xref: /linux/drivers/pinctrl/pinmux.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 /*
2  * Core driver for the pin muxing portions of the pin control subsystem
3  *
4  * Copyright (C) 2011-2012 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  * Based on bits of regulator core, gpio core and clk core
7  *
8  * Author: Linus Walleij <linus.walleij@linaro.org>
9  *
10  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
11  *
12  * License terms: GNU General Public License (GPL) version 2
13  */
14 #define pr_fmt(fmt) "pinmux core: " fmt
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/device.h>
20 #include <linux/slab.h>
21 #include <linux/radix-tree.h>
22 #include <linux/err.h>
23 #include <linux/list.h>
24 #include <linux/string.h>
25 #include <linux/sysfs.h>
26 #include <linux/debugfs.h>
27 #include <linux/seq_file.h>
28 #include <linux/pinctrl/machine.h>
29 #include <linux/pinctrl/pinmux.h>
30 #include "core.h"
31 #include "pinmux.h"
32 
33 int pinmux_check_ops(struct pinctrl_dev *pctldev)
34 {
35 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
36 	unsigned nfuncs;
37 	unsigned selector = 0;
38 
39 	/* Check that we implement required operations */
40 	if (!ops ||
41 	    !ops->get_functions_count ||
42 	    !ops->get_function_name ||
43 	    !ops->get_function_groups ||
44 	    !ops->set_mux) {
45 		dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
46 		return -EINVAL;
47 	}
48 	/* Check that all functions registered have names */
49 	nfuncs = ops->get_functions_count(pctldev);
50 	while (selector < nfuncs) {
51 		const char *fname = ops->get_function_name(pctldev,
52 							   selector);
53 		if (!fname) {
54 			dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
55 				selector);
56 			return -EINVAL;
57 		}
58 		selector++;
59 	}
60 
61 	return 0;
62 }
63 
64 int pinmux_validate_map(struct pinctrl_map const *map, int i)
65 {
66 	if (!map->data.mux.function) {
67 		pr_err("failed to register map %s (%d): no function given\n",
68 		       map->name, i);
69 		return -EINVAL;
70 	}
71 
72 	return 0;
73 }
74 
75 /**
76  * pin_request() - request a single pin to be muxed in, typically for GPIO
77  * @pin: the pin number in the global pin space
78  * @owner: a representation of the owner of this pin; typically the device
79  *	name that controls its mux function, or the requested GPIO name
80  * @gpio_range: the range matching the GPIO pin if this is a request for a
81  *	single GPIO pin
82  */
83 static int pin_request(struct pinctrl_dev *pctldev,
84 		       int pin, const char *owner,
85 		       struct pinctrl_gpio_range *gpio_range)
86 {
87 	struct pin_desc *desc;
88 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
89 	int status = -EINVAL;
90 
91 	desc = pin_desc_get(pctldev, pin);
92 	if (desc == NULL) {
93 		dev_err(pctldev->dev,
94 			"pin %d is not registered so it cannot be requested\n",
95 			pin);
96 		goto out;
97 	}
98 
99 	dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
100 		pin, desc->name, owner);
101 
102 	if ((!gpio_range || ops->strict) &&
103 	    desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
104 		dev_err(pctldev->dev,
105 			"pin %s already requested by %s; cannot claim for %s\n",
106 			desc->name, desc->mux_owner, owner);
107 		goto out;
108 	}
109 
110 	if ((gpio_range || ops->strict) && desc->gpio_owner) {
111 		dev_err(pctldev->dev,
112 			"pin %s already requested by %s; cannot claim for %s\n",
113 			desc->name, desc->gpio_owner, owner);
114 		goto out;
115 	}
116 
117 	if (gpio_range) {
118 		desc->gpio_owner = owner;
119 	} else {
120 		desc->mux_usecount++;
121 		if (desc->mux_usecount > 1)
122 			return 0;
123 
124 		desc->mux_owner = owner;
125 	}
126 
127 	/* Let each pin increase references to this module */
128 	if (!try_module_get(pctldev->owner)) {
129 		dev_err(pctldev->dev,
130 			"could not increase module refcount for pin %d\n",
131 			pin);
132 		status = -EINVAL;
133 		goto out_free_pin;
134 	}
135 
136 	/*
137 	 * If there is no kind of request function for the pin we just assume
138 	 * we got it by default and proceed.
