/* ir-register.c - handle IR scancode->keycode tables
*
* Copyright (C) 2009 by Mauro Carvalho Chehab <mchehab@redhat.com>
*/
#include <linux/usb/input.h>
#include <media/ir-common.h>
#define IR_TAB_MIN_SIZE 32
/**
* 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;
}
/**
* 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) {
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", j);
return 0;
}
/**
* 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 i;
struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
struct ir_scancode *keymap = rc_tab->scan;
/* See if we can match the raw key code. */
for (i = 0; i < rc_tab->size; i++)
if (keymap[i].scancode == scancode) {
*keycode = keymap[i].keycode;
return 0;
}
/*
* If is there extra space, returns KEY_RESERVED,
* otherwise, input core won't let ir_setkeycode
* to work
*/
for (i = 0; i < rc_tab->size; i++)
if (keymap[i].keycode == KEY_RESERVED ||
keymap[i].keycode == KEY_UNKNOWN) {
*keycode = KEY_RESERVED;
return 0;
}
return -EINVAL;
}
/**
* 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 i;
struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
struct ir_scancode *keymap = rc_tab->scan;
/* Search if it is replacing an existing keycode */
for (i = 0; i < rc_tab->size; i++)
if (keymap[i].scancode == scancode) {
keymap[i].keycode = keycode;
return 0;
}
/* Search if is there a clean entry. If so, use it */
for (i = 0; i < rc_tab->size; i++)
if (keymap[i].keycode == KEY_RESERVED ||
keymap[i].keycode == KEY_UNKNOWN) {
keymap[i].scancode = scancode;
keymap[i].keycode = keycode;
return 0;
}
/*
* FIXME: Currently, it is not possible to increase the size of
* scancode table. For it to happen, one possibility
* would be to allocate a table with key_map_size + 1,
* copying data, appending the new key on it, and freeing
* the old one - or maybe just allocating some spare space
*/
return -EINVAL;
}
/**
* ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode
* @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.
*/
u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
{
int i;
struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
struct ir_scancode *keymap = rc_tab->scan;
for (i = 0; i < rc_tab->size; i++)
if (keymap[i].scancode == scancode) {
IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n",
dev->name, scancode, keymap[i].keycode);
return keymap[i].keycode;
}
printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
dev->name, scancode);
return KEY_UNKNOWN;
}
/**
* ir_set_keycode_table() - 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 requires that the caller initializes the input_dev struct with
* some fields: name,
*/
int ir_set_keycode_table(struct input_dev *input_dev,
struct ir_scancode_table *rc_tab)
{
struct ir_scancode *keymap = rc_tab->scan;
int i;
if (rc_tab->scan == NULL || !rc_tab->size)
return -EINVAL;
/* 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);
}
input_dev->getkeycode = ir_getkeycode;
input_dev->setkeycode = ir_setkeycode;
input_set_drvdata(input_dev, rc_tab);
return 0;
}
void ir_input_free(struct input_dev *dev)
{
struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
IR_dprintk(1, "Freed keycode table\n");
rc_tab->size = 0;
kfree(rc_tab->scan);
rc_tab->scan = NULL;
}
EXPORT_SYMBOL_GPL(ir_input_free);
