drivers/media/IR/ir-keytable.c - kernel/msm-4.19 - Gitiles

 /* ir-register.c - handle IR scancode->keycode tables
  *
  * Copyright (C) 2009 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 <linux/usb/input.h>
 #include <media/ir-common.h>

 #define IR_TAB_MIN_SIZE	32
 #define IR_TAB_MAX_SIZE	1024

 /**
  * ir_seek_table() - returns the element order on the table
  * @rc_tab:	the ir_scancode_table with the keymap to be used
  * @scancode:	the scancode that we're seeking
  *
  * This routine is used by the input routines when a key is pressed at the
  * IR. The scancode is received and needs to be converted into a keycode.
  * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
  * corresponding keycode from the table.
  */
 static int ir_seek_table(struct ir_scancode_table *rc_tab, u32 scancode)
 {
 	int rc;
 	unsigned long flags;
 	struct ir_scancode *keymap = rc_tab->scan;

 	spin_lock_irqsave(&rc_tab->lock, flags);

 	/* FIXME: replace it by a binary search */

 	for (rc = 0; rc < rc_tab->size; rc++)
 		if (keymap[rc].scancode == scancode)
 			goto exit;

 	/* Not found */
 	rc = -EINVAL;

 exit:
 	spin_unlock_irqrestore(&rc_tab->lock, flags);
 	return rc;
 }

 /**
  * ir_roundup_tablesize() - gets an optimum value for the table size
  * @n_elems:		minimum number of entries to store keycodes
  *
  * This routine is used to choose the keycode table size.
  *
  * In order to have some empty space for new keycodes,
  * and knowing in advance that kmalloc allocates only power of two
  * segments, it optimizes the allocated space to have some spare space
  * for those new keycodes by using the maximum number of entries that
  * will be effectively be allocated by kmalloc.
  * In order to reduce the quantity of table resizes, it has a minimum
  * table size of IR_TAB_MIN_SIZE.
  */
 int ir_roundup_tablesize(int n_elems)
 {
 	size_t size;

 	if (n_elems < IR_TAB_MIN_SIZE)
 		n_elems = IR_TAB_MIN_SIZE;

 	/*
 	 * As kmalloc only allocates sizes of power of two, get as
 	 * much entries as possible for the allocated memory segment
 	 */
 	size = roundup_pow_of_two(n_elems * sizeof(struct ir_scancode));
 	n_elems = size / sizeof(struct ir_scancode);

 	return n_elems;
 }
 EXPORT_SYMBOL_GPL(ir_roundup_tablesize);

 /**
  * ir_copy_table() - copies a keytable, discarding the unused entries
  * @destin:	destin table
  * @origin:	origin table
  *
  * Copies all entries where the keycode is not KEY_UNKNOWN/KEY_RESERVED
  */

 int ir_copy_table(struct ir_scancode_table *destin,
 		 const struct ir_scancode_table *origin)
 {
 	int i, j = 0;

 	for (i = 0; i < origin->size; i++) {
 		if (origin->scan[i].keycode == KEY_UNKNOWN ||
 		   origin->scan[i].keycode == KEY_RESERVED)
 			continue;

 		memcpy(&destin->scan[j], &origin->scan[i], sizeof(struct ir_scancode));
 		j++;
 	}
 	destin->size = j;

 	IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(ir_copy_table);

 /**
  * ir_getkeycode() - get a keycode at the evdev scancode ->keycode table
  * @dev:	the struct input_dev device descriptor
  * @scancode:	the desired scancode
  * @keycode:	the keycode to be retorned.
  *
  * This routine is used to handle evdev EVIOCGKEY ioctl.
  * If the key is not found, returns -EINVAL, otherwise, returns 0.
  */
 static int ir_getkeycode(struct input_dev *dev,
 			 int scancode, int *keycode)
 {
 	int elem;
 	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
 	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;

 	elem = ir_seek_table(rc_tab, scancode);
 	if (elem >= 0) {
 		*keycode = rc_tab->scan[elem].keycode;
 		return 0;
 	}

 	/*
 	 * Scancode not found and table can't be expanded
 	 */
 	if (elem < 0 && rc_tab->size == IR_TAB_MAX_SIZE)
 		return -EINVAL;

 	/*
 	 * If is there extra space, returns KEY_RESERVED,
 	 * otherwise, input core won't let ir_setkeycode to work
 	 */
 	*keycode = KEY_RESERVED;
 	return 0;
 }