139 	 */
140 	if (gpio_range && ops->gpio_request_enable)
141 		/* This requests and enables a single GPIO pin */
142 		status = ops->gpio_request_enable(pctldev, gpio_range, pin);
143 	else if (ops->request)
144 		status = ops->request(pctldev, pin);
145 	else
146 		status = 0;
147 
148 	if (status) {
149 		dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
150 		module_put(pctldev->owner);
151 	}
152 
153 out_free_pin:
154 	if (status) {
155 		if (gpio_range) {
156 			desc->gpio_owner = NULL;
157 		} else {
158 			desc->mux_usecount--;
159 			if (!desc->mux_usecount)
160 				desc->mux_owner = NULL;
161 		}
162 	}
163 out:
164 	if (status)
165 		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
166 			pin, owner, status);
167 
168 	return status;
169 }
170 
171 /**
172  * pin_free() - release a single muxed in pin so something else can be muxed
173  * @pctldev: pin controller device handling this pin
174  * @pin: the pin to free
175  * @gpio_range: the range matching the GPIO pin if this is a request for a
176  *	single GPIO pin
177  *
178  * This function returns a pointer to the previous owner. This is used
179  * for callers that dynamically allocate an owner name so it can be freed
180  * once the pin is free. This is done for GPIO request functions.
181  */
182 static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
183 			    struct pinctrl_gpio_range *gpio_range)
184 {
185 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
186 	struct pin_desc *desc;
187 	const char *owner;
188 
189 	desc = pin_desc_get(pctldev, pin);
190 	if (desc == NULL) {
191 		dev_err(pctldev->dev,
192 			"pin is not registered so it cannot be freed\n");
193 		return NULL;
194 	}
195 
196 	if (!gpio_range) {
197 		/*
198 		 * A pin should not be freed more times than allocated.
199 		 */
200 		if (WARN_ON(!desc->mux_usecount))
201 			return NULL;
202 		desc->mux_usecount--;
203 		if (desc->mux_usecount)
204 			return NULL;
205 	}
206 
207 	/*
208 	 * If there is no kind of request function for the pin we just assume
209 	 * we got it by default and proceed.
210 	 */
211 	if (gpio_range && ops->gpio_disable_free)
212 		ops->gpio_disable_free(pctldev, gpio_range, pin);
213 	else if (ops->free)
214 		ops->free(pctldev, pin);
215 
216 	if (gpio_range) {
217 		owner = desc->gpio_owner;
218 		desc->gpio_owner = NULL;
219 	} else {
220 		owner = desc->mux_owner;
221 		desc->mux_owner = NULL;
222 		desc->mux_setting = NULL;
223 	}
224 
225 	module_put(pctldev->owner);
226 
227 	return owner;
228 }
229 
230 /**
231  * pinmux_request_gpio() - request pinmuxing for a GPIO pin
232  * @pctldev: pin controller device affected
233  * @pin: the pin to mux in for GPIO
234  * @range: the applicable GPIO range
235  */
236 int pinmux_request_gpio(struct pinctrl_dev *pctldev,
237 			struct pinctrl_gpio_range *range,
238 			unsigned pin, unsigned gpio)
239 {
240 	const char *owner;
241 	int ret;
242 
243 	/* Conjure some name stating what chip and pin this is taken by */
244 	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
245 	if (!owner)
246 		return -ENOMEM;
247 
248 	ret = pin_request(pctldev, pin, owner, range);
249 	if (ret < 0)
250 		kfree(owner);
251 
252 	return ret;
253 }
254 
255 /**
256  * pinmux_free_gpio() - release a pin from GPIO muxing
257  * @pctldev: the pin controller device for the pin
258  * @pin: the affected currently GPIO-muxed in pin
259  * @range: applicable GPIO range
260  */
261 void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
262 		      struct pinctrl_gpio_range *range)
263 {
264 	const char *owner;
265 
266 	owner = pin_free(pctldev, pin, range);
267 	kfree(owner);
268 }
269 
270 /**
271  * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
272  * @pctldev: the pin controller handling this pin
273  * @range: applicable GPIO range
274  * @pin: the affected GPIO pin in this controller
275  * @input: true if we set the pin as input, false for output
276  */
277 int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
278 			  struct pinctrl_gpio_range *range,
279 			  unsigned pin, bool input)
280 {
