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 53 static struct gpio_chip twl_gpiochip; 54 static int twl4030_gpio_base; 55 static 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 */ 73 static DEFINE_MUTEX(gpio_lock); 74 75 /* store usage of each GPIO. - each bit represents one GPIO */ 76 static unsigned int gpio_usage_count; 77 78 /*----------------------------------------------------------------------*/ 79 80 /* 81 * To configure TWL4030 GPIO module registers 82 */ 83 static 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 */ 118 static 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 /*----------------------------------------------------------------------*/ 128 129 static 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 */ 135 static 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 } 152 153 static 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 } 174 175 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 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 /*----------------------------------------------------------------------*/ 209 210 static 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); 271 272 done: 273 mutex_unlock(&gpio_lock); 274 return status; 275 } 276 277 static 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 } 294 295 static 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 } 301 302 static 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 } 314 315 static 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 } 325 326 static 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 } 333 334 static 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 } 340 341 static 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 /*----------------------------------------------------------------------*/ 355 356 static 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 } 380 381 static 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 } 397 398 static int gpio_twl4030_remove(struct platform_device *pdev); 399 400 static 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 } 422 423 static 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; 449 450 no_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 } 504 505 out: 506 return ret; 507 } 508 509 /* Cannot use as gpio_twl4030_probe() calls us */ 510 static 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 } 535 536 static const struct of_device_id twl_gpio_match[] = { 537 { .compatible = "ti,twl4030-gpio", }, 538 { }, 539 }; 540 MODULE_DEVICE_TABLE(of, twl_gpio_match); 541 542 /* Note: this hardware lives inside an I2C-based multi-function device. */ 543 MODULE_ALIAS("platform:twl4030_gpio"); 544 545 static 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 }; 554 555 static int __init gpio_twl4030_init(void) 556 { 557 return platform_driver_register(&gpio_twl4030_driver); 558 } 559 subsys_initcall(gpio_twl4030_init); 560 561 static void __exit gpio_twl4030_exit(void) 562 { 563 platform_driver_unregister(&gpio_twl4030_driver); 564 } 565 module_exit(gpio_twl4030_exit); 566 567 MODULE_AUTHOR("Texas Instruments, Inc."); 568 MODULE_DESCRIPTION("GPIO interface for TWL4030"); 569 MODULE_LICENSE("GPL"); 570