From: Stephen Warren <swarren@wwwdotorg.org>
To: David Collins <collinsd@codeaurora.org>
Cc: devicetree-discuss@lists.ozlabs.org,
linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: How to represent negative values for device tree property
Date: Mon, 01 Apr 2013 16:00:47 -0600 [thread overview]
Message-ID: <515A038F.2090902@wwwdotorg.org> (raw)
In-Reply-To: <5159F760.1080605@codeaurora.org>
On 04/01/2013 03:08 PM, David Collins wrote:
> Hi,
>
> I am working on a thermal driver which needs to be able to read a
> temperature threshold from a device tree property. The hardware supports
> thresholds in the range -204.8 to +204.7 C in 0.1 C steps. I have found,
> as I am sure others have as well, that dtc treats a '-' before an integer
> in a dtsi file as a syntax error. Therefore, I need some artificial way
> to represent negative numbers in device tree. Here are the possibilities
> that I have thought of so far:
Doesn't the very latest dtc, which contains integer expression support,
allow unary -? I thought that code had been imported into the kernel
(goes and checks) yes it has. What's the error you're seeing;
over/underflow or syntax?
That said, DT cells are supposed to be u32 not s32, so perhaps this
isn't unexpected.
WARNING: multiple messages have this Message-ID (diff)
From: swarren@wwwdotorg.org (Stephen Warren)
To: linux-arm-kernel@lists.infradead.org
Subject: How to represent negative values for device tree property
Date: Mon, 01 Apr 2013 16:00:47 -0600 [thread overview]
Message-ID: <515A038F.2090902@wwwdotorg.org> (raw)
In-Reply-To: <5159F760.1080605@codeaurora.org>
On 04/01/2013 03:08 PM, David Collins wrote:
> Hi,
>
> I am working on a thermal driver which needs to be able to read a
> temperature threshold from a device tree property. The hardware supports
> thresholds in the range -204.8 to +204.7 C in 0.1 C steps. I have found,
> as I am sure others have as well, that dtc treats a '-' before an integer
> in a dtsi file as a syntax error. Therefore, I need some artificial way
> to represent negative numbers in device tree. Here are the possibilities
> that I have thought of so far:
Doesn't the very latest dtc, which contains integer expression support,
allow unary -? I thought that code had been imported into the kernel
(goes and checks) yes it has. What's the error you're seeing;
over/underflow or syntax?
That said, DT cells are supposed to be u32 not s32, so perhaps this
isn't unexpected.
next prev parent reply other threads:[~2013-04-01 22:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-01 21:08 How to represent negative values for device tree property David Collins
2013-04-01 21:08 ` David Collins
2013-04-01 22:00 ` Stephen Warren [this message]
2013-04-01 22:00 ` Stephen Warren
2013-04-02 0:24 ` David Collins
2013-04-02 0:24 ` David Collins
2013-04-02 6:29 ` David Gibson
2013-04-02 6:29 ` David Gibson
2013-04-02 15:36 ` Stephen Warren
2013-04-02 15:36 ` Stephen Warren
2013-04-02 6:17 ` David Gibson
2013-04-02 6:17 ` David Gibson
-- strict thread matches above, loose matches on Subject: below --
2013-03-29 20:13 David Collins
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