281 	const struct pinmux_ops *ops;
282 	int ret;
283 
284 	ops = pctldev->desc->pmxops;
285 
286 	if (ops->gpio_set_direction)
287 		ret = ops->gpio_set_direction(pctldev, range, pin, input);
288 	else
289 		ret = 0;
290 
291 	return ret;
292 }
293 
294 static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
295 					const char *function)
296 {
297 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
298 	unsigned nfuncs = ops->get_functions_count(pctldev);
299 	unsigned selector = 0;
300 
301 	/* See if this pctldev has this function */
302 	while (selector < nfuncs) {
303 		const char *fname = ops->get_function_name(pctldev, selector);
304 
305 		if (!strcmp(function, fname))
306 			return selector;
307 
308 		selector++;
309 	}
310 
311 	dev_err(pctldev->dev, "function '%s' not supported\n", function);
312 	return -EINVAL;
313 }
314 
315 int pinmux_map_to_setting(struct pinctrl_map const *map,
316 			  struct pinctrl_setting *setting)
317 {
318 	struct pinctrl_dev *pctldev = setting->pctldev;
319 	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
320 	char const * const *groups;
321 	unsigned num_groups;
322 	int ret;
323 	const char *group;
324 
325 	if (!pmxops) {
326 		dev_err(pctldev->dev, "does not support mux function\n");
327 		return -EINVAL;
328 	}
329 
330 	ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
331 	if (ret < 0) {
332 		dev_err(pctldev->dev, "invalid function %s in map table\n",
333 			map->data.mux.function);
334 		return ret;
335 	}
336 	setting->data.mux.func = ret;
337 
338 	ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
339 					  &groups, &num_groups);
340 	if (ret < 0) {
341 		dev_err(pctldev->dev, "can't query groups for function %s\n",
342 			map->data.mux.function);
343 		return ret;
344 	}
345 	if (!num_groups) {
346 		dev_err(pctldev->dev,
347 			"function %s can't be selected on any group\n",
348 			map->data.mux.function);
349 		return -EINVAL;
350 	}
351 	if (map->data.mux.group) {
352 		group = map->data.mux.group;
353 		ret = match_string(groups, num_groups, group);
354 		if (ret < 0) {
355 			dev_err(pctldev->dev,
356 				"invalid group \"%s\" for function \"%s\"\n",
357 				group, map->data.mux.function);
358 			return ret;
359 		}
360 	} else {
361 		group = groups[0];
362 	}
363 
364 	ret = pinctrl_get_group_selector(pctldev, group);
365 	if (ret < 0) {
366 		dev_err(pctldev->dev, "invalid group %s in map table\n",
367 			map->data.mux.group);
368 		return ret;
369 	}
370 	setting->data.mux.group = ret;
371 
372 	return 0;
373 }
374 
375 void pinmux_free_setting(struct pinctrl_setting const *setting)
376 {
377 	/* This function is currently unused */
378 }
379 
380 int pinmux_enable_setting(struct pinctrl_setting const *setting)
381 {
382 	struct pinctrl_dev *pctldev = setting->pctldev;
383 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
384 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
385 	int ret = 0;
386 	const unsigned *pins = NULL;
387 	unsigned num_pins = 0;
388 	int i;
389 	struct pin_desc *desc;
390 
391 	if (pctlops->get_group_pins)
392 		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
393 					      &pins, &num_pins);
394 
395 	if (ret) {
396 		const char *gname;
397 
398 		/* errors only affect debug data, so just warn */
399 		gname = pctlops->get_group_name(pctldev,
400 						setting->data.mux.group);
401 		dev_warn(pctldev->dev,
402 			 "could not get pins for group %s\n",
403 			 gname);
404 		num_pins = 0;
405 	}
406 
407 	/* Try to allocate all pins in this group, one by one */
408 	for (i = 0; i < num_pins; i++) {
409 		ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
410 		if (ret) {
411 			const char *gname;
412 			const char *pname;
413 
414 			desc = pin_desc_get(pctldev, pins[i]);
415 			pname = desc ? desc->name : "non-existing";
416 			gname = pctlops->get_group_name(pctldev,
417 						setting->data.mux.group);
418 			dev_err(pctldev->dev,
419 				"could not request pin %d (%s) from group %s "
420 				" on device %s\n",
421 				pins[i], pname, gname,
422 				pinctrl_dev_get_name(pctldev));
423 			goto err_pin_request;
424 		}
