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/fwnode.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.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: The empty GPIO specifiers count too.
50 *
51 * Returns:
52 * Either number of GPIOs defined in the property, or
53 * * %-EINVAL for an incorrectly formed "gpios" property, or
54 * * %-ENOENT for a missing "gpios" property.
55 *
56 * Example::
57 *
58 * gpios = <0
59 * &gpio1 1 2
60 * 0
61 * &gpio2 3 4>;
62 *
63 * The above example defines four GPIOs, two of which are not specified.
64 * This function will return '4'
65 */
of_gpio_named_count(const struct device_node * np,const char * propname)66 static int of_gpio_named_count(const struct device_node *np,
67 const char *propname)
68 {
69 return of_count_phandle_with_args(np, propname, "#gpio-cells");
70 }
71
72 /**
73 * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
74 * @np: Consuming device node
75 * @con_id: Function within the GPIO consumer
76 *
77 * Some elder GPIO controllers need special quirks. Currently we handle
78 * the Freescale and PPC GPIO controller with bindings that doesn't use the
79 * established "cs-gpios" for chip selects but instead rely on
80 * "gpios" for the chip select lines. If we detect this, we redirect
81 * the counting of "cs-gpios" to count "gpios" transparent to the
82 * driver.
83 *
84 * Returns:
85 * Either number of GPIOs defined in the property, or
86 * * %-EINVAL for an incorrectly formed "gpios" property, or
87 * * %-ENOENT for a missing "gpios" property.
88 */
of_gpio_spi_cs_get_count(const struct device_node * np,const char * con_id)89 static int of_gpio_spi_cs_get_count(const struct device_node *np,
90 const char *con_id)
91 {
92 if (!IS_ENABLED(CONFIG_SPI_MASTER))
93 return 0;
94 if (!con_id || strcmp(con_id, "cs"))
95 return 0;
96 if (!of_device_is_compatible(np, "fsl,spi") &&
97 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
98 !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
99 return 0;
100 return of_gpio_named_count(np, "gpios");
101 }
102
of_gpio_count(const struct fwnode_handle * fwnode,const char * con_id)103 int of_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
104 {
105 const struct device_node *np = to_of_node(fwnode);
106 int ret;
107 char propname[32];
108
109 ret = of_gpio_spi_cs_get_count(np, con_id);
110 if (ret > 0)
111 return ret;
112
113 for_each_gpio_property_name(propname, con_id) {
114 ret = of_gpio_named_count(np, propname);
115 if (ret > 0)
116 break;
117 }
118 return ret ? ret : -ENOENT;
119 }
120
of_gpiochip_match_node_and_xlate(struct gpio_chip * chip,const void * data)121 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip,
122 const void *data)
123 {
124 const struct of_phandle_args *gpiospec = data;
125
126 return device_match_of_node(&chip->gpiodev->dev, gpiospec->np) &&
127 chip->of_xlate &&
128 chip->of_xlate(chip, gpiospec, NULL) >= 0;
129 }
130
131 static struct gpio_device *
of_find_gpio_device_by_xlate(const struct of_phandle_args * gpiospec)132 of_find_gpio_device_by_xlate(const struct of_phandle_args *gpiospec)
133 {
134 return gpio_device_find(gpiospec, of_gpiochip_match_node_and_xlate);
135 }
136
of_xlate_and_get_gpiod_flags(struct gpio_chip * chip,struct of_phandle_args * gpiospec,enum of_gpio_flags * flags)137 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
138 struct of_phandle_args *gpiospec,
139 enum of_gpio_flags *flags)
140 {
141 int ret;
142
143 if (chip->of_gpio_n_cells != gpiospec->args_count)
144 return ERR_PTR(-EINVAL);
145
146 ret = chip->of_xlate(chip, gpiospec, flags);
147 if (ret < 0)
148 return ERR_PTR(ret);
149
150 return gpiochip_get_desc(chip, ret);
151 }
152
153 /*
154 * Overrides stated polarity of a gpio line and warns when there is a
155 * discrepancy.
156 */
of_gpio_quirk_polarity(const struct device_node * np,bool active_high,enum of_gpio_flags * flags)157 static void of_gpio_quirk_polarity(const struct device_node *np,
158 bool active_high,
159 enum of_gpio_flags *flags)
160 {
161 if (active_high) {
162 if (*flags & OF_GPIO_ACTIVE_LOW) {
163 pr_warn("%s GPIO handle specifies active low - ignored\n",
164 of_node_full_name(np));
165 *flags &= ~OF_GPIO_ACTIVE_LOW;
166 }
167 } else {
168 if (!(*flags & OF_GPIO_ACTIVE_LOW))
169 pr_info("%s enforce active low on GPIO handle\n",
170 of_node_full_name(np));
171 *flags |= OF_GPIO_ACTIVE_LOW;
172 }
173 }
174
175 /*
176 * This quirk does static polarity overrides in cases where existing
177 * DTS specified incorrect polarity.