 /**
  * ir_is_resize_needed() - Check if the table needs rezise
  * @table:		keycode table that may need to resize
  * @n_elems:		minimum number of entries to store keycodes
  *
  * Considering that kmalloc uses power of two storage areas, this
  * routine detects if the real alloced size will change. If not, it
  * just returns without doing nothing. Otherwise, it will extend or
  * reduce the table size to meet the new needs.
  *
  * It returns 0 if no resize is needed, 1 otherwise.
  */
 static int ir_is_resize_needed(struct ir_scancode_table *table, int n_elems)
 {
 	int cur_size = ir_roundup_tablesize(table->size);
 	int new_size = ir_roundup_tablesize(n_elems);

 	if (cur_size == new_size)
 		return 0;

 	/* Resize is needed */
 	return 1;
 }

 /**
  * ir_delete_key() - remove a keycode from the table
  * @rc_tab:		keycode table
  * @elem:		element to be removed
  *
  */
 static void ir_delete_key(struct ir_scancode_table *rc_tab, int elem)
 {
 	unsigned long flags = 0;
 	int newsize = rc_tab->size - 1;
 	int resize = ir_is_resize_needed(rc_tab, newsize);
 	struct ir_scancode *oldkeymap = rc_tab->scan;
 	struct ir_scancode *newkeymap;

 	if (resize) {
 		newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
 				    sizeof(*newkeymap), GFP_ATOMIC);

 		/* There's no memory for resize. Keep the old table */
 		if (!newkeymap)
 			resize = 0;
 	}

 	if (!resize) {
 		newkeymap = oldkeymap;

 		/* We'll modify the live table. Lock it */
 		spin_lock_irqsave(&rc_tab->lock, flags);
 	}

 	/*
 	 * Copy the elements before the one that will be deleted
 	 * if (!resize), both oldkeymap and newkeymap points
 	 * to the same place, so, there's no need to copy
 	 */
 	if (resize && elem > 0)
 		memcpy(newkeymap, oldkeymap,
 		       elem * sizeof(*newkeymap));

 	/*
 	 * Copy the other elements overwriting the element to be removed
 	 * This operation applies to both resize and non-resize case
 	 */
 	if (elem < newsize)
 		memcpy(&newkeymap[elem], &oldkeymap[elem + 1],
 		       (newsize - elem) * sizeof(*newkeymap));

 	if (resize) {
 		/*
 		 * As the copy happened to a temporary table, only here
 		 * it needs to lock while replacing the table pointers
 		 * to use the new table
 		 */
 		spin_lock_irqsave(&rc_tab->lock, flags);
 		rc_tab->size = newsize;
 		rc_tab->scan = newkeymap;
 		spin_unlock_irqrestore(&rc_tab->lock, flags);

 		/* Frees the old keytable */
 		kfree(oldkeymap);
 	} else {
 		rc_tab->size = newsize;
 		spin_unlock_irqrestore(&rc_tab->lock, flags);
 	}
 }

 /**
  * ir_insert_key() - insert a keycode at the table
  * @rc_tab:		keycode table
  * @scancode:	the desired scancode
  * @keycode:	the keycode to be retorned.
  *
  */
 static int ir_insert_key(struct ir_scancode_table *rc_tab,
 			  int scancode, int keycode)
 {
 	unsigned long flags;
 	int elem = rc_tab->size;
 	int newsize = rc_tab->size + 1;
 	int resize = ir_is_resize_needed(rc_tab, newsize);
 	struct ir_scancode *oldkeymap = rc_tab->scan;
 	struct ir_scancode *newkeymap;

 	if (resize) {
 		newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
 				    sizeof(*newkeymap), GFP_ATOMIC);
 		if (!newkeymap)
 			return -ENOMEM;

 		memcpy(newkeymap, oldkeymap,
 		       rc_tab->size * sizeof(*newkeymap));
 	} else
 		newkeymap  = oldkeymap;

