1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * OF helpers for the GPIO API 4 * 5 * Copyright (c) 2007-2008 MontaVista Software, Inc. 6 * 7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 8 */ 9 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/errno.h> 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/of_address.h> 17 #include <linux/of_gpio.h> 18 #include <linux/pinctrl/pinctrl.h> 19 #include <linux/slab.h> 20 #include <linux/string.h> 21 22 #include <linux/gpio/consumer.h> 23 #include <linux/gpio/machine.h> 24 25 #include "gpiolib.h" 26 #include "gpiolib-of.h" 27 28 /* 29 * This is Linux-specific flags. By default controllers' and Linux' mapping 30 * match, but GPIO controllers are free to translate their own flags to 31 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 32 */ 33 enum of_gpio_flags { 34 OF_GPIO_ACTIVE_LOW = 0x1, 35 OF_GPIO_SINGLE_ENDED = 0x2, 36 OF_GPIO_OPEN_DRAIN = 0x4, 37 OF_GPIO_TRANSITORY = 0x8, 38 OF_GPIO_PULL_UP = 0x10, 39 OF_GPIO_PULL_DOWN = 0x20, 40 OF_GPIO_PULL_DISABLE = 0x40, 41 }; 42 43 /** 44 * of_gpio_named_count() - Count GPIOs for a device 45 * @np: device node to count GPIOs for 46 * @propname: property name containing gpio specifier(s) 47 * 48 * The function returns the count of GPIOs specified for a node. 49 * Note that the empty GPIO specifiers count too. Returns either 50 * Number of gpios defined in property, 51 * -EINVAL for an incorrectly formed gpios property, or 52 * -ENOENT for a missing gpios property 53 * 54 * Example: 55 * gpios = <0 56 * &gpio1 1 2 57 * 0 58 * &gpio2 3 4>; 59 * 60 * The above example defines four GPIOs, two of which are not specified. 61 * This function will return '4' 62 */ 63 static int of_gpio_named_count(const struct device_node *np, 64 const char *propname) 65 { 66 return of_count_phandle_with_args(np, propname, "#gpio-cells"); 67 } 68 69 /** 70 * of_gpio_spi_cs_get_count() - special GPIO counting for SPI 71 * @dev: Consuming device 72 * @con_id: Function within the GPIO consumer 73 * 74 * Some elder GPIO controllers need special quirks. Currently we handle 75 * the Freescale and PPC GPIO controller with bindings that doesn't use the 76 * established "cs-gpios" for chip selects but instead rely on 77 * "gpios" for the chip select lines. If we detect this, we redirect 78 * the counting of "cs-gpios" to count "gpios" transparent to the 79 * driver. 80 */ 81 static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id) 82 { 83 struct device_node *np = dev->of_node; 84 85 if (!IS_ENABLED(CONFIG_SPI_MASTER)) 86 return 0; 87 if (!con_id || strcmp(con_id, "cs")) 88 return 0; 89 if (!of_device_is_compatible(np, "fsl,spi") && 90 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") && 91 !of_device_is_compatible(np, "ibm,ppc4xx-spi")) 92 return 0; 93 return of_gpio_named_count(np, "gpios"); 94 } 95 96 int of_gpio_get_count(struct device *dev, const char *con_id) 97 { 98 int ret; 99 char propname[32]; 100 unsigned int i; 101 102 ret = of_gpio_spi_cs_get_count(dev, con_id); 103 if (ret > 0) 104 return ret; 105 106 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { 107 if (con_id) 108 snprintf(propname, sizeof(propname), "%s-%s", 109 con_id, gpio_suffixes[i]); 110 else 111 snprintf(propname, sizeof(propname), "%s", 112 gpio_suffixes[i]); 113 114 ret = of_gpio_named_count(dev->of_node, propname); 115 if (ret > 0) 116 break; 117 } 118 return ret ? ret : -ENOENT; 119 } 120 121 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data) 122 { 123 struct of_phandle_args *gpiospec = data; 124 125 return device_match_of_node(&chip->gpiodev->dev, gpiospec->np) && 126 chip->of_xlate && 127 chip->of_xlate(chip, gpiospec, NULL) >= 0; 128 } 129 130 static struct gpio_chip *of_find_gpiochip_by_xlate( 131 struct of_phandle_args *gpiospec) 132 { 133 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate); 134 } 135 136 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, 137 struct of_phandle_args *gpiospec, 138 enum of_gpio_flags *flags) 139 { 140 int ret; 141 142 if (chip->of_gpio_n_cells != gpiospec->args_count) 143 return ERR_PTR(-EINVAL); 144 145 ret = chip->of_xlate(chip, gpiospec, flags); 146 if (ret < 0) 147 return ERR_PTR(ret); 148 149 return gpiochip_get_desc(chip, ret); 150 } 151 152 /* 153 * Overrides stated polarity of a gpio line and warns when there is a 154 * discrepancy. 