178 */
of_gpio_try_fixup_polarity(const struct device_node * np,const char * propname,enum of_gpio_flags * flags)179 static void of_gpio_try_fixup_polarity(const struct device_node *np,
180 const char *propname,
181 enum of_gpio_flags *flags)
182 {
183 static const struct {
184 const char *compatible;
185 const char *propname;
186 bool active_high;
187 } gpios[] = {
188 #if IS_ENABLED(CONFIG_LCD_HX8357)
189 /*
190 * Himax LCD controllers used incorrectly named
191 * "gpios-reset" property and also specified wrong
192 * polarity.
193 */
194 { "himax,hx8357", "gpios-reset", false },
195 { "himax,hx8369", "gpios-reset", false },
196 #endif
197 #if IS_ENABLED(CONFIG_MTD_NAND_JZ4780)
198 /*
199 * The rb-gpios semantics was undocumented and qi,lb60 (along with
200 * the ingenic driver) got it wrong. The active state encodes the
201 * NAND ready state, which is high level. Since there's no signal
202 * inverter on this board, it should be active-high. Let's fix that
203 * here for older DTs so we can re-use the generic nand_gpio_waitrdy()
204 * helper, and be consistent with what other drivers do.
205 */
206 { "qi,lb60", "rb-gpios", true },
207 #endif
208 #if IS_ENABLED(CONFIG_IEEE802154_CA8210)
209 /*
210 * According to the datasheet, the NRST pin 27 is an active-low
211 * signal. However, the device tree schema and admittedly
212 * the out-of-tree implementations have been used for a long
213 * time incorrectly by describing reset GPIO as active-high.
214 */
215 { "cascoda,ca8210", "reset-gpio", false },
216 #endif
217 #if IS_ENABLED(CONFIG_PCI_LANTIQ)
218 /*
219 * According to the PCI specification, the RST# pin is an
220 * active-low signal. However, most of the device trees that
221 * have been widely used for a long time incorrectly describe
222 * reset GPIO as active-high, and were also using wrong name
223 * for the property.
224 */
225 { "lantiq,pci-xway", "gpio-reset", false },
226 #endif
227 #if IS_ENABLED(CONFIG_REGULATOR_S5M8767)
228 /*
229 * According to S5M8767, the DVS and DS pin are
230 * active-high signals. However, exynos5250-spring.dts use
231 * active-low setting.
232 */
233 { "samsung,s5m8767-pmic", "s5m8767,pmic-buck-dvs-gpios", true },
234 { "samsung,s5m8767-pmic", "s5m8767,pmic-buck-ds-gpios", true },
235 #endif
236 #if IS_ENABLED(CONFIG_TOUCHSCREEN_TSC2005)
237 /*
238 * DTS for Nokia N900 incorrectly specified "active high"
239 * polarity for the reset line, while the chip actually
240 * treats it as "active low".
241 */
242 { "ti,tsc2005", "reset-gpios", false },
243 #endif
244 #if IS_ENABLED(CONFIG_SND_SOC_WSA881X)
245 /*
246 * WSA881 powerdown is always active low, but some device trees
247 * missed this when first contributed. It also has a very strange
248 * compatible.
249 */
250 { "sdw10217201000", "powerdown-gpios", false },
251 #endif
252 };
253 unsigned int i;
254
255 for (i = 0; i < ARRAY_SIZE(gpios); i++) {
256 if (of_device_is_compatible(np, gpios[i].compatible) &&
257 !strcmp(propname, gpios[i].propname)) {
258 of_gpio_quirk_polarity(np, gpios[i].active_high, flags);
259 break;
260 }
261 }
262 }
263
of_gpio_set_polarity_by_property(const struct device_node * np,const char * propname,enum of_gpio_flags * flags)264 static void of_gpio_set_polarity_by_property(const struct device_node *np,
265 const char *propname,
266 enum of_gpio_flags *flags)
267 {
268 const struct device_node *np_compat = np;
269 const struct device_node *np_propname = np;
270 static const struct {
271 const char *compatible;
272 const char *gpio_propname;
273 const char *polarity_propname;
274 } gpios[] = {
275 #if IS_ENABLED(CONFIG_FEC)
276 /* Freescale Fast Ethernet Controller */
277 { "fsl,imx25-fec", "phy-reset-gpios", "phy-reset-active-high" },
278 { "fsl,imx27-fec", "phy-reset-gpios", "phy-reset-active-high" },
279 { "fsl,imx28-fec", "phy-reset-gpios", "phy-reset-active-high" },
280 { "fsl,imx6q-fec", "phy-reset-gpios", "phy-reset-active-high" },
281 { "fsl,mvf600-fec", "phy-reset-gpios", "phy-reset-active-high" },
282 { "fsl,imx6sx-fec", "phy-reset-gpios", "phy-reset-active-high" },
283 { "fsl,imx6ul-fec", "phy-reset-gpios", "phy-reset-active-high" },
284 { "fsl,imx8mq-fec", "phy-reset-gpios", "phy-reset-active-high" },
285 { "fsl,imx8qm-fec", "phy-reset-gpios", "phy-reset-active-high" },
286 { "fsl,s32v234-fec", "phy-reset-gpios", "phy-reset-active-high" },
287 #endif
288 #if IS_ENABLED(CONFIG_MMC_ATMELMCI)
289 { "atmel,hsmci", "cd-gpios", "cd-inverted" },
290 #endif
291 #if IS_ENABLED(CONFIG_PCI_IMX6)
292 { "fsl,imx6q-pcie", "reset-gpio", "reset-gpio-active-high" },
293 { "fsl,imx6sx-pcie", "reset-gpio", "reset-gpio-active-high" },
294 { "fsl,imx6qp-pcie", "reset-gpio", "reset-gpio-active-high" },
295 { "fsl,imx7d-pcie", "reset-gpio", "reset-gpio-active-high" },
296 { "fsl,imx8mq-pcie", "reset-gpio", "reset-gpio-active-high" },
297 { "fsl,imx8mm-pcie", "reset-gpio", "reset-gpio-active-high" },
298 { "fsl,imx8mp-pcie", "reset-gpio", "reset-gpio-active-high" },
299 #endif
300
301 /*
302 * The regulator GPIO handles are specified such that the
303 * presence or absence of "enable-active-high" solely controls
304 * the polarity of the GPIO line. Any phandle flags must
305 * be actively ignored.
