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
27int 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
40int 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
58int 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
72int 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
105unlock:
106	mutex_unlock(&pctldev->mutex);
107	return ret;
108}
109
110int 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
147void pinconf_free_setting(struct pinctrl_setting const *setting)
148{
149}
150
151int 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
205static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
206		      unsigned long *configs, unsigned num_configs)
207{
208	const struct pinconf_ops *confops;
209	int i;
210
211	if (pctldev)
212		confops = pctldev->desc->confops;
213	else
214		confops = NULL;
215
216	for (i = 0; i < num_configs; i++) {
217		seq_puts(s, "config ");
218		if (confops && confops->pin_config_config_dbg_show)
219			confops->pin_config_config_dbg_show(pctldev, s,
220							    configs[i]);
221		else
222			seq_printf(s, "%08lx", configs[i]);
223		seq_puts(s, "\n");
224	}
225}
226
227void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
228{
229	struct pinctrl_dev *pctldev;
230
231	pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
232
233	switch (map->type) {
234	case PIN_MAP_TYPE_CONFIGS_PIN:
235		seq_printf(s, "pin ");
236		break;
237	case PIN_MAP_TYPE_CONFIGS_GROUP:
238		seq_printf(s, "group ");
239		break;
240	default:
241		break;
242	}
243
244	seq_printf(s, "%s\n", map->data.configs.group_or_pin);
245
246	pinconf_show_config(s, pctldev, map->data.configs.configs,
247			    map->data.configs.num_configs);
248}
249
250void pinconf_show_setting(struct seq_file *s,
251			  struct pinctrl_setting const *setting)
252{
253	struct pinctrl_dev *pctldev = setting->pctldev;
254	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
255	struct pin_desc *desc;
256
257	switch (setting->type) {
258	case PIN_MAP_TYPE_CONFIGS_PIN:
259		desc = pin_desc_get(setting->pctldev,
260				    setting->data.configs.group_or_pin);
261		seq_printf(s, "pin %s (%d)",
262			   desc->name ? desc->name : "unnamed",
263			   setting->data.configs.group_or_pin);
264		break;
265	case PIN_MAP_TYPE_CONFIGS_GROUP:
266		seq_printf(s, "group %s (%d)",
267			   pctlops->get_group_name(pctldev,
268					setting->data.configs.group_or_pin),
269			   setting->data.configs.group_or_pin);
270		break;
271	default:
272		break;
273	}
274
275	/*
276	 * FIXME: We should really get the pin controler to dump the config
277	 * values, so they can be decoded to something meaningful.
278	 */
279	pinconf_show_config(s, pctldev, setting->data.configs.configs,
280			    setting->data.configs.num_configs);
281}
282
283static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
284			     struct seq_file *s, int pin)
285{
286	const struct pinconf_ops *ops = pctldev->desc->confops;
287
288	/* no-op when not using generic pin config */
289	pinconf_generic_dump_pins(pctldev, s, NULL, pin);
290	if (ops && ops->pin_config_dbg_show)
291		ops->pin_config_dbg_show(pctldev, s, pin);
292}
293
294static int pinconf_pins_show(struct seq_file *s, void *what)
295{
296	struct pinctrl_dev *pctldev = s->private;
297	unsigned i, pin;
298
299	seq_puts(s, "Pin config settings per pin\n");
300	seq_puts(s, "Format: pin (name): configs\n");
301
302	mutex_lock(&pctldev->mutex);
303
304	/* The pin number can be retrived from the pin controller descriptor */
305	for (i = 0; i < pctldev->desc->npins; i++) {
306		struct pin_desc *desc;
307
308		pin = pctldev->desc->pins[i].number;
309		desc = pin_desc_get(pctldev, pin);
310		/* Skip if we cannot search the pin */
311		if (desc == NULL)
312			continue;
313
314		seq_printf(s, "pin %d (%s):", pin,
315			   desc->name ? desc->name : "unnamed");
316
317		pinconf_dump_pin(pctldev, s, pin);
318
319		seq_printf(s, "\n");
320	}
321
322	mutex_unlock(&pctldev->mutex);
323
324	return 0;
325}
326
327static void pinconf_dump_group(struct pinctrl_dev *pctldev,
328			       struct seq_file *s, unsigned selector,
329			       const char *gname)
330{
331	const struct pinconf_ops *ops = pctldev->desc->confops;
332
333	/* no-op when not using generic pin config */
