Re: PSC clock divider
On Fri, Aug 7, 2009 at 10:34 AM, Jon Smirl wrote: > On Fri, Aug 7, 2009 at 12:15 PM, Grant Likely > wrote: >>> Should I modify mpc52xx_set_psc_clkdiv() to take in a frequency and >>> them move this code into mpc52xx_common.c? That allows the sysclk >>> parameter to be eliminated for SPI. >> >> Yes, please do. > > Can mpc5xxx_clocks.c be eliminated and this function: > > mpc5xxx_get_bus_frequency(struct device_node *node) > > be moved into mpc52cc_common.c? No. mpc5xxx_get_bus_frequency is not mpc5200 specific. It is used by mpc5121 also. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: PSC clock divider
On Fri, Aug 7, 2009 at 12:15 PM, Grant Likely wrote: >> Should I modify mpc52xx_set_psc_clkdiv() to take in a frequency and >> them move this code into mpc52xx_common.c? That allows the sysclk >> parameter to be eliminated for SPI. > > Yes, please do. Can mpc5xxx_clocks.c be eliminated and this function: mpc5xxx_get_bus_frequency(struct device_node *node) be moved into mpc52cc_common.c? -- Jon Smirl jonsm...@gmail.com ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: PSC clock divider
On Fri, Aug 7, 2009 at 10:03 AM, Jon Smirl wrote:
> mpc52xx_set_psc_clkdiv() has problems. It take the clk divider as a
> parameter. But this divisor is not always gettting calculated
> correctly. My code in i2s was doing it wrong.
>
> Take this snippet from the SPI driver, it just assumes a fsystem of
> 512Mhz. fsystem is 533Mhz on my boards.
>
> /* default sysclk is 512MHz */
> mclken_div = (mps->sysclk ? mps->sysclk : 51200) / MCLK;
> mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
>
> Is it also not accounting for the hardware adding one to the divisor.
>
> I've change i2s to this:
>
> if (!fsystem) {
> np = of_find_matching_node(NULL,
> mpc52xx_cdm_ids);
> mpc52xx_cdm = of_iomap(np, 0);
> fsystem = mpc5xxx_get_bus_frequency(np);
> of_node_put(np);
> val = in_be32(&mpc52xx_cdm->rstcfg);
> if (val & (1 << 5))
> fsystem *= 8;
> else
> fsystem *= 4;
> iounmap(mpc52xx_cdm);
> }
> clkdiv = fsystem / freq;
> err = fsystem % freq;
> if (err > freq / 2)
> clkdiv++;
>
> dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(clkdiv %d
> freq error=%dHz)\n",
> clkdiv, (fsystem / clkdiv - freq));
>
> /* PSC is 1-6 */
> /* Hardware adds 1 to divisor */
> return mpc52xx_set_psc_clkdiv(psc_dma->id + 1, clkdiv
> - 1);
>
>
> Should I modify mpc52xx_set_psc_clkdiv() to take in a frequency and
> them move this code into mpc52xx_common.c? That allows the sysclk
> parameter to be eliminated for SPI.
Yes, please do.
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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PSC clock divider
mpc52xx_set_psc_clkdiv() has problems. It take the clk divider as a
parameter. But this divisor is not always gettting calculated
correctly. My code in i2s was doing it wrong.
Take this snippet from the SPI driver, it just assumes a fsystem of
512Mhz. fsystem is 533Mhz on my boards.
/* default sysclk is 512MHz */
mclken_div = (mps->sysclk ? mps->sysclk : 51200) / MCLK;
mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
Is it also not accounting for the hardware adding one to the divisor.
I've change i2s to this:
if (!fsystem) {
np = of_find_matching_node(NULL,
mpc52xx_cdm_ids);
mpc52xx_cdm = of_iomap(np, 0);
fsystem = mpc5xxx_get_bus_frequency(np);
of_node_put(np);
val = in_be32(&mpc52xx_cdm->rstcfg);
if (val & (1 << 5))
fsystem *= 8;
else
fsystem *= 4;
iounmap(mpc52xx_cdm);
}
clkdiv = fsystem / freq;
err = fsystem % freq;
if (err > freq / 2)
clkdiv++;
dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(clkdiv %d
freq error=%dHz)\n",
clkdiv, (fsystem / clkdiv - freq));
/* PSC is 1-6 */
/* Hardware adds 1 to divisor */
return mpc52xx_set_psc_clkdiv(psc_dma->id + 1, clkdiv -
1);
Should I modify mpc52xx_set_psc_clkdiv() to take in a frequency and
them move this code into mpc52xx_common.c? That allows the sysclk
parameter to be eliminated for SPI.
--
Jon Smirl
jonsm...@gmail.com
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