425 	}
426 
427 	/* Now that we have acquired the pins, encode the mux setting */
428 	for (i = 0; i < num_pins; i++) {
429 		desc = pin_desc_get(pctldev, pins[i]);
430 		if (desc == NULL) {
431 			dev_warn(pctldev->dev,
432 				 "could not get pin desc for pin %d\n",
433 				 pins[i]);
434 			continue;
435 		}
436 		desc->mux_setting = &(setting->data.mux);
437 	}
438 
439 	ret = ops->set_mux(pctldev, setting->data.mux.func,
440 			   setting->data.mux.group);
441 
442 	if (ret)
443 		goto err_set_mux;
444 
445 	return 0;
446 
447 err_set_mux:
448 	for (i = 0; i < num_pins; i++) {
449 		desc = pin_desc_get(pctldev, pins[i]);
450 		if (desc)
451 			desc->mux_setting = NULL;
452 	}
453 err_pin_request:
454 	/* On error release all taken pins */
455 	while (--i >= 0)
456 		pin_free(pctldev, pins[i], NULL);
457 
458 	return ret;
459 }
460 
461 void pinmux_disable_setting(struct pinctrl_setting const *setting)
462 {
463 	struct pinctrl_dev *pctldev = setting->pctldev;
464 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
465 	int ret = 0;
466 	const unsigned *pins = NULL;
467 	unsigned num_pins = 0;
468 	int i;
469 	struct pin_desc *desc;
470 
471 	if (pctlops->get_group_pins)
472 		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
473 					      &pins, &num_pins);
474 	if (ret) {
475 		const char *gname;
476 
477 		/* errors only affect debug data, so just warn */
478 		gname = pctlops->get_group_name(pctldev,
479 						setting->data.mux.group);
480 		dev_warn(pctldev->dev,
481 			 "could not get pins for group %s\n",
482 			 gname);
483 		num_pins = 0;
484 	}
485 
486 	/* Flag the descs that no setting is active */
487 	for (i = 0; i < num_pins; i++) {
488 		desc = pin_desc_get(pctldev, pins[i]);
489 		if (desc == NULL) {
490 			dev_warn(pctldev->dev,
491 				 "could not get pin desc for pin %d\n",
492 				 pins[i]);
493 			continue;
494 		}
495 		if (desc->mux_setting == &(setting->data.mux)) {
496 			desc->mux_setting = NULL;
497 			/* And release the pin */
498 			pin_free(pctldev, pins[i], NULL);
499 		} else {
500 			const char *gname;
501 
502 			gname = pctlops->get_group_name(pctldev,
503 						setting->data.mux.group);
504 			dev_warn(pctldev->dev,
505 				 "not freeing pin %d (%s) as part of "
506 				 "deactivating group %s - it is already "
507 				 "used for some other setting",
508 				 pins[i], desc->name, gname);
509 		}
510 	}
511 }
512 
513 #ifdef CONFIG_DEBUG_FS
514 
515 /* Called from pincontrol core */
516 static int pinmux_functions_show(struct seq_file *s, void *what)
517 {
518 	struct pinctrl_dev *pctldev = s->private;
519 	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
520 	unsigned nfuncs;
521 	unsigned func_selector = 0;
522 
523 	if (!pmxops)
524 		return 0;
525 
526 	mutex_lock(&pctldev->mutex);
527 	nfuncs = pmxops->get_functions_count(pctldev);
528 	while (func_selector < nfuncs) {
529 		const char *func = pmxops->get_function_name(pctldev,
530 							  func_selector);
531 		const char * const *groups;
532 		unsigned num_groups;
533 		int ret;
534 		int i;
535 
536 		ret = pmxops->get_function_groups(pctldev, func_selector,
537 						  &groups, &num_groups);
538 		if (ret) {
539 			seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
540 				   func);
541 			func_selector++;
542 			continue;
543 		}
544 
545 		seq_printf(s, "function: %s, groups = [ ", func);
546 		for (i = 0; i < num_groups; i++)
547 			seq_printf(s, "%s ", groups[i]);
548 		seq_puts(s, "]\n");
549 
550 		func_selector++;
551 	}
552 
553 	mutex_unlock(&pctldev->mutex);
554 
555 	return 0;
556 }
557 
558 static int pinmux_pins_show(struct seq_file *s, void *what)
559 {
560 	struct pinctrl_dev *pctldev = s->private;
561 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
562 	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
563 	unsigned i, pin;
564 
565 	if (!pmxops)
566 		return 0;
567 
568 	seq_puts(s, "Pinmux settings per pin\n");
569 	if (pmxops->strict)
570 		seq_puts(s,
571 		 "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
572 	else
573 		seq_puts(s,
574 		"Format: pin (name): mux_owner gpio_owner hog?\n");
