xref: /openbmc/linux/drivers/pinctrl/pinconf.c (revision 4f6cce39)
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,
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, "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 int pinconf_set_config(struct pinctrl_dev *pctldev, unsigned pin,
204 		       unsigned long *configs, size_t nconfigs)
205 {
206 	const struct pinconf_ops *ops;
207 
208 	ops = pctldev->desc->confops;
209 	if (!ops)
210 		return -ENOTSUPP;
211 
212 	return ops->pin_config_set(pctldev, pin, configs, nconfigs);
213 }
214 
215 #ifdef CONFIG_DEBUG_FS
216 
217 static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
218 		      unsigned long *configs, unsigned num_configs)
219 {
220 	const struct pinconf_ops *confops;
221 	int i;
222 
223 	if (pctldev)
224 		confops = pctldev->desc->confops;
225 	else
226 		confops = NULL;
227 
228 	for (i = 0; i < num_configs; i++) {
229 		seq_puts(s, "config ");
230 		if (confops && confops->pin_config_config_dbg_show)
231 			confops->pin_config_config_dbg_show(pctldev, s,
232 							    configs[i]);
233 		else
234 			seq_printf(s, "%08lx", configs[i]);
235 		seq_puts(s, "\n");
236 	}
237 }
238 
239 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
240 {
241 	struct pinctrl_dev *pctldev;
242 
243 	pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
244 
245 	switch (map->type) {
246 	case PIN_MAP_TYPE_CONFIGS_PIN:
247 		seq_printf(s, "pin ");
248 		break;
249 	case PIN_MAP_TYPE_CONFIGS_GROUP:
250 		seq_printf(s, "group ");
251 		break;
252 	default:
253 		break;
254 	}
255 
256 	seq_printf(s, "%s\n", map->data.configs.group_or_pin);
257 
258 	pinconf_show_config(s, pctldev, map->data.configs.configs,
259 			    map->data.configs.num_configs);
260 }
261 
262 void pinconf_show_setting(struct seq_file *s,
263 			  struct pinctrl_setting const *setting)
264 {
265 	struct pinctrl_dev *pctldev = setting->pctldev;
266 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
267 	struct pin_desc *desc;
268 
269 	switch (setting->type) {
270 	case PIN_MAP_TYPE_CONFIGS_PIN:
271 		desc = pin_desc_get(setting->pctldev,
272 				    setting->data.configs.group_or_pin);
273 		seq_printf(s, "pin %s (%d)", desc->name,
274 			   setting->data.configs.group_or_pin);
275 		break;
276 	case PIN_MAP_TYPE_CONFIGS_GROUP:
277 		seq_printf(s, "group %s (%d)",
278 			   pctlops->get_group_name(pctldev,
279 					setting->data.configs.group_or_pin),
280 			   setting->data.configs.group_or_pin);
281 		break;
282 	default:
283 		break;
284 	}
285 
286 	/*
287 	 * FIXME: We should really get the pin controler to dump the config
288 	 * values, so they can be decoded to something meaningful.
289 	 */
290 	pinconf_show_config(s, pctldev, setting->data.configs.configs,
291 			    setting->data.configs.num_configs);
292 }
293 
294 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
295 			     struct seq_file *s, int pin)
296 {
297 	const struct pinconf_ops *ops = pctldev->desc->confops;
298 
299 	/* no-op when not using generic pin config */
300 	pinconf_generic_dump_pins(pctldev, s, NULL, pin);
301 	if (ops && ops->pin_config_dbg_show)
302 		ops->pin_config_dbg_show(pctldev, s, pin);
303 }
304 
305 static int pinconf_pins_show(struct seq_file *s, void *what)
306 {
307 	struct pinctrl_dev *pctldev = s->private;
308 	unsigned i, pin;
309 
310 	seq_puts(s, "Pin config settings per pin\n");
311 	seq_puts(s, "Format: pin (name): configs\n");
312 
313 	mutex_lock(&pctldev->mutex);
314 
315 	/* The pin number can be retrived from the pin controller descriptor */
316 	for (i = 0; i < pctldev->desc->npins; i++) {
317 		struct pin_desc *desc;
318 
319 		pin = pctldev->desc->pins[i].number;
320 		desc = pin_desc_get(pctldev, pin);
321 		/* Skip if we cannot search the pin */
322 		if (desc == NULL)
323 			continue;
324 
325 		seq_printf(s, "pin %d (%s): ", pin, desc->name);
326 
327 		pinconf_dump_pin(pctldev, s, pin);
328 
329 		seq_printf(s, "\n");
330 	}
331 
332 	mutex_unlock(&pctldev->mutex);
333 
334 	return 0;
335 }
336 
337 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
338 			       struct seq_file *s, unsigned selector,
339 			       const char *gname)
340 {
341 	const struct pinconf_ops *ops = pctldev->desc->confops;
342 
343 	/* no-op when not using generic pin config */