 	/* Stores the new code at the table */
 	IR_dprintk(1, "#%d: New scan 0x%04x with key 0x%04x\n",
 		   rc_tab->size, scancode, keycode);

 	spin_lock_irqsave(&rc_tab->lock, flags);
 	rc_tab->size = newsize;
 	if (resize) {
 		rc_tab->scan = newkeymap;
 		kfree(oldkeymap);
 	}
 	newkeymap[elem].scancode = scancode;
 	newkeymap[elem].keycode  = keycode;
 	spin_unlock_irqrestore(&rc_tab->lock, flags);

 	return 0;
 }

 /**
  * ir_setkeycode() - set a keycode at the evdev scancode ->keycode table
  * @dev:	the struct input_dev device descriptor
  * @scancode:	the desired scancode
  * @keycode:	the keycode to be retorned.
  *
  * This routine is used to handle evdev EVIOCSKEY ioctl.
  * There's one caveat here: how can we increase the size of the table?
  * If the key is not found, returns -EINVAL, otherwise, returns 0.
  */
 static int ir_setkeycode(struct input_dev *dev,
 			 int scancode, int keycode)
 {
 	int rc = 0;
 	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
 	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;
 	struct ir_scancode *keymap = rc_tab->scan;
 	unsigned long flags;

 	/*
 	 * Handle keycode table deletions
 	 *
 	 * If userspace is adding a KEY_UNKNOWN or KEY_RESERVED,
 	 * deal as a trial to remove an existing scancode attribution
 	 * if table become too big, reduce it to save space
 	 */
 	if (keycode == KEY_UNKNOWN || keycode == KEY_RESERVED) {
 		rc = ir_seek_table(rc_tab, scancode);
 		if (rc < 0)
 			return 0;

 		IR_dprintk(1, "#%d: Deleting scan 0x%04x\n", rc, scancode);
 		clear_bit(keymap[rc].keycode, dev->keybit);
 		ir_delete_key(rc_tab, rc);

 		return 0;
 	}

 	/*
 	 * Handle keycode replacements
 	 *
 	 * If the scancode exists, just replace by the new value
 	 */
 	rc = ir_seek_table(rc_tab, scancode);
 	if (rc >= 0) {
 		IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n",
 			rc, scancode, keycode);

 		clear_bit(keymap[rc].keycode, dev->keybit);

 		spin_lock_irqsave(&rc_tab->lock, flags);
 		keymap[rc].keycode = keycode;
 		spin_unlock_irqrestore(&rc_tab->lock, flags);

 		set_bit(keycode, dev->keybit);

 		return 0;
 	}

 	/*
 	 * Handle new scancode inserts
 	 *
 	 * reallocate table if needed and insert a new keycode
 	 */

 	/* Avoid growing the table indefinitely */
 	if (rc_tab->size + 1 > IR_TAB_MAX_SIZE)
 		return -EINVAL;

 	rc = ir_insert_key(rc_tab, scancode, keycode);
 	if (rc < 0)
 		return rc;
 	set_bit(keycode, dev->keybit);

 	return 0;
 }

 /**
  * ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode
  * @input_dev:	the struct input_dev descriptor of the device
  * @scancode:	the scancode that we're seeking
  *
  * This routine is used by the input routines when a key is pressed at the
  * IR. The scancode is received and needs to be converted into a keycode.
  * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
  * corresponding keycode from the table.
  */
 u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
 {
 	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
 	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;
 	struct ir_scancode *keymap = rc_tab->scan;
 	int elem;

 	elem = ir_seek_table(rc_tab, scancode);
 	if (elem >= 0) {
 		IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n",
 			   dev->name, scancode, keymap[elem].keycode);

 		return rc_tab->scan[elem].keycode;
 	}

 	printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
 	       dev->name, scancode);

 	/* Reports userspace that an unknown keycode were got */
 	return KEY_RESERVED;
 }
 EXPORT_SYMBOL_GPL(ir_g_keycode_from_table);

 /**
  * ir_input_register() - sets the IR keycode table and add the handlers
  *			    for keymap table get/set
  * @input_dev:	the struct input_dev descriptor of the device
  * @rc_tab:	the struct ir_scancode_table table of scancode/keymap
  *
  * This routine is used to initialize the input infrastructure to work with
  * an IR.
  * It should be called before registering the IR device.
  */
 int ir_input_register(struct input_dev *input_dev,
 		      struct ir_scancode_table *rc_tab)
 {
 	struct ir_input_dev *ir_dev;
 	struct ir_scancode  *keymap    = rc_tab->scan;
 	int i, rc;

 	if (rc_tab->scan == NULL || !rc_tab->size)
 		return -EINVAL;

 	ir_dev = kzalloc(sizeof(*ir_dev), GFP_KERNEL);
 	if (!ir_dev)
 		return -ENOMEM;

 	spin_lock_init(&rc_tab->lock);

 	ir_dev->rc_tab.size = ir_roundup_tablesize(rc_tab->size);
 	ir_dev->rc_tab.scan = kzalloc(ir_dev->rc_tab.size *
 				    sizeof(struct ir_scancode), GFP_KERNEL);
 	if (!ir_dev->rc_tab.scan)
 		return -ENOMEM;

