Daniel Ng99 wrote:

MPC8247 Clock Configuration
 - Bus-to-Core Mult 5x, VCO Div 2, 60x Bus Freq  20-60 , Core Freq 100-300
 - dfbrg 1, corecnf 0x1b, busdf 7, cpmdf 1, plldf 0, pllmf 7, pcidf 7
 - vco_out  528000000, scc_clk  132000000, brg_clk   33000000
 - cpu_clk  330000000, cpm_clk  264000000, bus_clk   66000000

So maybe 35 x 2 = 70 is the correct value?

Anyway, I tried all these but still they made no difference:

clock-frequency = <35>
clock-frequency = <0x23>
clock-frequency = <115200>
clock-frequency = <1c200>
clock-frequency = <70>
clock-frequency = <17>
clock-frequency = <66>
clock-frequency = <33>

Can you suggest any other values? 

Don't set it to the BRG divider, set it to the BRG *input* clock, which 
appears to be 33000000.

What is the effect of just not calling set_brg()? I still get console
output, so am I setting myself up for some sort of problem in the future?

You will not be able to change the baud rate from Linux.

What is the effect of setting "fsl,cpm-brg = <0>" in the 'serial' device
tree node?

You'll have an invalid device tree, which will cause the kernel to write 
to a reserved register.

-Scott