155 */ 156 static void of_gpio_quirk_polarity(const struct device_node *np, 157 bool active_high, 158 enum of_gpio_flags *flags) 159 { 160 if (active_high) { 161 if (*flags & OF_GPIO_ACTIVE_LOW) { 162 pr_warn("%s GPIO handle specifies active low - ignored\n", 163 of_node_full_name(np)); 164 *flags &= ~OF_GPIO_ACTIVE_LOW; 165 } 166 } else { 167 if (!(*flags & OF_GPIO_ACTIVE_LOW)) 168 pr_info("%s enforce active low on GPIO handle\n", 169 of_node_full_name(np)); 170 *flags |= OF_GPIO_ACTIVE_LOW; 171 } 172 } 173 174 /* 175 * This quirk does static polarity overrides in cases where existing 176 * DTS specified incorrect polarity. 177 */ 178 static void of_gpio_try_fixup_polarity(const struct device_node *np, 179 const char *propname, 180 enum of_gpio_flags *flags) 181 { 182 static const struct { 183 const char *compatible; 184 const char *propname; 185 bool active_high; 186 } gpios[] = { 187 #if !IS_ENABLED(CONFIG_LCD_HX8357) 188 /* 189 * Himax LCD controllers used incorrectly named 190 * "gpios-reset" property and also specified wrong 191 * polarity. 192 */ 193 { "himax,hx8357", "gpios-reset", false }, 194 { "himax,hx8369", "gpios-reset", false }, 195 #endif 196 }; 197 unsigned int i; 198 199 for (i = 0; i < ARRAY_SIZE(gpios); i++) { 200 if (of_device_is_compatible(np, gpios[i].compatible) && 201 !strcmp(propname, gpios[i].propname)) { 202 of_gpio_quirk_polarity(np, gpios[i].active_high, flags); 203 break; 204 } 205 } 206 } 207 208 static void of_gpio_set_polarity_by_property(const struct device_node *np, 209 const char *propname, 210 enum of_gpio_flags *flags) 211 { 212 const struct device_node *np_compat = np; 213 const struct device_node *np_propname = np; 214 static const struct { 215 const char *compatible; 216 const char *gpio_propname; 217 const char *polarity_propname; 218 } gpios[] = { 219 #if IS_ENABLED(CONFIG_FEC) 220 /* Freescale Fast Ethernet Controller */ 221 { "fsl,imx25-fec", "phy-reset-gpios", "phy-reset-active-high" }, 222 { "fsl,imx27-fec", "phy-reset-gpios", "phy-reset-active-high" }, 223 { "fsl,imx28-fec", "phy-reset-gpios", "phy-reset-active-high" }, 224 { "fsl,imx6q-fec", "phy-reset-gpios", "phy-reset-active-high" }, 225 { "fsl,mvf600-fec", "phy-reset-gpios", "phy-reset-active-high" }, 226 { "fsl,imx6sx-fec", "phy-reset-gpios", "phy-reset-active-high" }, 227 { "fsl,imx6ul-fec", "phy-reset-gpios", "phy-reset-active-high" }, 228 { "fsl,imx8mq-fec", "phy-reset-gpios", "phy-reset-active-high" }, 229 { "fsl,imx8qm-fec", "phy-reset-gpios", "phy-reset-active-high" }, 230 { "fsl,s32v234-fec", "phy-reset-gpios", "phy-reset-active-high" }, 231 #endif 232 #if IS_ENABLED(CONFIG_PCI_IMX6) 233 { "fsl,imx6q-pcie", "reset-gpio", "reset-gpio-active-high" }, 234 { "fsl,imx6sx-pcie", "reset-gpio", "reset-gpio-active-high" }, 235 { "fsl,imx6qp-pcie", "reset-gpio", "reset-gpio-active-high" }, 236 { "fsl,imx7d-pcie", "reset-gpio", "reset-gpio-active-high" }, 237 { "fsl,imx8mq-pcie", "reset-gpio", "reset-gpio-active-high" }, 238 { "fsl,imx8mm-pcie", "reset-gpio", "reset-gpio-active-high" }, 239 { "fsl,imx8mp-pcie", "reset-gpio", "reset-gpio-active-high" }, 240 #endif 241 242 /* 243 * The regulator GPIO handles are specified such that the 244 * presence or absence of "enable-active-high" solely controls 245 * the polarity of the GPIO line. Any phandle flags must 246 * be actively ignored. 