575 
576 	mutex_lock(&pctldev->mutex);
577 
578 	/* The pin number can be retrived from the pin controller descriptor */
579 	for (i = 0; i < pctldev->desc->npins; i++) {
580 		struct pin_desc *desc;
581 		bool is_hog = false;
582 
583 		pin = pctldev->desc->pins[i].number;
584 		desc = pin_desc_get(pctldev, pin);
585 		/* Skip if we cannot search the pin */
586 		if (desc == NULL)
587 			continue;
588 
589 		if (desc->mux_owner &&
590 		    !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
591 			is_hog = true;
592 
593 		if (pmxops->strict) {
594 			if (desc->mux_owner)
595 				seq_printf(s, "pin %d (%s): device %s%s",
596 					   pin, desc->name, desc->mux_owner,
597 					   is_hog ? " (HOG)" : "");
598 			else if (desc->gpio_owner)
599 				seq_printf(s, "pin %d (%s): GPIO %s",
600 					   pin, desc->name, desc->gpio_owner);
601 			else
602 				seq_printf(s, "pin %d (%s): UNCLAIMED",
603 					   pin, desc->name);
604 		} else {
605 			/* For non-strict controllers */
606 			seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
607 				   desc->mux_owner ? desc->mux_owner
608 				   : "(MUX UNCLAIMED)",
609 				   desc->gpio_owner ? desc->gpio_owner
610 				   : "(GPIO UNCLAIMED)",
611 				   is_hog ? " (HOG)" : "");
612 		}
613 
614 		/* If mux: print function+group claiming the pin */
615 		if (desc->mux_setting)
616 			seq_printf(s, " function %s group %s\n",
617 				   pmxops->get_function_name(pctldev,
618 					desc->mux_setting->func),
619 				   pctlops->get_group_name(pctldev,
620 					desc->mux_setting->group));
621 		else
622 			seq_printf(s, "\n");
623 	}
624 
625 	mutex_unlock(&pctldev->mutex);
626 
627 	return 0;
628 }
629 
630 void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
631 {
632 	seq_printf(s, "group %s\nfunction %s\n",
633 		map->data.mux.group ? map->data.mux.group : "(default)",
634 		map->data.mux.function);
635 }
636 
637 void pinmux_show_setting(struct seq_file *s,
638 			 struct pinctrl_setting const *setting)
639 {
640 	struct pinctrl_dev *pctldev = setting->pctldev;
641 	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
642 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
643 
644 	seq_printf(s, "group: %s (%u) function: %s (%u)\n",
645 		   pctlops->get_group_name(pctldev, setting->data.mux.group),
646 		   setting->data.mux.group,
647 		   pmxops->get_function_name(pctldev, setting->data.mux.func),
648 		   setting->data.mux.func);
649 }
650 
651 static int pinmux_functions_open(struct inode *inode, struct file *file)
652 {
653 	return single_open(file, pinmux_functions_show, inode->i_private);
654 }
655 
656 static int pinmux_pins_open(struct inode *inode, struct file *file)
657 {
658 	return single_open(file, pinmux_pins_show, inode->i_private);
659 }
660 
661 static const struct file_operations pinmux_functions_ops = {
662 	.open		= pinmux_functions_open,
663 	.read		= seq_read,
664 	.llseek		= seq_lseek,
665 	.release	= single_release,
666 };
667 
668 static const struct file_operations pinmux_pins_ops = {
669 	.open		= pinmux_pins_open,
670 	.read		= seq_read,
671 	.llseek		= seq_lseek,
672 	.release	= single_release,
673 };
674 
675 void pinmux_init_device_debugfs(struct dentry *devroot,
676 			 struct pinctrl_dev *pctldev)
677 {
678 	debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
679 			    devroot, pctldev, &pinmux_functions_ops);
680 	debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
681 			    devroot, pctldev, &pinmux_pins_ops);
682 }
683 
684 #endif /* CONFIG_DEBUG_FS */
685 
686 #ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
687 
688 /**
689  * pinmux_generic_get_function_count() - returns number of functions
690  * @pctldev: pin controller device
691  */
692 int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
693 {
694 	return pctldev->num_functions;
695 }
696 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
697 
698 /**
699  * pinmux_generic_get_function_name() - returns the function name
700  * @pctldev: pin controller device
701  * @selector: function number
702  */
703 const char *
