On 08/17/2013 02:09 PM, Tomasz Figa wrote:
On Friday 16 of August 2013 17:29:00 Stephen Warren wrote:
On 08/15/2013 10:27 AM, Ezequiel Garcia wrote:
...
Armada XP
---------
Two clock sources are available for timer and watchdog counters:
Just as explained for the Armada 370, the timer and watchdog counters
decrement rate is a configurable ratio of the L2/coherency fabric
clock. The current clocksource driver implementation chooses an
abritrary ratio.
In addition to this, both timer and watchdog counter rate can be
configured to use an (internal) 25 MHz fixed clock.
So there are clearly two clocks fed into the HW block here. The DT
should reflect that.
I fully agree. DT should list all the input clocks that are fed into the
IP block being described.
I don't object to the above, but strictly speaking the consequence
would be, that all nodes require a clocks property. For A370/XP timer
the fabric clock is configurable and needs to be passed among core
clocks and timer, the 25MHz clock is not and _could_ be seen as an extra
feature of the core.
But in the end, passing it by DT should be the way to go. I cannot look
into the XP datasheet, but I would guess that the exact feature of the
ip is not to use _the_ fixed 25MHz clock but XTAL as reference. Maybe
one of the free-electrons guys can look it up?
Sebastian
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