247 */ 248 #if IS_ENABLED(CONFIG_REGULATOR_FIXED_VOLTAGE) 249 { "regulator-fixed", "gpios", "enable-active-high" }, 250 { "regulator-fixed", "gpio", "enable-active-high" }, 251 { "reg-fixed-voltage", "gpios", "enable-active-high" }, 252 { "reg-fixed-voltage", "gpio", "enable-active-high" }, 253 #endif 254 #if IS_ENABLED(CONFIG_REGULATOR_GPIO) 255 { "regulator-gpio", "enable-gpio", "enable-active-high" }, 256 { "regulator-gpio", "enable-gpios", "enable-active-high" }, 257 #endif 258 #if IS_ENABLED(CONFIG_MMC_ATMELMCI) 259 { "atmel,hsmci", "cd-gpios", "cd-inverted" }, 260 #endif 261 }; 262 unsigned int i; 263 bool active_high; 264 265 #if IS_ENABLED(CONFIG_MMC_ATMELMCI) 266 /* 267 * The Atmel HSMCI has compatible property in the parent node and 268 * gpio property in a child node 269 */ 270 if (of_device_is_compatible(np->parent, "atmel,hsmci")) { 271 np_compat = np->parent; 272 np_propname = np; 273 } 274 #endif 275 276 for (i = 0; i < ARRAY_SIZE(gpios); i++) { 277 if (of_device_is_compatible(np_compat, gpios[i].compatible) && 278 !strcmp(propname, gpios[i].gpio_propname)) { 279 active_high = of_property_read_bool(np_propname, 280 gpios[i].polarity_propname); 281 of_gpio_quirk_polarity(np, active_high, flags); 282 break; 283 } 284 } 285 } 286 287 static void of_gpio_flags_quirks(const struct device_node *np, 288 const char *propname, 289 enum of_gpio_flags *flags, 290 int index) 291 { 292 of_gpio_try_fixup_polarity(np, propname, flags); 293 of_gpio_set_polarity_by_property(np, propname, flags); 294 295 /* 296 * Legacy open drain handling for fixed voltage regulators. 297 */ 298 if (IS_ENABLED(CONFIG_REGULATOR) && 299 of_device_is_compatible(np, "reg-fixed-voltage") && 300 of_property_read_bool(np, "gpio-open-drain")) { 301 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN); 302 pr_info("%s uses legacy open drain flag - update the DTS if you can\n", 303 of_node_full_name(np)); 304 } 305 306 /* 307 * Legacy handling of SPI active high chip select. If we have a 308 * property named "cs-gpios" we need to inspect the child node 309 * to determine if the flags should have inverted semantics. 310 */ 311 if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") && 312 of_property_read_bool(np, "cs-gpios")) { 313 struct device_node *child; 314 u32 cs; 315 int ret; 316 317 for_each_child_of_node(np, child) { 318 ret = of_property_read_u32(child, "reg", &cs); 319 if (ret) 320 continue; 321 if (cs == index) { 322 /* 323 * SPI children have active low chip selects 324 * by default. This can be specified negatively 325 * by just omitting "spi-cs-high" in the 326 * device node, or actively by tagging on 327 * GPIO_ACTIVE_LOW as flag in the device 328 * tree. If the line is simultaneously 329 * tagged as active low in the device tree 330 * and has the "spi-cs-high" set, we get a 331 * conflict and the "spi-cs-high" flag will 332 * take precedence. 333 */ 334 bool active_high = of_property_read_bool(child, 335 "spi-cs-high"); 336 of_gpio_quirk_polarity(child, active_high, 337 flags); 338 of_node_put(child); 339 break; 340 } 341 } 342 } 343 344 /* Legacy handling of stmmac's active-low PHY reset line */ 345 if (IS_ENABLED(CONFIG_STMMAC_ETH) && 346 !strcmp(propname, "snps,reset-gpio") && 347 of_property_read_bool(np, "snps,reset-active-low")) 348 *flags |= OF_GPIO_ACTIVE_LOW; 349 } 350 351 /** 352 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API 353 * @np: device node to get GPIO from 354 * @propname: property name containing gpio specifier(s) 355 * @index: index of the GPIO 356 * @flags: a flags pointer to fill in 357 * 358 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno 359 * value on the error condition. If @flags is not NULL the function also fills 360 * in flags for the GPIO. 361 */ 362 static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np, 363 const char *propname, int index, enum of_gpio_flags *flags) 364 { 365 struct of_phandle_args gpiospec; 366 struct gpio_chip *chip; 367 struct gpio_desc *desc; 368 int ret; 369 370 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index, 371 &gpiospec); 372 if (ret) { 373 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n", 374 __func__, propname, np, index); 375 return ERR_PTR(ret); 376 } 377 378 chip = of_find_gpiochip_by_xlate(&gpiospec); 379 if (!chip) { 380 desc = ERR_PTR(-EPROBE_DEFER); 