[RFC] Using two baud rate generators with the cpm_uart driver

[Scott Wood]

Laurent Pinchart wrote:
>> The clean solution would be to have an abstracted clock API, similar to 
>> phylib, where the caller doesn't know details about BRGs and such. 
>> Maybe the linux/clk.h API would be suitable; I haven't looked at it in 
>> detail.
> 
> The clock API would have to be quite advanced to express things like "the SCC4 
> clock is a combination of BRG2 and BRG5" (and I don't even consider 
> adding "with BRG2 set to 16x the baud rate and BRG5 to the baud rate").

What I was picturing was platform code providing a clock object that the 
cpm_uart driver could be pointed at (possibly by modifying the device 
tree in platform init); the knowledge of the multiple BRG weirdness 
would be contained in platform code.

-Scott