[PATCH 2/8] clk: bcm2835: add missing PLL clock divider

Eric Anholt eric at anholt.net
Thu Mar 17 10:58:20 PDT 2016


Martin Sperl <kernel at martin.sperl.org> writes:

>> On 17.03.2016, at 17:57, Eric Anholt <eric at anholt.net> wrote:
>> 
>> 
>> These don't exist on the hardware as far as I've been able to find.  "I
>> found it in a header file somewhere" is not sufficient justification to
>> expose it.
>> 
>> I'm working on getting a series of all of these reviewed and ready, so
>> I'm just dropping these PLLB hunks.
>
> Fine with that - my test shows that these are not configured by the firmware.
>
> As for headers: my experience is that these are the better resource
> compared to all the public available documentation…
>
> If you remember the “frac” bit discussion where you said:
>
>   Once again, trusting the docs turns out to be a bad idea.  You're right,
>   the non-MASH clocks *do* have a bit 9 to enable fractional mode.  Sigh.
>
> Also my understanding is that those headers are still used by the firmware
> developers, so I guess that these are pretty stable and well maintained
> (even if the ones available are by now a bit dated).
>
> They even contain ifdefs for some earlier versions of the chip - 
> see the dma-channels and their interrupts…
> I.e: BCM2708A0 which does not have the DMA channels 9 to 15
>
> So I would not discount all those pieces of information as totally
> irrelevant.

I'm looking at the hardware source, and at the place where all the other
PLL dividers are, PLLB only has ARM.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-rpi-kernel/attachments/20160317/ba579f79/attachment.sig>


More information about the linux-rpi-kernel mailing list