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 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 } 154 155 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 = chip->dev->platform_data; 260 if (pdata) 261 value |= pdata->mmc_cd & 0x03; 262 263 status = gpio_twl4030_write(REG_GPIO_CTRL, value); 264 } 265 266 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; 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); 357 358 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 } 369 370 static 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 } 378 379 static 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 /*----------------------------------------------------------------------*/ 393 394 static 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 } 418 419 static 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 } 435 436 static int gpio_twl4030_remove(struct platform_device *pdev); 437 438 static 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 } 460 461 static 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; 493 494 no_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 } 551 552 out: 553 return ret; 554 } 555 556 /* Cannot use as gpio_twl4030_probe() calls us */ 557 static 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 } 583 584 static const struct of_device_id twl_gpio_match[] = { 585 { .compatible = "ti,twl4030-gpio", }, 586 { }, 587 }; 588 MODULE_DEVICE_TABLE(of, twl_gpio_match); 589 590 /* Note: this hardware lives inside an I2C-based multi-function device. */ 591 MODULE_ALIAS("platform:twl4030_gpio"); 592 593 static 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 }; 602 603 static int __init gpio_twl4030_init(void) 604 { 605 return platform_driver_register(&gpio_twl4030_driver); 606 } 607 subsys_initcall(gpio_twl4030_init); 608 609 static void __exit gpio_twl4030_exit(void) 610 { 611 platform_driver_unregister(&gpio_twl4030_driver); 612 } 613 module_exit(gpio_twl4030_exit); 614 615 MODULE_AUTHOR("Texas Instruments, Inc."); 616 MODULE_DESCRIPTION("GPIO interface for TWL4030"); 617 MODULE_LICENSE("GPL"); 618