334	pinconf_generic_dump_pins(pctldev, s, gname, 0);
335	if (ops && ops->pin_config_group_dbg_show)
336		ops->pin_config_group_dbg_show(pctldev, s, selector);
337}
338
339static int pinconf_groups_show(struct seq_file *s, void *what)
340{
341	struct pinctrl_dev *pctldev = s->private;
342	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
343	unsigned ngroups = pctlops->get_groups_count(pctldev);
344	unsigned selector = 0;
345
346	seq_puts(s, "Pin config settings per pin group\n");
347	seq_puts(s, "Format: group (name): configs\n");
348
349	while (selector < ngroups) {
350		const char *gname = pctlops->get_group_name(pctldev, selector);
351
352		seq_printf(s, "%u (%s):", selector, gname);
353		pinconf_dump_group(pctldev, s, selector, gname);
354		seq_printf(s, "\n");
355
356		selector++;
357	}
358
359	return 0;
360}
361
362static int pinconf_pins_open(struct inode *inode, struct file *file)
363{
364	return single_open(file, pinconf_pins_show, inode->i_private);
365}
366
367static int pinconf_groups_open(struct inode *inode, struct file *file)
368{
369	return single_open(file, pinconf_groups_show, inode->i_private);
370}
371
372static const struct file_operations pinconf_pins_ops = {
373	.open		= pinconf_pins_open,
374	.read		= seq_read,
375	.llseek		= seq_lseek,
376	.release	= single_release,
377};
378
379static const struct file_operations pinconf_groups_ops = {
380	.open		= pinconf_groups_open,
381	.read		= seq_read,
382	.llseek		= seq_lseek,
383	.release	= single_release,
384};
385
386#define MAX_NAME_LEN 15
387
388struct dbg_cfg {
389	enum pinctrl_map_type map_type;
390	char dev_name[MAX_NAME_LEN+1];
391	char state_name[MAX_NAME_LEN+1];
392	char pin_name[MAX_NAME_LEN+1];
393};
394
395/*
396 * Goal is to keep this structure as global in order to simply read the
397 * pinconf-config file after a write to check config is as expected
398 */
399static struct dbg_cfg pinconf_dbg_conf;
400
401/**
402 * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
403 * map, of the dev/pin/state that was last written to pinconf-config file.
404 * @s: string filled in  with config description
405 * @d: not used
406 */
407static int pinconf_dbg_config_print(struct seq_file *s, void *d)
408{
409	struct pinctrl_maps *maps_node;
410	const struct pinctrl_map *map;
411	const struct pinctrl_map *found = NULL;
412	struct pinctrl_dev *pctldev;
413	struct dbg_cfg *dbg = &pinconf_dbg_conf;
414	int i;
415
416	mutex_lock(&pinctrl_maps_mutex);
417
418	/* Parse the pinctrl map and look for the elected pin/state */
419	for_each_maps(maps_node, i, map) {
420		if (map->type != dbg->map_type)
421			continue;
422		if (strcmp(map->dev_name, dbg->dev_name))
423			continue;
424		if (strcmp(map->name, dbg->state_name))
425			continue;
426
427		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
428			/* We found the right pin */
429			found = map;
430			break;
431		}
432	}
433
434	if (!found) {
435		seq_printf(s, "No config found for dev/state/pin, expected:\n");
436		seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
437		seq_printf(s, "Searched state:%s\n", dbg->state_name);
438		seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
439		seq_printf(s, "Use: modify config_pin <devname> "\
440				"<state> <pinname> <value>\n");
441		goto exit;
442	}
443
444	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
445	seq_printf(s, "Dev %s has config of %s in state %s:\n",
446		   dbg->dev_name, dbg->pin_name, dbg->state_name);
447	pinconf_show_config(s, pctldev, found->data.configs.configs,
448			    found->data.configs.num_configs);
449
450exit:
451	mutex_unlock(&pinctrl_maps_mutex);
452
453	return 0;
454}
455
456/**
457 * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
458 * map, of a dev/pin/state entry based on user entries to pinconf-config
459 * @user_buf: contains the modification request with expected format:
460 *     modify <config> <devicename> <state> <name> <newvalue>
461 * modify is literal string, alternatives like add/delete not supported yet
462 * <config> is the configuration to be changed. Supported configs are
463 *     "config_pin" or "config_group", alternatives like config_mux are not
464 *     supported yet.
