xref: /openbmc/linux/drivers/pinctrl/pinconf.c (revision 275876e2)
1 /*
2  * Core driver for the pin config portions of the pin control subsystem
3  *
4  * Copyright (C) 2011 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  *
7  * Author: Linus Walleij <linus.walleij@linaro.org>
8  *
9  * License terms: GNU General Public License (GPL) version 2
10  */
11 #define pr_fmt(fmt) "pinconfig core: " fmt
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/slab.h>
18 #include <linux/debugfs.h>
19 #include <linux/seq_file.h>
20 #include <linux/uaccess.h>
21 #include <linux/pinctrl/machine.h>
22 #include <linux/pinctrl/pinctrl.h>
23 #include <linux/pinctrl/pinconf.h>
24 #include "core.h"
25 #include "pinconf.h"
26 
27 int pinconf_check_ops(struct pinctrl_dev *pctldev)
28 {
29 	const struct pinconf_ops *ops = pctldev->desc->confops;
30 
31 	/* We have to be able to config the pins in SOME way */
32 	if (!ops->pin_config_set && !ops->pin_config_group_set) {
33 		dev_err(pctldev->dev,
34 			"pinconf has to be able to set a pins config\n");
35 		return -EINVAL;
36 	}
37 	return 0;
38 }
39 
40 int pinconf_validate_map(struct pinctrl_map const *map, int i)
41 {
42 	if (!map->data.configs.group_or_pin) {
43 		pr_err("failed to register map %s (%d): no group/pin given\n",
44 		       map->name, i);
45 		return -EINVAL;
46 	}
47 
48 	if (!map->data.configs.num_configs ||
49 			!map->data.configs.configs) {
50 		pr_err("failed to register map %s (%d): no configs given\n",
51 		       map->name, i);
52 		return -EINVAL;
53 	}
54 
55 	return 0;
56 }
57 
58 int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
59 			   unsigned long *config)
60 {
61 	const struct pinconf_ops *ops = pctldev->desc->confops;
62 
63 	if (!ops || !ops->pin_config_get) {
64 		dev_dbg(pctldev->dev, "cannot get pin configuration, missing "
65 			"pin_config_get() function in driver\n");
66 		return -ENOTSUPP;
67 	}
68 
69 	return ops->pin_config_get(pctldev, pin, config);
70 }
71 
72 int pin_config_group_get(const char *dev_name, const char *pin_group,
73 			 unsigned long *config)
74 {
75 	struct pinctrl_dev *pctldev;
76 	const struct pinconf_ops *ops;
77 	int selector, ret;
78 
79 	pctldev = get_pinctrl_dev_from_devname(dev_name);
80 	if (!pctldev) {
81 		ret = -EINVAL;
82 		return ret;
83 	}
84 
85 	mutex_lock(&pctldev->mutex);
86 
87 	ops = pctldev->desc->confops;
88 
89 	if (!ops || !ops->pin_config_group_get) {
90 		dev_dbg(pctldev->dev, "cannot get configuration for pin "
91 			"group, missing group config get function in "
92 			"driver\n");
93 		ret = -ENOTSUPP;
94 		goto unlock;
95 	}
96 
97 	selector = pinctrl_get_group_selector(pctldev, pin_group);
98 	if (selector < 0) {
99 		ret = selector;
100 		goto unlock;
101 	}
102 
103 	ret = ops->pin_config_group_get(pctldev, selector, config);
104 
105 unlock:
106 	mutex_unlock(&pctldev->mutex);
107 	return ret;
108 }
109 
110 int pinconf_map_to_setting(struct pinctrl_map const *map,
111 			  struct pinctrl_setting *setting)
112 {
113 	struct pinctrl_dev *pctldev = setting->pctldev;
114 	int pin;
115 
116 	switch (setting->type) {
117 	case PIN_MAP_TYPE_CONFIGS_PIN:
118 		pin = pin_get_from_name(pctldev,
119 					map->data.configs.group_or_pin);
120 		if (pin < 0) {
121 			dev_err(pctldev->dev, "could not map pin config for \"%s\"",
122 				map->data.configs.group_or_pin);
123 			return pin;
124 		}
125 		setting->data.configs.group_or_pin = pin;
126 		break;
127 	case PIN_MAP_TYPE_CONFIGS_GROUP:
128 		pin = pinctrl_get_group_selector(pctldev,
129 					 map->data.configs.group_or_pin);
130 		if (pin < 0) {
131 			dev_err(pctldev->dev, "could not map group config for \"%s\"",
132 				map->data.configs.group_or_pin);
133 			return pin;
134 		}
135 		setting->data.configs.group_or_pin = pin;
136 		break;
137 	default:
138 		return -EINVAL;
139 	}
140 
141 	setting->data.configs.num_configs = map->data.configs.num_configs;
142 	setting->data.configs.configs = map->data.configs.configs;
143 
144 	return 0;
145 }
146 
147 void pinconf_free_setting(struct pinctrl_setting const *setting)
148 {
149 }
150 
151 int pinconf_apply_setting(struct pinctrl_setting const *setting)
152 {
153 	struct pinctrl_dev *pctldev = setting->pctldev;
154 	const struct pinconf_ops *ops = pctldev->desc->confops;
155 	int ret;
156 
157 	if (!ops) {
158 		dev_err(pctldev->dev, "missing confops\n");
159 		return -EINVAL;
160 	}
161 
162 	switch (setting->type) {
163 	case PIN_MAP_TYPE_CONFIGS_PIN:
164 		if (!ops->pin_config_set) {
165 			dev_err(pctldev->dev, "missing pin_config_set op\n");
166 			return -EINVAL;
167 		}
168 		ret = ops->pin_config_set(pctldev,
169 				setting->data.configs.group_or_pin,
170 				setting->data.configs.configs,
171 				setting->data.configs.num_configs);
172 		if (ret < 0) {
173 			dev_err(pctldev->dev,
174 				"pin_config_set op failed for pin %d\n",
175 				setting->data.configs.group_or_pin);
176 			return ret;
177 		}
178 		break;
179 	case PIN_MAP_TYPE_CONFIGS_GROUP:
180 		if (!ops->pin_config_group_set) {
181 			dev_err(pctldev->dev,
182 				"missing pin_config_group_set op\n");
183 			return -EINVAL;
184 		}
185 		ret = ops->pin_config_group_set(pctldev,
186 				setting->data.configs.group_or_pin,
187 				setting->data.configs.configs,
188 				setting->data.configs.num_configs);
189 		if (ret < 0) {
190 			dev_err(pctldev->dev,
191 				"pin_config_group_set op failed for group %d\n",
192 				setting->data.configs.group_or_pin);
193 			return ret;
194 		}
195 		break;
196 	default:
197 		return -EINVAL;
198 	}
199 
200 	return 0;
201 }
202 
203 #ifdef CONFIG_DEBUG_FS
204 
205 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
206 {
207 	struct pinctrl_dev *pctldev;
208 	const struct pinconf_ops *confops;
209 	int i;
210 
211 	pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
212 	if (pctldev)
213 		confops = pctldev->desc->confops;
214 	else
215 		confops = NULL;
216 
217 	switch (map->type) {
218 	case PIN_MAP_TYPE_CONFIGS_PIN:
219 		seq_printf(s, "pin ");
220 		break;
221 	case PIN_MAP_TYPE_CONFIGS_GROUP:
222 		seq_printf(s, "group ");
223 		break;
224 	default:
225 		break;
226 	}
227 
228 	seq_printf(s, "%s\n", map->data.configs.group_or_pin);
229 
230 	for (i = 0; i < map->data.configs.num_configs; i++) {
231 		seq_printf(s, "config ");
232 		if (confops && confops->pin_config_config_dbg_show)
233 			confops->pin_config_config_dbg_show(pctldev, s,
234 						map->data.configs.configs[i]);
235 		else
236 			seq_printf(s, "%08lx", map->data.configs.configs[i]);
237 		seq_printf(s, "\n");
238 	}
239 }
240 
241 void pinconf_show_setting(struct seq_file *s,
242 			  struct pinctrl_setting const *setting)
243 {
244 	struct pinctrl_dev *pctldev = setting->pctldev;
245 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
246 	const struct pinconf_ops *confops = pctldev->desc->confops;
247 	struct pin_desc *desc;
248 	int i;
249 
250 	switch (setting->type) {
251 	case PIN_MAP_TYPE_CONFIGS_PIN:
252 		desc = pin_desc_get(setting->pctldev,
253 				    setting->data.configs.group_or_pin);
254 		seq_printf(s, "pin %s (%d)",
255 			   desc->name ? desc->name : "unnamed",
256 			   setting->data.configs.group_or_pin);
257 		break;
258 	case PIN_MAP_TYPE_CONFIGS_GROUP:
259 		seq_printf(s, "group %s (%d)",
260 			   pctlops->get_group_name(pctldev,
261 					setting->data.configs.group_or_pin),
262 			   setting->data.configs.group_or_pin);
263 		break;
264 	default:
265 		break;
266 	}
267 
268 	/*
269 	 * FIXME: We should really get the pin controler to dump the config
270 	 * values, so they can be decoded to something meaningful.