306 */
307 #if IS_ENABLED(CONFIG_REGULATOR_FIXED_VOLTAGE)
308 { "regulator-fixed", "gpios", "enable-active-high" },
309 { "regulator-fixed", "gpio", "enable-active-high" },
310 { "reg-fixed-voltage", "gpios", "enable-active-high" },
311 { "reg-fixed-voltage", "gpio", "enable-active-high" },
312 #endif
313 #if IS_ENABLED(CONFIG_REGULATOR_GPIO)
314 { "regulator-gpio", "enable-gpio", "enable-active-high" },
315 { "regulator-gpio", "enable-gpios", "enable-active-high" },
316 #endif
317 };
318 unsigned int i;
319 bool active_high;
320
321 #if IS_ENABLED(CONFIG_MMC_ATMELMCI)
322 /*
323 * The Atmel HSMCI has compatible property in the parent node and
324 * gpio property in a child node
325 */
326 if (of_device_is_compatible(np->parent, "atmel,hsmci")) {
327 np_compat = np->parent;
328 np_propname = np;
329 }
330 #endif
331
332 for (i = 0; i < ARRAY_SIZE(gpios); i++) {
333 if (of_device_is_compatible(np_compat, gpios[i].compatible) &&
334 !strcmp(propname, gpios[i].gpio_propname)) {
335 active_high = of_property_read_bool(np_propname,
336 gpios[i].polarity_propname);
337 of_gpio_quirk_polarity(np, active_high, flags);
338 break;
339 }
340 }
341 }
342
of_gpio_flags_quirks(const struct device_node * np,const char * propname,enum of_gpio_flags * flags,int index)343 static void of_gpio_flags_quirks(const struct device_node *np,
344 const char *propname,
345 enum of_gpio_flags *flags,
346 int index)
347 {
348 of_gpio_try_fixup_polarity(np, propname, flags);
349 of_gpio_set_polarity_by_property(np, propname, flags);
350
351 /*
352 * Legacy open drain handling for fixed voltage regulators.
353 */
354 if (IS_ENABLED(CONFIG_REGULATOR) &&
355 of_device_is_compatible(np, "reg-fixed-voltage") &&
356 of_property_read_bool(np, "gpio-open-drain")) {
357 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
358 pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
359 of_node_full_name(np));
360 }
361
362 /*
363 * Legacy handling of SPI active high chip select. If we have a
364 * property named "cs-gpios" we need to inspect the child node
365 * to determine if the flags should have inverted semantics.
366 */
367 if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
368 of_property_present(np, "cs-gpios")) {
369 u32 cs;
370 int ret;
371
372 for_each_child_of_node_scoped(np, child) {
373 ret = of_property_read_u32(child, "reg", &cs);
374 if (ret)
375 continue;
376 if (cs == index) {
377 /*
378 * SPI children have active low chip selects
379 * by default. This can be specified negatively
380 * by just omitting "spi-cs-high" in the
381 * device node, or actively by tagging on
382 * GPIO_ACTIVE_LOW as flag in the device
383 * tree. If the line is simultaneously
384 * tagged as active low in the device tree
385 * and has the "spi-cs-high" set, we get a
386 * conflict and the "spi-cs-high" flag will
387 * take precedence.
388 */
389 bool active_high = of_property_read_bool(child,
390 "spi-cs-high");
391 of_gpio_quirk_polarity(child, active_high,
392 flags);
393 break;
394 }
395 }
396 }
397
398 /* Legacy handling of stmmac's active-low PHY reset line */
399 if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
400 !strcmp(propname, "snps,reset-gpio") &&
401 of_property_read_bool(np, "snps,reset-active-low"))
402 *flags |= OF_GPIO_ACTIVE_LOW;
403 }
404
405 /**
406 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
407 * @np: device node to get GPIO from
408 * @propname: property name containing gpio specifier(s)
409 * @index: index of the GPIO
410 * @flags: a flags pointer to fill in
411 *
412 * Returns:
413 * GPIO descriptor to use with Linux GPIO API, or one of the errno
414 * value on the error condition. If @flags is not NULL the function also fills
415 * in flags for the GPIO.