381 goto out; 382 } 383 384 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); 385 if (IS_ERR(desc)) 386 goto out; 387 388 if (flags) 389 of_gpio_flags_quirks(np, propname, flags, index); 390 391 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", 392 __func__, propname, np, index, 393 PTR_ERR_OR_ZERO(desc)); 394 395 out: 396 of_node_put(gpiospec.np); 397 398 return desc; 399 } 400 401 /** 402 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 403 * @np: device node to get GPIO from 404 * @propname: Name of property containing gpio specifier(s) 405 * @index: index of the GPIO 406 * 407 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 408 * value on the error condition. 409 */ 410 int of_get_named_gpio(const struct device_node *np, const char *propname, 411 int index) 412 { 413 struct gpio_desc *desc; 414 415 desc = of_get_named_gpiod_flags(np, propname, index, NULL); 416 417 if (IS_ERR(desc)) 418 return PTR_ERR(desc); 419 else 420 return desc_to_gpio(desc); 421 } 422 EXPORT_SYMBOL_GPL(of_get_named_gpio); 423 424 /* Converts gpio_lookup_flags into bitmask of GPIO_* values */ 425 static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags) 426 { 427 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT; 428 429 if (flags & OF_GPIO_ACTIVE_LOW) 430 lflags |= GPIO_ACTIVE_LOW; 431 432 if (flags & OF_GPIO_SINGLE_ENDED) { 433 if (flags & OF_GPIO_OPEN_DRAIN) 434 lflags |= GPIO_OPEN_DRAIN; 435 else 436 lflags |= GPIO_OPEN_SOURCE; 437 } 438 439 if (flags & OF_GPIO_TRANSITORY) 440 lflags |= GPIO_TRANSITORY; 441 442 if (flags & OF_GPIO_PULL_UP) 443 lflags |= GPIO_PULL_UP; 444 445 if (flags & OF_GPIO_PULL_DOWN) 446 lflags |= GPIO_PULL_DOWN; 447 448 if (flags & OF_GPIO_PULL_DISABLE) 449 lflags |= GPIO_PULL_DISABLE; 450 451 return lflags; 452 } 453 454 static struct gpio_desc *of_find_gpio_rename(struct device_node *np, 455 const char *con_id, 456 unsigned int idx, 457 enum of_gpio_flags *of_flags) 458 { 459 static const struct of_rename_gpio { 460 const char *con_id; 461 const char *legacy_id; /* NULL - same as con_id */ 462 /* 463 * Compatible string can be set to NULL in case where 464 * matching to a particular compatible is not practical, 465 * but it should only be done for gpio names that have 466 * vendor prefix to reduce risk of false positives. 467 * Addition of such entries is strongly discouraged. 468 */ 469 const char *compatible; 470 } gpios[] = { 471 #if !IS_ENABLED(CONFIG_LCD_HX8357) 472 /* Himax LCD controllers used "gpios-reset" */ 473 { "reset", "gpios-reset", "himax,hx8357" }, 474 { "reset", "gpios-reset", "himax,hx8369" }, 475 #endif 476 #if IS_ENABLED(CONFIG_MFD_ARIZONA) 477 { "wlf,reset", NULL, NULL }, 478 #endif 479 #if IS_ENABLED(CONFIG_RTC_DRV_MOXART) 480 { "rtc-data", "gpio-rtc-data", "moxa,moxart-rtc" }, 481 { "rtc-sclk", "gpio-rtc-sclk", "moxa,moxart-rtc" }, 482 { "rtc-reset", "gpio-rtc-reset", "moxa,moxart-rtc" }, 483 #endif 484 #if IS_ENABLED(CONFIG_NFC_MRVL_I2C) 485 { "reset", "reset-n-io", "marvell,nfc-i2c" }, 486 #endif 487 #if IS_ENABLED(CONFIG_NFC_MRVL_SPI) 488 { "reset", "reset-n-io", "marvell,nfc-spi" }, 489 #endif 490 #if IS_ENABLED(CONFIG_NFC_MRVL_UART) 491 { "reset", "reset-n-io", "marvell,nfc-uart" }, 492 { "reset", "reset-n-io", "mrvl,nfc-uart" }, 493 #endif 494 #if !IS_ENABLED(CONFIG_PCI_LANTIQ) 495 /* MIPS Lantiq PCI */ 496 { "reset", "gpios-reset", "lantiq,pci-xway" }, 497 #endif 498 499 /* 500 * Some regulator bindings happened before we managed to 501 * establish that GPIO properties should be named 502 * "foo-gpios" so we have this special kludge for them. 503 */ 504 #if IS_ENABLED(CONFIG_REGULATOR_ARIZONA_LDO1) 505 { "wlf,ldoena", NULL, NULL }, /* Arizona */ 506 #endif 507 #if IS_ENABLED(CONFIG_REGULATOR_WM8994) 508 { "wlf,ldo1ena", NULL, NULL }, /* WM8994 */ 509 { "wlf,ldo2ena", NULL, NULL }, /* WM8994 */ 510 #endif 511 512 #if IS_ENABLED(CONFIG_SND_SOC_CS42L56) 513 { "reset", "cirrus,gpio-nreset", "cirrus,cs42l56" }, 514 #endif 515 #if IS_ENABLED(CONFIG_SND_SOC_TLV320AIC3X) 