AT91SAM9260: How to output PCK0 clock on a GPIO pin

[Pedro I. Sanchez]

On Tue, 1 Sep 2009 00:35:46 +0400, Sergey Matyukevich <geomatsi at gmail.com>
wrote:
>> So are the following statements correct?
>> 
>> 1. The pck0 clock I've been playing with has nothing to do with the
>> clock I want on PC6 (TIOB2).
> 
> Yes. PCK's (programmable clocks) are assigned to different pins:  
> PB30, PC1 for PCK0 and to  PB31, PC2 for PCK1. 
> For PCK see ch. 26 of at91sam9260 datasheet.
> 
>> 2. I have to use instead the "tc2_clk" as defined in
>> arch/arm/mach-at-91/at91sam9260.c.
> 
> Yes
> 
>> 3. I have to access the TC_CMR register directly to set things up. I
>> mean, there are no macros already defined to access these structures.
> 
> You have to 'ioremap' required registers and write to those
> registers directly using memory-writing macroses iowriteXX.
> 
> But at first decide what you need, TIOB or PCK. If you don't need all
> the power of Ryan Mallon's pwm driver (see below in the thread) and
> all you need is clocking output on GPIO pin, then you might be happy
> with PCK. Note that PMC_PCK registers allows several dividers, if
> original clock is too high.
> 
> Sergey

Well, the board I'm working on, as well several others already on my shelf
:-(, is already wired to use PC6 so I have to go the TC way. So this is the
way to go for me.

-- 
Pedro