416 */
of_get_named_gpiod_flags(const struct device_node * np,const char * propname,int index,enum of_gpio_flags * flags)417 static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np,
418 const char *propname, int index, enum of_gpio_flags *flags)
419 {
420 struct of_phandle_args gpiospec;
421 struct gpio_desc *desc;
422 int ret;
423
424 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
425 &gpiospec);
426 if (ret) {
427 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
428 __func__, propname, np, index);
429 return ERR_PTR(ret);
430 }
431
432 struct gpio_device *gdev __free(gpio_device_put) =
433 of_find_gpio_device_by_xlate(&gpiospec);
434 if (!gdev) {
435 desc = ERR_PTR(-EPROBE_DEFER);
436 goto out;
437 }
438
439 desc = of_xlate_and_get_gpiod_flags(gpio_device_get_chip(gdev),
440 &gpiospec, flags);
441 if (IS_ERR(desc))
442 goto out;
443
444 if (flags)
445 of_gpio_flags_quirks(np, propname, flags, index);
446
447 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
448 __func__, propname, np, index,
449 PTR_ERR_OR_ZERO(desc));
450
451 out:
452 of_node_put(gpiospec.np);
453
454 return desc;
455 }
456
457 /* Converts gpio_lookup_flags into bitmask of GPIO_* values */
of_convert_gpio_flags(enum of_gpio_flags flags)458 static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags)
459 {
460 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
461
462 if (flags & OF_GPIO_ACTIVE_LOW)
463 lflags |= GPIO_ACTIVE_LOW;
464
465 if (flags & OF_GPIO_SINGLE_ENDED) {
466 if (flags & OF_GPIO_OPEN_DRAIN)
467 lflags |= GPIO_OPEN_DRAIN;
468 else
469 lflags |= GPIO_OPEN_SOURCE;
470 }
471
472 if (flags & OF_GPIO_TRANSITORY)
473 lflags |= GPIO_TRANSITORY;
474
475 if (flags & OF_GPIO_PULL_UP)
476 lflags |= GPIO_PULL_UP;
477
478 if (flags & OF_GPIO_PULL_DOWN)
479 lflags |= GPIO_PULL_DOWN;
480
481 if (flags & OF_GPIO_PULL_DISABLE)
482 lflags |= GPIO_PULL_DISABLE;
483
484 return lflags;
485 }
486
of_find_gpio_rename(struct device_node * np,const char * con_id,unsigned int idx,enum of_gpio_flags * of_flags)487 static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
488 const char *con_id,
489 unsigned int idx,
490 enum of_gpio_flags *of_flags)
491 {
492 static const struct of_rename_gpio {
493 const char *con_id;
494 const char *legacy_id; /* NULL - same as con_id */
495 /*
496 * Compatible string can be set to NULL in case where
497 * matching to a particular compatible is not practical,
498 * but it should only be done for gpio names that have
499 * vendor prefix to reduce risk of false positives.
500 * Addition of such entries is strongly discouraged.
501 */
502 const char *compatible;
503 } gpios[] = {
504 #if IS_ENABLED(CONFIG_LCD_HX8357)
505 /* Himax LCD controllers used "gpios-reset" */
506 { "reset", "gpios-reset", "himax,hx8357" },
507 { "reset", "gpios-reset", "himax,hx8369" },
508 #endif
509 #if IS_ENABLED(CONFIG_MFD_ARIZONA)
510 { "wlf,reset", NULL, NULL },
511 #endif
512 #if IS_ENABLED(CONFIG_RTC_DRV_MOXART)
513 { "rtc-data", "gpio-rtc-data", "moxa,moxart-rtc" },
514 { "rtc-sclk", "gpio-rtc-sclk", "moxa,moxart-rtc" },
515 { "rtc-reset", "gpio-rtc-reset", "moxa,moxart-rtc" },
516 #endif
517 #if IS_ENABLED(CONFIG_NFC_MRVL_I2C)
518 { "reset", "reset-n-io", "marvell,nfc-i2c" },
519 #endif
520 #if IS_ENABLED(CONFIG_NFC_MRVL_SPI)
521 { "reset", "reset-n-io", "marvell,nfc-spi" },
522 #endif
523 #if IS_ENABLED(CONFIG_NFC_MRVL_UART)
524 { "reset", "reset-n-io", "marvell,nfc-uart" },
525 { "reset", "reset-n-io", "mrvl,nfc-uart" },
526 #endif
527 #if IS_ENABLED(CONFIG_NFC_S3FWRN5_I2C)
528 { "en", "s3fwrn5,en-gpios", "samsung,s3fwrn5-i2c" },
529 { "wake", "s3fwrn5,fw-gpios", "samsung,s3fwrn5-i2c" },
530 #endif
531 #if IS_ENABLED(CONFIG_PCI_LANTIQ)
532 /* MIPS Lantiq PCI */
533 { "reset", "gpio-reset", "lantiq,pci-xway" },
534 #endif
535
536 /*
537 * Some regulator bindings happened before we managed to
538 * establish that GPIO properties should be named
539 * "foo-gpios" so we have this special kludge for them.