516 { "reset", "gpio-reset", "ti,tlv320aic3x" }, 517 { "reset", "gpio-reset", "ti,tlv320aic33" }, 518 { "reset", "gpio-reset", "ti,tlv320aic3007" }, 519 { "reset", "gpio-reset", "ti,tlv320aic3104" }, 520 { "reset", "gpio-reset", "ti,tlv320aic3106" }, 521 #endif 522 #if IS_ENABLED(CONFIG_SPI_GPIO) 523 /* 524 * The SPI GPIO bindings happened before we managed to 525 * establish that GPIO properties should be named 526 * "foo-gpios" so we have this special kludge for them. 527 */ 528 { "miso", "gpio-miso", "spi-gpio" }, 529 { "mosi", "gpio-mosi", "spi-gpio" }, 530 { "sck", "gpio-sck", "spi-gpio" }, 531 #endif 532 533 /* 534 * The old Freescale bindings use simply "gpios" as name 535 * for the chip select lines rather than "cs-gpios" like 536 * all other SPI hardware. Allow this specifically for 537 * Freescale and PPC devices. 538 */ 539 #if IS_ENABLED(CONFIG_SPI_FSL_SPI) 540 { "cs", "gpios", "fsl,spi" }, 541 { "cs", "gpios", "aeroflexgaisler,spictrl" }, 542 #endif 543 #if IS_ENABLED(CONFIG_SPI_PPC4xx) 544 { "cs", "gpios", "ibm,ppc4xx-spi" }, 545 #endif 546 547 #if IS_ENABLED(CONFIG_TYPEC_FUSB302) 548 /* 549 * Fairchild FUSB302 host is using undocumented "fcs,int_n" 550 * property without the compulsory "-gpios" suffix. 551 */ 552 { "fcs,int_n", NULL, "fcs,fusb302" }, 553 #endif 554 }; 555 struct gpio_desc *desc; 556 const char *legacy_id; 557 unsigned int i; 558 559 if (!con_id) 560 return ERR_PTR(-ENOENT); 561 562 for (i = 0; i < ARRAY_SIZE(gpios); i++) { 563 if (strcmp(con_id, gpios[i].con_id)) 564 continue; 565 566 if (gpios[i].compatible && 567 !of_device_is_compatible(np, gpios[i].compatible)) 568 continue; 569 570 legacy_id = gpios[i].legacy_id ?: gpios[i].con_id; 571 desc = of_get_named_gpiod_flags(np, legacy_id, idx, of_flags); 572 if (!gpiod_not_found(desc)) { 573 pr_info("%s uses legacy gpio name '%s' instead of '%s-gpios'\n", 574 of_node_full_name(np), legacy_id, con_id); 575 return desc; 576 } 577 } 578 579 return ERR_PTR(-ENOENT); 580 } 581 582 static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np, 583 const char *con_id, 584 unsigned int idx, 585 enum of_gpio_flags *of_flags) 586 { 587 struct gpio_desc *desc; 588 const char *legacy_id; 589 590 if (!IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448)) 591 return ERR_PTR(-ENOENT); 592 593 if (!of_device_is_compatible(np, "mediatek,mt2701-cs42448-machine")) 594 return ERR_PTR(-ENOENT); 595 596 if (!con_id || strcmp(con_id, "i2s1-in-sel")) 597 return ERR_PTR(-ENOENT); 598 599 if (idx == 0) 600 legacy_id = "i2s1-in-sel-gpio1"; 601 else if (idx == 1) 602 legacy_id = "i2s1-in-sel-gpio2"; 603 else 604 return ERR_PTR(-ENOENT); 605 606 desc = of_get_named_gpiod_flags(np, legacy_id, 0, of_flags); 607 if (!gpiod_not_found(desc)) 608 pr_info("%s is using legacy gpio name '%s' instead of '%s-gpios'\n", 609 of_node_full_name(np), legacy_id, con_id); 610 611 return desc; 612 } 613 614 typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np, 615 const char *con_id, 616 unsigned int idx, 617 enum of_gpio_flags *of_flags); 618 static const of_find_gpio_quirk of_find_gpio_quirks[] = { 619 of_find_gpio_rename, 620 of_find_mt2701_gpio, 621 NULL 622 }; 623 624 struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id, 625 unsigned int idx, unsigned long *flags) 626 { 627 char prop_name[32]; /* 32 is max size of property name */ 628 enum of_gpio_flags of_flags; 629 const of_find_gpio_quirk *q; 630 struct gpio_desc *desc; 631 unsigned int i; 632 633 /* Try GPIO property "foo-gpios" and "foo-gpio" */ 634 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { 635 if (con_id) 636 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, 637 gpio_suffixes[i]); 638 else 639 snprintf(prop_name, sizeof(prop_name), "%s", 640 gpio_suffixes[i]); 641 642 desc = of_get_named_gpiod_flags(np, prop_name, idx, &of_flags); 643 644 if (!gpiod_not_found(desc)) 645 break; 646 } 647 648 /* Properly named GPIO was not found, try workarounds */ 649 for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++) 