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 * 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/* genirq interfaces are not available to modules */
  52#ifdef MODULE
  53#define is_module()     true
  54#else
  55#define is_module()     false
  56#endif
  57
  58/* GPIO_CTRL Fields */
  59#define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  60#define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  61#define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  62
  63/* Mask for GPIO registers when aggregated into a 32-bit integer */
  64#define GPIO_32_MASK                    0x0003ffff
  65
  66struct gpio_twl4030_priv {
  67        struct gpio_chip gpio_chip;
  68        struct mutex mutex;
  69        int irq_base;
  70
  71        /* Bitfields for state caching */
  72        unsigned int usage_count;
  73        unsigned int direction;
  74        unsigned int out_state;
  75};
  76
  77/*----------------------------------------------------------------------*/
  78
  79static inline struct gpio_twl4030_priv *to_gpio_twl4030(struct gpio_chip *chip)
  80{
  81        return container_of(chip, struct gpio_twl4030_priv, gpio_chip);
  82}
  83
  84/*
  85 * To configure TWL4030 GPIO module registers
  86 */
  87static inline int gpio_twl4030_write(u8 address, u8 data)
  88{
  89        return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  90}
  91
  92/*----------------------------------------------------------------------*/
  93
  94/*
  95 * LED register offsets from TWL_MODULE_LED base
  96 * PWMs A and B are dedicated to LEDs A and B, respectively.
  97 */
  98
  99#define TWL4030_LED_LEDEN_REG   0x00
 100#define TWL4030_PWMAON_REG      0x01
 101#define TWL4030_PWMAOFF_REG     0x02
 102#define TWL4030_PWMBON_REG      0x03
 103#define TWL4030_PWMBOFF_REG     0x04
 104
 105/* LEDEN bits */
 106#define LEDEN_LEDAON            BIT(0)
 107#define LEDEN_LEDBON            BIT(1)
 108#define LEDEN_LEDAEXT           BIT(2)
 109#define LEDEN_LEDBEXT           BIT(3)
 110#define LEDEN_LEDAPWM           BIT(4)
 111#define LEDEN_LEDBPWM           BIT(5)
 112#define LEDEN_PWM_LENGTHA       BIT(6)
 113#define LEDEN_PWM_LENGTHB       BIT(7)
 114
 115#define PWMxON_LENGTH           BIT(7)
 116
 117/*----------------------------------------------------------------------*/
 118
 119/*
 120 * To read a TWL4030 GPIO module register
 121 */
 122static inline int gpio_twl4030_read(u8 address)
 123{
 124        u8 data;
 125        int ret = 0;
 126
 127        ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 128        return (ret < 0) ? ret : data;
 129}
 130
 131/*----------------------------------------------------------------------*/
 132
 133static u8 cached_leden;
 134
 135/* The LED lines are open drain outputs ... a FET pulls to GND, so an
 136 * external pullup is needed.  We could also expose the integrated PWM
 137 * as a LED brightness control; we initialize it as "always on".