540 */
541 #if IS_ENABLED(CONFIG_REGULATOR_ARIZONA_LDO1)
542 { "wlf,ldoena", NULL, NULL }, /* Arizona */
543 #endif
544 #if IS_ENABLED(CONFIG_REGULATOR_WM8994)
545 { "wlf,ldo1ena", NULL, NULL }, /* WM8994 */
546 { "wlf,ldo2ena", NULL, NULL }, /* WM8994 */
547 #endif
548
549 #if IS_ENABLED(CONFIG_SND_SOC_CS42L56)
550 { "reset", "cirrus,gpio-nreset", "cirrus,cs42l56" },
551 #endif
552 #if IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448)
553 { "i2s1-in-sel-gpio1", NULL, "mediatek,mt2701-cs42448-machine" },
554 { "i2s1-in-sel-gpio2", NULL, "mediatek,mt2701-cs42448-machine" },
555 #endif
556 #if IS_ENABLED(CONFIG_SND_SOC_TLV320AIC3X)
557 { "reset", "gpio-reset", "ti,tlv320aic3x" },
558 { "reset", "gpio-reset", "ti,tlv320aic33" },
559 { "reset", "gpio-reset", "ti,tlv320aic3007" },
560 { "reset", "gpio-reset", "ti,tlv320aic3104" },
561 { "reset", "gpio-reset", "ti,tlv320aic3106" },
562 #endif
563 #if IS_ENABLED(CONFIG_SPI_GPIO)
564 /*
565 * The SPI GPIO bindings happened before we managed to
566 * establish that GPIO properties should be named
567 * "foo-gpios" so we have this special kludge for them.
568 */
569 { "miso", "gpio-miso", "spi-gpio" },
570 { "mosi", "gpio-mosi", "spi-gpio" },
571 { "sck", "gpio-sck", "spi-gpio" },
572 #endif
573
574 /*
575 * The old Freescale bindings use simply "gpios" as name
576 * for the chip select lines rather than "cs-gpios" like
577 * all other SPI hardware. Allow this specifically for
578 * Freescale and PPC devices.
579 */
580 #if IS_ENABLED(CONFIG_SPI_FSL_SPI)
581 { "cs", "gpios", "fsl,spi" },
582 { "cs", "gpios", "aeroflexgaisler,spictrl" },
583 #endif
584 #if IS_ENABLED(CONFIG_SPI_PPC4xx)
585 { "cs", "gpios", "ibm,ppc4xx-spi" },
586 #endif
587
588 #if IS_ENABLED(CONFIG_TYPEC_FUSB302)
589 /*
590 * Fairchild FUSB302 host is using undocumented "fcs,int_n"
591 * property without the compulsory "-gpios" suffix.
592 */
593 { "fcs,int_n", NULL, "fcs,fusb302" },
594 #endif
595 };
596 struct gpio_desc *desc;
597 const char *legacy_id;
598 unsigned int i;
599
600 if (!con_id)
601 return ERR_PTR(-ENOENT);
602
603 for (i = 0; i < ARRAY_SIZE(gpios); i++) {
604 if (strcmp(con_id, gpios[i].con_id))
605 continue;
606
607 if (gpios[i].compatible &&
608 !of_device_is_compatible(np, gpios[i].compatible))
609 continue;
610
611 legacy_id = gpios[i].legacy_id ?: gpios[i].con_id;
612 desc = of_get_named_gpiod_flags(np, legacy_id, idx, of_flags);
613 if (!gpiod_not_found(desc)) {
614 pr_info("%s uses legacy gpio name '%s' instead of '%s-gpios'\n",
615 of_node_full_name(np), legacy_id, con_id);
616 return desc;
617 }
618 }
619
620 return ERR_PTR(-ENOENT);
621 }
622
623 #if IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448)
of_find_mt2701_gpio(struct device_node * np,const char * con_id,unsigned int idx,enum of_gpio_flags * of_flags)624 static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np,
625 const char *con_id,
626 unsigned int idx,
627 enum of_gpio_flags *of_flags)
628 {
629 struct gpio_desc *desc;
630 const char *legacy_id;
631
632 if (!IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448))
633 return ERR_PTR(-ENOENT);
634
635 if (!of_device_is_compatible(np, "mediatek,mt2701-cs42448-machine"))
636 return ERR_PTR(-ENOENT);
637
638 if (!con_id || strcmp(con_id, "i2s1-in-sel"))
639 return ERR_PTR(-ENOENT);
640
641 if (idx == 0)
642 legacy_id = "i2s1-in-sel-gpio1";
643 else if (idx == 1)
644 legacy_id = "i2s1-in-sel-gpio2";
645 else
646 return ERR_PTR(-ENOENT);
647
648 desc = of_get_named_gpiod_flags(np, legacy_id, 0, of_flags);
649 if (!gpiod_not_found(desc))
650 pr_info("%s is using legacy gpio name '%s' instead of '%s-gpios'\n",
651 of_node_full_name(np), legacy_id, con_id);
652
653 return desc;
654 }
655 #endif
656
657 /*
658 * Trigger sources are special, they allow us to use any GPIO as a LED trigger
659 * and have the name "trigger-sources" no matter which kind of phandle it is
660 * pointing to, whether to a GPIO, a USB host, a network PHY etc. So in this case
661 * we allow looking something up that is not named "foo-gpios".
