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>
diff --git a/drivers/media/common/ir-keytable.c b/drivers/media/common/ir-keytable.c
index 6e3cc78..b06f023 100644
--- a/drivers/media/common/ir-keytable.c
+++ b/drivers/media/common/ir-keytable.c
@@ -10,6 +10,38 @@
#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 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 @@
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_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 @@
*/
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 @@
* @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 @@
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;
diff --git a/include/media/ir-common.h b/include/media/ir-common.h
index 452f6e8..e41a99e 100644
--- a/include/media/ir-common.h
+++ b/include/media/ir-common.h
@@ -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_table {
struct ir_scancode *scan;
int size;
+ spinlock_t lock;
};
#define RC5_START(x) (((x)>>12)&3)