271 	 */
272 	for (i = 0; i < setting->data.configs.num_configs; i++) {
273 		seq_printf(s, " ");
274 		if (confops && confops->pin_config_config_dbg_show)
275 			confops->pin_config_config_dbg_show(pctldev, s,
276 				setting->data.configs.configs[i]);
277 		else
278 			seq_printf(s, "%08lx",
279 				   setting->data.configs.configs[i]);
280 	}
281 
282 	seq_printf(s, "\n");
283 }
284 
285 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
286 			     struct seq_file *s, int pin)
287 {
288 	const struct pinconf_ops *ops = pctldev->desc->confops;
289 
290 	/* no-op when not using generic pin config */
291 	pinconf_generic_dump_pin(pctldev, s, pin);
292 	if (ops && ops->pin_config_dbg_show)
293 		ops->pin_config_dbg_show(pctldev, s, pin);
294 }
295 
296 static int pinconf_pins_show(struct seq_file *s, void *what)
297 {
298 	struct pinctrl_dev *pctldev = s->private;
299 	unsigned i, pin;
300 
301 	seq_puts(s, "Pin config settings per pin\n");
302 	seq_puts(s, "Format: pin (name): configs\n");
303 
304 	mutex_lock(&pctldev->mutex);
305 
306 	/* The pin number can be retrived from the pin controller descriptor */
307 	for (i = 0; i < pctldev->desc->npins; i++) {
308 		struct pin_desc *desc;
309 
310 		pin = pctldev->desc->pins[i].number;
311 		desc = pin_desc_get(pctldev, pin);
312 		/* Skip if we cannot search the pin */
313 		if (desc == NULL)
314 			continue;
315 
316 		seq_printf(s, "pin %d (%s):", pin,
317 			   desc->name ? desc->name : "unnamed");
318 
319 		pinconf_dump_pin(pctldev, s, pin);
320 
321 		seq_printf(s, "\n");
322 	}
323 
324 	mutex_unlock(&pctldev->mutex);
325 
326 	return 0;
327 }
328 
329 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
330 			       struct seq_file *s, unsigned selector,
331 			       const char *gname)
332 {
333 	const struct pinconf_ops *ops = pctldev->desc->confops;
334 
335 	/* no-op when not using generic pin config */
336 	pinconf_generic_dump_group(pctldev, s, gname);
337 	if (ops && ops->pin_config_group_dbg_show)
338 		ops->pin_config_group_dbg_show(pctldev, s, selector);
339 }
340 
341 static int pinconf_groups_show(struct seq_file *s, void *what)
342 {
343 	struct pinctrl_dev *pctldev = s->private;
344 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
345 	unsigned ngroups = pctlops->get_groups_count(pctldev);
346 	unsigned selector = 0;
347 
348 	seq_puts(s, "Pin config settings per pin group\n");
349 	seq_puts(s, "Format: group (name): configs\n");
350 
351 	while (selector < ngroups) {
352 		const char *gname = pctlops->get_group_name(pctldev, selector);
353 
354 		seq_printf(s, "%u (%s):", selector, gname);
355 		pinconf_dump_group(pctldev, s, selector, gname);
356 		seq_printf(s, "\n");
357 
358 		selector++;
359 	}
360 
361 	return 0;
362 }
363 
364 static int pinconf_pins_open(struct inode *inode, struct file *file)
365 {
366 	return single_open(file, pinconf_pins_show, inode->i_private);
367 }
368 
369 static int pinconf_groups_open(struct inode *inode, struct file *file)
370 {
371 	return single_open(file, pinconf_groups_show, inode->i_private);
372 }
373 
374 static const struct file_operations pinconf_pins_ops = {
375 	.open		= pinconf_pins_open,
376 	.read		= seq_read,
377 	.llseek		= seq_lseek,
378 	.release	= single_release,
379 };
380 
381 static const struct file_operations pinconf_groups_ops = {
382 	.open		= pinconf_groups_open,
383 	.read		= seq_read,
384 	.llseek		= seq_lseek,
385 	.release	= single_release,
386 };
387 
388 #define MAX_NAME_LEN 15
389 
390 struct dbg_cfg {
391 	enum pinctrl_map_type map_type;
392 	char dev_name[MAX_NAME_LEN+1];
393 	char state_name[MAX_NAME_LEN+1];
394 	char pin_name[MAX_NAME_LEN+1];
395 };
396 
397 /*
398  * Goal is to keep this structure as global in order to simply read the
399  * pinconf-config file after a write to check config is as expected
400  */
401 static struct dbg_cfg pinconf_dbg_conf;
402 
403 /**
404  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
405  * map, of the dev/pin/state that was last written to pinconf-config file.
