svn commit: r237742 - in head/sys/arm: at91 conf

[Daan Vreeken]

Hi Warner,


On Friday 29 June 2012 06:18:52 Warner Losh wrote:
> Author: imp
> Date: Fri Jun 29 04:18:52 2012
> New Revision: 237742
> URL: http://svn.freebsd.org/changeset/base/237742
>
> Log:
>   Initital support for AT91SAM9X25 SoC and the SAM9X25-EK evaluation
>   board.  Much work remains.
...
> Added: head/sys/arm/at91/at91sam9x25.c
> ===========================================================================
>=== --- /dev/null	00:00:00 1970	(empty, because file is newly added)
> +++ head/sys/arm/at91/at91sam9x25.c	Fri Jun 29 04:18:52 2012	(r237742)
> @@ -0,0 +1,343 @@
...
> +static uint32_t
> +at91_pll_outa(int freq)
> +{
> +
> +	switch (freq / 10000000) {

You seem to be dividing freq into multiples of 10MHz instead of 1MHz here. I 
think dividing by 1e6 was the intention.

> +		case 747 ... 801: return ((1 << 29) | (0 << 14));
> +		case 697 ... 746: return ((1 << 29) | (1 << 14));
> +		case 647 ... 696: return ((1 << 29) | (2 << 14));
> +		case 597 ... 646: return ((1 << 29) | (3 << 14));
> +		case 547 ... 596: return ((1 << 29) | (1 << 14));
> +		case 497 ... 546: return ((1 << 29) | (2 << 14));
> +		case 447 ... 496: return ((1 << 29) | (3 << 14));

> +		case 397 ... 446: return ((1 << 29) | (4 << 14));

The (4 << 14) looks a bit strange here, as OUTA only occupies bit 14 and 15 of 
CKGR_PLLAR. (See Atmel doc11054, page 201 and 1103.)

Maybe this entire routine could be written as something like:
	uint8_t		outa;

	freq /= 1000000;
	// optional:
	//freq += 3;
	// see doc11054, page 1103
	outa = 3 - ((freq / 50) & 3);

	return ((1 << 29) | (outa << 14));

Just glancing at the code, setting ICPLLA in PMC_PLLICPR for frequencies <= 
600MHz seems to be missing at this moment (or I'm just not seeing it).
(see page 212 and 1103)


Regards,
-- 
Daan Vreeken
Vitsch Electronics
http://Vitsch.nl/
http://VitschVPN.nl/
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