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From: Alexander Stein <alexander.stein@systec-electronic.com>
To: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [RFC] irqchip: add support for LS1021A external interrupt lines
Date: Mon, 11 Dec 2017 15:38:13 +0100	[thread overview]
Message-ID: <2302267.dSSx8ic0iv@ws-stein> (raw)
In-Reply-To: <7badefae-a952-7839-0bfe-dcd09ea1204f@prevas.dk>

On Monday, December 11, 2017, 3:06:52 PM CET Rasmus Villemoes wrote:
> On 2017-12-11 14:45, Rasmus Villemoes wrote:
> > On 2017-12-11 11:02, Alexander Stein wrote:
> > 
> >> Oh, and what is the content of register SCFG_SCFGREVCR?
> > 
> > Good point. On my board it's 0xffffffff, set even before U-boot starts,
> > and lots board support code in U-boot expects this. I can't immediately
> > find examples in the linux source code that actually writes to the scfg,
> 
> Not a write, but we do already implicitly assume SCFG_SCFGREVCR is set
> to all-ones: In drivers/pci/dwc/pci-layerscape.c, bits which are
> numbered 6-11 in the reference manual are extracted with a regmap_read()
> followed by a left-shift by 20 and mask with 0x3f. That's consistent
> with me setting bit 0 (reference manual enumeration) using 1U<<31.

We set SCFG_SCFGREVCR to all-ones too, even before u-boot in rcw. Problem
is, this bit-reversal is only valid for SCFG. It's a shame, but at least add
a comment in the code you expect SCFG_SCFGREVCR as 0xffffffff.

Best regards,
Alexander

  reply	other threads:[~2017-12-11 14:38 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-04 15:11 polarity inversion on LS1021a Rasmus Villemoes
2017-12-04 15:23 ` Marc Zyngier
2017-12-08 14:33   ` [RFC] irqchip: add support for LS1021A external interrupt lines Rasmus Villemoes
2017-12-08 15:11     ` Alexander Stein
2017-12-08 16:09       ` Marc Zyngier
2017-12-11  9:08         ` Rasmus Villemoes
2017-12-11  9:45           ` Alexander Stein
2017-12-11 10:02             ` Alexander Stein
2017-12-11 13:45               ` Rasmus Villemoes
2017-12-11 14:06                 ` Rasmus Villemoes
2017-12-11 14:38                   ` Alexander Stein [this message]
2017-12-08 16:02     ` Marc Zyngier
2017-12-11  9:30       ` Rasmus Villemoes
2017-12-11 18:29         ` Marc Zyngier
2017-12-12 23:28     ` Rob Herring
2017-12-15 22:55       ` Rasmus Villemoes
2017-12-21 22:45         ` Rob Herring
2017-12-20  8:30     ` [PATCH v2 1/2] irqchip: add support for Layerscape " Rasmus Villemoes
2017-12-20  8:30       ` [PATCH v2 2/2] dt/bindings: Add bindings for Layerscape external irqs Rasmus Villemoes
2017-12-21 22:44         ` Rob Herring
2018-01-22  9:21       ` [PATCH v3 1/2] irqchip: add support for Layerscape external interrupt lines Rasmus Villemoes
2018-01-22  9:21         ` [PATCH v3 2/2] dt/bindings: Add bindings for Layerscape external irqs Rasmus Villemoes
2018-01-24 15:28           ` Marc Zyngier
2018-01-25 15:02         ` [PATCH v4 1/2] irqchip: add support for Layerscape external interrupt lines Rasmus Villemoes
2018-01-25 15:02           ` [PATCH v4 2/2] dt/bindings: Add bindings for Layerscape external irqs Rasmus Villemoes
2018-02-05  6:07             ` Rob Herring
2018-02-08 15:08               ` Rasmus Villemoes
2018-02-09  9:47                 ` Marc Zyngier
2018-02-23 21:08           ` [PATCH v5 0/2] irqchip: add support for Layerscape external interrupt lines Rasmus Villemoes
2018-02-23 21:08             ` [PATCH v5 1/2] " Rasmus Villemoes
2018-03-01 12:16               ` Thomas Gleixner
2018-05-04  7:44                 ` Rasmus Villemoes
2019-09-17  9:39                   ` Kurt Kanzenbach
2018-02-23 21:09             ` [PATCH v5 2/2] dt/bindings: Add bindings for Layerscape external irqs Rasmus Villemoes
2018-03-02 19:49               ` Rob Herring
2018-05-04  8:07                 ` Rasmus Villemoes
2017-12-04 15:31 ` polarity inversion on LS1021a Alexander Stein
2017-12-04 15:37   ` Marc Zyngier
2017-12-04 16:04     ` Alexander Stein

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