 	IR_dprintk(1, "Allocated space for %d keycode entries (%zd bytes)\n",
 		ir_dev->rc_tab.size,
 		ir_dev->rc_tab.size * sizeof(ir_dev->rc_tab.scan));

 	ir_copy_table(&ir_dev->rc_tab, rc_tab);

 	/* set the bits for the keys */
 	IR_dprintk(1, "key map size: %d\n", rc_tab->size);
 	for (i = 0; i < rc_tab->size; i++) {
 		IR_dprintk(1, "#%d: setting bit for keycode 0x%04x\n",
 			i, keymap[i].keycode);
 		set_bit(keymap[i].keycode, input_dev->keybit);
 	}
 	clear_bit(0, input_dev->keybit);

 	set_bit(EV_KEY, input_dev->evbit);

 	input_dev->getkeycode = ir_getkeycode;
 	input_dev->setkeycode = ir_setkeycode;
 	input_set_drvdata(input_dev, ir_dev);

 	rc = input_register_device(input_dev);
 	if (rc < 0) {
 		kfree(rc_tab->scan);
 		kfree(ir_dev);
 		input_set_drvdata(input_dev, NULL);
 	}

 	return rc;
 }
 EXPORT_SYMBOL_GPL(ir_input_register);

 void ir_input_unregister(struct input_dev *dev)
 {
 	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
 	struct ir_scancode_table *rc_tab;

 	if (!ir_dev)
 		return;

 	IR_dprintk(1, "Freed keycode table\n");

 	rc_tab = &ir_dev->rc_tab;
 	rc_tab->size = 0;
 	kfree(rc_tab->scan);
 	rc_tab->scan = NULL;

 	kfree(ir_dev);
 	input_unregister_device(dev);
 }
 EXPORT_SYMBOL_GPL(ir_input_unregister);

 int ir_core_debug;    /* ir_debug level (0,1,2) */
 EXPORT_SYMBOL_GPL(ir_core_debug);
 module_param_named(debug, ir_core_debug, int, 0644);

 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
 MODULE_LICENSE("GPL");
	/* ir-register.c - handle IR scancode->keycode tables
	*
	* Copyright (C) 2009 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 <linux/usb/input.h>
	#include <media/ir-common.h>

	#define IR_TAB_MIN_SIZE 32
	#define IR_TAB_MAX_SIZE 1024

	/**
	* ir_seek_table() - returns the element order on the table
	* @rc_tab: the ir_scancode_table with the keymap to be used
	* @scancode: the scancode that we're seeking
	*
	* This routine is used by the input routines when a key is pressed at the
	* IR. The scancode is received and needs to be converted into a keycode.
	* If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
	* corresponding keycode from the table.
	*/
	static int ir_seek_table(struct ir_scancode_table *rc_tab, u32 scancode)
	{
	int rc;
	unsigned long flags;
	struct ir_scancode *keymap = rc_tab->scan;

	spin_lock_irqsave(&rc_tab->lock, flags);

	/* FIXME: replace it by a binary search */

	for (rc = 0; rc < rc_tab->size; rc++)
	if (keymap[rc].scancode == scancode)
	goto exit;

	/* Not found */
	rc = -EINVAL;

	exit:
	spin_unlock_irqrestore(&rc_tab->lock, flags);
	return rc;
	}

	/**
	* ir_roundup_tablesize() - gets an optimum value for the table size
	* @n_elems: minimum number of entries to store keycodes
	*
	* This routine is used to choose the keycode table size.
	*
	* In order to have some empty space for new keycodes,
	* and knowing in advance that kmalloc allocates only power of two
	* segments, it optimizes the allocated space to have some spare space
	* for those new keycodes by using the maximum number of entries that
	* will be effectively be allocated by kmalloc.
	* In order to reduce the quantity of table resizes, it has a minimum
	* table size of IR_TAB_MIN_SIZE.
	*/
	int ir_roundup_tablesize(int n_elems)
	{
	size_t size;

	if (n_elems < IR_TAB_MIN_SIZE)
	n_elems = IR_TAB_MIN_SIZE;

