[u-boot.git] / common / menu.c

/*
 * Copyright 2010-2011 Calxeda, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <malloc.h>
#include <errno.h>
#include <linux/list.h>

#include "menu.h"

/*
 * Internally, each item in a menu is represented by a struct menu_item.
 *
 * These items will be alloc'd and initialized by menu_item_add and destroyed
 * by menu_item_destroy, and the consumer of the interface never sees that
 * this struct is used at all.
 */
struct menu_item {
	char *key;
	void *data;
	struct list_head list;
};

/*
 * The menu is composed of a list of items along with settings and callbacks
 * provided by the user. An incomplete definition of this struct is available
 * in menu.h, but the full definition is here to prevent consumers from
 * relying on its contents.
 */
struct menu {
	struct menu_item *default_item;
	int timeout;
	char *title;
	int prompt;
	void (*item_data_print)(void *);
	struct list_head items;
};

/*
 * An iterator function for menu items. callback will be called for each item
 * in m, with m, a pointer to the item, and extra being passed to callback. If
 * callback returns a value other than NULL, iteration stops and the value
 * return by callback is returned from menu_items_iter.  This allows it to be
 * used for search type operations. It is also safe for callback to remove the
 * item from the list of items.
 */
static inline void *menu_items_iter(struct menu *m,
		void *(*callback)(struct menu *, struct menu_item *, void *),
		void *extra)
{
	struct list_head *pos, *n;
	struct menu_item *item;
	void *ret;

	list_for_each_safe(pos, n, &m->items) {
		item = list_entry(pos, struct menu_item, list);

		ret = callback(m, item, extra);

		if (ret)
			return ret;
	}

	return NULL;
}

/*
 * Print a menu_item. If the consumer provided an item_data_print function
 * when creating the menu, call it with a pointer to the item's private data.
 * Otherwise, print the key of the item.
 */
static inline void *menu_item_print(struct menu *m,
				struct menu_item *item,
				void *extra)
{
	if (!m->item_data_print) {
		puts(item->key);
		putc('\n');
	} else {
		m->item_data_print(item->data);
	}

	return NULL;
}

/*
 * Free the memory used by a menu item. This includes the memory used by its
 * key.
 */
static inline void *menu_item_destroy(struct menu *m,
				struct menu_item *item,
				void *extra)
{
	if (item->key)
		free(item->key);

	free(item);

	return NULL;
}

/*
 * Display a menu so the user can make a choice of an item. First display its
 * title, if any, and then each item in the menu.
 */
static inline void menu_display(struct menu *m)
{
	if (m->title) {
		puts(m->title);
		putc('\n');
	}

	menu_items_iter(m, menu_item_print, NULL);
}

/*
 * Check if an item's key matches a provided string, pointed to by extra. If
 * extra is NULL, an item with a NULL key will match. Otherwise, the item's
 * key has to match according to strcmp.
 *
 * This is called via menu_items_iter, so it returns a pointer to the item if
 * the key matches, and returns NULL otherwise.
 */
static inline void *menu_item_key_match(struct menu *m,
			struct menu_item *item, void *extra)
{
	char *item_key = extra;

	if (!item_key || !item->key) {
		if (item_key == item->key)
			return item;

		return NULL;
	}

	if (strcmp(item->key, item_key) == 0)
		return item;

	return NULL;
}

/*
 * Find the first item with a key matching item_key, if any exists.
 */
static inline struct menu_item *menu_item_by_key(struct menu *m,
							char *item_key)
{
	return menu_items_iter(m, menu_item_key_match, item_key);
}

/*
 * Wait for the user to hit a key according to the timeout set for the menu.
 * Returns 1 if the user hit a key, or 0 if the timeout expired.
 */
static inline int menu_interrupted(struct menu *m)
{
	if (!m->timeout)
		return 0;

	if (abortboot(m->timeout/10))
		return 1;

	return 0;
}

/*
 * Checks whether or not the default menu item should be used without
 * prompting for a user choice. If the menu is set to always prompt, or the
 * user hits a key during the timeout period, return 0. Otherwise, return 1 to
 * indicate we should use the default menu item.
 */
static inline int menu_use_default(struct menu *m)
{
	return !m->prompt && !menu_interrupted(m);
}

