[U-Boot-Users] [PATCH] Move conditional compilation of MPC8XXX SPI driver to Makefile

[Ben Warren <biggerbadderben@gmail.com>]

Wolfgang Denk wrote:
> In message <483AD1FC.7040805@gmail.com> you wrote:
>   
>> If CONFIG_MPC8XXX_SPI is defined but CONFIG_HARD_SPI is not, compilation 
>> will fail, since CONFIG_HARD_SPI activates the common SPI code on 
>>     
>
> How would I configure a system to use CONFIG_SOFT_SPI on a MPC8XXX
> system?
>
>   
That's actually pretty easy:

1. #define CONFIG_SOFT_SPI in board config
2. define bit-bang parameters in board code
3. Call spi_init() from board code

The CONFIG_HARD_SPI define doesn't actually do anything 
hardware-related.  The only place it's used is in lib_ppc/board.c to 
initialize a SPI controller, but the code could equally-well start a 
soft SPI controller.  I would have used CONFIG_SPI, but that was already 
taken by SPI EEPROM stuff.  Maybe it's time to refactor a bit more...

>> PowerPC.  I guess I figured Kconfig would eventually manage the 
>> dependencies of these options, but I will put the #ifdef back in if you 
>> want.
>>     
>
> At the moment it seems logical to me to leave this test as it was.
>
> Best regards,
>
> Wolfgang Denk
>
>   
regards,
Ben