344 	pinconf_generic_dump_pins(pctldev, s, gname, 0);
345 	if (ops && ops->pin_config_group_dbg_show)
346 		ops->pin_config_group_dbg_show(pctldev, s, selector);
347 }
348 
349 static int pinconf_groups_show(struct seq_file *s, void *what)
350 {
351 	struct pinctrl_dev *pctldev = s->private;
352 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
353 	unsigned ngroups = pctlops->get_groups_count(pctldev);
354 	unsigned selector = 0;
355 
356 	seq_puts(s, "Pin config settings per pin group\n");
357 	seq_puts(s, "Format: group (name): configs\n");
358 
359 	while (selector < ngroups) {
360 		const char *gname = pctlops->get_group_name(pctldev, selector);
361 
362 		seq_printf(s, "%u (%s): ", selector, gname);
363 		pinconf_dump_group(pctldev, s, selector, gname);
364 		seq_printf(s, "\n");
365 
366 		selector++;
367 	}
368 
369 	return 0;
370 }
371 
372 static int pinconf_pins_open(struct inode *inode, struct file *file)
373 {
374 	return single_open(file, pinconf_pins_show, inode->i_private);
375 }
376 
377 static int pinconf_groups_open(struct inode *inode, struct file *file)
378 {
379 	return single_open(file, pinconf_groups_show, inode->i_private);
380 }
381 
382 static const struct file_operations pinconf_pins_ops = {
383 	.open		= pinconf_pins_open,
384 	.read		= seq_read,
385 	.llseek		= seq_lseek,
386 	.release	= single_release,
387 };
388 
389 static const struct file_operations pinconf_groups_ops = {
390 	.open		= pinconf_groups_open,
391 	.read		= seq_read,
392 	.llseek		= seq_lseek,
393 	.release	= single_release,
394 };
395 
396 #define MAX_NAME_LEN 15
397 
398 struct dbg_cfg {
399 	enum pinctrl_map_type map_type;
400 	char dev_name[MAX_NAME_LEN+1];
401 	char state_name[MAX_NAME_LEN+1];
402 	char pin_name[MAX_NAME_LEN+1];
403 };
404 
405 /*
406  * Goal is to keep this structure as global in order to simply read the
407  * pinconf-config file after a write to check config is as expected
408  */
409 static struct dbg_cfg pinconf_dbg_conf;
410 
411 /**
412  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
413  * map, of the dev/pin/state that was last written to pinconf-config file.
414  * @s: string filled in  with config description
415  * @d: not used
416  */
417 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
418 {
419 	struct pinctrl_maps *maps_node;
420 	const struct pinctrl_map *map;
421 	const struct pinctrl_map *found = NULL;
422 	struct pinctrl_dev *pctldev;
423 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
424 	int i;
425 
426 	mutex_lock(&pinctrl_maps_mutex);
427 
428 	/* Parse the pinctrl map and look for the elected pin/state */
429 	for_each_maps(maps_node, i, map) {
430 		if (map->type != dbg->map_type)
431 			continue;
432 		if (strcmp(map->dev_name, dbg->dev_name))
433 			continue;
434 		if (strcmp(map->name, dbg->state_name))
435 			continue;
436 
437 		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
438 			/* We found the right pin */
439 			found = map;
440 			break;
441 		}
442 	}
443 
444 	if (!found) {
445 		seq_printf(s, "No config found for dev/state/pin, expected:\n");
446 		seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
447 		seq_printf(s, "Searched state:%s\n", dbg->state_name);
448 		seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
449 		seq_printf(s, "Use: modify config_pin <devname> "\
450 				"<state> <pinname> <value>\n");
451 		goto exit;
452 	}
453 
454 	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
455 	seq_printf(s, "Dev %s has config of %s in state %s:\n",
456 		   dbg->dev_name, dbg->pin_name, dbg->state_name);
457 	pinconf_show_config(s, pctldev, found->data.configs.configs,
458 			    found->data.configs.num_configs);
459 
460 exit:
461 	mutex_unlock(&pinctrl_maps_mutex);
462 
463 	return 0;
464 }
465 
466 /**
467  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
468  * map, of a dev/pin/state entry based on user entries to pinconf-config
469  * @user_buf: contains the modification request with expected format:
470  *     modify <config> <devicename> <state> <name> <newvalue>
471  * modify is literal string, alternatives like add/delete not supported yet
472  * <config> is the configuration to be changed. Supported configs are
473  *     "config_pin" or "config_group", alternatives like config_mux are not
474  *     supported yet.
