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 (file)
--- 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 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;
-               }
-
-       /* 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;
-               }
+       rc = ir_seek_table(rc_tab, scancode);
+       if (rc <0)
+               return rc;
 
-       /*
-        * 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
-        */
+       IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n",
+               rc, scancode, keycode);
 
-       return -EINVAL;
+       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;
 }
 
 /**
  * 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;
 

diff --git a/include/media/ir-common.h b/include/media/ir-common.h
index 452f6e8..e41a99e 100644 (file)
--- 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 {
 struct ir_scancode_table {
        struct ir_scancode *scan;
        int size;
+       spinlock_t lock;
 };
 
 #define RC5_START(x)   (((x)>>12)&3)