 138 */
 139static void twl4030_led_set_value(int led, int value)
 140{
 141        u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 142        int status;
 143
 144        if (led)
 145                mask <<= 1;
 146
 147        if (value)
 148                cached_leden &= ~mask;
 149        else
 150                cached_leden |= mask;
 151        status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 152                                  TWL4030_LED_LEDEN_REG);
 153}
 154
 155static int twl4030_set_gpio_direction(int gpio, int is_input)
 156{
 157        u8 d_bnk = gpio >> 3;
 158        u8 d_msk = BIT(gpio & 0x7);
 159        u8 reg = 0;
 160        u8 base = REG_GPIODATADIR1 + d_bnk;
 161        int ret = 0;
 162
 163        ret = gpio_twl4030_read(base);
 164        if (ret >= 0) {
 165                if (is_input)
 166                        reg = ret & ~d_msk;
 167                else
 168                        reg = ret | d_msk;
 169
 170                ret = gpio_twl4030_write(base, reg);
 171        }
 172        return ret;
 173}
 174
 175static 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
 189static 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        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
 206static int twl_request(struct gpio_chip *chip, unsigned offset)
 207{
 208        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 209        int status = 0;
 210
 211        mutex_lock(&priv->mutex);
 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      reg = TWL4030_PWMAON_REG;
 218
 219                offset -= TWL4030_GPIO_MAX;
 220                if (offset) {
 221                        ledclr_mask <<= 1;
 222                        reg = TWL4030_PWMBON_REG;
 223                }
 224
 225                /* initialize PWM to always-drive */
 226                /* Configure PWM OFF register first */
 227                status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1);
 228                if (status < 0)
 229                        goto done;
 230
 231                /* Followed by PWM ON register */
 232                status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg);
 233                if (status < 0)
 234                        goto done;
 235
 236                /* init LED to not-driven (high) */
 237                status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden,
 238                                         TWL4030_LED_LEDEN_REG);
 239                if (status < 0)
 240                        goto done;
 241                cached_leden &= ~ledclr_mask;
 242                status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 243                                          TWL4030_LED_LEDEN_REG);
 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 (!priv->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                if (pdata)
 261                        value |= pdata->mmc_cd & 0x03;
 262
 263                status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 264        }
 265
 266done:
 267        if (!status)
 268                priv->usage_count |= BIT(offset);
 269
 270        mutex_unlock(&priv->mutex);
 271        return status;
 272}
 273
 274static void twl_free(struct gpio_chip *chip, unsigned offset)
 275{
 276        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 277
 278        mutex_lock(&priv->mutex);
 279        if (offset >= TWL4030_GPIO_MAX) {
 280                twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 281                goto out;
 282        }
 283
 284        priv->usage_count &= ~BIT(offset);
 285
 286        /* on last use, switch off GPIO module */
 287        if (!priv->usage_count)
 288                gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 289
 290out:
 291        mutex_unlock(&priv->mutex);
 292}
 293
 294static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 295{
 296        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 297        int ret;
 298
 299        mutex_lock(&priv->mutex);
 300        if (offset < TWL4030_GPIO_MAX)
 301                ret = twl4030_set_gpio_direction(offset, 1);
 302        else
 303                ret = -EINVAL;
 304
 305        if (!ret)
 306                priv->direction &= ~BIT(offset);
 307
 308        mutex_unlock(&priv->mutex);
 309
 310        return ret;
 311}
 312
 313static int twl_get(struct gpio_chip *chip, unsigned offset)
 314{
 315        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 316        int ret;
 317        int status = 0;
 318
 319        mutex_lock(&priv->mutex);
 320        if (!(priv->usage_count & BIT(offset))) {
 321                ret = -EPERM;
 322                goto out;
 323        }
 324
 325        if (priv->direction & BIT(offset))
 326                status = priv->out_state & BIT(offset);
 327        else
 328                status = twl4030_get_gpio_datain(offset);
 329
 330        ret = (status <= 0) ? 0 : 1;
 331out:
 332        mutex_unlock(&priv->mutex);
 333        return ret;
 334}
 335
 336static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 337{
 338        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 339
 340        mutex_lock(&priv->mutex);
 341        if (offset < TWL4030_GPIO_MAX)
 342                twl4030_set_gpio_dataout(offset, value);
 343        else
 344                twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 345
 346        if (value)
 347                priv->out_state |= BIT(offset);
 348        else
 349                priv->out_state &= ~BIT(offset);
 350
 351        mutex_unlock(&priv->mutex);
 352}
 353
 354static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 355{
 356        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 357
 358        mutex_lock(&priv->mutex);
 359        if (offset < TWL4030_GPIO_MAX)
 360                twl4030_set_gpio_dataout(offset, value);
 361
 362        priv->direction |= BIT(offset);
 363        mutex_unlock(&priv->mutex);
 364
 365        twl_set(chip, offset, value);
 366
 367        return 0;
 368}
 369
 370static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 371{
 372        struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
 373
 374        return (priv->irq_base && (offset < TWL4030_GPIO_MAX))
 375                ? (priv->irq_base + offset)
 376                : -EINVAL;
 377}
 378
 379static struct gpio_chip template_chip = {
 380        .label                  = "twl4030",
 381        .owner                  = THIS_MODULE,
 382        .request                = twl_request,
 383        .free                   = twl_free,
 384        .direction_input        = twl_direction_in,
 385        .get                    = twl_get,
 386        .direction_output       = twl_direction_out,
 387        .set                    = twl_set,
 388        .to_irq                 = twl_to_irq,
 389        .can_sleep              = 1,
 390};
 391
 392/*----------------------------------------------------------------------*/
 393
 394static int gpio_twl4030_pulls(u32 ups, u32 downs)
 395{
 396        u8              message[5];
 397        unsigned        i, gpio_bit;
 398
 399        /* For most pins, a pulldown was enabled by default.