	/*
	* As kmalloc only allocates sizes of power of two, get as
	* much entries as possible for the allocated memory segment
	*/
	size = roundup_pow_of_two(n_elems * sizeof(struct ir_scancode));
	n_elems = size / sizeof(struct ir_scancode);

	return n_elems;
	}
	EXPORT_SYMBOL_GPL(ir_roundup_tablesize);

	/**
	* ir_copy_table() - copies a keytable, discarding the unused entries
	* @destin: destin table
	* @origin: origin table
	*
	* Copies all entries where the keycode is not KEY_UNKNOWN/KEY_RESERVED
	*/

	int ir_copy_table(struct ir_scancode_table *destin,
	const struct ir_scancode_table *origin)
	{
	int i, j = 0;

	for (i = 0; i < origin->size; i++) {
	if (origin->scan[i].keycode == KEY_UNKNOWN \|\|
	origin->scan[i].keycode == KEY_RESERVED)
	continue;

	memcpy(&destin->scan[j], &origin->scan[i], sizeof(struct ir_scancode));
	j++;
	}
	destin->size = j;

	IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size);

	return 0;
	}
	EXPORT_SYMBOL_GPL(ir_copy_table);

	/**
	* ir_getkeycode() - get a keycode at the evdev scancode ->keycode table
	* @dev: the struct input_dev device descriptor
	* @scancode: the desired scancode
	* @keycode: the keycode to be retorned.
	*
	* This routine is used to handle evdev EVIOCGKEY ioctl.
	* If the key is not found, returns -EINVAL, otherwise, returns 0.
	*/
	static int ir_getkeycode(struct input_dev *dev,
	int scancode, int *keycode)
	{
	int elem;
	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;

	elem = ir_seek_table(rc_tab, scancode);
	if (elem >= 0) {
	*keycode = rc_tab->scan[elem].keycode;
	return 0;
	}

	/*
	* Scancode not found and table can't be expanded
	*/
	if (elem < 0 && rc_tab->size == IR_TAB_MAX_SIZE)
	return -EINVAL;

	/*
	* If is there extra space, returns KEY_RESERVED,
	* otherwise, input core won't let ir_setkeycode to work
	*/
	*keycode = KEY_RESERVED;
	return 0;
	}

	/**
	* ir_is_resize_needed() - Check if the table needs rezise
	* @table: keycode table that may need to resize
	* @n_elems: minimum number of entries to store keycodes
	*
	* Considering that kmalloc uses power of two storage areas, this
	* routine detects if the real alloced size will change. If not, it
	* just returns without doing nothing. Otherwise, it will extend or
	* reduce the table size to meet the new needs.
	*
	* It returns 0 if no resize is needed, 1 otherwise.
	*/
	static int ir_is_resize_needed(struct ir_scancode_table *table, int n_elems)
	{
	int cur_size = ir_roundup_tablesize(table->size);
	int new_size = ir_roundup_tablesize(n_elems);

	if (cur_size == new_size)
	return 0;

	/* Resize is needed */
	return 1;
	}

	/**
	* ir_delete_key() - remove a keycode from the table
	* @rc_tab: keycode table
	* @elem: element to be removed
	*
	*/
	static void ir_delete_key(struct ir_scancode_table *rc_tab, int elem)
	{
	unsigned long flags = 0;
	int newsize = rc_tab->size - 1;
	int resize = ir_is_resize_needed(rc_tab, newsize);
	struct ir_scancode *oldkeymap = rc_tab->scan;
	struct ir_scancode *newkeymap;

	if (resize) {
	newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
	sizeof(*newkeymap), GFP_ATOMIC);

	/* There's no memory for resize. Keep the old table */
	if (!newkeymap)
	resize = 0;
	}

	if (!resize) {
	newkeymap = oldkeymap;

	/* We'll modify the live table. Lock it */
	spin_lock_irqsave(&rc_tab->lock, flags);
	}

	/*
	* Copy the elements before the one that will be deleted
	* if (!resize), both oldkeymap and newkeymap points
	* to the same place, so, there's no need to copy
	*/
	if (resize && elem > 0)
	memcpy(newkeymap, oldkeymap,
	elem * sizeof(*newkeymap));