465 * <devicename> <state> <name> are values that should match the pinctrl-maps
466 * <newvalue> reflects the new config and is driver dependant
467 */
468static ssize_t pinconf_dbg_config_write(struct file *file,
469	const char __user *user_buf, size_t count, loff_t *ppos)
470{
471	struct pinctrl_maps *maps_node;
472	const struct pinctrl_map *map;
473	const struct pinctrl_map *found = NULL;
474	struct pinctrl_dev *pctldev;
475	const struct pinconf_ops *confops = NULL;
476	struct dbg_cfg *dbg = &pinconf_dbg_conf;
477	const struct pinctrl_map_configs *configs;
478	char config[MAX_NAME_LEN+1];
479	char buf[128];
480	char *b = &buf[0];
481	int buf_size;
482	char *token;
483	int i;
484
485	/* Get userspace string and assure termination */
486	buf_size = min(count, sizeof(buf) - 1);
487	if (copy_from_user(buf, user_buf, buf_size))
488		return -EFAULT;
489	buf[buf_size] = 0;
490
491	/*
492	 * need to parse entry and extract parameters:
493	 * modify configs_pin devicename state pinname newvalue
494	 */
495
496	/* Get arg: 'modify' */
497	token = strsep(&b, " ");
498	if (!token)
499		return -EINVAL;
500	if (strcmp(token, "modify"))
501		return -EINVAL;
502
503	/*
504	 * Get arg type: "config_pin" and "config_group"
505	 *                types are supported so far
506	 */
507	token = strsep(&b, " ");
508	if (!token)
509		return -EINVAL;
510	if (!strcmp(token, "config_pin"))
511		dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
512	else if (!strcmp(token, "config_group"))
513		dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
514	else
515		return -EINVAL;
516
517	/* get arg 'device_name' */
518	token = strsep(&b, " ");
519	if (token == NULL)
520		return -EINVAL;
521	if (strlen(token) >= MAX_NAME_LEN)
522		return -EINVAL;
523	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
524
525	/* get arg 'state_name' */
526	token = strsep(&b, " ");
527	if (token == NULL)
528		return -EINVAL;
529	if (strlen(token) >= MAX_NAME_LEN)
530		return -EINVAL;
531	strncpy(dbg->state_name, token, MAX_NAME_LEN);
532
533	/* get arg 'pin_name' */
534	token = strsep(&b, " ");
535	if (token == NULL)
536		return -EINVAL;
537	if (strlen(token) >= MAX_NAME_LEN)
538		return -EINVAL;
539	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
540
541	/* get new_value of config' */
542	token = strsep(&b, " ");
543	if (token == NULL)
544		return -EINVAL;
545	if (strlen(token) >= MAX_NAME_LEN)
546		return -EINVAL;
547	strncpy(config, token, MAX_NAME_LEN);
548
549	mutex_lock(&pinctrl_maps_mutex);
550
551	/* Parse the pinctrl map and look for the selected dev/state/pin */
552	for_each_maps(maps_node, i, map) {
553		if (strcmp(map->dev_name, dbg->dev_name))
554			continue;
555		if (map->type != dbg->map_type)
556			continue;
557		if (strcmp(map->name, dbg->state_name))
558			continue;
559
560		/*  we found the right pin / state, so overwrite config */
561		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
562			found = map;
563			break;
564		}
565	}
566
567	if (!found) {
568		count = -EINVAL;
569		goto exit;
570	}
571
572	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);
573	if (pctldev)
574		confops = pctldev->desc->confops;
575
576	if (confops && confops->pin_config_dbg_parse_modify) {
577		configs = &found->data.configs;
578		for (i = 0; i < configs->num_configs; i++) {
579			confops->pin_config_dbg_parse_modify(pctldev,
580						     config,
581						     &configs->configs[i]);
582		}
583	}
584
585exit:
586	mutex_unlock(&pinctrl_maps_mutex);
587
588	return count;
589}
590
591static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
592{
593	return single_open(file, pinconf_dbg_config_print, inode->i_private);
594}
595
596static const struct file_operations pinconf_dbg_pinconfig_fops = {
597	.open = pinconf_dbg_config_open,
598	.write = pinconf_dbg_config_write,
599	.read = seq_read,
600	.llseek = seq_lseek,
601	.release = single_release,
602	.owner = THIS_MODULE,
603};
604
605void pinconf_init_device_debugfs(struct dentry *devroot,
606			 struct pinctrl_dev *pctldev)
607{
608	debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
609			    devroot, pctldev, &pinconf_pins_ops);
610	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
611			    devroot, pctldev, &pinconf_groups_ops);
612	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
613			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);
614}
615
616#endif
617