1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Core driver for the pin muxing portions of the pin control subsystem
4 *
5 * Copyright (C) 2011-2012 ST-Ericsson SA
6 * Written on behalf of Linaro for ST-Ericsson
7 * Based on bits of regulator core, gpio core and clk core
8 *
9 * Author: Linus Walleij <linus.walleij@linaro.org>
10 *
11 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
12 */
13#define pr_fmt(fmt) "pinmux core: " fmt
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/device.h>
19#include <linux/slab.h>
20#include <linux/radix-tree.h>
21#include <linux/err.h>
22#include <linux/list.h>
23#include <linux/string.h>
24#include <linux/debugfs.h>
25#include <linux/seq_file.h>
26#include <linux/pinctrl/machine.h>
27#include <linux/pinctrl/pinmux.h>
28#include "core.h"
29#include "pinmux.h"
30
31int pinmux_check_ops(struct pinctrl_dev *pctldev)
32{
33	const struct pinmux_ops *ops = pctldev->desc->pmxops;
34	unsigned nfuncs;
35	unsigned selector = 0;
36
37	/* Check that we implement required operations */
38	if (!ops ||
39	    !ops->get_functions_count ||
40	    !ops->get_function_name ||
41	    !ops->get_function_groups ||
42	    !ops->set_mux) {
43		dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
44		return -EINVAL;
45	}
46	/* Check that all functions registered have names */
47	nfuncs = ops->get_functions_count(pctldev);
48	while (selector < nfuncs) {
49		const char *fname = ops->get_function_name(pctldev,
50							   selector);
51		if (!fname) {
52			dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
53				selector);
54			return -EINVAL;
55		}
56		selector++;
57	}
58
59	return 0;
60}
61
62int pinmux_validate_map(const struct pinctrl_map *map, int i)
63{
64	if (!map->data.mux.function) {
65		pr_err("failed to register map %s (%d): no function given\n",
66		       map->name, i);
67		return -EINVAL;
68	}
69
70	return 0;
71}
72
73/**
74 * pinmux_can_be_used_for_gpio() - check if a specific pin
75 *	is either muxed to a different function or used as gpio.
76 *
77 * @pctldev: the associated pin controller device
78 * @pin: the pin number in the global pin space
79 *
80 * Controllers not defined as strict will always return true,
81 * menaning that the gpio can be used.
82 */
83bool pinmux_can_be_used_for_gpio(struct pinctrl_dev *pctldev, unsigned pin)
84{
85	struct pin_desc *desc = pin_desc_get(pctldev, pin);
86	const struct pinmux_ops *ops = pctldev->desc->pmxops;
87
88	/* Can't inspect pin, assume it can be used */
89	if (!desc || !ops)
90		return true;
91
92	if (ops->strict && desc->mux_usecount)
93		return false;
94
95	return !(ops->strict && !!desc->gpio_owner);
96}
97
98/**
99 * pin_request() - request a single pin to be muxed in, typically for GPIO
100 * @pctldev: the associated pin controller device
101 * @pin: the pin number in the global pin space
102 * @owner: a representation of the owner of this pin; typically the device
103 *	name that controls its mux function, or the requested GPIO name
104 * @gpio_range: the range matching the GPIO pin if this is a request for a
105 *	single GPIO pin
106 */
107static int pin_request(struct pinctrl_dev *pctldev,
108		       int pin, const char *owner,
109		       struct pinctrl_gpio_range *gpio_range)
110{
111	struct pin_desc *desc;
112	const struct pinmux_ops *ops = pctldev->desc->pmxops;
113	int status = -EINVAL;
114
115	desc = pin_desc_get(pctldev, pin);
116	if (desc == NULL) {
117		dev_err(pctldev->dev,
118			"pin %d is not registered so it cannot be requested\n",
119			pin);
120		goto out;
121	}
122
123	dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
124		pin, desc->name, owner);
125
126	if ((!gpio_range || ops->strict) &&
127	    desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
128		dev_err(pctldev->dev,
129			"pin %s already requested by %s; cannot claim for %s\n",
130			desc->name, desc->mux_owner, owner);
131		goto out;
132	}
133
134	if ((gpio_range || ops->strict) && desc->gpio_owner) {
135		dev_err(pctldev->dev,
136			"pin %s already requested by %s; cannot claim for %s\n",
137			desc->name, desc->gpio_owner, owner);
138		goto out;
139	}
140
141	if (gpio_range) {
142		desc->gpio_owner = owner;
143	} else {
144		desc->mux_usecount++;
145		if (desc->mux_usecount > 1)
146			return 0;
147
148		desc->mux_owner = owner;
149	}
150
151	/* Let each pin increase references to this module */
152	if (!try_module_get(pctldev->owner)) {
153		dev_err(pctldev->dev,
154			"could not increase module refcount for pin %d\n",
155			pin);
156		status = -EINVAL;
157		goto out_free_pin;
158	}
159
160	/*
161	 * If there is no kind of request function for the pin we just assume
162	 * we got it by default and proceed.