/*
 * Set *choice to point to the default item's data, if any default item was
 * set, and returns 1. If no default item was set, returns -ENOENT.
 */
static inline int menu_default_choice(struct menu *m, void **choice)
{
	if (m->default_item) {
		*choice = m->default_item->data;
		return 1;
	}

	return -ENOENT;
}

/*
 * Displays the menu and asks the user to choose an item. *choice will point
 * to the private data of the item the user chooses. The user makes a choice
 * by inputting a string matching the key of an item. Invalid choices will
 * cause the user to be prompted again, repeatedly, until the user makes a
 * valid choice. The user can exit the menu without making a choice via ^c.
 *
 * Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
 */
static inline int menu_interactive_choice(struct menu *m, void **choice)
{
	char cbuf[CONFIG_SYS_CBSIZE];
	struct menu_item *choice_item = NULL;
	int readret;

	while (!choice_item) {
		cbuf[0] = '\0';

		menu_display(m);

		readret = readline_into_buffer("Enter choice: ", cbuf);

		if (readret >= 0) {
			choice_item = menu_item_by_key(m, cbuf);

			if (!choice_item)
				printf("%s not found\n", cbuf);
		} else {
			puts("^C\n");
			return -EINTR;
		}
	}

	*choice = choice_item->data;

	return 1;
}

/*
 * menu_default_set() - Sets the default choice for the menu. This is safe to
 * call more than once on a menu.
 *
 * m - Points to a menu created by menu_create().
 *
 * item_key - Points to a string that, when compared using strcmp, matches the
 * key for an existing item in the menu.
 *
 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
 * key matching item_key is found.
 */
int menu_default_set(struct menu *m, char *item_key)
{
	struct menu_item *item;

	if (!m)
		return -EINVAL;

	item = menu_item_by_key(m, item_key);

	if (!item)
		return -ENOENT;

	m->default_item = item;

	return 1;
}

/*
 * menu_get_choice() - Returns the user's selected menu entry, or the default
 * if the menu is set to not prompt or the timeout expires. This is safe to
 * call more than once.
 *
 * m - Points to a menu created by menu_create().
 *
 * choice - Points to a location that will store a pointer to the selected
 * menu item. If no item is selected or there is an error, no value will be
 * written at the location it points to.
 *
 * Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
 * default has been set and the menu is set to not prompt or the timeout
 * expires, or -EINTR if the user exits the menu via ^c.
 */
int menu_get_choice(struct menu *m, void **choice)
{
	if (!m || !choice)
		return -EINVAL;

	if (menu_use_default(m))
		return menu_default_choice(m, choice);

	return menu_interactive_choice(m, choice);
}

/*
 * menu_item_add() - Adds or replaces a menu item. Note that this replaces the
 * data of an item if it already exists, but doesn't change the order of the
 * item.
 *
 * m - Points to a menu created by menu_create().
 *
 * item_key - Points to a string that will uniquely identify the item.  The
 * string will be copied to internal storage, and is safe to discard after
 * passing to menu_item_add.
 *
 * item_data - An opaque pointer associated with an item. It is never
 * dereferenced internally, but will be passed to the item_data_print, and
 * will be returned from menu_get_choice if the menu item is selected.
 *
 * Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
 * insufficient memory to add the menu item.
 */
int menu_item_add(struct menu *m, char *item_key, void *item_data)
{
	struct menu_item *item;

	if (!m)
		return -EINVAL;

	item = menu_item_by_key(m, item_key);

	if (item) {
		item->data = item_data;
		return 1;
	}

	item = malloc(sizeof *item);
	if (!item)
		return -ENOMEM;