406  * @s: string filled in  with config description
407  * @d: not used
408  */
409 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
410 {
411 	struct pinctrl_maps *maps_node;
412 	const struct pinctrl_map *map;
413 	const struct pinctrl_map *found = NULL;
414 	struct pinctrl_dev *pctldev;
415 	const struct pinconf_ops *confops = NULL;
416 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
417 	int i, j;
418 	unsigned long config;
419 
420 	mutex_lock(&pinctrl_maps_mutex);
421 
422 	/* Parse the pinctrl map and look for the elected pin/state */
423 	for_each_maps(maps_node, i, map) {
424 		if (map->type != dbg->map_type)
425 			continue;
426 		if (strcmp(map->dev_name, dbg->dev_name))
427 			continue;
428 		if (strcmp(map->name, dbg->state_name))
429 			continue;
430 
431 		for (j = 0; j < map->data.configs.num_configs; j++) {
432 			if (!strcmp(map->data.configs.group_or_pin,
433 					dbg->pin_name)) {
434 				/* We found the right pin / state */
435 				found = map;
436 				break;
437 			}
438 		}
439 	}
440 
441 	if (!found) {
442 		seq_printf(s, "No config found for dev/state/pin, expected:\n");
443 		seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
444 		seq_printf(s, "Searched state:%s\n", dbg->state_name);
445 		seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
446 		seq_printf(s, "Use: modify config_pin <devname> "\
447 				"<state> <pinname> <value>\n");
448 		goto exit;
449 	}
450 
451 	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
452 	config = *found->data.configs.configs;
453 	seq_printf(s, "Dev %s has config of %s in state %s: 0x%08lX\n",
454 			dbg->dev_name, dbg->pin_name,
455 			dbg->state_name, config);
456 
457 	if (pctldev)
458 		confops = pctldev->desc->confops;
459 
460 	if (confops && confops->pin_config_config_dbg_show)
461 		confops->pin_config_config_dbg_show(pctldev, s, config);
462 
463 exit:
464 	mutex_unlock(&pinctrl_maps_mutex);
465 
466 	return 0;
467 }
468 
469 /**
470  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
471  * map, of a dev/pin/state entry based on user entries to pinconf-config
472  * @user_buf: contains the modification request with expected format:
473  *     modify config_pin <devicename> <state> <pinname> <newvalue>
474  * modify is literal string, alternatives like add/delete not supported yet
475  * config_pin is literal, alternatives like config_mux not supported yet
476  * <devicename> <state> <pinname> are values that should match the pinctrl-maps
477  * <newvalue> reflects the new config and is driver dependant
478  */
479 static ssize_t pinconf_dbg_config_write(struct file *file,
480 	const char __user *user_buf, size_t count, loff_t *ppos)
481 {
482 	struct pinctrl_maps *maps_node;
483 	const struct pinctrl_map *map;
484 	const struct pinctrl_map *found = NULL;
485 	struct pinctrl_dev *pctldev;
486 	const struct pinconf_ops *confops = NULL;
487 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
488 	const struct pinctrl_map_configs *configs;
489 	char config[MAX_NAME_LEN+1];
490 	char buf[128];
491 	char *b = &buf[0];
492 	int buf_size;
493 	char *token;
494 	int i;
495 
496 	/* Get userspace string and assure termination */
497 	buf_size = min(count, sizeof(buf) - 1);
498 	if (copy_from_user(buf, user_buf, buf_size))
499 		return -EFAULT;
500 	buf[buf_size] = 0;
501 
502 	/*
503 	 * need to parse entry and extract parameters:
