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V4L/DVB (13540): ir-common: Cleanup get key evdev code 

The same loop to seek for a key were used on different places. Also,
no spinlock were protecting it to avoid the risk of replacing a keycode
while seeking for a new code.

This cleanup does:
	- create an unique function to seek for a code;
	- adds an spinlock to protect the table lookup;
	- remove some unused code;
	- simplifies to code to make it easier to understand.

Basically no change in behavior should be noticed after this patch.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2009-12-02 15:56:47 -03:00
parent a53e212571
commit 7fee03e487
2 changed files with 76 additions and 61 deletions
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135
drivers/media/common/ir-keytable.c
View File

@ -9,6 +9,38 @@
#define IR_TAB_MIN_SIZE 32
/**
* 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
@ -54,21 +86,20 @@ int ir_copy_table(struct ir_scancode_table *destin,
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++;
}
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", j);
IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size);
return 0;
}
/**
* ir_getkeycode() - get a keycode at the evdev scancode ->keycode table
* @dev: the struct input_dev device descriptor
@ -81,28 +112,14 @@ int ir_copy_table(struct ir_scancode_table *destin,
static int ir_getkeycode(struct input_dev *dev,
int scancode, int *keycode)
{
int i;
int elem;
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;
}
elem = ir_seek_table(rc_tab, scancode);
if (elem >= 0) {
*keycode = rc_tab->scan[elem].keycode;
return 0;
}
return -EINVAL;
}
@ -120,40 +137,33 @@ static int ir_getkeycode(struct input_dev *dev,
static int ir_setkeycode(struct input_dev *dev,
int scancode, int keycode)
{
int i;
int rc = 0;
struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
struct ir_scancode *keymap = rc_tab->scan;
unsigned long flags;
/* 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;
}
rc = ir_seek_table(rc_tab, scancode);
if (rc <0)
return rc;
/* 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;
}
IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n",
rc, scancode, keycode);
/*
* 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
*/
clear_bit(keymap[rc].keycode, dev->keybit);
return -EINVAL;
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;
}
/**
* 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
* @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
@ -163,22 +173,23 @@ static int ir_setkeycode(struct input_dev *dev,
*/
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;
int elem;
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);
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 keymap[i].keycode;
}
return rc_tab->scan[elem].keycode;
}
printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
dev->name, scancode);
return KEY_UNKNOWN;
/* Reports userspace that an unknown keycode were got */
return KEY_RESERVED;
}
/**
@ -188,8 +199,8 @@ u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
* @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,
* an IR.
* It should be called before registering the IR device.
*/
int ir_set_keycode_table(struct input_dev *input_dev,
struct ir_scancode_table *rc_tab)
@ -197,6 +208,8 @@ int ir_set_keycode_table(struct input_dev *input_dev,
struct ir_scancode *keymap = rc_tab->scan;
int i;
spin_lock_init(&rc_tab->lock);
if (rc_tab->scan == NULL || !rc_tab->size)
return -EINVAL;

2
include/media/ir-common.h
View File

@ -26,6 +26,7 @@
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
extern int media_ir_debug; /* media_ir_debug level (0,1,2) */
#define IR_dprintk(level, fmt, arg...) if (media_ir_debug >= level) \
@ -43,6 +44,7 @@ struct ir_scancode {
struct ir_scancode_table {
struct ir_scancode *scan;
int size;
spinlock_t lock;
};
#define RC5_START(x) (((x)>>12)&3)