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

[Warner Losh]

Thanks for the review.  I'm pretty sure that code is wrong.  I'll go over your comments with a printed datasheet.  They are likely correct.  This code suffers a bitt too much from being cut and pasted too many times.

Warner


On Jul 30, 2012, at 4:28 PM, Daan Vreeken wrote:

> 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/
> tel: +31-(0)40-7113051
> KvK nr: 17174380