linux/drivers/gpio/gpio-twl4030.c
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   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
  53static struct gpio_chip twl_gpiochip;
  54static 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 */
  72static DEFINE_MUTEX(gpio_lock);
  73
  74/* store usage of each GPIO. - each bit represents one GPIO */
  75static unsigned int gpio_usage_count;
  76
  77/*----------------------------------------------------------------------*/
  78
  79/*
  80 * To configure TWL4030 GPIO module registers
  81 */
  82static 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 */
 116static 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
 127static 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 */
 133static 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
 151static 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
 173static 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
 187static 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
 208static 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
 270done:
 271        mutex_unlock(&gpio_lock);
 272        return status;
 273}
 274
 275static 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
 293static 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
 300static 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
 313static 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
 324static 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
 332static 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
 339static 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
 354static 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
 379static 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
 396static int gpio_twl4030_remove(struct platform_device *pdev);
 397
 398static 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
 425no_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 */
 477static 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
 503static const struct of_device_id twl_gpio_match[] = {
 504        { .compatible = "ti,twl4030-gpio", },
 505        { },
 506};
 507MODULE_DEVICE_TABLE(of, twl_gpio_match);
 508
 509/* Note:  this hardware lives inside an I2C-based multi-function device. */
 510MODULE_ALIAS("platform:twl4030_gpio");
 511
 512static 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
 522static int __init gpio_twl4030_init(void)
 523{
 524        return platform_driver_register(&gpio_twl4030_driver);
 525}
 526subsys_initcall(gpio_twl4030_init);
 527
 528static void __exit gpio_twl4030_exit(void)
 529{
 530        platform_driver_unregister(&gpio_twl4030_driver);
 531}
 532module_exit(gpio_twl4030_exit);
 533
 534MODULE_AUTHOR("Texas Instruments, Inc.");
 535MODULE_DESCRIPTION("GPIO interface for TWL4030");
 536MODULE_LICENSE("GPL");
 537
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