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_base;
  55static int twl4030_gpio_irq_base;
  56
  57/* genirq interfaces are not available to modules */
  58#ifdef MODULE
  59#define is_module()     true
  60#else
  61#define is_module()     false
  62#endif
  63
  64/* GPIO_CTRL Fields */
  65#define MASK_GPIO_CTRL_GPIO0CD1         BIT(0)
  66#define MASK_GPIO_CTRL_GPIO1CD2         BIT(1)
  67#define MASK_GPIO_CTRL_GPIO_ON          BIT(2)
  68
  69/* Mask for GPIO registers when aggregated into a 32-bit integer */
  70#define GPIO_32_MASK                    0x0003ffff
  71
  72/* Data structures */
  73static DEFINE_MUTEX(gpio_lock);
  74
  75/* store usage of each GPIO. - each bit represents one GPIO */
  76static unsigned int gpio_usage_count;
  77
  78/*----------------------------------------------------------------------*/
  79
  80/*
  81 * To configure TWL4030 GPIO module registers
  82 */
  83static inline int gpio_twl4030_write(u8 address, u8 data)
  84{
  85        return twl_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
  86}
  87
  88/*----------------------------------------------------------------------*/
  89
  90/*
  91 * LED register offsets from TWL_MODULE_LED base
  92 * PWMs A and B are dedicated to LEDs A and B, respectively.
  93 */
  94
  95#define TWL4030_LED_LEDEN_REG   0x00
  96#define TWL4030_PWMAON_REG      0x01
  97#define TWL4030_PWMAOFF_REG     0x02
  98#define TWL4030_PWMBON_REG      0x03
  99#define TWL4030_PWMBOFF_REG     0x04
 100
 101/* LEDEN bits */
 102#define LEDEN_LEDAON            BIT(0)
 103#define LEDEN_LEDBON            BIT(1)
 104#define LEDEN_LEDAEXT           BIT(2)
 105#define LEDEN_LEDBEXT           BIT(3)
 106#define LEDEN_LEDAPWM           BIT(4)
 107#define LEDEN_LEDBPWM           BIT(5)
 108#define LEDEN_PWM_LENGTHA       BIT(6)
 109#define LEDEN_PWM_LENGTHB       BIT(7)
 110
 111#define PWMxON_LENGTH           BIT(7)
 112
 113/*----------------------------------------------------------------------*/
 114
 115/*
 116 * To read a TWL4030 GPIO module register
 117 */
 118static inline int gpio_twl4030_read(u8 address)
 119{
 120        u8 data;
 121        int ret = 0;
 122
 123        ret = twl_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
 124        return (ret < 0) ? ret : data;
 125}
 126
 127/*----------------------------------------------------------------------*/
 128
 129static u8 cached_leden;         /* protected by gpio_lock */
 130
 131/* The LED lines are open drain outputs ... a FET pulls to GND, so an
 132 * external pullup is needed.  We could also expose the integrated PWM
 133 * as a LED brightness control; we initialize it as "always on".
