Re: Timers on mpc8248 etc...

["Alan Bennett" <embedded@akb.net>]

My uboot is new-ish, but I don't have the fdt commands?  U-Boot 1.3.0
g992742a5-dirty

u-boot:clock configuration
===========================
MPC8248 Clock Configuration
 - Bus-to-Core Mult 3.5x, VCO Div 2, 60x Bus Freq  30-85 , Core Freq 100-300
 - dfbrg 1, corecnf 0x1e, busdf 3, cpmdf 1, plldf 0, pllmf 5, pcidf 5
 - vco_out  396000000, scc_clk   99000000, brg_clk   24750000
 - cpu_clk  231000000, cpm_clk  198000000, bus_clk   66000000

Boot Wrapper Reporting
===========================
Memory <- <0x0 0x8000000> (128MB)
CPU clock-frequency <- 0xdc4c7c0 (231MHz)
CPU timebase-frequency <- 0xfbc520 (17MHz)
CPU bus-frequency <- 0x3ef1480 (66MHz)

Kernel reporting
===========================
clocksource: timebase mult[f26c9b2] shift[22] registered

device tree in kernel (hex= `od -x`:
===========================
/proc/device-tree/cpus/PowerPC,8248@0/name
    PowerPC,8248
/proc/device-tree/cpus/PowerPC,8248@0/bus-frequency
    0000000 03ef 1480
/proc/device-tree/cpus/PowerPC,8248@0/clock-frequency
    0000000 0dc4 c7c0
/proc/device-tree/cpus/PowerPC,8248@0/timebase-frequency
    0000000 00fb c520
/proc/device-tree/cpus/PowerPC,8248@0/i-cache-size
    0000000 0000 4000



On 11/29/07, Vitaly Bordug <vitb@kernel.crashing.org> wrote:
> On Wed, 28 Nov 2007 21:06:36 -0700
> Alan Bennett wrote:
>
> > It comes from uboot.  Can you point me in the right direction to make
> > sure its right?
> >                PowerPC,8248@0 {
> >                        device_type = "cpu";
> >                        reg = <0>;
> >                        d-cache-line-size = <d#32>;
> >                        i-cache-line-size = <d#32>;
> >                        d-cache-size = <d#16384>;
> >                        i-cache-size = <d#16384>;
> >                        timebase-frequency = <0>;
> >                        clock-frequency = <0>;
> >                };
> >
> if your u-boot is up to  date, it will have fdt command, and by
> fdt boardsetup
> fdt print /
>
> inspect what u-boot did. Of course you should have dtb preloaded to memory and
> fdt addr <offset> should be said to let u-boot know where dtb resides.
>
>
> >
> > On 11/28/07, Scott Wood <scottwood@freescale.com> wrote:
> > > Alan Bennett wrote:
> > > > I've got a routine that needs to delay for X microseconds, this
> > > > is a must.  The command after schedule_timeout must has to wait
> > > > for the HW to complete a task that takes X microseconds.
> > > >
> > > > I would think that one way to do this is with a simple
> > > > schedule_timeout.  But in the example below, the time that passes
> > > > from run1() to dontrun() is far less than 3.2 msecs.  Infact,
> > > > sometimes its ~ 800 micros according the a analyzer looking at
> > > > points triggered in run1() and donrun().  Could this be a
> > > > configuration problem with the timer/interrupt that generates the
> > > > jiffies?
> > >
> > > Are you sure the timebase frequency is set correctly in the device
> > > tree?
> > >
> > > -Scott
> > >
> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev@ozlabs.org
> > https://ozlabs.org/mailman/listinfo/linuxppc-dev
>
>
> --
> Sincerely, Vitaly
>