662 */
of_find_trigger_gpio(struct device_node * np,const char * con_id,unsigned int idx,enum of_gpio_flags * of_flags)663 static struct gpio_desc *of_find_trigger_gpio(struct device_node *np,
664 const char *con_id,
665 unsigned int idx,
666 enum of_gpio_flags *of_flags)
667 {
668 struct gpio_desc *desc;
669
670 if (!IS_ENABLED(CONFIG_LEDS_TRIGGER_GPIO))
671 return ERR_PTR(-ENOENT);
672
673 if (!con_id || strcmp(con_id, "trigger-sources"))
674 return ERR_PTR(-ENOENT);
675
676 desc = of_get_named_gpiod_flags(np, con_id, idx, of_flags);
677 if (!gpiod_not_found(desc))
678 pr_debug("%s is used as a trigger\n", of_node_full_name(np));
679
680 return desc;
681 }
682
683
684 typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
685 const char *con_id,
686 unsigned int idx,
687 enum of_gpio_flags *of_flags);
688 static const of_find_gpio_quirk of_find_gpio_quirks[] = {
689 of_find_gpio_rename,
690 #if IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448)
691 of_find_mt2701_gpio,
692 #endif
693 of_find_trigger_gpio,
694 NULL
695 };
696
of_find_gpio(struct device_node * np,const char * con_id,unsigned int idx,unsigned long * flags)697 struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id,
698 unsigned int idx, unsigned long *flags)
699 {
700 char propname[32]; /* 32 is max size of property name */
701 enum of_gpio_flags of_flags = 0;
702 const of_find_gpio_quirk *q;
703 struct gpio_desc *desc;
704
705 /* Try GPIO property "foo-gpios" and "foo-gpio" */
706 for_each_gpio_property_name(propname, con_id) {
707 desc = of_get_named_gpiod_flags(np, propname, idx, &of_flags);
708 if (!gpiod_not_found(desc))
709 break;
710 }
711
712 /* Properly named GPIO was not found, try workarounds */
713 for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++)
714 desc = (*q)(np, con_id, idx, &of_flags);
715
716 if (IS_ERR(desc))
717 return desc;
718
719 *flags = of_convert_gpio_flags(of_flags);
720
721 return desc;
722 }
723
of_gpiochip_get_lflags(struct gpio_chip * chip,struct fwnode_reference_args * gpiospec,unsigned long * lflags)724 int of_gpiochip_get_lflags(struct gpio_chip *chip,
725 struct fwnode_reference_args *gpiospec,
726 unsigned long *lflags)
727 {
728 enum of_gpio_flags xlate_flags;
729 struct of_phandle_args args;
730 struct gpio_desc *desc;
731
732 args.np = to_of_node(gpiospec->fwnode);
733 args.args_count = gpiospec->nargs;
734
735 for (int i = 0; i < args.args_count; i++)
736 args.args[i] = gpiospec->args[i];
737
738 desc = of_xlate_and_get_gpiod_flags(chip, &args, &xlate_flags);
739 if (IS_ERR(desc))
740 return PTR_ERR(desc);
741
742 *lflags = of_convert_gpio_flags(xlate_flags);
743
744 return 0;
745 }
746
747 #ifdef CONFIG_OF_DYNAMIC
748 /**
749 * of_gpiochip_remove_hog - Remove all hogs in a hog device node
750 * @chip: gpio chip to act on
751 * @hog: device node describing the hogs
752 */
of_gpiochip_remove_hog(struct gpio_chip * chip,struct device_node * hog)753 static void of_gpiochip_remove_hog(struct gpio_chip *chip,
754 struct device_node *hog)
755 {
756 struct gpio_desc *desc;
757
758 for_each_gpio_desc_with_flag(chip, desc, GPIOD_FLAG_IS_HOGGED)
759 if (READ_ONCE(desc->hog) == hog)
760 gpiochip_free_own_desc(desc);
761 }
762
of_gpiochip_match_node(struct gpio_chip * chip,const void * data)763 static int of_gpiochip_match_node(struct gpio_chip *chip, const void *data)
764 {
765 return device_match_of_node(&chip->gpiodev->dev, data);
766 }
767
of_find_gpio_device_by_node(struct device_node * np)768 static struct gpio_device *of_find_gpio_device_by_node(struct device_node *np)
769 {
770 return gpio_device_find(np, of_gpiochip_match_node);
771 }
772
of_gpio_notify(struct notifier_block * nb,unsigned long action,void * arg)773 static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
774 void *arg)
775 {
776 struct gpio_device *gdev __free(gpio_device_put) = NULL;
777 struct of_reconfig_data *rd = arg;
778 int ret;
779
780 /*
781 * This only supports adding and removing complete gpio-hog nodes.
782 * Modifying an existing gpio-hog node is not supported (except for
783 * changing its "status" property, which is treated the same as
784 * addition/removal).
