rc-main.c

/* rc-main.c - Remote Controller core module
 *
 * Copyright (C) 2009-2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
 *
 * 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 version 2 of the License.
 *
 *  This program is distributed in the hope that 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.
 */

#include <media/rc-core.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
#include "rc-core-priv.h"

/* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */
#define IR_TAB_MIN_SIZE	256
#define IR_TAB_MAX_SIZE	8192

/* FIXME: IR_KEYPRESS_TIMEOUT should be protocol specific */
#define IR_KEYPRESS_TIMEOUT 250

/* Used to keep track of known keymaps */
static LIST_HEAD(rc_map_list);
static DEFINE_SPINLOCK(rc_map_lock);

static struct rc_map_list *seek_rc_map(const char *name)
{
	struct rc_map_list *map = NULL;

	spin_lock(&rc_map_lock);
	list_for_each_entry(map, &rc_map_list, list) {
		if (!strcmp(name, map->map.name)) {
			spin_unlock(&rc_map_lock);
			return map;
		}
	}
	spin_unlock(&rc_map_lock);

	return NULL;
}

struct rc_map *rc_map_get(const char *name)
{

	struct rc_map_list *map;

	map = seek_rc_map(name);
#ifdef MODULE
	if (!map) {
		int rc = request_module(name);
		if (rc < 0) {
			printk(KERN_ERR "Couldn't load IR keymap %s\n", name);
			return NULL;
		}
		msleep(20);	/* Give some time for IR to register */

		map = seek_rc_map(name);
	}
#endif
	if (!map) {
		printk(KERN_ERR "IR keymap %s not found\n", name);
		return NULL;
	}

	printk(KERN_INFO "Registered IR keymap %s\n", map->map.name);

	return &map->map;
}
EXPORT_SYMBOL_GPL(rc_map_get);

int rc_map_register(struct rc_map_list *map)
{
	spin_lock(&rc_map_lock);
	list_add_tail(&map->list, &rc_map_list);
	spin_unlock(&rc_map_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(rc_map_register);

void rc_map_unregister(struct rc_map_list *map)
{
	spin_lock(&rc_map_lock);
	list_del(&map->list);
	spin_unlock(&rc_map_lock);
}
EXPORT_SYMBOL_GPL(rc_map_unregister);


static struct rc_map_table empty[] = {
	{ 0x2a, KEY_COFFEE },
};

static struct rc_map_list empty_map = {
	.map = {
		.scan    = empty,
		.size    = ARRAY_SIZE(empty),
		.rc_type = RC_TYPE_UNKNOWN,	/* Legacy IR type */
		.name    = RC_MAP_EMPTY,
	}
};

/**
 * ir_create_table() - initializes a scancode table
 * @rc_map:	the rc_map to initialize
 * @name:	name to assign to the table
 * @rc_type:	ir type to assign to the new table
 * @size:	initial size of the table
 * @return:	zero on success or a negative error code
 *
 * This routine will initialize the rc_map and will allocate
 * memory to hold at least the specified number of elements.
 */
static int ir_create_table(struct rc_map *rc_map,
			   const char *name, u64 rc_type, size_t size)
{
	rc_map->name = name;
	rc_map->rc_type = rc_type;
	rc_map->alloc = roundup_pow_of_two(size * sizeof(struct rc_map_table));
	rc_map->size = rc_map->alloc / sizeof(struct rc_map_table);
	rc_map->scan = kmalloc(rc_map->alloc, GFP_KERNEL);
	if (!rc_map->scan)
		return -ENOMEM;

	IR_dprintk(1, "Allocated space for %u keycode entries (%u bytes)\n",
		   rc_map->size, rc_map->alloc);
	return 0;
}

/**
 * ir_free_table() - frees memory allocated by a scancode table
 * @rc_map:	the table whose mappings need to be freed
 *
 * This routine will free memory alloctaed for key mappings used by given
 * scancode table.
 */
static void ir_free_table(struct rc_map *rc_map)
{
	rc_map->size = 0;
	kfree(rc_map->scan);
	rc_map->scan = NULL;
}

/**
 * ir_resize_table() - resizes a scancode table if necessary
 * @rc_map:	the rc_map to resize
 * @gfp_flags:	gfp flags to use when allocating memory
 * @return:	zero on success or a negative error code
 *
 * This routine will shrink the rc_map if it has lots of
 * unused entries and grow it if it is full.
 */
static int ir_resize_table(struct rc_map *rc_map, gfp_t gfp_flags)
{
	unsigned int oldalloc = rc_map->alloc;
	unsigned int newalloc = oldalloc;
	struct rc_map_table *oldscan = rc_map->scan;
	struct rc_map_table *newscan;

	if (rc_map->size == rc_map->len) {
		/* All entries in use -> grow keytable */
		if (rc_map->alloc >= IR_TAB_MAX_SIZE)
			return -ENOMEM;

		newalloc *= 2;
		IR_dprintk(1, "Growing table to %u bytes\n", newalloc);
	}

	if ((rc_map->len * 3 < rc_map->size) && (oldalloc > IR_TAB_MIN_SIZE)) {
		/* Less than 1/3 of entries in use -> shrink keytable */
		newalloc /= 2;
		IR_dprintk(1, "Shrinking table to %u bytes\n", newalloc);
	}

	if (newalloc == oldalloc)
		return 0;

	newscan = kmalloc(newalloc, gfp_flags);
	if (!newscan) {
		IR_dprintk(1, "Failed to kmalloc %u bytes\n", newalloc);
		return -ENOMEM;
	}

	memcpy(newscan, rc_map->scan, rc_map->len * sizeof(struct rc_map_table));
	rc_map->scan = newscan;
	rc_map->alloc = newalloc;
	rc_map->size = rc_map->alloc / sizeof(struct rc_map_table);
	kfree(oldscan);
	return 0;
}

/**