163	 */
164	if (gpio_range && ops->gpio_request_enable)
165		/* This requests and enables a single GPIO pin */
166		status = ops->gpio_request_enable(pctldev, gpio_range, pin);
167	else if (ops->request)
168		status = ops->request(pctldev, pin);
169	else
170		status = 0;
171
172	if (status) {
173		dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
174		module_put(pctldev->owner);
175	}
176
177out_free_pin:
178	if (status) {
179		if (gpio_range) {
180			desc->gpio_owner = NULL;
181		} else {
182			desc->mux_usecount--;
183			if (!desc->mux_usecount)
184				desc->mux_owner = NULL;
185		}
186	}
187out:
188	if (status)
189		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
190			pin, owner, status);
191
192	return status;
193}
194
195/**
196 * pin_free() - release a single muxed in pin so something else can be muxed
197 * @pctldev: pin controller device handling this pin
198 * @pin: the pin to free
199 * @gpio_range: the range matching the GPIO pin if this is a request for a
200 *	single GPIO pin
201 *
202 * This function returns a pointer to the previous owner. This is used
203 * for callers that dynamically allocate an owner name so it can be freed
204 * once the pin is free. This is done for GPIO request functions.
205 */
206static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
207			    struct pinctrl_gpio_range *gpio_range)
208{
209	const struct pinmux_ops *ops = pctldev->desc->pmxops;
210	struct pin_desc *desc;
211	const char *owner;
212
213	desc = pin_desc_get(pctldev, pin);
214	if (desc == NULL) {
215		dev_err(pctldev->dev,
216			"pin is not registered so it cannot be freed\n");
217		return NULL;
218	}
219
220	if (!gpio_range) {
221		/*
222		 * A pin should not be freed more times than allocated.
223		 */
224		if (WARN_ON(!desc->mux_usecount))
225			return NULL;
226		desc->mux_usecount--;
227		if (desc->mux_usecount)
228			return NULL;
229	}
230
231	/*
232	 * If there is no kind of request function for the pin we just assume
233	 * we got it by default and proceed.