475  * <devicename> <state> <name> are values that should match the pinctrl-maps
476  * <newvalue> reflects the new config and is driver dependant
477  */
478 static ssize_t pinconf_dbg_config_write(struct file *file,
479 	const char __user *user_buf, size_t count, loff_t *ppos)
480 {
481 	struct pinctrl_maps *maps_node;
482 	const struct pinctrl_map *map;
483 	const struct pinctrl_map *found = NULL;
484 	struct pinctrl_dev *pctldev;
485 	const struct pinconf_ops *confops = NULL;
486 	struct dbg_cfg *dbg = &pinconf_dbg_conf;
487 	const struct pinctrl_map_configs *configs;
488 	char config[MAX_NAME_LEN+1];
489 	char buf[128];
490 	char *b = &buf[0];
491 	int buf_size;
492 	char *token;
493 	int i;
494 
495 	/* Get userspace string and assure termination */
496 	buf_size = min(count, sizeof(buf) - 1);
497 	if (copy_from_user(buf, user_buf, buf_size))
498 		return -EFAULT;
499 	buf[buf_size] = 0;
500 
501 	/*
502 	 * need to parse entry and extract parameters:
503 	 * modify configs_pin devicename state pinname newvalue
504 	 */
505 
506 	/* Get arg: 'modify' */
507 	token = strsep(&b, " ");
508 	if (!token)
509 		return -EINVAL;
510 	if (strcmp(token, "modify"))
511 		return -EINVAL;
512 
513 	/*
514 	 * Get arg type: "config_pin" and "config_group"
515 	 *                types are supported so far
516 	 */
517 	token = strsep(&b, " ");
518 	if (!token)
519 		return -EINVAL;
520 	if (!strcmp(token, "config_pin"))
521 		dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
522 	else if (!strcmp(token, "config_group"))
523 		dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
524 	else
525 		return -EINVAL;
526 
527 	/* get arg 'device_name' */
528 	token = strsep(&b, " ");
529 	if (token == NULL)
530 		return -EINVAL;
531 	if (strlen(token) >= MAX_NAME_LEN)
532 		return -EINVAL;
533 	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
534 
535 	/* get arg 'state_name' */
536 	token = strsep(&b, " ");
537 	if (token == NULL)
538 		return -EINVAL;
539 	if (strlen(token) >= MAX_NAME_LEN)
540 		return -EINVAL;
541 	strncpy(dbg->state_name, token, MAX_NAME_LEN);
542 
543 	/* get arg 'pin_name' */
544 	token = strsep(&b, " ");
545 	if (token == NULL)
546 		return -EINVAL;
547 	if (strlen(token) >= MAX_NAME_LEN)
548 		return -EINVAL;
549 	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
550 
551 	/* get new_value of config' */
552 	token = strsep(&b, " ");
553 	if (token == NULL)
554 		return -EINVAL;
555 	if (strlen(token) >= MAX_NAME_LEN)
556 		return -EINVAL;
557 	strncpy(config, token, MAX_NAME_LEN);
558 
559 	mutex_lock(&pinctrl_maps_mutex);
560 
561 	/* Parse the pinctrl map and look for the selected dev/state/pin */
562 	for_each_maps(maps_node, i, map) {
563 		if (strcmp(map->dev_name, dbg->dev_name))
564 			continue;
565 		if (map->type != dbg->map_type)
566 			continue;
567 		if (strcmp(map->name, dbg->state_name))
568 			continue;
569 
570 		/*  we found the right pin / state, so overwrite config */
571 		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
572 			found = map;
573 			break;
574 		}
575 	}
576 
577 	if (!found) {
578 		count = -EINVAL;
579 		goto exit;
580 	}
581 
582 	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
583 	if (pctldev)
584 		confops = pctldev->desc->confops;
585 
586 	if (confops && confops->pin_config_dbg_parse_modify) {
587 		configs = &found->data.configs;
588 		for (i = 0; i < configs->num_configs; i++) {
589 			confops->pin_config_dbg_parse_modify(pctldev,
590 						     config,
591 						     &configs->configs[i]);
592 		}
593 	}
594 
595 exit:
596 	mutex_unlock(&pinctrl_maps_mutex);
597 
598 	return count;
599 }
600 
601 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
602 {
603 	return single_open(file, pinconf_dbg_config_print, inode->i_private);
604 }
605 
606 static const struct file_operations pinconf_dbg_pinconfig_fops = {
607 	.open = pinconf_dbg_config_open,
608 	.write = pinconf_dbg_config_write,
609 	.read = seq_read,
610 	.llseek = seq_lseek,
611 	.release = single_release,
612 	.owner = THIS_MODULE,
613 };
614 
615 void pinconf_init_device_debugfs(struct dentry *devroot,
616 			 struct pinctrl_dev *pctldev)
617 {
618 	debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
619 			    devroot, pctldev, &pinconf_pins_ops);
620 	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
621 			    devroot, pctldev, &pinconf_groups_ops);
622 	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
623 			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);
624 }
625 
626 #endif
627