	item->key = strdup(item_key);

	if (!item->key) {
		free(item);
		return -ENOMEM;
	}

	item->data = item_data;

	list_add_tail(&item->list, &m->items);

	return 1;
}

/*
 * menu_create() - Creates a menu handle with default settings
 *
 * title - If not NULL, points to a string that will be displayed before the
 * list of menu items. It will be copied to internal storage, and is safe to
 * discard after passing to menu_create().
 *
 * timeout - A delay in seconds to wait for user input. If 0, timeout is
 * disabled, and the default choice will be returned unless prompt is 1.
 *
 * prompt - If 0, don't ask for user input unless there is an interrupted
 * timeout. If 1, the user will be prompted for input regardless of the value
 * of timeout.
 *
 * item_data_print - If not NULL, will be called for each item when the menu
 * is displayed, with the pointer to the item's data passed as the argument.
 * If NULL, each item's key will be printed instead.  Since an item's key is
 * what must be entered to select an item, the item_data_print function should
 * make it obvious what the key for each entry is.
 *
 * Returns a pointer to the menu if successful, or NULL if there is
 * insufficient memory available to create the menu.
 */
struct menu *menu_create(char *title, int timeout, int prompt,
				void (*item_data_print)(void *))
{
	struct menu *m;

	m = malloc(sizeof *m);

	if (!m)
		return NULL;

	m->default_item = NULL;
	m->prompt = prompt;
	m->timeout = timeout;
	m->item_data_print = item_data_print;

	if (title) {
		m->title = strdup(title);
		if (!m->title) {
			free(m);
			return NULL;
		}
	} else
		m->title = NULL;


	INIT_LIST_HEAD(&m->items);

	return m;
}

/*
 * menu_destroy() - frees the memory used by a menu and its items.
 *
 * m - Points to a menu created by menu_create().
 *
 * Returns 1 if successful, or -EINVAL if m is NULL.
 */
int menu_destroy(struct menu *m)
{
	if (!m)
		return -EINVAL;

	menu_items_iter(m, menu_item_destroy, NULL);

	if (m->title)
		free(m->title);

	free(m);