785 */
786 switch (of_reconfig_get_state_change(action, arg)) {
787 case OF_RECONFIG_CHANGE_ADD:
788 if (!of_property_read_bool(rd->dn, "gpio-hog"))
789 return NOTIFY_DONE; /* not for us */
790
791 gdev = of_find_gpio_device_by_node(rd->dn->parent);
792 if (!gdev)
793 return NOTIFY_DONE; /* not for us */
794
795 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
796 return NOTIFY_DONE;
797
798 ret = gpiochip_add_hog(gpio_device_get_chip(gdev), of_fwnode_handle(rd->dn));
799 if (ret < 0) {
800 pr_err("%s: failed to add hogs for %pOF\n", __func__,
801 rd->dn);
802 of_node_clear_flag(rd->dn, OF_POPULATED);
803 return notifier_from_errno(ret);
804 }
805 return NOTIFY_OK;
806
807 case OF_RECONFIG_CHANGE_REMOVE:
808 if (!of_node_check_flag(rd->dn, OF_POPULATED))
809 return NOTIFY_DONE; /* already depopulated */
810
811 gdev = of_find_gpio_device_by_node(rd->dn->parent);
812 if (!gdev)
813 return NOTIFY_DONE; /* not for us */
814
815 of_gpiochip_remove_hog(gpio_device_get_chip(gdev), rd->dn);
816 of_node_clear_flag(rd->dn, OF_POPULATED);
817 return NOTIFY_OK;
818 }
819
820 return NOTIFY_DONE;
821 }
822
823 struct notifier_block gpio_of_notifier = {
824 .notifier_call = of_gpio_notify,
825 };
826 #endif /* CONFIG_OF_DYNAMIC */
827
828 /**
829 * of_gpio_twocell_xlate - translate twocell gpiospec to the GPIO number and flags
830 * @gc: pointer to the gpio_chip structure
831 * @gpiospec: GPIO specifier as found in the device tree
832 * @flags: a flags pointer to fill in
833 *
834 * This is simple translation function, suitable for the most 1:1 mapped
835 * GPIO chips. This function performs only one sanity check: whether GPIO
836 * is less than ngpios (that is specified in the gpio_chip).
837 *
838 * Returns:
839 * GPIO number (>= 0) on success, negative errno on failure.
840 */
of_gpio_twocell_xlate(struct gpio_chip * gc,const struct of_phandle_args * gpiospec,u32 * flags)841 static int of_gpio_twocell_xlate(struct gpio_chip *gc,
842 const struct of_phandle_args *gpiospec,
843 u32 *flags)
844 {
845 /*
846 * We're discouraging gpio_cells < 2, since that way you'll have to
847 * write your own xlate function (that will have to retrieve the GPIO
848 * number and the flags from a single gpio cell -- this is possible,
849 * but not recommended).
850 */
851 if (gc->of_gpio_n_cells != 2) {
852 WARN_ON(1);
853 return -EINVAL;
854 }
855
856 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
857 return -EINVAL;
858
859 if (gpiospec->args[0] >= gc->ngpio)
860 return -EINVAL;
861
862 if (flags)
863 *flags = gpiospec->args[1];
864
865 return gpiospec->args[0];
866 }
867
868 /**
869 * of_gpio_threecell_xlate - translate threecell gpiospec to the GPIO number and flags
870 * @gc: pointer to the gpio_chip structure
871 * @gpiospec: GPIO specifier as found in the device tree
872 * @flags: a flags pointer to fill in
873 *
874 * This is simple translation function, suitable for the most 1:n mapped
875 * GPIO chips, i.e. several GPIO chip instances from one device tree node.
876 * In this case the following binding is implied:
877 *
878 * foo-gpios = <&gpio instance offset flags>;
879 *
880 * Returns:
881 * GPIO number (>= 0) on success, negative errno on failure.
882 */
of_gpio_threecell_xlate(struct gpio_chip * gc,const struct of_phandle_args * gpiospec,u32 * flags)883 static int of_gpio_threecell_xlate(struct gpio_chip *gc,
884 const struct of_phandle_args *gpiospec,
885 u32 *flags)
886 {
887 if (gc->of_gpio_n_cells != 3) {
888 WARN_ON(1);
889 return -EINVAL;
890 }
891
892 if (WARN_ON(gpiospec->args_count != 3))
893 return -EINVAL;
894
895 /*
896 * Check chip instance number, the driver responds with true if
897 * this is the chip we are looking for.
