[U-Boot] [PATCH v2] powerpc/mpc85xx: Set SYSCLK to the required frequency

[Kumar Gala]

On Nov 3, 2011, at 2:18 AM, <Chang-Ming.Huang at freescale.com> <Chang-Ming.Huang at freescale.com> wrote:

> From: Jerry Huang <Chang-Ming.Huang at freescale.com>
> 
> For ICS307-02, there is one general expression to generate SYSCLK:
> CLK1Frequency = InputFrequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
> 
> If we want the required frequency for SYSCLK, we must find one solution
> to generate this frequency, this solution includes VDW, RDW and OD.
> For OD, there are only eight option value: 10, 2, 8, 4, 5, 7, 3, 6.
> For RDW, the range is 1 to 127.
> For VDW, the range is 4 to 511.
> 
> First, we use one OD, RDW and required SYSCLK to calculate the VDW,
> if VDW is in it's range, we will calculate the CLK1Frequency with
> the OD, RDW and VDW calculated, and we will check this percent
> (CLK1Frequency / required SYSCLK), and the precision is 1/1000.
> if the percent is less than 1/1000, we think the CLK1Frequency is we want.
> Otherwise, We will continue to calculate it with the next OD and RDW.
> 
> Signed-off-by: Jerry Huang <Chang-Ming.Huang at freescale.com>
> CC: Kumar Gala <kumar.gala at freescale.com>
> ---
> changes for v2:
> 	- move these macro to .c file
> 	- change the subject to powerpc/mpc85xx
> 	- add CC
> 
> board/freescale/common/ics307_clk.c |   69 +++++++++++++++++++++++++++++++++++
> board/freescale/common/ics307_clk.h |    4 ++-
> board/freescale/common/ngpixis.c    |   27 ++++++++++++++
> 3 files changed, 99 insertions(+), 1 deletions(-)

applied to 85xx

- k