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From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Joel Stanley <joel@jms•id.au>
Cc: dri-devel@lists•freedesktop.org, linuxppc-dev@ozlabs•org,
	airlied@redhat•com, "Y . C . Chen" <yc_chen@aspeedtech•com>,
	eich@suse•come
Subject: Re: [PATCH 02/12] drm/ast: Handle configuration without P2A bridge
Date: Fri, 24 Feb 2017 13:32:50 +1100	[thread overview]
Message-ID: <1487903570.23576.252.camel@kernel.crashing.org> (raw)
In-Reply-To: <CACPK8XfqnCm7ufoXQhvpx3tbhcoJtrtEzxJFrhmY-Q4Oif5Q_Q@mail.gmail.com>

On Fri, 2017-02-24 at 12:51 +1030, Joel Stanley wrote:
> 
> Are these properties supposed to repeat the prefix "ast,ast"?
> 
> We've chosen aspeed as the vendor prefix for Aspeed stuff.

Sent my reply too early ... so yes, I can change that, our FW hasn't
merge the FW side yet. I'll respin now.

> > +       if (mcr_scu_strap & 0x2000)
> 
> This bit confused me. Bit 13 of the strap (SCU70) is the SPI mode.

The register is actually "MCR170: AST2000 Backward Compatible SCU
Hardware Strapping Value"

> > +               ref_pll = 14318;
> > +       else
> > +               ref_pll = 12000;
> > +
> > +       denum = mcr_scu_mpll & 0x1f;
> > +       num = (mcr_scu_mpll & 0x3fe0) >> 5;
> > +       dsel = (mcr_scu_mpll & 0xc000) >> 14;
> 
> These calculations don't make sense for the ast2400 or ast2500.

They do if you look at this:

MCR120: AST2000 Backward Compatible SCU MPLL Parameter

It's not the SCU version of the register it's the MCU "copy" of it
that maintains some kind of legacy layout. Hence "mcr_scu" prefix
not "scu".

> > +       switch (dsel) {
> > +       case 3:
> > +               div = 0x4;
> > +               break;
> > +       case 2:
> > +       case 1:
> > +               div = 0x2;
> > +               break;
> > +       default:
> > +               div = 0x1;
> > +               break;
> >         }
> > +       ast->mclk = ref_pll * (num + 2) / (denum + 2) * (div *
> > 1000);
> >         return 0;
> >  }

  parent reply	other threads:[~2017-02-24  2:33 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-23 22:53 [PATCH 01/12] drm/ast: Fix AST2400 POST failure without BMC FW or VBIOS Benjamin Herrenschmidt
2017-02-23 22:53 ` [PATCH 02/12] drm/ast: Handle configuration without P2A bridge Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-24  2:26     ` Benjamin Herrenschmidt
2017-02-24  2:32     ` Benjamin Herrenschmidt [this message]
2017-02-24  2:41     ` [PATCH v5 2/12] " Benjamin Herrenschmidt
2017-02-24  2:43       ` Joel Stanley
2017-02-24  7:06   ` [PATCH 02/12] " YC Chen
2017-02-23 22:53 ` [PATCH 03/12] drm/ast: const'ify mode setting tables Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-23 22:53 ` [PATCH 04/12] drm/ast: Remove spurrious include Benjamin Herrenschmidt
2017-02-24  2:24   ` Joel Stanley
2017-02-23 22:53 ` [PATCH 05/12] drm/ast: Fix calculation of MCLK Benjamin Herrenschmidt
2017-02-24  2:24   ` Joel Stanley
2017-02-24  2:38     ` Benjamin Herrenschmidt
2017-02-24  3:12       ` Joel Stanley
2017-02-24  7:06   ` YC Chen
2017-02-23 22:53 ` [PATCH 06/12] drm/ast: Base support for AST2500 Benjamin Herrenschmidt
2017-02-24  2:22   ` Joel Stanley
2017-02-23 22:53 ` [PATCH 07/12] drm/ast: Fixed vram size incorrect issue on POWER Benjamin Herrenschmidt
2017-02-24  2:24   ` Joel Stanley
2017-02-24  7:07   ` YC Chen
2017-02-23 22:53 ` [PATCH 08/12] drm/ast: Factor mmc_test code in POST code Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-24  7:07   ` YC Chen
2017-02-23 22:53 ` [PATCH 09/12] drm/ast: Rename ast_init_dram_2300 to ast_post_chip_2300 Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-24  7:08   ` YC Chen
2017-02-23 22:53 ` [PATCH 10/12] drm/ast: POST code for the new AST2500 Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-23 22:53 ` [PATCH 11/12] drm/ast: Fix test for VGA enabled Benjamin Herrenschmidt
2017-02-23 23:24   ` Benjamin Herrenschmidt
2017-02-24  7:09   ` YC Chen
2017-02-23 22:53 ` [PATCH 12/12] drm/ast: Call open_key before enable_mmio in POST code Benjamin Herrenschmidt
2017-02-24  2:21   ` Joel Stanley
2017-02-24  7:09   ` YC Chen
2017-02-23 23:07 ` [PATCH 01/12] drm/ast: Fix AST2400 POST failure without BMC FW or VBIOS Benjamin Herrenschmidt
2017-02-24  2:23 ` Joel Stanley
2017-02-24  7:04 ` YC Chen

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