xref: /openbmc/linux/drivers/pinctrl/pinconf.c (revision e3b9f1e8)
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(const struct pinctrl_map *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,
65 			"cannot get pin configuration, .pin_config_get missing 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,
91 			"cannot get configuration for pin group, missing group config get function in driver\n");
92 		ret = -ENOTSUPP;
93 		goto unlock;
94 	}
95 
96 	selector = pinctrl_get_group_selector(pctldev, pin_group);
97 	if (selector < 0) {
98 		ret = selector;
99 		goto unlock;
100 	}
101 
102 	ret = ops->pin_config_group_get(pctldev, selector, config);
103 
104 unlock:
105 	mutex_unlock(&pctldev->mutex);
106 	return ret;
107 }
108 
109 int pinconf_map_to_setting(const struct pinctrl_map *map,
110 			  struct pinctrl_setting *setting)
111 {
112 	struct pinctrl_dev *pctldev = setting->pctldev;
113 	int pin;
114 
115 	switch (setting->type) {
116 	case PIN_MAP_TYPE_CONFIGS_PIN:
117 		pin = pin_get_from_name(pctldev,
118 					map->data.configs.group_or_pin);
119 		if (pin < 0) {
120 			dev_err(pctldev->dev, "could not map pin config for \"%s\"",
121 				map->data.configs.group_or_pin);
122 			return pin;
123 		}
124 		setting->data.configs.group_or_pin = pin;
125 		break;
126 	case PIN_MAP_TYPE_CONFIGS_GROUP:
127 		pin = pinctrl_get_group_selector(pctldev,
128 					 map->data.configs.group_or_pin);
129 		if (pin < 0) {
130 			dev_err(pctldev->dev, "could not map group config for \"%s\"",
131 				map->data.configs.group_or_pin);
132 			return pin;
133 		}
134 		setting->data.configs.group_or_pin = pin;
135 		break;
136 	default:
137 		return -EINVAL;
138 	}
139 
140 	setting->data.configs.num_configs = map->data.configs.num_configs;
141 	setting->data.configs.configs = map->data.configs.configs;
142 
143 	return 0;
144 }
145 
146 void pinconf_free_setting(const struct pinctrl_setting *setting)
147 {
148 }
149 
150 int pinconf_apply_setting(const struct pinctrl_setting *setting)
151 {
152 	struct pinctrl_dev *pctldev = setting->pctldev;
153 	const struct pinconf_ops *ops = pctldev->desc->confops;
154 	int ret;
155 
156 	if (!ops) {
157 		dev_err(pctldev->dev, "missing confops\n");
158 		return -EINVAL;
159 	}
160 
161 	switch (setting->type) {
162 	case PIN_MAP_TYPE_CONFIGS_PIN:
163 		if (!ops->pin_config_set) {
164 			dev_err(pctldev->dev, "missing pin_config_set op\n");
165 			return -EINVAL;
166 		}
167 		ret = ops->pin_config_set(pctldev,
168 				setting->data.configs.group_or_pin,
169 				setting->data.configs.configs,
170 				setting->data.configs.num_configs);
171 		if (ret < 0) {
172 			dev_err(pctldev->dev,
173 				"pin_config_set op failed for pin %d\n",
174 				setting->data.configs.group_or_pin);
175 			return ret;
176 		}
177 		break;
178 	case PIN_MAP_TYPE_CONFIGS_GROUP:
179 		if (!ops->pin_config_group_set) {
180 			dev_err(pctldev->dev,
181 				"missing pin_config_group_set op\n");
182 			return -EINVAL;
183 		}
184 		ret = ops->pin_config_group_set(pctldev,
185 				setting->data.configs.group_or_pin,
186 				setting->data.configs.configs,
187 				setting->data.configs.num_configs);
188 		if (ret < 0) {
189 			dev_err(pctldev->dev,
190 				"pin_config_group_set op failed for group %d\n",
191 				setting->data.configs.group_or_pin);
192 			return ret;
193 		}
194 		break;
195 	default:
196 		return -EINVAL;
197 	}
198 
199 	return 0;
200 }
201 
202 int pinconf_set_config(struct pinctrl_dev *pctldev, unsigned pin,
203 		       unsigned long *configs, size_t nconfigs)
204 {
205 	const struct pinconf_ops *ops;
206 
207 	ops = pctldev->desc->confops;
208 	if (!ops || !ops->pin_config_set)
209 		return -ENOTSUPP;
210 
211 	return ops->pin_config_set(pctldev, pin, configs, nconfigs);
212 }
213 
214 #ifdef CONFIG_DEBUG_FS