704 pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
705 				 unsigned int selector)
706 {
707 	struct function_desc *function;
708 
709 	function = radix_tree_lookup(&pctldev->pin_function_tree,
710 				     selector);
711 	if (!function)
712 		return NULL;
713 
714 	return function->name;
715 }
716 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
717 
718 /**
719  * pinmux_generic_get_function_groups() - gets the function groups
720  * @pctldev: pin controller device
721  * @selector: function number
722  * @groups: array of pin groups
723  * @num_groups: number of pin groups
724  */
725 int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
726 				       unsigned int selector,
727 				       const char * const **groups,
728 				       unsigned * const num_groups)
729 {
730 	struct function_desc *function;
731 
732 	function = radix_tree_lookup(&pctldev->pin_function_tree,
733 				     selector);
734 	if (!function) {
735 		dev_err(pctldev->dev, "%s could not find function%i\n",
736 			__func__, selector);
737 		return -EINVAL;
738 	}
739 	*groups = function->group_names;
740 	*num_groups = function->num_group_names;
741 
742 	return 0;
743 }
744 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
745 
746 /**
747  * pinmux_generic_get_function() - returns a function based on the number
748  * @pctldev: pin controller device
749  * @group_selector: function number
750  */
751 struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
752 						  unsigned int selector)
753 {
754 	struct function_desc *function;
755 
756 	function = radix_tree_lookup(&pctldev->pin_function_tree,
757 				     selector);
758 	if (!function)
759 		return NULL;
760 
761 	return function;
762 }
763 EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
764 
765 /**
766  * pinmux_generic_add_function() - adds a function group
767  * @pctldev: pin controller device
768  * @name: name of the function
769  * @groups: array of pin groups
770  * @num_groups: number of pin groups
771  * @data: pin controller driver specific data
772  */
773 int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
774 				const char *name,
775 				const char **groups,
776 				const unsigned int num_groups,
777 				void *data)
778 {
779 	struct function_desc *function;
780 
781 	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
782 	if (!function)
783 		return -ENOMEM;
784 
785 	function->name = name;
786 	function->group_names = groups;
787 	function->num_group_names = num_groups;
788 	function->data = data;
789 
790 	radix_tree_insert(&pctldev->pin_function_tree, pctldev->num_functions,
791 			  function);
792 
793 	pctldev->num_functions++;
794 
795 	return 0;
796 }
797 EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
798 
799 /**
800  * pinmux_generic_remove_function() - removes a numbered function
801  * @pctldev: pin controller device
802  * @selector: function number
803  *
804  * Note that the caller must take care of locking.
805  */
806 int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
807 				   unsigned int selector)
808 {
809 	struct function_desc *function;
810 
811 	function = radix_tree_lookup(&pctldev->pin_function_tree,
812 				     selector);
813 	if (!function)
814 		return -ENOENT;
815 
816 	radix_tree_delete(&pctldev->pin_function_tree, selector);
817 	devm_kfree(pctldev->dev, function);
818 
819 	pctldev->num_functions--;
820 
821 	return 0;
822 }
823 EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
824 
825 /**
826  * pinmux_generic_free_functions() - removes all functions
827  * @pctldev: pin controller device
828  *
829  * Note that the caller must take care of locking. The pinctrl
830  * functions are allocated with devm_kzalloc() so no need to free
831  * them here.
832  */
833 void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
834 {
835 	struct radix_tree_iter iter;
836 	void **slot;
837 
838 	radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
839 		radix_tree_delete(&pctldev->pin_function_tree, iter.index);
840 
841 	pctldev->num_functions = 0;
842 }
843 
844 #endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */
845