[U-Boot-Users] dynamic setting of CONFIG_SYS_CLK_FREQ

Kumar Gala
2004-04-22T17:28:57Z

How bad would it be to do something like:

#define CONFIG_SYS_CLK_FREQ (gd->sys_clk)

or is this what you meant by 'provide a suitable init fuction'

- kumar

On Apr 22, 2004, at 12:14 PM, Wolfgang Denk wrote:

> In message <66FC73FC-9476-11D8-A48D-000393DBC2E8@motorola.com> you
> wrote:
>> I was wondering if there where an examples in the current u-boot
>> source
>> tree in which CONFIG_SYS_CLK_FREQ was determined dynamically. I have
>> a
>
> Not exactly for CONFIG_SYS_CLK_FREQ - but the TQM8xxL boards contain
> code to measure the input clock against the (known) 32kHz clock.
>
>> system in which I can read a config register on the board to let me
>> know if the CONFIG_SYS_CLK_FREQ is 66Mhz or 33Mhz. I was hoping to
>> have the 16550 uart (and anything else) that needed
>> CONFIG_SYS_CLK_FREQ
>> grab it from a variable instead.
>
> If you provide a suitable init fuction which sets the value in the
> global data section eraly enough, you can probably shortcut the use
> of CONFIG_SYS_CLK_FREQ.
>
>> This is on an MPC85xx platform system.
>
> ...or any other.
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> Software Engineering: Embedded and Realtime Systems, Embedded Linux
> Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
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