215 
216 static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
217 		      unsigned long *configs, unsigned num_configs)
218 {
219 	const struct pinconf_ops *confops;
220 	int i;
221 
222 	if (pctldev)
223 		confops = pctldev->desc->confops;
224 	else
225 		confops = NULL;
226 
227 	for (i = 0; i < num_configs; i++) {
228 		seq_puts(s, "config ");
229 		if (confops && confops->pin_config_config_dbg_show)
230 			confops->pin_config_config_dbg_show(pctldev, s,
231 							    configs[i]);
232 		else
233 			seq_printf(s, "%08lx", configs[i]);
234 		seq_putc(s, '\n');
235 	}
236 }
237 
238 void pinconf_show_map(struct seq_file *s, const struct pinctrl_map *map)
239 {
240 	struct pinctrl_dev *pctldev;
241 
242 	pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
243 
244 	switch (map->type) {
245 	case PIN_MAP_TYPE_CONFIGS_PIN:
246 		seq_puts(s, "pin ");
247 		break;
248 	case PIN_MAP_TYPE_CONFIGS_GROUP:
249 		seq_puts(s, "group ");
250 		break;
251 	default:
252 		break;
253 	}
254 
255 	seq_printf(s, "%s\n", map->data.configs.group_or_pin);
256 
257 	pinconf_show_config(s, pctldev, map->data.configs.configs,
258 			    map->data.configs.num_configs);
259 }
260 
261 void pinconf_show_setting(struct seq_file *s,
262 			  const struct pinctrl_setting *setting)
263 {
264 	struct pinctrl_dev *pctldev = setting->pctldev;
265 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
266 	struct pin_desc *desc;
267 
268 	switch (setting->type) {
269 	case PIN_MAP_TYPE_CONFIGS_PIN:
270 		desc = pin_desc_get(setting->pctldev,
271 				    setting->data.configs.group_or_pin);
272 		seq_printf(s, "pin %s (%d)", desc->name,
273 			   setting->data.configs.group_or_pin);
274 		break;
275 	case PIN_MAP_TYPE_CONFIGS_GROUP:
276 		seq_printf(s, "group %s (%d)",
277 			   pctlops->get_group_name(pctldev,
278 					setting->data.configs.group_or_pin),
279 			   setting->data.configs.group_or_pin);
280 		break;
281 	default:
282 		break;
283 	}
284 
285 	/*
286 	 * FIXME: We should really get the pin controller to dump the config
287 	 * values, so they can be decoded to something meaningful.
288 	 */
289 	pinconf_show_config(s, pctldev, setting->data.configs.configs,
290 			    setting->data.configs.num_configs);
291 }
292 
293 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
294 			     struct seq_file *s, int pin)
295 {
296 	const struct pinconf_ops *ops = pctldev->desc->confops;
297 
298 	/* no-op when not using generic pin config */
299 	pinconf_generic_dump_pins(pctldev, s, NULL, pin);
300 	if (ops && ops->pin_config_dbg_show)
301 		ops->pin_config_dbg_show(pctldev, s, pin);
302 }
303 
304 static int pinconf_pins_show(struct seq_file *s, void *what)
305 {
306 	struct pinctrl_dev *pctldev = s->private;
307 	unsigned i, pin;
308 
309 	seq_puts(s, "Pin config settings per pin\n");
310 	seq_puts(s, "Format: pin (name): configs\n");
311 
312 	mutex_lock(&pctldev->mutex);
313 
314 	/* The pin number can be retrived from the pin controller descriptor */
315 	for (i = 0; i < pctldev->desc->npins; i++) {
316 		struct pin_desc *desc;
317 
318 		pin = pctldev->desc->pins[i].number;
319 		desc = pin_desc_get(pctldev, pin);
320 		/* Skip if we cannot search the pin */
321 		if (!desc)
322 			continue;
323 
324 		seq_printf(s, "pin %d (%s): ", pin, desc->name);
325 
326 		pinconf_dump_pin(pctldev, s, pin);
327 		seq_putc(s, '\n');
328 	}
329 
330 	mutex_unlock(&pctldev->mutex);
331 
332 	return 0;
333 }
334 
335 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
336 			       struct seq_file *s, unsigned selector,
337 			       const char *gname)
338 {
339 	const struct pinconf_ops *ops = pctldev->desc->confops;
340 
341 	/* no-op when not using generic pin config */
342 	pinconf_generic_dump_pins(pctldev, s, gname, 0);
343 	if (ops && ops->pin_config_group_dbg_show)