 134 */
 135static void twl4030_led_set_value(int led, int value)
 136{
 137        u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
 138        int status;
 139
 140        if (led)
 141                mask <<= 1;
 142
 143        mutex_lock(&gpio_lock);
 144        if (value)
 145                cached_leden &= ~mask;
 146        else
 147                cached_leden |= mask;
 148        status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 149                                  TWL4030_LED_LEDEN_REG);
 150        mutex_unlock(&gpio_lock);
 151}
 152
 153static int twl4030_set_gpio_direction(int gpio, int is_input)
 154{
 155        u8 d_bnk = gpio >> 3;
 156        u8 d_msk = BIT(gpio & 0x7);
 157        u8 reg = 0;
 158        u8 base = REG_GPIODATADIR1 + d_bnk;
 159        int ret = 0;
 160
 161        mutex_lock(&gpio_lock);
 162        ret = gpio_twl4030_read(base);
 163        if (ret >= 0) {
 164                if (is_input)
 165                        reg = ret & ~d_msk;
 166                else
 167                        reg = ret | d_msk;
 168
 169                ret = gpio_twl4030_write(base, reg);
 170        }
 171        mutex_unlock(&gpio_lock);
 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        if (unlikely((gpio >= TWL4030_GPIO_MAX)
 197                || !(gpio_usage_count & BIT(gpio))))
 198                return -EPERM;
 199
 200        base = REG_GPIODATAIN1 + d_bnk;
 201        ret = gpio_twl4030_read(base);
 202        if (ret > 0)
 203                ret = (ret >> d_off) & 0x1;
 204
 205        return ret;
 206}
 207
 208/*----------------------------------------------------------------------*/
 209
 210static int twl_request(struct gpio_chip *chip, unsigned offset)
 211{
 212        int status = 0;
 213
 214        mutex_lock(&gpio_lock);
 215
 216        /* Support the two LED outputs as output-only GPIOs. */
 217        if (offset >= TWL4030_GPIO_MAX) {
 218                u8      ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
 219                                | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
 220                u8      reg = TWL4030_PWMAON_REG;
 221
 222                offset -= TWL4030_GPIO_MAX;
 223                if (offset) {
 224                        ledclr_mask <<= 1;
 225                        reg = TWL4030_PWMBON_REG;
 226                }
 227
 228                /* initialize PWM to always-drive */
 229                /* Configure PWM OFF register first */
 230                status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg + 1);
 231                if (status < 0)
 232                        goto done;
 233
 234                /* Followed by PWM ON register */
 235                status = twl_i2c_write_u8(TWL4030_MODULE_LED, 0x7f, reg);
 236                if (status < 0)
 237                        goto done;
 238
 239                /* init LED to not-driven (high) */
 240                status = twl_i2c_read_u8(TWL4030_MODULE_LED, &cached_leden,
 241                                         TWL4030_LED_LEDEN_REG);
 242                if (status < 0)
 243                        goto done;
 244                cached_leden &= ~ledclr_mask;
 245                status = twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
 246                                          TWL4030_LED_LEDEN_REG);
 247                if (status < 0)
 248                        goto done;
 249
 250                status = 0;
 251                goto done;
 252        }
 253
 254        /* on first use, turn GPIO module "on" */
 255        if (!gpio_usage_count) {
 256                struct twl4030_gpio_platform_data *pdata;
 257                u8 value = MASK_GPIO_CTRL_GPIO_ON;
 258
 259                /* optionally have the first two GPIOs switch vMMC1
 260                 * and vMMC2 power supplies based on card presence.
 261                 */
 262                pdata = chip->dev->platform_data;
 263                if (pdata)
 264                        value |= pdata->mmc_cd & 0x03;
 265
 266                status = gpio_twl4030_write(REG_GPIO_CTRL, value);
 267        }
 268
 269        if (!status)
 270                gpio_usage_count |= (0x1 << offset);
 271
 272done:
 273        mutex_unlock(&gpio_lock);
 274        return status;
 275}
 276
 277static void twl_free(struct gpio_chip *chip, unsigned offset)
 278{
 279        if (offset >= TWL4030_GPIO_MAX) {
 280                twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
 281                return;
 282        }
 283
 284        mutex_lock(&gpio_lock);
 285
 286        gpio_usage_count &= ~BIT(offset);
 287
 288        /* on last use, switch off GPIO module */
 289        if (!gpio_usage_count)
 290                gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
 291
 292        mutex_unlock(&gpio_lock);
 293}
 294
 295static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 296{
 297        return (offset < TWL4030_GPIO_MAX)
 298                ? twl4030_set_gpio_direction(offset, 1)
 299                : -EINVAL;
 300}
 301
 302static int twl_get(struct gpio_chip *chip, unsigned offset)
 303{
 304        int status = 0;
 305
 306        if (offset < TWL4030_GPIO_MAX)
 307                status = twl4030_get_gpio_datain(offset);
 308        else if (offset == TWL4030_GPIO_MAX)
 309                status = cached_leden & LEDEN_LEDAON;
 310        else
 311                status = cached_leden & LEDEN_LEDBON;
 312        return (status < 0) ? 0 : status;
 313}
 314
 315static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 316{
 317        if (offset < TWL4030_GPIO_MAX) {
