• Mauro Carvalho Chehab's avatar
    V4L/DVB (12595): common/ir: use a struct for keycode tables · 715a2233
    Mauro Carvalho Chehab authored
    Currently, V4L uses a scancode table whose index is the scancode and
    the value is the keycode. While this works, it has some drawbacks:
    
    1) It requires that the scancode to be at the range 00-7f;
    
    2) keycodes should be masked on 7 bits in order for it to work;
    
    3) due to the 7 bits approach, sometimes it is not possible to replace
    the default keyboard to another one with a different encoding rule;
    
    4) it is different than what is done with dvb-usb approach;
    
    5) it requires a typedef for it to work. This is not a recommended
    Linux CodingStyle.
    
    This patch is part of a larger series of IR changes. It basically
    replaces the IR_KEYTAB_TYPE tables by a structured table:
    struct ir_scancode {
           u16     scancode;
           u32     keycode;
    };
    
    This is very close to what dvb does. So, a further integration with DVB
    code will be easy.
    
    While we've changed the tables, for now, the IR keycode handling is still
    based on the old approach.
    
    The only notable effect is the redution of about 35% of the ir-common
    module size:
    
       text    data     bss     dec     hex filename
       6721   29208       4   35933    8c5d old/ir-common.ko
       5756   18040       4   23800    5cf8 new/ir-common.ko
    
    In thesis, we could be using above u8 for scancode, reducing even more the size
    of the module, but defining it as u16 is more convenient, since, on dvb, each
    scancode has up to 16 bits, and we currently have a few troubles with rc5, as their
    scancodes are defined with more than 8 bits.
    
    This patch itself shouldn't be doing any functional changes.
    Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
    715a2233
ir-functions.c 8.63 KB