	return 1;
}
Commit	Line	Data
b69bf52d JH	1	/*
	2	* Copyright 2010-2011 Calxeda, Inc.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the Free
	6	* Software Foundation; either version 2 of the License, or (at your option)
	7	* any later version.
	8	*
	9	* This program is distributed in the hope it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program. If not, see <http://www.gnu.org/licenses/>.
	16	*/
	17
	18	#include <common.h>
	19	#include <malloc.h>
	20	#include <errno.h>
	21	#include <linux/list.h>
	22
	23	#include "menu.h"
	24
	25	/*
	26	* Internally, each item in a menu is represented by a struct menu_item.
	27	*
	28	* These items will be alloc'd and initialized by menu_item_add and destroyed
	29	* by menu_item_destroy, and the consumer of the interface never sees that
	30	* this struct is used at all.
	31	*/
	32	struct menu_item {
	33	char *key;
	34	void *data;
	35	struct list_head list;
	36	};
	37
	38	/*
	39	* The menu is composed of a list of items along with settings and callbacks
	40	* provided by the user. An incomplete definition of this struct is available
	41	* in menu.h, but the full definition is here to prevent consumers from
	42	* relying on its contents.
	43	*/
	44	struct menu {
	45	struct menu_item *default_item;
b41bc5a8	46	int timeout;
b69bf52d JH	47	char *title;
	48	int prompt;
	49	void (item_data_print)(void );
	50	struct list_head items;
	51	};
	52
	53	/*
	54	* An iterator function for menu items. callback will be called for each item
	55	* in m, with m, a pointer to the item, and extra being passed to callback. If
	56	* callback returns a value other than NULL, iteration stops and the value
	57	* return by callback is returned from menu_items_iter. This allows it to be
	58	* used for search type operations. It is also safe for callback to remove the
	59	* item from the list of items.
	60	*/
	61	static inline void menu_items_iter(struct menu m,
	62	void (callback)(struct menu , struct menu_item , void *),
	63	void *extra)
	64	{
	65	struct list_head pos, n;
	66	struct menu_item *item;
	67	void *ret;
	68
	69	list_for_each_safe(pos, n, &m->items) {
	70	item = list_entry(pos, struct menu_item, list);
	71
	72	ret = callback(m, item, extra);
	73
	74	if (ret)
	75	return ret;
	76	}
	77
	78	return NULL;
	79	}
	80
	81	/*
	82	* Print a menu_item. If the consumer provided an item_data_print function
	83	* when creating the menu, call it with a pointer to the item's private data.
	84	* Otherwise, print the key of the item.
	85	*/
	86	static inline void menu_item_print(struct menu m,
	87	struct menu_item *item,
	88	void *extra)
	89	{
d887ad54	90	if (!m->item_data_print) {
21574976	91	puts(item->key);
d887ad54 WD	92	putc('\n');
d887ad54 WD	93	} else {
b69bf52d	94	m->item_data_print(item->data);
d887ad54	95	}
b69bf52d JH	96
	97	return NULL;
	98	}
	99
	100	/*
	101	* Free the memory used by a menu item. This includes the memory used by its
	102	* key.
	103	*/
	104	static inline void menu_item_destroy(struct menu m,
	105	struct menu_item *item,
	106	void *extra)
	107	{
	108	if (item->key)
	109	free(item->key);
	110
	111	free(item);
	112
	113	return NULL;
	114	}
	115
	116	/*
	117	* Display a menu so the user can make a choice of an item. First display its
	118	* title, if any, and then each item in the menu.
	119	*/
	120	static inline void menu_display(struct menu *m)
	121	{
d887ad54 WD	122	if (m->title) {
	123	puts(m->title);
	124	putc('\n');
	125	}
b69bf52d JH	126
	127	menu_items_iter(m, menu_item_print, NULL);
	128	}
	129
	130	/*
	131	* Check if an item's key matches a provided string, pointed to by extra. If
	132	* extra is NULL, an item with a NULL key will match. Otherwise, the item's
	133	* key has to match according to strcmp.
	134	*
	135	* This is called via menu_items_iter, so it returns a pointer to the item if
	136	* the key matches, and returns NULL otherwise.
	137	*/
	138	static inline void menu_item_key_match(struct menu m,
	139	struct menu_item item, void extra)
	140	{
	141	char *item_key = extra;
	142
	143	if (!item_key \|\| !item->key) {
	144	if (item_key == item->key)
