock(&gpio_lock);
 159         ret = gpio_twl4030_read(base);
 160         if (ret >= 0) {
 161                 if (is_input)
 162                         reg = ret & ~d_msk;
 163                 else
 164                         reg = ret | d_msk;
 165
 166                 ret = gpio_twl4030_write(base, reg);
 167         }
 168         mutex_unlock(&gpio_lock);
 169         return ret;
 170 }
 171
 172 static int twl4030_set_gpio_dataout(int gpio, int enable)
 173 {
 174         u8 d_bnk = gpio >> 3;
 175         u8 d_msk = BIT(gpio & 0x7);
 176         u8 base = 0;
 177
 178         if (enable)
 179                 base = REG_SETGPIODATAOUT1 + d_bnk;
 180         else
 181                 base = REG_CLEARGPIODATAOUT1 + d_bnk;
 182
 183         return gpio_twl4030_write(base, d_msk);
 184 }
 185
 186 static int twl4030_get_gpio_datain(int gpio)
 187 {
 188         u8 d_bnk = gpio >> 3;
 189         u8 d_off = gpio & 0x7;
 190         u8 base = 0;
 191         int ret = 0;
 192
 193         if (unlikely((gpio >= TWL4030_GPIO_MAX)
 194                 || !(gpio_usage_count & BIT(gpio))))
 195                 return -EPERM;
 196
 197         base = REG_GPIODATAIN1 + d_bnk;
 198         ret = gpio_twl4030_read(base);
 199         if (ret > 0)
 200                 ret = (ret >> d_off) & 0x1;
 201
 202         return ret;
 203 }
 204
 205 /*----------------------------------------------------------------------*/
 206
 207 static int twl_request(struct gpio_chip *chip, unsigned offset)
 208 {
 209         int status = 0;
 210
 211         mutex_lock(&gpio_lock);
 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      module = TWL4030_MODULE_PWMA;
 218
 219                 offset -= TWL4030_GPIO_MAX;
 220                 if (offset) {
 221                         ledclr_mask <<= 1;
 222                         module = TWL4030_MODULE_PWMB;
 223                 }
 224
 225                 /* initialize PWM to always-drive */
 226                 status = twl4030_i2c_write_u8(module, 0x7f,
 227                                 TWL4030_PWMx_PWMxOFF);
 228                 if (status < 0)
 229                         goto done;
 230                 status = twl4030_i2c_write_u8(module, 0x7f,
 231                                 TWL4030_PWMx_PWMxON);
 232                 if (status < 0)
 233                         goto done;
 234
 235                 /* init LED to not-driven (high) */
 236                 module = TWL4030_MODULE_LED;
 237                 status = twl4030_i2c_read_u8(module, &cached_leden,
 238                                 TWL4030_LED_LEDEN);
 239                 if (status < 0)
 240                         goto done;
 241                 cached_leden &= ~ledclr_mask;
 242                 status = twl4030_i2c_write_u8(module, cached_leden,
 243                                 TWL4030_LED_LEDEN);
 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 (!gpio_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                 value |= pdata->mmc_cd & 0x03;
 261
 262                 status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 263         }
 264
 265         if (!status)
 266                 gpio_usage_count |= (0x1 << offset);
 267
 268 done:
 269         mutex_unlock(&gpio_lock);
 270         return status;
 271 }
 272
 273 static void twl_free(struct gpio_chip *chip, unsigned offset)
 274 {
 275         if (offset >= TWL4030_GPIO_MAX) {
 276                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 277                 return;
 278         }
 279
 280         mutex_lock(&gpio_lock);
 281
 282         gpio_usage_count &= ~BIT(offset);
 283
 284         /* on last use, switch off GPIO module */
 285         if (!gpio_usage_count)
 286                 gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 287
 288         mutex_unlock(&gpio_lock);
 289 }
 290
 291 static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 292 {
 293         return (offset < TWL4030_GPIO_MAX)
 294                 ? twl4030_set_gpio_direction(offset, 1)
 295                 : -EINVAL;
 296 }
 297
 298 static int twl_get(struct gpio_chip *chip, unsigned offset)
 299 {
 300         int status = 0;
 301
 302         if (offset < TWL4030_GPIO_MAX)
 303                 status = twl4030_get_gpio_datain(offset);
 304         else if (offset == TWL4030_GPIO_MAX)
 305                 status = cached_leden & LEDEN_LEDAON;
 306         else
 307                 status = cached_leden & LEDEN_LEDBON;
 308         return (status < 0) ? 0 : status;
 309 }
 310
 311 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 312 {
 313         if (offset < TWL4030_GPIO_MAX) {
 314                 twl4030_set_gpio_dataout(offset, value);
 315                 return twl4030_set_gpio_direction(offset, 0);
 316         } else {
 317                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 318                 return 0;
 319         }
 320 }
 321
 322 static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 323 {
 324         if (offset < TWL4030_GPIO_MAX)
 325                 twl4030_set_gpio_dataout(offset, value);
 326         else
 327                 twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 328 }
 329
 330 static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 331 {
 332         return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
 333                 ? (twl4030_gpio_irq_base + offset)
 334                 : -EINVAL;
 335 }
 336
 337 static struct gpio_chip twl_gpiochip = {
 338         .label                  = "twl4030",
 339         .owner                  = THIS_MODULE,
 340         .request                = twl_request,
 341         .free                   = twl_free,
 342         .direction_input        = twl_direction_in,
 343         .get                    = twl_get,
 344         .direction_output       = twl_direction_out,
 345         .set                    = twl_set,
 346         .to_irq                 = twl_to_irq,
 347         .can_sleep              = 1,
 348 };
 349
 350 /*----------------------------------------------------------------------*/
 351
 352 static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
 353 {
 354         u8              message[6];
 355         unsigned        i, gpio_bit;
 356
 357         /* For most pins, a pulldown was enabled by default.
