[PATCH 2/7] ARM: bcm2835: Add a Raspberry Pi-specific clock driver.
eric at anholt.net
Fri May 29 12:09:41 PDT 2015
Stephen Warren <swarren at wwwdotorg.org> writes:
> On 05/18/2015 01:43 PM, Eric Anholt wrote:
>> + init.flags = CLK_IS_ROOT;
> Is it possible to add clock parent information to the driver, so the
> clocks are all hooked together into the correct tree, rather than all
> looking like root clocks?
> One of the many reasons I didn't do anything FW-wise for the kernel was
> the hope that such information would be forthcoming, and hence we could
> have complete kernel drivers.
As far as I can tell, none of these clocks are the parent of any other.
There's a layer of PLLs, then clockman almost always just dividing off
of those. In response to a clockman request (which is what this
property tag quickly maps to), only PLLH ever gets changed as a result
of RPI_CLOCK_PIXEL. PLLH feeds the HDMI and VEC (SDTV). We don't have
an SDTV clock for us to control through these interfaces, so there are
no conflicts that I can see. Only two clockman clocks I see divide off
of on other clockman clocks, and we don't have access to those.
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