On Fri, 2011-09-23 at 20:43 -0300, Mauro Carvalho Chehab wrote: > Em 19-09-2011 08:12, Lawrence Rust escreveu: > > The current decoder for the RC6 IR protocol supports mode 0 (16 bit) and > > mode 6A. In mode 6A the decoder supports either 32-bit data (for > > Microsoft's MCE RC) or 24 bit. > > > > I would like to support a Sky/Sky+ standard RC which transmits RC6-6-20 > > i.e. 20 bit data. The transmitted frame format is identical to the 24 > > bit form so I'm curious as to what remotes transmit 24 bit data or was > > this an error and it should be 20? > > > > RC6-6-20 is explained here: > > http://www.guiott.com/wrc/RC6-6.html > > > > If 24-bit mode is in use, is there a way to select between 20 and 24 bit > > operation? > > You'll need to figure out a way to detect between them. It is probably not > hard to detect, and add support for both at the decider. > Maybe you can find something useful here: > http://www.sbprojects.com/knowledge/ir/rc6.php Lawrence: Some RC-6 explanations with more detail could be found here: http://slycontrol.ru/scr/kb/rc6.htm (dead; not in the Wayback machine :( ) http://www.picbasic.nl/info_rc6_uk.htm You might also find this thread of interest for some history: http://www.spinics.net/lists/linux-input/msg07983.html The take away is that the data length is, in theory, OEM dependent for RC-6 Mode 6A, limited to a max of 24 bits (3 bytes) after a short customer code and 128 bits (16 bytes) after a long customer code. In that previous thread, I suggested it might be better to look for the signal free time of 6 RC6_UNITs to declare the end of reception, instead of a bit count. Maybe that is a way to deal with the current problem. Regards, Andy > > > > I made the following simple mod to ir-rc6-decoder.c and my Sky/Sky+ RCs > > decode correctly (with a custom keytable): > > > > --- a/drivers/media/rc/ir-rc6-decoder.c 2011-05-19 06:06:34.000000000 +0200 > > +++ b/drivers/media/rc/ir-rc6-decoder.c 2011-09-19 13:02:35.000000000 +0200 > > @@ -17,14 +17,14 @@ > > /* > > * This decoder currently supports: > > * RC6-0-16 (standard toggle bit in header) > > - * RC6-6A-24 (no toggle bit) > > + * RC6-6A-20 (no toggle bit) > > * RC6-6A-32 (MCE version with toggle bit in body) > > */ > > > > #define RC6_UNIT 444444 /* us */ > > #define RC6_HEADER_NBITS 4 /* not including toggle bit */ > > #define RC6_0_NBITS 16 > > -#define RC6_6A_SMALL_NBITS 24 > > +#define RC6_6A_SMALL_NBITS 20 > > #define RC6_6A_LARGE_NBITS 32 > > #define RC6_PREFIX_PULSE (6 * RC6_UNIT) > > #define RC6_PREFIX_SPACE (2 * RC6_UNIT) > > @@ -231,7 +231,7 @@ again: > > scancode = data->body & ~RC6_6A_MCE_TOGGLE_MASK; > > } else { > > toggle = 0; > > - scancode = data->body & 0xffffff; > > + scancode = data->body; > > } > > > > IR_dprintk(1, "RC6(6A) scancode 0x%08x (toggle: %u)\n", > > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