234	 */
235	if (gpio_range && ops->gpio_disable_free)
236		ops->gpio_disable_free(pctldev, gpio_range, pin);
237	else if (ops->free)
238		ops->free(pctldev, pin);
239
240	if (gpio_range) {
241		owner = desc->gpio_owner;
242		desc->gpio_owner = NULL;
243	} else {
244		owner = desc->mux_owner;
245		desc->mux_owner = NULL;
246		desc->mux_setting = NULL;
247	}
248
249	module_put(pctldev->owner);
250
251	return owner;
252}
253
254/**
255 * pinmux_request_gpio() - request pinmuxing for a GPIO pin
256 * @pctldev: pin controller device affected
257 * @pin: the pin to mux in for GPIO
258 * @range: the applicable GPIO range
259 * @gpio: number of requested GPIO
260 */
261int pinmux_request_gpio(struct pinctrl_dev *pctldev,
262			struct pinctrl_gpio_range *range,
263			unsigned pin, unsigned gpio)
264{
265	const char *owner;
266	int ret;
267
268	/* Conjure some name stating what chip and pin this is taken by */
269	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
270	if (!owner)
271		return -ENOMEM;
272
273	ret = pin_request(pctldev, pin, owner, range);
274	if (ret < 0)
275		kfree(owner);
276
277	return ret;
278}
279
280/**
281 * pinmux_free_gpio() - release a pin from GPIO muxing
282 * @pctldev: the pin controller device for the pin
283 * @pin: the affected currently GPIO-muxed in pin
284 * @range: applicable GPIO range
285 */
286void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
287		      struct pinctrl_gpio_range *range)
288{
289	const char *owner;
290
291	owner = pin_free(pctldev, pin, range);
292	kfree(owner);
293}
294
295/**
296 * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
297 * @pctldev: the pin controller handling this pin
298 * @range: applicable GPIO range
299 * @pin: the affected GPIO pin in this controller
300 * @input: true if we set the pin as input, false for output
301 */
302int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
303			  struct pinctrl_gpio_range *range,
304			  unsigned pin, bool input)
305{
306	const struct pinmux_ops *ops;
307	int ret;
308
309	ops = pctldev->desc->pmxops;
310
311	if (ops->gpio_set_direction)
312		ret = ops->gpio_set_direction(pctldev, range, pin, input);
313	else
314		ret = 0;
315
316	return ret;
317}
318
319static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
320					const char *function)
321{
322	const struct pinmux_ops *ops = pctldev->desc->pmxops;
323	unsigned nfuncs = ops->get_functions_count(pctldev);
324	unsigned selector = 0;
325
326	/* See if this pctldev has this function */
327	while (selector < nfuncs) {
328		const char *fname = ops->get_function_name(pctldev, selector);
329
330		if (!strcmp(function, fname))
331			return selector;
332
333		selector++;
334	}
335
336	return -EINVAL;
337}
338
339int pinmux_map_to_setting(const struct pinctrl_map *map,
340			  struct pinctrl_setting *setting)
341{
342	struct pinctrl_dev *pctldev = setting->pctldev;
343	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
344	char const * const *groups;
345	unsigned num_groups;
346	int ret;
347	const char *group;
348
349	if (!pmxops) {
350		dev_err(pctldev->dev, "does not support mux function\n");
351		return -EINVAL;
352	}
353
354	ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
355	if (ret < 0) {
356		dev_err(pctldev->dev, "invalid function %s in map table\n",
357			map->data.mux.function);
358		return ret;
359	}
360	setting->data.mux.func = ret;
361
362	ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
363					  &groups, &num_groups);
364	if (ret < 0) {
365		dev_err(pctldev->dev, "can't query groups for function %s\n",
366			map->data.mux.function);
367		return ret;
368	}
369	if (!num_groups) {
370		dev_err(pctldev->dev,
371			"function %s can't be selected on any group\n",
372			map->data.mux.function);
373		return -EINVAL;
374	}
375	if (map->data.mux.group) {
376		group = map->data.mux.group;
377		ret = match_string(groups, num_groups, group);
378		if (ret < 0) {
379			dev_err(pctldev->dev,
380				"invalid group \"%s\" for function \"%s\"\n",
381				group, map->data.mux.function);
382			return ret;
383		}
384	} else {
385		group = groups[0];
386	}
387
388	ret = pinctrl_get_group_selector(pctldev, group);
389	if (ret < 0) {
390		dev_err(pctldev->dev, "invalid group %s in map table\n",
391			map->data.mux.group);
392		return ret;
393	}
394	setting->data.mux.group = ret;
395