650 desc = (*q)(np, con_id, idx, &of_flags); 651 652 if (IS_ERR(desc)) 653 return desc; 654 655 *flags = of_convert_gpio_flags(of_flags); 656 657 return desc; 658 } 659 660 /** 661 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API 662 * @np: device node to get GPIO from 663 * @chip: GPIO chip whose hog is parsed 664 * @idx: Index of the GPIO to parse 665 * @name: GPIO line name 666 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from 667 * of_find_gpio() or of_parse_own_gpio() 668 * @dflags: gpiod_flags - optional GPIO initialization flags 669 * 670 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno 671 * value on the error condition. 672 */ 673 static struct gpio_desc *of_parse_own_gpio(struct device_node *np, 674 struct gpio_chip *chip, 675 unsigned int idx, const char **name, 676 unsigned long *lflags, 677 enum gpiod_flags *dflags) 678 { 679 struct device_node *chip_np; 680 enum of_gpio_flags xlate_flags; 681 struct of_phandle_args gpiospec; 682 struct gpio_desc *desc; 683 unsigned int i; 684 u32 tmp; 685 int ret; 686 687 chip_np = dev_of_node(&chip->gpiodev->dev); 688 if (!chip_np) 689 return ERR_PTR(-EINVAL); 690 691 xlate_flags = 0; 692 *lflags = GPIO_LOOKUP_FLAGS_DEFAULT; 693 *dflags = GPIOD_ASIS; 694 695 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); 696 if (ret) 697 return ERR_PTR(ret); 698 699 gpiospec.np = chip_np; 700 gpiospec.args_count = tmp; 701 702 for (i = 0; i < tmp; i++) { 703 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i, 704 &gpiospec.args[i]); 705 if (ret) 706 return ERR_PTR(ret); 707 } 708 709 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags); 710 if (IS_ERR(desc)) 711 return desc; 712 713 *lflags = of_convert_gpio_flags(xlate_flags); 714 715 if (of_property_read_bool(np, "input")) 716 *dflags |= GPIOD_IN; 717 else if (of_property_read_bool(np, "output-low")) 718 *dflags |= GPIOD_OUT_LOW; 719 else if (of_property_read_bool(np, "output-high")) 720 *dflags |= GPIOD_OUT_HIGH; 721 else { 722 pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n", 723 desc_to_gpio(desc), np); 724 return ERR_PTR(-EINVAL); 725 } 726 727 if (name && of_property_read_string(np, "line-name", name)) 728 *name = np->name; 729 730 return desc; 731 } 732 733 /** 734 * of_gpiochip_add_hog - Add all hogs in a hog device node 735 * @chip: gpio chip to act on 736 * @hog: device node describing the hogs 737 * 738 * Returns error if it fails otherwise 0 on success. 739 */ 740 static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog) 741 { 742 enum gpiod_flags dflags; 743 struct gpio_desc *desc; 744 unsigned long lflags; 745 const char *name; 746 unsigned int i; 747 int ret; 748 749 for (i = 0;; i++) { 750 desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags); 751 if (IS_ERR(desc)) 752 break; 753 754 ret = gpiod_hog(desc, name, lflags, dflags); 755 if (ret < 0) 756 return ret; 757 758 #ifdef CONFIG_OF_DYNAMIC 759 desc->hog = hog; 760 #endif 761 } 762 763 return 0; 764 } 765 766 /** 767 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions 768 * @chip: gpio chip to act on 769 * 770 * This is only used by of_gpiochip_add to request/set GPIO initial 771 * configuration. 772 * It returns error if it fails otherwise 0 on success. 773 */ 774 static int of_gpiochip_scan_gpios(struct gpio_chip *chip) 775 { 776 struct device_node *np; 777 int ret; 778 779 for_each_available_child_of_node(dev_of_node(&chip->gpiodev->dev), np) { 780 if (!of_property_read_bool(np, "gpio-hog")) 781 continue; 782 783 ret = of_gpiochip_add_hog(chip, np); 784 if (ret < 0) { 785 of_node_put(np); 786 return ret; 787 } 788 789 of_node_set_flag(np, OF_POPULATED); 790 } 791 792 return 0; 793 } 794 795 #ifdef CONFIG_OF_DYNAMIC 796 /** 797 * of_gpiochip_remove_hog - Remove all hogs in a hog device node 798 * @chip: gpio chip to act on 799 * @hog: device node describing the hogs 800 */ 801 static void of_gpiochip_remove_hog(struct gpio_chip *chip, 802 struct device_node *hog) 803 { 804 struct gpio_desc *desc; 805 