lkml.org 
[lkml]   [2006]   [Sep]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: SDIO card support in Linux
Ian Stirling wrote:
>>
>> SD mandates a star topology (just a single card per bus), so we'll just
>> force a single card into the list. SD memory cards can actually work on
>> a shared bus, SDIO can not. It's not a big problem in practice though.
>
> Is this true in SD-1 bit mode, or SPI?

Yes, no. :)

> I see nothing on a quick read-through of the abbreviated SDIO spec
> precluding this.
> Of course, it'd mean wire-or'd interrupt lines.
>

The problem is that there is no "king-of-the-hill" mechanism in the SDIO
init sequence (like there is in SD mem). The protocol assumes that the
desired card always receives the command.

Rgds
Pierre

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-09-01 17:57    [W:0.068 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site