396	return 0;
397}
398
399void pinmux_free_setting(const struct pinctrl_setting *setting)
400{
401	/* This function is currently unused */
402}
403
404int pinmux_enable_setting(const struct pinctrl_setting *setting)
405{
406	struct pinctrl_dev *pctldev = setting->pctldev;
407	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
408	const struct pinmux_ops *ops = pctldev->desc->pmxops;
409	int ret = 0;
410	const unsigned *pins = NULL;
411	unsigned num_pins = 0;
412	int i;
413	struct pin_desc *desc;
414
415	if (pctlops->get_group_pins)
416		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
417					      &pins, &num_pins);
418
419	if (ret) {
420		const char *gname;
421
422		/* errors only affect debug data, so just warn */
423		gname = pctlops->get_group_name(pctldev,
424						setting->data.mux.group);
425		dev_warn(pctldev->dev,
426			 "could not get pins for group %s\n",
427			 gname);
428		num_pins = 0;
429	}
430
431	/* Try to allocate all pins in this group, one by one */
432	for (i = 0; i < num_pins; i++) {
433		ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
434		if (ret) {
435			const char *gname;
436			const char *pname;
437
438			desc = pin_desc_get(pctldev, pins[i]);
439			pname = desc ? desc->name : "non-existing";
440			gname = pctlops->get_group_name(pctldev,
441						setting->data.mux.group);
442			dev_err(pctldev->dev,
443				"could not request pin %d (%s) from group %s "
444				" on device %s\n",
445				pins[i], pname, gname,
446				pinctrl_dev_get_name(pctldev));
447			goto err_pin_request;
448		}
449	}
450
451	/* Now that we have acquired the pins, encode the mux setting */
452	for (i = 0; i < num_pins; i++) {
453		desc = pin_desc_get(pctldev, pins[i]);
454		if (desc == NULL) {
455			dev_warn(pctldev->dev,
456				 "could not get pin desc for pin %d\n",
457				 pins[i]);
458			continue;
459		}
460		desc->mux_setting = &(setting->data.mux);
461	}
462
463	ret = ops->set_mux(pctldev, setting->data.mux.func,
464			   setting->data.mux.group);
465
466	if (ret)
467		goto err_set_mux;
468
469	return 0;
470
471err_set_mux:
472	for (i = 0; i < num_pins; i++) {
473		desc = pin_desc_get(pctldev, pins[i]);
474		if (desc)
475			desc->mux_setting = NULL;
476	}
477err_pin_request:
478	/* On error release all taken pins */
479	while (--i >= 0)
480		pin_free(pctldev, pins[i], NULL);
481
482	return ret;
483}
484
485void pinmux_disable_setting(const struct pinctrl_setting *setting)
486{
487	struct pinctrl_dev *pctldev = setting->pctldev;
488	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
489	int ret = 0;
490	const unsigned *pins = NULL;
491	unsigned num_pins = 0;
492	int i;
493	struct pin_desc *desc;
494
495	if (pctlops->get_group_pins)
496		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
497					      &pins, &num_pins);
498	if (ret) {
499		const char *gname;
500
501		/* errors only affect debug data, so just warn */
502		gname = pctlops->get_group_name(pctldev,
503						setting->data.mux.group);
504		dev_warn(pctldev->dev,
505			 "could not get pins for group %s\n",
506			 gname);
507		num_pins = 0;
508	}
509
510	/* Flag the descs that no setting is active */
511	for (i = 0; i < num_pins; i++) {
512		desc = pin_desc_get(pctldev, pins[i]);
513		if (desc == NULL) {
514			dev_warn(pctldev->dev,
515				 "could not get pin desc for pin %d\n",
516				 pins[i]);
517			continue;
518		}
519		if (desc->mux_setting == &(setting->data.mux)) {
520			pin_free(pctldev, pins[i], NULL);
521		} else {
522			const char *gname;
523
524			gname = pctlops->get_group_name(pctldev,
525						setting->data.mux.group);
526			dev_warn(pctldev->dev,
527				 "not freeing pin %d (%s) as part of "
528				 "deactivating group %s - it is already "
529				 "used for some other setting",
530				 pins[i], desc->name, gname);
531		}
532	}
533}
534
535#ifdef CONFIG_DEBUG_FS
536
537/* Called from pincontrol core */
538static int pinmux_functions_show(struct seq_file *s, void *what)
539{
540	struct pinctrl_dev *pctldev = s->private;
541	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
542	unsigned nfuncs;
543	unsigned func_selector = 0;
544
545	if (!pmxops)
546		return 0;
547
548	mutex_lock(&pctldev->mutex);
549	nfuncs = pmxops->get_functions_count(pctldev);
550	while (func_selector < nfuncs) {
551		const char *func = pmxops->get_function_name(pctldev,
552							  func_selector);