898 */
899 if (!gc->of_node_instance_match(gc, gpiospec->args[0]))
900 return -EINVAL;
901
902 if (gpiospec->args[1] >= gc->ngpio)
903 return -EINVAL;
904
905 if (flags)
906 *flags = gpiospec->args[2];
907
908 return gpiospec->args[1];
909 }
910
911 #ifdef CONFIG_PINCTRL
of_gpiochip_add_pin_range(struct gpio_chip * chip)912 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
913 {
914 struct of_phandle_args pinspec;
915 struct pinctrl_dev *pctldev;
916 struct device_node *np;
917 int index = 0, ret, trim;
918 const char *name;
919 static const char group_names_propname[] = "gpio-ranges-group-names";
920 bool has_group_names;
921 int offset; /* Offset of the first GPIO line on the chip */
922 int pin; /* Pin base number in the range */
923 int count; /* Number of pins/GPIO lines to map */
924
925 np = dev_of_node(&chip->gpiodev->dev);
926 if (!np)
927 return 0;
928
929 has_group_names = of_property_present(np, group_names_propname);
930
931 for (;; index++) {
932 /*
933 * Ordinary phandles contain 2-3 cells:
934 * gpios = <&gpio [instance] offset flags>;
935 * Ranges always contain one more cell:
936 * gpio-ranges <&pinctrl [gpio_instance] gpio_offet pin_offet count>;
937 * This is why we parse chip->of_gpio_n_cells + 1 cells
938 */
939 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges",
940 chip->of_gpio_n_cells + 1,
941 index, &pinspec);
942 if (ret)
943 break;
944
945 pctldev = of_pinctrl_get(pinspec.np);
946 of_node_put(pinspec.np);
947 if (!pctldev)
948 return -EPROBE_DEFER;
949
950 if (chip->of_gpio_n_cells == 3) {
951 /* First cell is the gpiochip instance number */
952 offset = pinspec.args[1];
953 pin = pinspec.args[2];
954 count = pinspec.args[3];
955 } else {
956 offset = pinspec.args[0];
957 pin = pinspec.args[1];
958 count = pinspec.args[2];
959 }
960
961 /*
962 * With multiple GPIO chips per node, check that this chip is the
963 * right instance.
964 */
965 if (chip->of_node_instance_match &&
966 (chip->of_gpio_n_cells == 3) &&
967 !chip->of_node_instance_match(chip, pinspec.args[0]))
968 continue;
969
970 /* Ignore ranges outside of this GPIO chip */
971 if (offset >= (chip->offset + chip->ngpio))
972 continue;
973 if (offset + count <= chip->offset)
974 continue;
975
976 if (count) {
977 /* npins != 0: linear range */
978 if (has_group_names) {
979 of_property_read_string_index(np,
980 group_names_propname,
981 index, &name);
982 if (strlen(name)) {
983 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
984 np);
985 break;
986 }
987 }
988
989 /* Trim the range to fit this GPIO chip */
990 if (chip->offset > offset) {
991 trim = chip->offset - offset;
992 count -= trim;
993 pin += trim;
994 offset = 0;
995 } else {
996 offset -= chip->offset;
997 }
998 if ((offset + count) > chip->ngpio)
999 count = chip->ngpio - offset;
1000
1001 ret = gpiochip_add_pin_range(chip,
1002 pinctrl_dev_get_devname(pctldev),
1003 offset,
1004 pin,
1005 count);
1006 if (ret)
1007 return ret;
1008 } else {
1009 /* npins == 0: special range */
1010 if (pin) {
1011 pr_err("%pOF: Illegal gpio-range format.\n",
1012 np);
1013 break;
1014 }
1015
1016 if (!has_group_names) {
1017 pr_err("%pOF: GPIO group range requested but no %s property.\n",
1018 np, group_names_propname);
1019 break;
1020 }
1021
1022 ret = of_property_read_string_index(np,
1023 group_names_propname,
1024 index, &name);
1025 if (ret)
1026 break;
1027
1028 if (!strlen(name)) {
1029 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
1030 np);
1031 break;
1032 }
1033
1034 ret = gpiochip_add_pingroup_range(chip, pctldev,
1035 offset, name);
1036 if (ret)
1037 return ret;
1038 }
1039 }
1040
1041 return 0;
1042 }
1043
1044 #else
of_gpiochip_add_pin_range(struct gpio_chip * chip)1045 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
1046 #endif
1047
of_gpiochip_add(struct gpio_chip * chip)1048 int of_gpiochip_add(struct gpio_chip *chip)
1049 {
1050 struct device_node *np;
1051 int ret;
1052
1053 np = dev_of_node(&chip->gpiodev->dev);
1054 if (!np)
1055 return 0;
1056
1057 if (!chip->of_xlate) {
1058 if (chip->of_gpio_n_cells == 3) {
1059 if (!chip->of_node_instance_match)
1060 return -EINVAL;
1061 chip->of_xlate = of_gpio_threecell_xlate;
1062 } else {
1063 chip->of_gpio_n_cells = 2;
1064 chip->of_xlate = of_gpio_twocell_xlate;
1065 }
1066 }
1067
1068 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
1069 return -EINVAL;
1070
1071 ret = of_gpiochip_add_pin_range(chip);
1072 if (ret)
1073 return ret;
1074
1075 of_node_get(np);
1076
1077 return ret;
1078 }
1079
of_gpiochip_remove(struct gpio_chip * chip)1080 void of_gpiochip_remove(struct gpio_chip *chip)
1081 {
1082 struct device_node *np = dev_of_node(&chip->gpiodev->dev);
1083
1084 for_each_child_of_node_scoped(np, child) {
1085 if (of_property_present(child, "gpio-hog"))
1086 of_node_clear_flag(child, OF_POPULATED);
1087 }
1088
1089 of_node_put(np);
1090 }
1091
of_gpiochip_instance_match(struct gpio_chip * gc,unsigned int index)1092 bool of_gpiochip_instance_match(struct gpio_chip *gc, unsigned int index)
1093 {
1094 if (gc->of_node_instance_match)
1095 return gc->of_node_instance_match(gc, index);
1096
1097 return false;
1098 }
1099