806 for_each_gpio_desc_with_flag(chip, desc, FLAG_IS_HOGGED) 807 if (desc->hog == hog) 808 gpiochip_free_own_desc(desc); 809 } 810 811 static int of_gpiochip_match_node(struct gpio_chip *chip, void *data) 812 { 813 return device_match_of_node(&chip->gpiodev->dev, data); 814 } 815 816 static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np) 817 { 818 return gpiochip_find(np, of_gpiochip_match_node); 819 } 820 821 static int of_gpio_notify(struct notifier_block *nb, unsigned long action, 822 void *arg) 823 { 824 struct of_reconfig_data *rd = arg; 825 struct gpio_chip *chip; 826 int ret; 827 828 /* 829 * This only supports adding and removing complete gpio-hog nodes. 830 * Modifying an existing gpio-hog node is not supported (except for 831 * changing its "status" property, which is treated the same as 832 * addition/removal). 833 */ 834 switch (of_reconfig_get_state_change(action, arg)) { 835 case OF_RECONFIG_CHANGE_ADD: 836 if (!of_property_read_bool(rd->dn, "gpio-hog")) 837 return NOTIFY_OK; /* not for us */ 838 839 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) 840 return NOTIFY_OK; 841 842 chip = of_find_gpiochip_by_node(rd->dn->parent); 843 if (chip == NULL) 844 return NOTIFY_OK; /* not for us */ 845 846 ret = of_gpiochip_add_hog(chip, rd->dn); 847 if (ret < 0) { 848 pr_err("%s: failed to add hogs for %pOF\n", __func__, 849 rd->dn); 850 of_node_clear_flag(rd->dn, OF_POPULATED); 851 return notifier_from_errno(ret); 852 } 853 break; 854 855 case OF_RECONFIG_CHANGE_REMOVE: 856 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 857 return NOTIFY_OK; /* already depopulated */ 858 859 chip = of_find_gpiochip_by_node(rd->dn->parent); 860 if (chip == NULL) 861 return NOTIFY_OK; /* not for us */ 862 863 of_gpiochip_remove_hog(chip, rd->dn); 864 of_node_clear_flag(rd->dn, OF_POPULATED); 865 break; 866 } 867 868 return NOTIFY_OK; 869 } 870 871 struct notifier_block gpio_of_notifier = { 872 .notifier_call = of_gpio_notify, 873 }; 874 #endif /* CONFIG_OF_DYNAMIC */ 875 876 /** 877 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags 878 * @gc: pointer to the gpio_chip structure 879 * @gpiospec: GPIO specifier as found in the device tree 880 * @flags: a flags pointer to fill in 881 * 882 * This is simple translation function, suitable for the most 1:1 mapped 883 * GPIO chips. This function performs only one sanity check: whether GPIO 884 * is less than ngpios (that is specified in the gpio_chip). 885 */ 886 static int of_gpio_simple_xlate(struct gpio_chip *gc, 887 const struct of_phandle_args *gpiospec, 888 u32 *flags) 889 { 890 /* 891 * We're discouraging gpio_cells < 2, since that way you'll have to 892 * write your own xlate function (that will have to retrieve the GPIO 893 * number and the flags from a single gpio cell -- this is possible, 894 * but not recommended). 895 */ 896 if (gc->of_gpio_n_cells < 2) { 897 WARN_ON(1); 898 return -EINVAL; 899 } 900 901 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) 902 return -EINVAL; 903 904 if (gpiospec->args[0] >= gc->ngpio) 905 return -EINVAL; 906 907 if (flags) 908 *flags = gpiospec->args[1]; 909 910 return gpiospec->args[0]; 911 } 912 913 #if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP) 914 #include <linux/gpio/legacy-of-mm-gpiochip.h> 915 /** 916 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) 917 * @np: device node of the GPIO chip 918 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 919 * @data: driver data to store in the struct gpio_chip 920 * 921 * To use this function you should allocate and fill mm_gc with: 922 * 923 * 1) In the gpio_chip structure: 924 * - all the callbacks 925 * - of_gpio_n_cells 926 * - of_xlate callback (optional) 927 * 928 * 3) In the of_mm_gpio_chip structure: 929 * - save_regs callback (optional) 930 * 931 * If succeeded, this function will map bank's memory and will 932 * do all necessary work for you. Then you'll able to use .regs 933 * to manage GPIOs from the callbacks. 