504 	 * modify configs_pin devicename state pinname newvalue
505 	 */
506 
507 	/* Get arg: 'modify' */
508 	token = strsep(&b, " ");
509 	if (!token)
510 		return -EINVAL;
511 	if (strcmp(token, "modify"))
512 		return -EINVAL;
513 
514 	/* Get arg type: "config_pin" type supported so far */
515 	token = strsep(&b, " ");
516 	if (!token)
517 		return -EINVAL;
518 	if (strcmp(token, "config_pin"))
519 		return -EINVAL;
520 	dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
521 
522 	/* get arg 'device_name' */
523 	token = strsep(&b, " ");
524 	if (token == NULL)
525 		return -EINVAL;
526 	if (strlen(token) >= MAX_NAME_LEN)
527 		return -EINVAL;
528 	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
529 
530 	/* get arg 'state_name' */
531 	token = strsep(&b, " ");
532 	if (token == NULL)
533 		return -EINVAL;
534 	if (strlen(token) >= MAX_NAME_LEN)
535 		return -EINVAL;
536 	strncpy(dbg->state_name, token, MAX_NAME_LEN);
537 
538 	/* get arg 'pin_name' */
539 	token = strsep(&b, " ");
540 	if (token == NULL)
541 		return -EINVAL;
542 	if (strlen(token) >= MAX_NAME_LEN)
543 		return -EINVAL;
544 	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
545 
546 	/* get new_value of config' */
547 	token = strsep(&b, " ");
548 	if (token == NULL)
549 		return -EINVAL;
550 	if (strlen(token) >= MAX_NAME_LEN)
551 		return -EINVAL;
552 	strncpy(config, token, MAX_NAME_LEN);
553 
554 	mutex_lock(&pinctrl_maps_mutex);
555 
556 	/* Parse the pinctrl map and look for the selected dev/state/pin */
557 	for_each_maps(maps_node, i, map) {
558 		if (strcmp(map->dev_name, dbg->dev_name))
559 			continue;
560 		if (map->type != dbg->map_type)
561 			continue;
562 		if (strcmp(map->name, dbg->state_name))
563 			continue;
564 
565 		/*  we found the right pin / state, so overwrite config */
566 		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
567 			found = map;
568 			break;
569 		}
570 	}
571 
572 	if (!found) {
573 		count = -EINVAL;
574 		goto exit;
575 	}
576 
577 	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
578 	if (pctldev)
579 		confops = pctldev->desc->confops;
580 
581 	if (confops && confops->pin_config_dbg_parse_modify) {
582 		configs = &found->data.configs;
583 		for (i = 0; i < configs->num_configs; i++) {
584 			confops->pin_config_dbg_parse_modify(pctldev,
585 						     config,
586 						     &configs->configs[i]);
587 		}
588 	}
589 
590 exit:
591 	mutex_unlock(&pinctrl_maps_mutex);
592 
593 	return count;
594 }
595 
596 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
597 {
598 	return single_open(file, pinconf_dbg_config_print, inode->i_private);
599 }
600 
601 static const struct file_operations pinconf_dbg_pinconfig_fops = {
602 	.open = pinconf_dbg_config_open,
603 	.write = pinconf_dbg_config_write,
604 	.read = seq_read,
605 	.llseek = seq_lseek,
606 	.release = single_release,
607 	.owner = THIS_MODULE,
608 };
609 
610 void pinconf_init_device_debugfs(struct dentry *devroot,
611 			 struct pinctrl_dev *pctldev)
612 {
613 	debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
614 			    devroot, pctldev, &pinconf_pins_ops);
615 	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
616 			    devroot, pctldev, &pinconf_groups_ops);
617 	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
618 			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);
619 }
620 
621 #endif
622