Subject: Re: [PATCH] qe: add function qe_clock_source

From: Timur Tabi <[email-masked]>
Date: Tue, 09 Oct 2007 11:43:20 -0500

Kumar Gala wrote:
> Ok, I went and looked at how rx-clock & tx-clock are spec'd in 
> booting-without-of.txt
> 
> Why dont we fix this so we have a property that says "BRG" or "CLK" and 
> another that has ID = [1.16] for BRG and [1..24] for CLK.

Because sometimes you can use both BRGs and CLKs.  Some operations can be done 
only on one or the other, and some can be done on both.  The enum itself is 
fine, I think.  I'd rather not split up the two, just report an error if you 
specify a clock source that's not support for that particular purpose.

UART, for instance, can use a CLK signal, but I wrote the driver to only 
support BRGs because there are plenty of them and it's a lot simpler.  But 
someone, for instance, could wire up his board to want to use external clocks 
for some UARTs, and so he'd need to modify the driver.

-- 
Timur Tabi
Linux Kernel Developer @ Freescale