diff options
Diffstat (limited to 'drivers/media/common/ir-keytable.c')
| -rw-r--r-- | drivers/media/common/ir-keytable.c | 207 |
1 files changed, 197 insertions, 10 deletions
diff --git a/drivers/media/common/ir-keytable.c b/drivers/media/common/ir-keytable.c index b06f023ca76..26ce5bc2fdd 100644 --- a/drivers/media/common/ir-keytable.c +++ b/drivers/media/common/ir-keytable.c @@ -8,6 +8,7 @@ #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 @@ -121,7 +122,154 @@ static int ir_getkeycode(struct input_dev *dev, return 0; } - return -EINVAL; + /* + * 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; } /** @@ -142,20 +290,59 @@ static int ir_setkeycode(struct input_dev *dev, struct ir_scancode *keymap = rc_tab->scan; unsigned long flags; - /* Search if it is replacing an existing keycode */ + /* + * 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) - return rc; + if (rc >= 0) { + IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n", + rc, scancode, keycode); - IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n", - rc, scancode, keycode); + clear_bit(keymap[rc].keycode, dev->keybit); - 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); - 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; |