934 */ 935 int of_mm_gpiochip_add_data(struct device_node *np, 936 struct of_mm_gpio_chip *mm_gc, 937 void *data) 938 { 939 int ret = -ENOMEM; 940 struct gpio_chip *gc = &mm_gc->gc; 941 942 gc->label = kasprintf(GFP_KERNEL, "%pOF", np); 943 if (!gc->label) 944 goto err0; 945 946 mm_gc->regs = of_iomap(np, 0); 947 if (!mm_gc->regs) 948 goto err1; 949 950 gc->base = -1; 951 952 if (mm_gc->save_regs) 953 mm_gc->save_regs(mm_gc); 954 955 fwnode_handle_put(mm_gc->gc.fwnode); 956 mm_gc->gc.fwnode = fwnode_handle_get(of_fwnode_handle(np)); 957 958 ret = gpiochip_add_data(gc, data); 959 if (ret) 960 goto err2; 961 962 return 0; 963 err2: 964 of_node_put(np); 965 iounmap(mm_gc->regs); 966 err1: 967 kfree(gc->label); 968 err0: 969 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret); 970 return ret; 971 } 972 EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data); 973 974 /** 975 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) 976 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 977 */ 978 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) 979 { 980 struct gpio_chip *gc = &mm_gc->gc; 981 982 gpiochip_remove(gc); 983 iounmap(mm_gc->regs); 984 kfree(gc->label); 985 } 986 EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove); 987 #endif 988 989 #ifdef CONFIG_PINCTRL 990 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) 991 { 992 struct of_phandle_args pinspec; 993 struct pinctrl_dev *pctldev; 994 struct device_node *np; 995 int index = 0, ret; 996 const char *name; 997 static const char group_names_propname[] = "gpio-ranges-group-names"; 998 struct property *group_names; 999 1000 np = dev_of_node(&chip->gpiodev->dev); 1001 if (!np) 1002 return 0; 1003 1004 group_names = of_find_property(np, group_names_propname, NULL); 1005 1006 for (;; index++) { 1007 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 1008 index, &pinspec); 1009 if (ret) 1010 break; 1011 1012 pctldev = of_pinctrl_get(pinspec.np); 1013 of_node_put(pinspec.np); 1014 if (!pctldev) 1015 return -EPROBE_DEFER; 1016 1017 if (pinspec.args[2]) { 1018 if (group_names) { 1019 of_property_read_string_index(np, 1020 group_names_propname, 1021 index, &name); 1022 if (strlen(name)) { 1023 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n", 1024 np); 1025 break; 1026 } 1027 } 1028 /* npins != 0: linear range */ 1029 ret = gpiochip_add_pin_range(chip, 1030 pinctrl_dev_get_devname(pctldev), 1031 pinspec.args[0], 1032 pinspec.args[1], 1033 pinspec.args[2]); 1034 if (ret) 1035 return ret; 1036 } else { 1037 /* npins == 0: special range */ 1038 if (pinspec.args[1]) { 1039 pr_err("%pOF: Illegal gpio-range format.\n", 1040 np); 1041 break; 1042 } 1043 1044 if (!group_names) { 1045 pr_err("%pOF: GPIO group range requested but no %s property.\n", 1046 np, group_names_propname); 1047 break; 1048 } 1049 1050 ret = of_property_read_string_index(np, 1051 group_names_propname, 1052 index, &name); 1053 if (ret) 1054 break; 1055 1056 if (!strlen(name)) { 1057 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n", 1058 np); 1059 break; 1060 } 1061 1062 ret = gpiochip_add_pingroup_range(chip, pctldev, 1063 pinspec.args[0], name); 1064 if (ret) 1065 return ret; 1066 } 1067 } 1068 1069 return 0; 1070 } 1071 1072 #else 1073 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } 1074 #endif 1075 1076 int of_gpiochip_add(struct gpio_chip *chip) 1077 { 1078 struct device_node *np; 1079 int ret; 1080 1081 np = dev_of_node(&chip->gpiodev->dev); 1082 if (!np) 1083 return 0; 1084 1085 if (!chip->of_xlate) { 1086 chip->of_gpio_n_cells = 2; 1087 chip->of_xlate = of_gpio_simple_xlate; 1088 } 1089 1090 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) 1091 return -EINVAL; 1092 1093 ret = of_gpiochip_add_pin_range(chip); 1094 if (ret) 1095 return ret; 1096 1097 of_node_get(np); 1098 1099 ret = of_gpiochip_scan_gpios(chip); 1100 if (ret) 1101 of_node_put(np); 1102 1103 return ret; 1104 } 1105 1106 void of_gpiochip_remove(struct gpio_chip *chip) 1107 { 1108 of_node_put(dev_of_node(&chip->gpiodev->dev)); 1109 } 1110