/* 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/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");