553		const char * const *groups;
554		unsigned num_groups;
555		int ret;
556		int i;
557
558		ret = pmxops->get_function_groups(pctldev, func_selector,
559						  &groups, &num_groups);
560		if (ret) {
561			seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
562				   func);
563			func_selector++;
564			continue;
565		}
566
567		seq_printf(s, "function: %s, groups = [ ", func);
568		for (i = 0; i < num_groups; i++)
569			seq_printf(s, "%s ", groups[i]);
570		seq_puts(s, "]\n");
571
572		func_selector++;
573	}
574
575	mutex_unlock(&pctldev->mutex);
576
577	return 0;
578}
579
580static int pinmux_pins_show(struct seq_file *s, void *what)
581{
582	struct pinctrl_dev *pctldev = s->private;
583	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
584	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
585	unsigned i, pin;
586
587	if (!pmxops)
588		return 0;
589
590	seq_puts(s, "Pinmux settings per pin\n");
591	if (pmxops->strict)
592		seq_puts(s,
593		 "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
594	else
595		seq_puts(s,
596		"Format: pin (name): mux_owner gpio_owner hog?\n");
597
598	mutex_lock(&pctldev->mutex);
599
600	/* The pin number can be retrived from the pin controller descriptor */
601	for (i = 0; i < pctldev->desc->npins; i++) {
602		struct pin_desc *desc;
603		bool is_hog = false;
604
605		pin = pctldev->desc->pins[i].number;
606		desc = pin_desc_get(pctldev, pin);
607		/* Skip if we cannot search the pin */
608		if (desc == NULL)
609			continue;
610
611		if (desc->mux_owner &&
612		    !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
613			is_hog = true;
614
615		if (pmxops->strict) {
616			if (desc->mux_owner)
617				seq_printf(s, "pin %d (%s): device %s%s",
618					   pin, desc->name, desc->mux_owner,
619					   is_hog ? " (HOG)" : "");
620			else if (desc->gpio_owner)
621				seq_printf(s, "pin %d (%s): GPIO %s",
622					   pin, desc->name, desc->gpio_owner);
623			else
624				seq_printf(s, "pin %d (%s): UNCLAIMED",
625					   pin, desc->name);
626		} else {
627			/* For non-strict controllers */
628			seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
629				   desc->mux_owner ? desc->mux_owner
630				   : "(MUX UNCLAIMED)",
631				   desc->gpio_owner ? desc->gpio_owner
632				   : "(GPIO UNCLAIMED)",
633				   is_hog ? " (HOG)" : "");
634		}
635
636		/* If mux: print function+group claiming the pin */
637		if (desc->mux_setting)
638			seq_printf(s, " function %s group %s\n",
639				   pmxops->get_function_name(pctldev,
640					desc->mux_setting->func),
641				   pctlops->get_group_name(pctldev,
642					desc->mux_setting->group));
643		else
644			seq_putc(s, '\n');
645	}
646
647	mutex_unlock(&pctldev->mutex);
648
649	return 0;
650}
651
652void pinmux_show_map(struct seq_file *s, const struct pinctrl_map *map)
653{
654	seq_printf(s, "group %s\nfunction %s\n",
655		map->data.mux.group ? map->data.mux.group : "(default)",
656		map->data.mux.function);
657}
658
659void pinmux_show_setting(struct seq_file *s,
660			 const struct pinctrl_setting *setting)
661{
662	struct pinctrl_dev *pctldev = setting->pctldev;
663	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
664	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
665
666	seq_printf(s, "group: %s (%u) function: %s (%u)\n",
667		   pctlops->get_group_name(pctldev, setting->data.mux.group),
668		   setting->data.mux.group,
669		   pmxops->get_function_name(pctldev, setting->data.mux.func),
670		   setting->data.mux.func);
671}
672
673DEFINE_SHOW_ATTRIBUTE(pinmux_functions);
674DEFINE_SHOW_ATTRIBUTE(pinmux_pins);
675
676void pinmux_init_device_debugfs(struct dentry *devroot,
677			 struct pinctrl_dev *pctldev)
678{
679	debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
680			    devroot, pctldev, &pinmux_functions_fops);
681	debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
682			    devroot, pctldev, &pinmux_pins_fops);
683}
684
685#endif /* CONFIG_DEBUG_FS */
686
687#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
688
689/**
690 * pinmux_generic_get_function_count() - returns number of functions
691 * @pctldev: pin controller device
692 */
693int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
694{
695	return pctldev->num_functions;
696}
697EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
698
699/**