	145	return item;
	146
	147	return NULL;
	148	}
	149
	150	if (strcmp(item->key, item_key) == 0)
	151	return item;
	152
	153	return NULL;
	154	}
	155
	156	/*
	157	* Find the first item with a key matching item_key, if any exists.
	158	*/
	159	static inline struct menu_item menu_item_by_key(struct menu m,
	160	char *item_key)
	161	{
	162	return menu_items_iter(m, menu_item_key_match, item_key);
	163	}
	164
b41bc5a8 JH	165	/*
	166	* Wait for the user to hit a key according to the timeout set for the menu.
	167	* Returns 1 if the user hit a key, or 0 if the timeout expired.
	168	*/
	169	static inline int menu_interrupted(struct menu *m)
	170	{
	171	if (!m->timeout)
	172	return 0;
	173
	174	if (abortboot(m->timeout/10))
	175	return 1;
	176
	177	return 0;
	178	}
	179
b69bf52d JH	180	/*
b69bf52d JH	181	* Checks whether or not the default menu item should be used without
b41bc5a8 JH	182	* prompting for a user choice. If the menu is set to always prompt, or the
	183	* user hits a key during the timeout period, return 0. Otherwise, return 1 to
	184	* indicate we should use the default menu item.
b69bf52d JH	185	*/
	186	static inline int menu_use_default(struct menu *m)
	187	{
b41bc5a8	188	return !m->prompt && !menu_interrupted(m);
b69bf52d JH	189	}
	190
	191	/*
	192	* Set *choice to point to the default item's data, if any default item was
	193	* set, and returns 1. If no default item was set, returns -ENOENT.
	194	*/
	195	static inline int menu_default_choice(struct menu m, void *choice)
	196	{
	197	if (m->default_item) {
	198	*choice = m->default_item->data;
	199	return 1;
	200	}
	201
	202	return -ENOENT;
	203	}
	204
	205	/*
	206	* Displays the menu and asks the user to choose an item. *choice will point
	207	* to the private data of the item the user chooses. The user makes a choice
	208	* by inputting a string matching the key of an item. Invalid choices will
	209	* cause the user to be prompted again, repeatedly, until the user makes a
	210	* valid choice. The user can exit the menu without making a choice via ^c.
	211	*
	212	* Returns 1 if the user made a choice, or -EINTR if they bail via ^c.
	213	*/
	214	static inline int menu_interactive_choice(struct menu m, void *choice)
	215	{
	216	char cbuf[CONFIG_SYS_CBSIZE];
	217	struct menu_item *choice_item = NULL;
	218	int readret;
	219
	220	while (!choice_item) {
	221	cbuf[0] = '\0';
	222
	223	menu_display(m);
	224
	225	readret = readline_into_buffer("Enter choice: ", cbuf);
	226
	227	if (readret >= 0) {
	228	choice_item = menu_item_by_key(m, cbuf);
	229
	230	if (!choice_item)
	231	printf("%s not found\n", cbuf);
	232	} else {
d887ad54	233	puts("^C\n");
b69bf52d JH	234	return -EINTR;
	235	}
	236	}
	237
	238	*choice = choice_item->data;
	239
	240	return 1;
	241	}
	242
	243	/*
	244	* menu_default_set() - Sets the default choice for the menu. This is safe to
	245	* call more than once on a menu.
	246	*
	247	* m - Points to a menu created by menu_create().
	248	*
	249	* item_key - Points to a string that, when compared using strcmp, matches the
	250	* key for an existing item in the menu.
	251	*
	252	* Returns 1 if successful, -EINVAL if m is NULL, or -ENOENT if no item with a
	253	* key matching item_key is found.
	254	*/
	255	int menu_default_set(struct menu m, char item_key)
	256	{
	257	struct menu_item *item;
	258
	259	if (!m)
	260	return -EINVAL;
	261
	262	item = menu_item_by_key(m, item_key);
	263
	264	if (!item)
	265	return -ENOENT;
	266
	267	m->default_item = item;
	268
	269	return 1;
	270	}
	271
	272	/*
	273	* menu_get_choice() - Returns the user's selected menu entry, or the default
b41bc5a8 JH	274	* if the menu is set to not prompt or the timeout expires. This is safe to
b41bc5a8 JH	275	* call more than once.
b69bf52d JH	276	*
	277	* m - Points to a menu created by menu_create().
	278	*
	279	* choice - Points to a location that will store a pointer to the selected
	280	* menu item. If no item is selected or there is an error, no value will be
	281	* written at the location it points to.
	282	*
	283	* Returns 1 if successful, -EINVAL if m or choice is NULL, -ENOENT if no