	/*
	* Copy the other elements overwriting the element to be removed
	* This operation applies to both resize and non-resize case
	*/
	if (elem < newsize)
	memcpy(&newkeymap[elem], &oldkeymap[elem + 1],
	(newsize - elem) * sizeof(*newkeymap));

	if (resize) {
	/*
	* As the copy happened to a temporary table, only here
	* it needs to lock while replacing the table pointers
	* to use the new table
	*/
	spin_lock_irqsave(&rc_tab->lock, flags);
	rc_tab->size = newsize;
	rc_tab->scan = newkeymap;
	spin_unlock_irqrestore(&rc_tab->lock, flags);

	/* Frees the old keytable */
	kfree(oldkeymap);
	} else {
	rc_tab->size = newsize;
	spin_unlock_irqrestore(&rc_tab->lock, flags);
	}
	}

	/**
	* ir_insert_key() - insert a keycode at the table
	* @rc_tab: keycode table
	* @scancode: the desired scancode
	* @keycode: the keycode to be retorned.
	*
	*/
	static int ir_insert_key(struct ir_scancode_table *rc_tab,
	int scancode, int keycode)
	{
	unsigned long flags;
	int elem = rc_tab->size;
	int newsize = rc_tab->size + 1;
	int resize = ir_is_resize_needed(rc_tab, newsize);
	struct ir_scancode *oldkeymap = rc_tab->scan;
	struct ir_scancode *newkeymap;

	if (resize) {
	newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
	sizeof(*newkeymap), GFP_ATOMIC);
	if (!newkeymap)
	return -ENOMEM;

	memcpy(newkeymap, oldkeymap,
	rc_tab->size * sizeof(*newkeymap));
	} else
	newkeymap = oldkeymap;

	/* Stores the new code at the table */
	IR_dprintk(1, "#%d: New scan 0x%04x with key 0x%04x\n",
	rc_tab->size, scancode, keycode);

	spin_lock_irqsave(&rc_tab->lock, flags);
	rc_tab->size = newsize;
	if (resize) {
	rc_tab->scan = newkeymap;
	kfree(oldkeymap);
	}
	newkeymap[elem].scancode = scancode;
	newkeymap[elem].keycode = keycode;
	spin_unlock_irqrestore(&rc_tab->lock, flags);

	return 0;
	}

	/**
	* ir_setkeycode() - set a keycode at the evdev scancode ->keycode table
	* @dev: the struct input_dev device descriptor
	* @scancode: the desired scancode
	* @keycode: the keycode to be retorned.
	*
	* This routine is used to handle evdev EVIOCSKEY ioctl.
	* There's one caveat here: how can we increase the size of the table?
	* If the key is not found, returns -EINVAL, otherwise, returns 0.
	*/
	static int ir_setkeycode(struct input_dev *dev,
	int scancode, int keycode)
	{
	int rc = 0;
	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;
	struct ir_scancode *keymap = rc_tab->scan;
	unsigned long flags;

	/*
	* Handle keycode table deletions
	*
	* If userspace is adding a KEY_UNKNOWN or KEY_RESERVED,
	* deal as a trial to remove an existing scancode attribution
	* if table become too big, reduce it to save space
	*/
	if (keycode == KEY_UNKNOWN \|\| keycode == KEY_RESERVED) {
	rc = ir_seek_table(rc_tab, scancode);
	if (rc < 0)
	return 0;

	IR_dprintk(1, "#%d: Deleting scan 0x%04x\n", rc, scancode);
	clear_bit(keymap[rc].keycode, dev->keybit);
	ir_delete_key(rc_tab, rc);

	return 0;
	}

	/*
	* Handle keycode replacements
	*
	* If the scancode exists, just replace by the new value
	*/
	rc = ir_seek_table(rc_tab, scancode);
	if (rc >= 0) {
	IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n",
	rc, scancode, keycode);

	clear_bit(keymap[rc].keycode, dev->keybit);

	spin_lock_irqsave(&rc_tab->lock, flags);
	keymap[rc].keycode = keycode;
	spin_unlock_irqrestore(&rc_tab->lock, flags);

	set_bit(keycode, dev->keybit);

	return 0;
	}

	/*
	* Handle new scancode inserts
	*
	* reallocate table if needed and insert a new keycode
	*/