344 		ops->pin_config_group_dbg_show(pctldev, s, selector);
345 }
346 
347 static int pinconf_groups_show(struct seq_file *s, void *what)
348 {
349 	struct pinctrl_dev *pctldev = s->private;
350 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
351 	unsigned ngroups = pctlops->get_groups_count(pctldev);
352 	unsigned selector = 0;
353 
354 	seq_puts(s, "Pin config settings per pin group\n");
355 	seq_puts(s, "Format: group (name): configs\n");
356 
357 	while (selector < ngroups) {
358 		const char *gname = pctlops->get_group_name(pctldev, selector);
359 
360 		seq_printf(s, "%u (%s): ", selector, gname);
361 		pinconf_dump_group(pctldev, s, selector, gname);
362 		seq_putc(s, '\n');
363 		selector++;
364 	}
365 
366 	return 0;
367 }
368 
369 static int pinconf_pins_open(struct inode *inode, struct file *file)
370 {
371 	return single_open(file, pinconf_pins_show, inode->i_private);
372 }
373 
374 static int pinconf_groups_open(struct inode *inode, struct file *file)
375 {
376 	return single_open(file, pinconf_groups_show, inode->i_private);
377 }
378 
379 static const struct file_operations pinconf_pins_ops = {
380 	.open		= pinconf_pins_open,
381 	.read		= seq_read,
382 	.llseek		= seq_lseek,
383 	.release	= single_release,
384 };
385 
386 static const struct file_operations pinconf_groups_ops = {
387 	.open		= pinconf_groups_open,
388 	.read		= seq_read,
389 	.llseek		= seq_lseek,
390 	.release	= single_release,
391 };
392 
393 #define MAX_NAME_LEN 15
394 
395 struct dbg_cfg {
396 	enum pinctrl_map_type map_type;
397 	char dev_name[MAX_NAME_LEN + 1];
398 	char state_name[MAX_NAME_LEN + 1];
399 	char pin_name[MAX_NAME_LEN + 1];
400 };
401 
402 /*
403  * Goal is to keep this structure as global in order to simply read the
404  * pinconf-config file after a write to check config is as expected
405  */
406 static struct dbg_cfg pinconf_dbg_conf;
407 
408 /**
409  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
410  * map, of the dev/pin/state that was last written to pinconf-config file.
411  * @s: string filled in  with config description
412  * @d: not used
413  */
414 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
415 {
416 	struct pinctrl_maps *maps_node;
417 	const struct pinctrl_map *map;
418 	const struct pinctrl_map *found = NULL;
419 	struct pinctrl_dev *pctldev;
420 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
421 	int i;
422 
423 	mutex_lock(&pinctrl_maps_mutex);
424 
425 	/* Parse the pinctrl map and look for the elected pin/state */
426 	for_each_maps(maps_node, i, map) {
427 		if (map->type != dbg->map_type)
428 			continue;
429 		if (strcmp(map->dev_name, dbg->dev_name))
430 			continue;
431 		if (strcmp(map->name, dbg->state_name))
432 			continue;
433 
434 		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
435 			/* We found the right pin */
436 			found = map;
437 			break;
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 	seq_printf(s, "Dev %s has config of %s in state %s:\n",
453 		   dbg->dev_name, dbg->pin_name, dbg->state_name);
454 	pinconf_show_config(s, pctldev, found->data.configs.configs,
455 			    found->data.configs.num_configs);
456 
457 exit:
458 	mutex_unlock(&pinctrl_maps_mutex);
459 
460 	return 0;
461 }
462 
463 /**
464  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
465  * map, of a dev/pin/state entry based on user entries to pinconf-config
466  * @user_buf: contains the modification request with expected format:
467  *     modify <config> <devicename> <state> <name> <newvalue>
468  * modify is literal string, alternatives like add/delete not supported yet
469  * <config> is the configuration to be changed. Supported configs are
470  *     "config_pin" or "config_group", alternatives like config_mux are not
471  *     supported yet.
