Re: [RFC 5/5] [powerpc] Implement a p1010rdb clock source.

On 08/08/2011 01:31 PM, Robin Holt wrote:

OK.  Dug a bit more.  The p1010 built-in clocksource seems to be the
periphereal clock frequency which is system bus frequency divided
by 2.  The clock source can not be changed, but the clock divider can

On arm the clock source is selected by bit 13 of CTRL:

This bit selects the clock source to the CAN protocol interface (CPI)
to be either the peripheral clock (driven by the PLL) or the crystal
oscillator clock. The selected clock is the one fed to the prescaler
to generate the SCLK (SCLK). In order to guarantee reliable
operation, this bit must only be changed while the module is in
disable mode. See Section 24.4.8.4, “Protocol Timing,” for more
information.

0 The CAN engine clock source is the oscillator clock (24.576 MHz)
1 The CAN engine clock source is the bus clock (66.5 MHz)

cheers, Marc

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