 318                twl4030_set_gpio_dataout(offset, value);
 319                return twl4030_set_gpio_direction(offset, 0);
 320        } else {
 321                twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 322                return 0;
 323        }
 324}
 325
 326static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 327{
 328        if (offset < TWL4030_GPIO_MAX)
 329                twl4030_set_gpio_dataout(offset, value);
 330        else
 331                twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
 332}
 333
 334static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
 335{
 336        return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
 337                ? (twl4030_gpio_irq_base + offset)
 338                : -EINVAL;
 339}
 340
 341static struct gpio_chip twl_gpiochip = {
 342        .label                  = "twl4030",
 343        .owner                  = THIS_MODULE,
 344        .request                = twl_request,
 345        .free                   = twl_free,
 346        .direction_input        = twl_direction_in,
 347        .get                    = twl_get,
 348        .direction_output       = twl_direction_out,
 349        .set                    = twl_set,
 350        .to_irq                 = twl_to_irq,
 351        .can_sleep              = 1,
 352};
 353
 354/*----------------------------------------------------------------------*/
 355
 356static int gpio_twl4030_pulls(u32 ups, u32 downs)
 357{
 358        u8              message[5];
 359        unsigned        i, gpio_bit;
 360
 361        /* For most pins, a pulldown was enabled by default.
 362         * We should have data that's specific to this board.
 363         */
 364        for (gpio_bit = 1, i = 0; i < 5; i++) {
 365                u8              bit_mask;
 366                unsigned        j;
 367
 368                for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
 369                        if (ups & gpio_bit)
 370                                bit_mask |= 1 << (j + 1);
 371                        else if (downs & gpio_bit)
 372                                bit_mask |= 1 << (j + 0);
 373                }
 374                message[i] = bit_mask;
 375        }
 376
 377        return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 378                                REG_GPIOPUPDCTR1, 5);
 379}
 380
 381static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 382{
 383        u8              message[3];
 384
 385        /* 30 msec of debouncing is always used for MMC card detect,
 386         * and is optional for everything else.
 387         */
 388        message[0] = (debounce & 0xff) | (mmc_cd & 0x03);
 389        debounce >>= 8;
 390        message[1] = (debounce & 0xff);
 391        debounce >>= 8;
 392        message[2] = (debounce & 0x03);
 393
 394        return twl_i2c_write(TWL4030_MODULE_GPIO, message,
 395                                REG_GPIO_DEBEN1, 3);
 396}
 397
 398static int gpio_twl4030_remove(struct platform_device *pdev);
 399
 400static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev)
 401{
 402        struct twl4030_gpio_platform_data *omap_twl_info;
 403
 404        omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 405        if (!omap_twl_info)
 406                return NULL;
 407
 408        omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 409                        "ti,use-leds");
 410
 411        of_property_read_u32(dev->of_node, "ti,debounce",
 412                             &omap_twl_info->debounce);
 413        of_property_read_u32(dev->of_node, "ti,mmc-cd",
 414                             (u32 *)&omap_twl_info->mmc_cd);
 415        of_property_read_u32(dev->of_node, "ti,pullups",
 416                             &omap_twl_info->pullups);
 417        of_property_read_u32(dev->of_node, "ti,pulldowns",
 418                             &omap_twl_info->pulldowns);
 419
 420        return omap_twl_info;
 421}
 422
 423static int gpio_twl4030_probe(struct platform_device *pdev)
 424{
 425        struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 426        struct device_node *node = pdev->dev.of_node;
 427        int ret, irq_base;
 428
 429        /* maybe setup IRQs */
 430        if (is_module()) {
 431                dev_err(&pdev->dev, "can't dispatch IRQs from modules\n");
 432                goto no_irqs;
 433        }
 434
 435        irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0);
 436        if (irq_base < 0) {
 437                dev_err(&pdev->dev, "Failed to alloc irq_descs\n");
 438                return irq_base;
 439        }
 440
 441        irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0,
 442                              &irq_domain_simple_ops, NULL);
 443
 444        ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base);
 445        if (ret < 0)
 446                return ret;
 447
 448        twl4030_gpio_irq_base = irq_base;
 449
 450no_irqs:
 451        twl_gpiochip.base = -1;
 452        twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
 453        twl_gpiochip.dev = &pdev->dev;
 454
 455        if (node)
 456                pdata = of_gpio_twl4030(&pdev->dev);
 457
 458        if (pdata == NULL) {
 459                dev_err(&pdev->dev, "Platform data is missing\n");
 460                return -ENXIO;
 461        }
 462
 463        /*
 464         * NOTE:  boards may waste power if they don't set pullups
 465         * and pulldowns correctly ... default for non-ULPI pins is
 466         * pulldown, and some other pins may have external pullups
 467         * or pulldowns.  Careful!