	/* Avoid growing the table indefinitely */
	if (rc_tab->size + 1 > IR_TAB_MAX_SIZE)
	return -EINVAL;

	rc = ir_insert_key(rc_tab, scancode, keycode);
	if (rc < 0)
	return rc;
	set_bit(keycode, dev->keybit);

	return 0;
	}

	/**
	* ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode
	* @input_dev: the struct input_dev descriptor of the device
	* @scancode: the scancode that we're seeking
	*
	* This routine is used by the input routines when a key is pressed at the
	* IR. The scancode is received and needs to be converted into a keycode.
	* If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
	* corresponding keycode from the table.
	*/
	u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
	{
	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
	struct ir_scancode_table *rc_tab = &ir_dev->rc_tab;
	struct ir_scancode *keymap = rc_tab->scan;
	int elem;

	elem = ir_seek_table(rc_tab, scancode);
	if (elem >= 0) {
	IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n",
	dev->name, scancode, keymap[elem].keycode);

	return rc_tab->scan[elem].keycode;
	}

	printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
	dev->name, scancode);

	/* Reports userspace that an unknown keycode were got */
	return KEY_RESERVED;
	}
	EXPORT_SYMBOL_GPL(ir_g_keycode_from_table);

	/**
	* ir_input_register() - sets the IR keycode table and add the handlers
	* for keymap table get/set
	* @input_dev: the struct input_dev descriptor of the device
	* @rc_tab: the struct ir_scancode_table table of scancode/keymap
	*
	* This routine is used to initialize the input infrastructure to work with
	* an IR.
	* It should be called before registering the IR device.
	*/
	int ir_input_register(struct input_dev *input_dev,
	struct ir_scancode_table *rc_tab)
	{
	struct ir_input_dev *ir_dev;
	struct ir_scancode *keymap = rc_tab->scan;
	int i, rc;

	if (rc_tab->scan == NULL \|\| !rc_tab->size)
	return -EINVAL;

	ir_dev = kzalloc(sizeof(*ir_dev), GFP_KERNEL);
	if (!ir_dev)
	return -ENOMEM;

	spin_lock_init(&rc_tab->lock);

	ir_dev->rc_tab.size = ir_roundup_tablesize(rc_tab->size);
	ir_dev->rc_tab.scan = kzalloc(ir_dev->rc_tab.size *
	sizeof(struct ir_scancode), GFP_KERNEL);
	if (!ir_dev->rc_tab.scan)
	return -ENOMEM;

	IR_dprintk(1, "Allocated space for %d keycode entries (%zd bytes)\n",
	ir_dev->rc_tab.size,
	ir_dev->rc_tab.size * sizeof(ir_dev->rc_tab.scan));

	ir_copy_table(&ir_dev->rc_tab, rc_tab);

	/* set the bits for the keys */
	IR_dprintk(1, "key map size: %d\n", rc_tab->size);
	for (i = 0; i < rc_tab->size; i++) {
	IR_dprintk(1, "#%d: setting bit for keycode 0x%04x\n",
	i, keymap[i].keycode);
	set_bit(keymap[i].keycode, input_dev->keybit);
	}
	clear_bit(0, input_dev->keybit);

	set_bit(EV_KEY, input_dev->evbit);

	input_dev->getkeycode = ir_getkeycode;
	input_dev->setkeycode = ir_setkeycode;
	input_set_drvdata(input_dev, ir_dev);

	rc = input_register_device(input_dev);
	if (rc < 0) {
	kfree(rc_tab->scan);
	kfree(ir_dev);
	input_set_drvdata(input_dev, NULL);
	}

	return rc;
	}
	EXPORT_SYMBOL_GPL(ir_input_register);

	void ir_input_unregister(struct input_dev *dev)
	{
	struct ir_input_dev *ir_dev = input_get_drvdata(dev);
	struct ir_scancode_table *rc_tab;

	if (!ir_dev)
	return;

	IR_dprintk(1, "Freed keycode table\n");

	rc_tab = &ir_dev->rc_tab;
	rc_tab->size = 0;
	kfree(rc_tab->scan);
	rc_tab->scan = NULL;

	kfree(ir_dev);
	input_unregister_device(dev);
	}
	EXPORT_SYMBOL_GPL(ir_input_unregister);

	int ir_core_debug; /* ir_debug level (0,1,2) */
	EXPORT_SYMBOL_GPL(ir_core_debug);
	module_param_named(debug, ir_core_debug, int, 0644);

	MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
	MODULE_LICENSE("GPL");