Am Donnerstag, den 21.08.2008, 10:46 +0200 schrieb Hendrik Sattler:
> Hi,
> 
> I contact you because you are mentioned in the MAINTAINERS file of  
> linux-2.6.26 for the mmc_spi drive and SPI subsystem.
> 
> I want to share the bus with other SPI devices. The drivers mentions  
> pending updates that would allow that.
> Are those available somewhere?
> 
> If not, the changes seem to fairly trivial: change SPI controller  
> drivers to allow adding a spi_transfer to an spi_message during the  
> complete() callback or add another callback that can do this.

Hi,

I have done this in a slightly different, rather simple way. I have
added a new "transfer_end" callback function pointer to the spi_transfer
structure. This function can have three return values: 

<0 ... stop spi message after the transfer
0  ... continue with next transfer 
1  ... repeat current transfer

If the transfer_end callback is not required, the function pointer must
be set to NULL.

I have modified the bitbang driver for this new functionality. In
addition, the mmc_spi driver has been changed to make use of the
callback function. It is necessary to pack all transfers that must be
done without being interrupted into a single message. I have done a lot
of testing with a SD card on a shared bus with a lot of other activity,
and I couldn't see any problems. 

Regards,
Erwin



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