700 * pinmux_generic_get_function_name() - returns the function name
701 * @pctldev: pin controller device
702 * @selector: function number
703 */
704const char *
705pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
706				 unsigned int selector)
707{
708	struct function_desc *function;
709
710	function = radix_tree_lookup(&pctldev->pin_function_tree,
711				     selector);
712	if (!function)
713		return NULL;
714
715	return function->name;
716}
717EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
718
719/**
720 * pinmux_generic_get_function_groups() - gets the function groups
721 * @pctldev: pin controller device
722 * @selector: function number
723 * @groups: array of pin groups
724 * @num_groups: number of pin groups
725 */
726int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
727				       unsigned int selector,
728				       const char * const **groups,
729				       unsigned * const num_groups)
730{
731	struct function_desc *function;
732
733	function = radix_tree_lookup(&pctldev->pin_function_tree,
734				     selector);
735	if (!function) {
736		dev_err(pctldev->dev, "%s could not find function%i\n",
737			__func__, selector);
738		return -EINVAL;
739	}
740	*groups = function->group_names;
741	*num_groups = function->num_group_names;
742
743	return 0;
744}
745EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
746
747/**
748 * pinmux_generic_get_function() - returns a function based on the number
749 * @pctldev: pin controller device
750 * @selector: function number
751 */
752struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
753						  unsigned int selector)
754{
755	struct function_desc *function;
756
757	function = radix_tree_lookup(&pctldev->pin_function_tree,
758				     selector);
759	if (!function)
760		return NULL;
761
762	return function;
763}
764EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
765
766/**
767 * pinmux_generic_add_function() - adds a function group
768 * @pctldev: pin controller device
769 * @name: name of the function
770 * @groups: array of pin groups
771 * @num_groups: number of pin groups
772 * @data: pin controller driver specific data
773 */
774int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
775				const char *name,
776				const char **groups,
777				const unsigned int num_groups,
778				void *data)
779{
780	struct function_desc *function;
781	int selector;
782
783	if (!name)
784		return -EINVAL;
785
786	selector = pinmux_func_name_to_selector(pctldev, name);
787	if (selector >= 0)
788		return selector;
789
790	selector = pctldev->num_functions;
791
792	function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
793	if (!function)
794		return -ENOMEM;
795
796	function->name = name;
797	function->group_names = groups;
798	function->num_group_names = num_groups;
799	function->data = data;
800
801	radix_tree_insert(&pctldev->pin_function_tree, selector, function);
802
803	pctldev->num_functions++;
804
805	return selector;
806}
807EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
808
809/**
810 * pinmux_generic_remove_function() - removes a numbered function
811 * @pctldev: pin controller device
812 * @selector: function number
813 *
814 * Note that the caller must take care of locking.
815 */
816int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
817				   unsigned int selector)
818{
819	struct function_desc *function;
820
821	function = radix_tree_lookup(&pctldev->pin_function_tree,
822				     selector);
823	if (!function)
824		return -ENOENT;
825
826	radix_tree_delete(&pctldev->pin_function_tree, selector);
827	devm_kfree(pctldev->dev, function);
828
829	pctldev->num_functions--;
830
831	return 0;
832}
833EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
834
835/**
836 * pinmux_generic_free_functions() - removes all functions
837 * @pctldev: pin controller device
838 *
839 * Note that the caller must take care of locking. The pinctrl
840 * functions are allocated with devm_kzalloc() so no need to free
841 * them here.
842 */
843void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
844{
845	struct radix_tree_iter iter;
846	void __rcu **slot;
847
848	radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
849		radix_tree_delete(&pctldev->pin_function_tree, iter.index);
850
851	pctldev->num_functions = 0;
852}
853
854#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */
855