 468         */
 469        ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
 470        if (ret)
 471                dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
 472                        pdata->pullups, pdata->pulldowns, ret);
 473
 474        ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
 475        if (ret)
 476                dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
 477                        pdata->debounce, pdata->mmc_cd, ret);
 478
 479        /*
 480         * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
 481         * is (still) clear if use_leds is set.
 482         */
 483        if (pdata->use_leds)
 484                twl_gpiochip.ngpio += 2;
 485
 486        ret = gpiochip_add(&twl_gpiochip);
 487        if (ret < 0) {
 488                dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
 489                twl_gpiochip.ngpio = 0;
 490                gpio_twl4030_remove(pdev);
 491                goto out;
 492        }
 493
 494        twl4030_gpio_base = twl_gpiochip.base;
 495
 496        if (pdata && pdata->setup) {
 497                int status;
 498
 499                status = pdata->setup(&pdev->dev,
 500                                twl4030_gpio_base, TWL4030_GPIO_MAX);
 501                if (status)
 502                        dev_dbg(&pdev->dev, "setup --> %d\n", status);
 503        }
 504
 505out:
 506        return ret;
 507}
 508
 509/* Cannot use as gpio_twl4030_probe() calls us */
 510static int gpio_twl4030_remove(struct platform_device *pdev)
 511{
 512        struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
 513        int status;
 514
 515        if (pdata && pdata->teardown) {
 516                status = pdata->teardown(&pdev->dev,
 517                                twl4030_gpio_base, TWL4030_GPIO_MAX);
 518                if (status) {
 519                        dev_dbg(&pdev->dev, "teardown --> %d\n", status);
 520                        return status;
 521                }
 522        }
 523
 524        status = gpiochip_remove(&twl_gpiochip);
 525        if (status < 0)
 526                return status;
 527
 528        if (is_module())
 529                return 0;
 530
 531        /* REVISIT no support yet for deregistering all the IRQs */
 532        WARN_ON(1);
 533        return -EIO;
 534}
 535
 536static const struct of_device_id twl_gpio_match[] = {
 537        { .compatible = "ti,twl4030-gpio", },
 538        { },
 539};
 540MODULE_DEVICE_TABLE(of, twl_gpio_match);
 541
 542/* Note:  this hardware lives inside an I2C-based multi-function device. */
 543MODULE_ALIAS("platform:twl4030_gpio");
 544
 545static struct platform_driver gpio_twl4030_driver = {
 546        .driver = {
 547                .name   = "twl4030_gpio",
 548                .owner  = THIS_MODULE,
 549                .of_match_table = of_match_ptr(twl_gpio_match),
 550        },
 551        .probe          = gpio_twl4030_probe,
 552        .remove         = gpio_twl4030_remove,
 553};
 554
 555static int __init gpio_twl4030_init(void)
 556{
 557        return platform_driver_register(&gpio_twl4030_driver);
 558}
 559subsys_initcall(gpio_twl4030_init);
 560
 561static void __exit gpio_twl4030_exit(void)
 562{
 563        platform_driver_unregister(&gpio_twl4030_driver);
 564}
 565module_exit(gpio_twl4030_exit);
 566
 567MODULE_AUTHOR("Texas Instruments, Inc.");
 568MODULE_DESCRIPTION("GPIO interface for TWL4030");
 569MODULE_LICENSE("GPL");
 570
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