 400         * We should have data that's specific to this board.
 401         */
 402        for (gpio_bit = 1, i = 0; i < 5; i++) {
 403                u8              bit_mask;
 404                unsigned        j;
 405
 406                for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 407                        if (ups & gpio_bit)
 408                                bit_mask |= 1 << (j + 1);
 409                        else if (downs & gpio_bit)
 410                                bit_mask |= 1 << (j + 0);
 411                }
 412                message[i] = bit_mask;
 413        }
 414
 415        return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 416                                REG_GPIOPUPDCTR1, 5);
 417}
 418
 419static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 420{
 421        u8              message[3];
 422
 423        /* 30 msec of debouncing is always used for MMC card detect,
 424         * and is optional for everything else.
 425         */
 426        message[0] = (debounce & 0xff) | (mmc_cd & 0x03);
 427        debounce >>= 8;
 428        message[1] = (debounce & 0xff);
 429        debounce >>= 8;
 430        message[2] = (debounce & 0x03);
 431
 432        return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 433                                REG_GPIO_DEBEN1, 3);
 434}
 435
 436static int gpio_twl4030_remove(struct platform_device *pdev);
 437
 438static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev)
 439{
 440        struct twl4030_gpio_platform_data *omap_twl_info;
 441
 442        omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 443        if (!omap_twl_info)
 444                return NULL;
 445
 446        omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 447                        "ti,use-leds");
 448
 449        of_property_read_u32(dev->of_node, "ti,debounce",
 450                             &omap_twl_info->debounce);
 451        of_property_read_u32(dev->of_node, "ti,mmc-cd",
 452                             (u32 *)&omap_twl_info->mmc_cd);
 453        of_property_read_u32(dev->of_node, "ti,pullups",
 454                             &omap_twl_info->pullups);
 455        of_property_read_u32(dev->of_node, "ti,pulldowns",
 456                             &omap_twl_info->pulldowns);
 457
 458        return omap_twl_info;
 459}
 460
 461static int gpio_twl4030_probe(struct platform_device *pdev)
 462{
 463        struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 464        struct device_node *node = pdev->dev.of_node;
 465        struct gpio_twl4030_priv *priv;
 466        int ret, irq_base;
 467
 468        priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv),
 469                            GFP_KERNEL);
 470        if (!priv)
 471                return -ENOMEM;
 472
 473        /* maybe setup IRQs */
 474        if (is_module()) {
 475                dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 476                goto no_irqs;
 477        }
 478
 479        irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 480        if (irq_base < 0) {
 481                dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 482                return irq_base;
 483        }
 484
 485        irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 486                              &irq_domain_simple_ops, NULL);
 487
 488        ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 489        if (ret < 0)
 490                return ret;
 491
 492        priv->irq_base = irq_base;
 493
 494no_irqs:
 495        priv->gpio_chip = template_chip;
 496        priv->gpio_chip.base = -1;
 497        priv->gpio_chip.ngpio = TWL4030_GPIO_MAX;
 498        priv->gpio_chip.dev = &pdev->dev;
 499
 500        mutex_init(&priv->mutex);
 501
 502        if (node)
 503                pdata = of_gpio_twl4030(&pdev->dev);
 504
 505        if (pdata == NULL) {
 506                dev_err(&pdev->dev, "Platform data is missing\n");
 507                return -ENXIO;
 508        }
 509
 510        /*
 511         * NOTE:  boards may waste power if they don't set pullups
 512         * and pulldowns correctly ... default for non-ULPI pins is
 513         * pulldown, and some other pins may have external pullups
 514         * or pulldowns.  Careful!