b41bc5a8 JH	284	* default has been set and the menu is set to not prompt or the timeout
b41bc5a8 JH	285	* expires, or -EINTR if the user exits the menu via ^c.
b69bf52d JH	286	*/
	287	int menu_get_choice(struct menu m, void *choice)
	288	{
	289	if (!m \|\| !choice)
	290	return -EINVAL;
	291
	292	if (menu_use_default(m))
	293	return menu_default_choice(m, choice);
	294
	295	return menu_interactive_choice(m, choice);
	296	}
	297
	298	/*
	299	* menu_item_add() - Adds or replaces a menu item. Note that this replaces the
	300	* data of an item if it already exists, but doesn't change the order of the
	301	* item.
	302	*
	303	* m - Points to a menu created by menu_create().
	304	*
	305	* item_key - Points to a string that will uniquely identify the item. The
	306	* string will be copied to internal storage, and is safe to discard after
	307	* passing to menu_item_add.
	308	*
	309	* item_data - An opaque pointer associated with an item. It is never
	310	* dereferenced internally, but will be passed to the item_data_print, and
	311	* will be returned from menu_get_choice if the menu item is selected.
	312	*
	313	* Returns 1 if successful, -EINVAL if m is NULL, or -ENOMEM if there is
	314	* insufficient memory to add the menu item.
	315	*/
	316	int menu_item_add(struct menu m, char item_key, void *item_data)
	317	{
	318	struct menu_item *item;
	319
	320	if (!m)
	321	return -EINVAL;
	322
	323	item = menu_item_by_key(m, item_key);
	324
	325	if (item) {
	326	item->data = item_data;
	327	return 1;
	328	}
	329
	330	item = malloc(sizeof *item);
	331	if (!item)
	332	return -ENOMEM;
	333
	334	item->key = strdup(item_key);
	335
	336	if (!item->key) {
	337	free(item);
	338	return -ENOMEM;
	339	}
	340
	341	item->data = item_data;
	342
	343	list_add_tail(&item->list, &m->items);
	344
	345	return 1;
	346	}
	347
	348	/*
	349	* menu_create() - Creates a menu handle with default settings
350	*
351	* title - If not NULL, points to a string that will be displayed before the
352	* list of menu items. It will be copied to internal storage, and is safe to
353	* discard after passing to menu_create().
354	*
b41bc5a8 JH	355	* timeout - A delay in seconds to wait for user input. If 0, timeout is
	356	* disabled, and the default choice will be returned unless prompt is 1.
	357	*
	358	* prompt - If 0, don't ask for user input unless there is an interrupted
	359	* timeout. If 1, the user will be prompted for input regardless of the value
	360	* of timeout.
b69bf52d JH	361	*
	362	* item_data_print - If not NULL, will be called for each item when the menu
	363	* is displayed, with the pointer to the item's data passed as the argument.
	364	* If NULL, each item's key will be printed instead. Since an item's key is
	365	* what must be entered to select an item, the item_data_print function should
	366	* make it obvious what the key for each entry is.
	367	*
	368	* Returns a pointer to the menu if successful, or NULL if there is
	369	* insufficient memory available to create the menu.
	370	*/
b41bc5a8	371	struct menu menu_create(char title, int timeout, int prompt,
b69bf52d JH	372	void (item_data_print)(void ))
	373	{
	374	struct menu *m;
	375
	376	m = malloc(sizeof *m);
	377
	378	if (!m)
	379	return NULL;
	380
	381	m->default_item = NULL;
	382	m->prompt = prompt;
b41bc5a8	383	m->timeout = timeout;
b69bf52d JH	384	m->item_data_print = item_data_print;
	385
	386	if (title) {
	387	m->title = strdup(title);
	388	if (!m->title) {
	389	free(m);
	390	return NULL;
	391	}
	392	} else
	393	m->title = NULL;
	394
	395
	396	INIT_LIST_HEAD(&m->items);
	397
	398	return m;
	399	}
	400
	401	/*
	402	* menu_destroy() - frees the memory used by a menu and its items.
	403	*
	404	* m - Points to a menu created by menu_create().
	405	*
	406	* Returns 1 if successful, or -EINVAL if m is NULL.
	407	*/
	408	int menu_destroy(struct menu *m)
	409	{
	410	if (!m)
	411	return -EINVAL;
	412
	413	menu_items_iter(m, menu_item_destroy, NULL);
	414
	415	if (m->title)
	416	free(m->title);
	417
	418	free(m);
	419
	420	return 1;
	421	}