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 66 struct 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 79 static 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 */ 87 static 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 */ 122 static 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 /*----------------------------------------------------------------------*/ 132 133 static 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 */ 139 static void twl4030_led_set_value(int led, int value) 140 { 141 u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM; 142 143 if (led) 144 mask <<= 1; 145 146 if (value) 147 cached_leden &= ~mask; 148 else 149 cached_leden |= mask; 150 151 WARN_ON_ONCE(twl_i2c_write_u8(TWL4030_MODULE_LED, cached_leden, 152 TWL4030_LED_LEDEN_REG)); 153 } 154 155 static 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 } 174 175 static 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 } 188 189 static 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 /*----------------------------------------------------------------------*/ 205 206 static 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 = dev_get_platdata(chip->dev); 260 if (pdata) 261 value |= pdata->mmc_cd & 0x03; 262 263 status = gpio_twl4030_write(REG_GPIO_CTRL, value); 264 } 265 266 done: 267 if (!status) 268 priv->usage_count |= BIT(offset); 269 270 mutex_unlock(&priv->mutex); 271 return status; 272 } 273 274 static 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); 289 290 out: 291 mutex_unlock(&priv->mutex); 292 } 293 294 static 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; /* LED outputs can't be set as input */ 304 305 if (!ret) 306 priv->direction &= ~BIT(offset); 307 308 mutex_unlock(&priv->mutex); 309 310 return ret; 311 } 312 313 static 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; 331 out: 332 mutex_unlock(&priv->mutex); 333 return ret; 334 } 335 336 static 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 } 353 354 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) 355 { 356 struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); 357 int ret = 0; 358 359 mutex_lock(&priv->mutex); 360 if (offset < TWL4030_GPIO_MAX) { 361 ret = twl4030_set_gpio_direction(offset, 0); 362 if (ret) { 363 mutex_unlock(&priv->mutex); 364 return ret; 365 } 366 } 367 368 /* 369 * LED gpios i.e. offset >= TWL4030_GPIO_MAX are always output 370 */ 371 372 priv->direction |= BIT(offset); 373 mutex_unlock(&priv->mutex); 374 375 twl_set(chip, offset, value); 376 377 return ret; 378 } 379 380 static int twl_to_irq(struct gpio_chip *chip, unsigned offset) 381 { 382 struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); 383 384 return (priv->irq_base && (offset < TWL4030_GPIO_MAX)) 385 ? (priv->irq_base + offset) 386 : -EINVAL; 387 } 388 389 static struct gpio_chip template_chip = { 390 .label = "twl4030", 391 .owner = THIS_MODULE, 392 .request = twl_request, 393 .free = twl_free, 394 .direction_input = twl_direction_in, 395 .get = twl_get, 396 .direction_output = twl_direction_out, 397 .set = twl_set, 398 .to_irq = twl_to_irq, 399 .can_sleep = true, 400 }; 401 402 /*----------------------------------------------------------------------*/ 403 404 static int gpio_twl4030_pulls(u32 ups, u32 downs) 405 { 406 u8 message[5]; 407 unsigned i, gpio_bit; 408 409 /* For most pins, a pulldown was enabled by default. 410 * We should have data that's specific to this board. 411 */ 412 for (gpio_bit = 1, i = 0; i < 5; i++) { 413 u8 bit_mask; 414 unsigned j; 415 416 for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) { 417 if (ups & gpio_bit) 418 bit_mask |= 1 << (j + 1); 419 else if (downs & gpio_bit) 420 bit_mask |= 1 << (j + 0); 421 } 422 message[i] = bit_mask; 423 } 424 425 return twl_i2c_write(TWL4030_MODULE_GPIO, message, 426 REG_GPIOPUPDCTR1, 5); 427 } 428 429 static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd) 430 { 431 u8 message[3]; 432 433 /* 30 msec of debouncing is always used for MMC card detect, 434 * and is optional for everything else. 435 */ 436 message[0] = (debounce & 0xff) | (mmc_cd & 0x03); 437 debounce >>= 8; 438 message[1] = (debounce & 0xff); 439 debounce >>= 8; 440 message[2] = (debounce & 0x03); 441 442 return twl_i2c_write(TWL4030_MODULE_GPIO, message, 443 REG_GPIO_DEBEN1, 3); 444 } 445 446 static int gpio_twl4030_remove(struct platform_device *pdev); 447 448 static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev, 449 struct twl4030_gpio_platform_data *pdata) 450 { 451 struct twl4030_gpio_platform_data *omap_twl_info; 452 453 omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL); 454 if (!omap_twl_info) 455 return NULL; 456 457 if (pdata) 458 *omap_twl_info = *pdata; 459 