472  * <devicename> <state> <name> are values that should match the pinctrl-maps
473  * <newvalue> reflects the new config and is driver dependent
474  */
475 static ssize_t pinconf_dbg_config_write(struct file *file,
476 	const char __user *user_buf, size_t count, loff_t *ppos)
477 {
478 	struct pinctrl_maps *maps_node;
479 	const struct pinctrl_map *map;
480 	const struct pinctrl_map *found = NULL;
481 	struct pinctrl_dev *pctldev;
482 	const struct pinconf_ops *confops = NULL;
483 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
484 	const struct pinctrl_map_configs *configs;
485 	char config[MAX_NAME_LEN + 1];
486 	char buf[128];
487 	char *b = &buf[0];
488 	int buf_size;
489 	char *token;
490 	int i;
491 
492 	/* Get userspace string and assure termination */
493 	buf_size = min(count, sizeof(buf) - 1);
494 	if (copy_from_user(buf, user_buf, buf_size))
495 		return -EFAULT;
496 	buf[buf_size] = 0;
497 
498 	/*
499 	 * need to parse entry and extract parameters:
500 	 * modify configs_pin devicename state pinname newvalue
501 	 */
502 
503 	/* Get arg: 'modify' */
504 	token = strsep(&b, " ");
505 	if (!token)
506 		return -EINVAL;
507 	if (strcmp(token, "modify"))
508 		return -EINVAL;
509 
510 	/*
511 	 * Get arg type: "config_pin" and "config_group"
512 	 *                types are supported so far
513 	 */
514 	token = strsep(&b, " ");
515 	if (!token)
516 		return -EINVAL;
517 	if (!strcmp(token, "config_pin"))
518 		dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
519 	else if (!strcmp(token, "config_group"))
520 		dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
521 	else
522 		return -EINVAL;
523 
524 	/* get arg 'device_name' */
525 	token = strsep(&b, " ");
526 	if (!token)
527 		return -EINVAL;
528 	if (strlen(token) >= MAX_NAME_LEN)
529 		return -EINVAL;
530 	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
531 
532 	/* get arg 'state_name' */
533 	token = strsep(&b, " ");
534 	if (!token)
535 		return -EINVAL;
536 	if (strlen(token) >= MAX_NAME_LEN)
537 		return -EINVAL;
538 	strncpy(dbg->state_name, token, MAX_NAME_LEN);
539 
540 	/* get arg 'pin_name' */
541 	token = strsep(&b, " ");
542 	if (!token)
543 		return -EINVAL;
544 	if (strlen(token) >= MAX_NAME_LEN)
545 		return -EINVAL;
546 	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
547 
548 	/* get new_value of config' */
549 	token = strsep(&b, " ");
550 	if (!token)
551 		return -EINVAL;
552 	if (strlen(token) >= MAX_NAME_LEN)
553 		return -EINVAL;
554 	strncpy(config, token, MAX_NAME_LEN);
555 
556 	mutex_lock(&pinctrl_maps_mutex);
557 
558 	/* Parse the pinctrl map and look for the selected dev/state/pin */
559 	for_each_maps(maps_node, i, map) {
560 		if (strcmp(map->dev_name, dbg->dev_name))
561 			continue;
562 		if (map->type != dbg->map_type)
563 			continue;
564 		if (strcmp(map->name, dbg->state_name))
565 			continue;
566 
567 		/*  we found the right pin / state, so overwrite config */
568 		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
569 			found = map;
570 			break;
571 		}
572 	}
573 
574 	if (!found) {
575 		count = -EINVAL;
576 		goto exit;
577 	}
578 
579 	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
580 	if (pctldev)
581 		confops = pctldev->desc->confops;
582 
583 	if (confops && confops->pin_config_dbg_parse_modify) {
584 		configs = &found->data.configs;
585 		for (i = 0; i < configs->num_configs; i++) {
586 			confops->pin_config_dbg_parse_modify(pctldev,
587 						     config,
588 						     &configs->configs[i]);
589 		}
590 	}
591 
592 exit:
593 	mutex_unlock(&pinctrl_maps_mutex);
594 
595 	return count;
596 }
597 
598 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
599 {
600 	return single_open(file, pinconf_dbg_config_print, inode->i_private);
601 }
602 
603 static const struct file_operations pinconf_dbg_pinconfig_fops = {
604 	.open = pinconf_dbg_config_open,
605 	.write = pinconf_dbg_config_write,
606 	.read = seq_read,
607 	.llseek = seq_lseek,
608 	.release = single_release,
609 	.owner = THIS_MODULE,
610 };
611 
612 void pinconf_init_device_debugfs(struct dentry *devroot,
613 			 struct pinctrl_dev *pctldev)
614 {
615 	debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
616 			    devroot, pctldev, &pinconf_pins_ops);
617 	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
618 			    devroot, pctldev, &pinconf_groups_ops);
619 	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
620 			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);
621 }
622 
623 #endif
624