 358          * We should have data that's specific to this board.
 359          */
 360         for (gpio_bit = 1, i = 1; i < 6; i++) {
 361                 u8              bit_mask;
 362                 unsigned        j;
 363
 364                 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 365                         if (ups & gpio_bit)
 366                                 bit_mask |= 1 << (j + 1);
 367                         else if (downs & gpio_bit)
 368                                 bit_mask |= 1 << (j + 0);
 369                 }
 370                 message[i] = bit_mask;
 371         }
 372
 373         return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
 374                                 REG_GPIOPUPDCTR1, 5);
 375 }
 376
 377 static int __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 378 {
 379         u8              message[4];
 380
 381         /* 30 msec of debouncing is always used for MMC card detect,
 382          * and is optional for everything else.
 383          */
 384         message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
 385         debounce >>= 8;
 386         message[2] = (debounce & 0xff);
 387         debounce >>= 8;
 388         message[3] = (debounce & 0x03);
 389
 390         return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
 391                                 REG_GPIO_DEBEN1, 3);
 392 }
 393
 394 static int gpio_twl4030_remove(struct platform_device *pdev);
 395
 396 static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
 397 {
 398         struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 399         int ret;
 400
 401         /* maybe setup IRQs */
 402         if (pdata->irq_base) {
 403                 if (is_module()) {
 404                         dev_err(&pdev->dev,
 405                                 "can't dispatch IRQs from modules\n");
 406                         goto no_irqs;
 407                 }
 408                 ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
 409                 if (ret < 0)
 410                         return ret;
 411                 WARN_ON(ret != pdata->irq_base);
 412                 twl4030_gpio_irq_base = ret;
 413         }
 414
 415 no_irqs:
 416         /*
 417          * NOTE:  boards may waste power if they don't set pullups
 418          * and pulldowns correctly ... default for non-ULPI pins is
 419          * pulldown, and some other pins may have external pullups
 420          * or pulldowns.  Careful!
 421          */
 422         ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 423         if (ret)
 424                 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 425                                 pdata->pullups, pdata->pulldowns,
 426                                 ret);
 427
 428         ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 429         if (ret)
 430                 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 431                                 pdata->debounce, pdata->mmc_cd,
 432                                 ret);
 433
 434         twl_gpiochip.base = pdata->gpio_base;
 435         twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
 436         twl_gpiochip.dev = &pdev->dev;
 437
 438         /* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 439          * is (still) clear if use_leds is set.
 440          */
 441         if (pdata->use_leds)
 442                 twl_gpiochip.ngpio += 2;
 443
 444         ret = gpiochip_add(&twl_gpiochip);
 445         if (ret < 0) {
 446                 dev_err(&pdev->dev,
 447                                 "could not register gpiochip, %d\n",
 448                                 ret);
 449                 twl_gpiochip.ngpio = 0;
 450                 gpio_twl4030_remove(pdev);
 451         } else if (pdata->setup) {
 452                 int status;
 453
 454                 status = pdata->setup(&pdev->dev,
 455                                 pdata->gpio_base, TWL4030_GPIO_MAX);
 456                 if (status)
 457                         dev_dbg(&pdev->dev, "setup --> %d\n", status);
 458         }
 459
 460         return ret;
 461 }
 462
 463 static int __devexit 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         = __devexit_p(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");