460 omap_twl_info->use_leds = of_property_read_bool(dev->of_node, 461 "ti,use-leds"); 462 463 of_property_read_u32(dev->of_node, "ti,debounce", 464 &omap_twl_info->debounce); 465 of_property_read_u32(dev->of_node, "ti,mmc-cd", 466 (u32 *)&omap_twl_info->mmc_cd); 467 of_property_read_u32(dev->of_node, "ti,pullups", 468 &omap_twl_info->pullups); 469 of_property_read_u32(dev->of_node, "ti,pulldowns", 470 &omap_twl_info->pulldowns); 471 472 return omap_twl_info; 473 } 474 475 static int gpio_twl4030_probe(struct platform_device *pdev) 476 { 477 struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 478 struct device_node *node = pdev->dev.of_node; 479 struct gpio_twl4030_priv *priv; 480 int ret, irq_base; 481 482 priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_twl4030_priv), 483 GFP_KERNEL); 484 if (!priv) 485 return -ENOMEM; 486 487 /* maybe setup IRQs */ 488 if (is_module()) { 489 dev_err(&pdev->dev, "can't dispatch IRQs from modules\n"); 490 goto no_irqs; 491 } 492 493 irq_base = irq_alloc_descs(-1, 0, TWL4030_GPIO_MAX, 0); 494 if (irq_base < 0) { 495 dev_err(&pdev->dev, "Failed to alloc irq_descs\n"); 496 return irq_base; 497 } 498 499 irq_domain_add_legacy(node, TWL4030_GPIO_MAX, irq_base, 0, 500 &irq_domain_simple_ops, NULL); 501 502 ret = twl4030_sih_setup(&pdev->dev, TWL4030_MODULE_GPIO, irq_base); 503 if (ret < 0) 504 return ret; 505 506 priv->irq_base = irq_base; 507 508 no_irqs: 509 priv->gpio_chip = template_chip; 510 priv->gpio_chip.base = -1; 511 priv->gpio_chip.ngpio = TWL4030_GPIO_MAX; 512 priv->gpio_chip.dev = &pdev->dev; 513 514 mutex_init(&priv->mutex); 515 516 if (node) 517 pdata = of_gpio_twl4030(&pdev->dev, pdata); 518 519 if (pdata == NULL) { 520 dev_err(&pdev->dev, "Platform data is missing\n"); 521 return -ENXIO; 522 } 523 524 /* 525 * NOTE: boards may waste power if they don't set pullups 526 * and pulldowns correctly ... default for non-ULPI pins is 527 * pulldown, and some other pins may have external pullups 528 * or pulldowns. Careful! 529 */ 530 ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns); 531 if (ret) 532 dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n", 533 pdata->pullups, pdata->pulldowns, ret); 534 535 ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd); 536 if (ret) 537 dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n", 538 pdata->debounce, pdata->mmc_cd, ret); 539 540 /* 541 * NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE, 542 * is (still) clear if use_leds is set. 543 */ 544 if (pdata->use_leds) 545 priv->gpio_chip.ngpio += 2; 546 547 ret = gpiochip_add(&priv->gpio_chip); 548 if (ret < 0) { 549 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret); 550 priv->gpio_chip.ngpio = 0; 551 gpio_twl4030_remove(pdev); 552 goto out; 553 } 554 555 platform_set_drvdata(pdev, priv); 556 557 if (pdata->setup) { 558 int status; 559 560 status = pdata->setup(&pdev->dev, priv->gpio_chip.base, 561 TWL4030_GPIO_MAX); 562 if (status) 563 dev_dbg(&pdev->dev, "setup --> %d\n", status); 564 } 565 566 out: 567 return ret; 568 } 569 570 /* Cannot use as gpio_twl4030_probe() calls us */ 571 static int gpio_twl4030_remove(struct platform_device *pdev) 572 { 573 struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 574 struct gpio_twl4030_priv *priv = platform_get_drvdata(pdev); 575 int status; 576 577 if (pdata && pdata->teardown) { 578 status = pdata->teardown(&pdev->dev, priv->gpio_chip.base, 579 TWL4030_GPIO_MAX); 580 if (status) { 581 dev_dbg(&pdev->dev, "teardown --> %d\n", status); 582 return status; 583 } 584 } 585 586 gpiochip_remove(&priv->gpio_chip); 587 588 if (is_module()) 589 return 0; 590 591 /* REVISIT no support yet for deregistering all the IRQs */ 592 WARN_ON(1); 593 return -EIO; 594 } 595 596 static const struct of_device_id twl_gpio_match[] = { 597 { .compatible = "ti,twl4030-gpio", }, 598 { }, 599 }; 600 MODULE_DEVICE_TABLE(of, twl_gpio_match); 601 602 /* Note: this hardware lives inside an I2C-based multi-function device. */ 603 MODULE_ALIAS("platform:twl4030_gpio"); 604 605 static struct platform_driver gpio_twl4030_driver = { 606 .driver = { 607 .name = "twl4030_gpio", 608 .owner = THIS_MODULE, 609 .of_match_table = twl_gpio_match, 610 }, 611 .probe = gpio_twl4030_probe, 612 .remove = gpio_twl4030_remove, 613 }; 614 615 static int __init gpio_twl4030_init(void) 616 { 617 return platform_driver_register(&gpio_twl4030_driver); 618 } 619 subsys_initcall(gpio_twl4030_init); 620 621 static void __exit gpio_twl4030_exit(void) 622 { 623 platform_driver_unregister(&gpio_twl4030_driver); 624 } 625 module_exit(gpio_twl4030_exit); 626 627 MODULE_AUTHOR("Texas Instruments, Inc."); 628 MODULE_DESCRIPTION("GPIO interface for TWL4030"); 629 MODULE_LICENSE("GPL"); 630