 515         */
 516        ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 517        if (ret)
 518                dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 519                        pdata->pullups, pdata->pulldowns, ret);
 520
 521        ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 522        if (ret)
 523                dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 524                        pdata->debounce, pdata->mmc_cd, ret);
 525
 526        /*
 527         * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 528         * is (still) clear if use_leds is set.
 529         */
 530        if (pdata->use_leds)
 531                priv->gpio_chip.ngpio += 2;
 532
 533        ret = gpiochip_add(&priv->gpio_chip);
 534        if (ret < 0) {
 535                dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 536                priv->gpio_chip.ngpio = 0;
 537                gpio_twl4030_remove(pdev);
 538                goto out;
 539        }
 540
 541        platform_set_drvdata(pdev, priv);
 542
 543        if (pdata && pdata->setup) {
 544                int status;
 545
 546                status = pdata->setup(&pdev->dev, priv->gpio_chip.base,
 547                                      TWL4030_GPIO_MAX);
 548                if (status)
 549                        dev_dbg(&pdev->dev, "setup --> %d\n", status);
 550        }
 551
 552out:
 553        return ret;
 554}
 555
 556/* Cannot use as gpio_twl4030_probe() calls us */
 557static int gpio_twl4030_remove(struct platform_device *pdev)
 558{
 559        struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 560        struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev);
 561        int status;
 562
 563        if (pdata && pdata->teardown) {
 564                status = pdata->teardown(&pdev->dev, priv->gpio_chip.base,
 565                                         TWL4030_GPIO_MAX);
 566                if (status) {
 567                        dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 568                        return status;
 569                }
 570        }
 571
 572        status = gpiochip_remove(&priv->gpio_chip);
 573        if (status < 0)
 574                return status;
 575
 576        if (is_module())
 577                return 0;
 578
 579        /* REVISIT no support yet for deregistering all the IRQs */
 580        WARN_ON(1);
 581        return -EIO;
 582}
 583
 584static const struct of_device_id twl_gpio_match[] = {
 585        { .compatible = "ti,twl4030-gpio", },
 586        { },
 587};
 588MODULE_DEVICE_TABLE(of, twl_gpio_match);
 589
 590/* Note:  this hardware lives inside an I2C-based multi-function device. */
 591MODULE_ALIAS("platform:twl4030_gpio");
 592
 593static struct platform_driver gpio_twl4030_driver = {
 594        .driver = {
 595                .name   = "twl4030_gpio",
 596                .owner  = THIS_MODULE,
 597                .of_match_table = of_match_ptr(twl_gpio_match),
 598        },
 599        .probe          = gpio_twl4030_probe,
 600        .remove         = gpio_twl4030_remove,
 601};
 602
 603static int __init gpio_twl4030_init(void)
 604{
 605        return platform_driver_register(&gpio_twl4030_driver);
 606}
 607subsys_initcall(gpio_twl4030_init);
 608
 609static void __exit gpio_twl4030_exit(void)
 610{
 611        platform_driver_unregister(&gpio_twl4030_driver);
 612}
 613module_exit(gpio_twl4030_exit);
 614
 615MODULE_AUTHOR("Texas Instruments, Inc.");
 616MODULE_DESCRIPTION("GPIO interface for TWL4030");
 617MODULE_LICENSE("GPL");
 618
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