From: slash.tmp@free.fr (Mason)
To: linux-arm-kernel@lists.infradead.org
Subject: Preprocessor arithmetic in dtsi files (base + offset)
Date: Thu, 26 Nov 2015 15:44:28 +0100 [thread overview]
Message-ID: <56571ACC.9080306@free.fr> (raw)
In-Reply-To: <20151126135957.GC8644@n2100.arm.linux.org.uk>
On 26/11/2015 14:59, Russell King - ARM Linux wrote:
> On Thu, Nov 26, 2015 at 02:16:16PM +0100, Mason wrote:
>> #define SCU_BASE 0x20000000
>>
>> scu: scu at XXX {
>> compatible = "arm,cortex-a9-scu";
>> reg = <SCU_BASE 0x100>;
>>
>> gic: interrupt-controller at XXX {
>> compatible = "arm,cortex-a9-gic";
>> reg = <SCU_BASE+0x1000 0x1000>, <SCU_BASE+0x100 0x0100>;
>
> You don't get preprocessor arithmetic here. What you get is this passed
> to DTC:
>
> reg = <0x20000000+0x1000 0x1000>...
>
> The only time the preprocessor does arithmetic is when it needs to
> evaluate an expression, eg, in an #if statement.
Doh! Brain malfunction. No arithmetic indeed.
Working with the preprocessor would have to involve token-pasting.
#define SCU_BASE(OFFSET) 2000##OFFSET
#define SCU_BASEX(OFFSET) 0x2000##OFFSET
gic: interrupt-controller at SCU_BASE(1000) {
reg = <SCU_BASEX(1000) 0x1000>, <SCU_BASEX(0100) 0x0100>;
};
My very own abomination!
Regards.
WARNING: multiple messages have this Message-ID (diff)
From: Mason <slash.tmp-GANU6spQydw@public.gmane.org>
To: Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
Cc: Linux ARM
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
DT <devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>,
Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
Sebastian Frias
<sebastian_frias-y1yR0Z3OICC7zZZRDBGcUA@public.gmane.org>
Subject: Re: Preprocessor arithmetic in dtsi files (base + offset)
Date: Thu, 26 Nov 2015 15:44:28 +0100 [thread overview]
Message-ID: <56571ACC.9080306@free.fr> (raw)
In-Reply-To: <20151126135957.GC8644-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
On 26/11/2015 14:59, Russell King - ARM Linux wrote:
> On Thu, Nov 26, 2015 at 02:16:16PM +0100, Mason wrote:
>> #define SCU_BASE 0x20000000
>>
>> scu: scu@XXX {
>> compatible = "arm,cortex-a9-scu";
>> reg = <SCU_BASE 0x100>;
>>
>> gic: interrupt-controller@XXX {
>> compatible = "arm,cortex-a9-gic";
>> reg = <SCU_BASE+0x1000 0x1000>, <SCU_BASE+0x100 0x0100>;
>
> You don't get preprocessor arithmetic here. What you get is this passed
> to DTC:
>
> reg = <0x20000000+0x1000 0x1000>...
>
> The only time the preprocessor does arithmetic is when it needs to
> evaluate an expression, eg, in an #if statement.
Doh! Brain malfunction. No arithmetic indeed.
Working with the preprocessor would have to involve token-pasting.
#define SCU_BASE(OFFSET) 2000##OFFSET
#define SCU_BASEX(OFFSET) 0x2000##OFFSET
gic: interrupt-controller@SCU_BASE(1000) {
reg = <SCU_BASEX(1000) 0x1000>, <SCU_BASEX(0100) 0x0100>;
};
My very own abomination!
Regards.
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next prev parent reply other threads:[~2015-11-26 14:44 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-26 13:16 Preprocessor arithmetic in dtsi files (base + offset) Mason
2015-11-26 13:16 ` Mason
2015-11-26 13:52 ` Mark Rutland
2015-11-26 13:52 ` Mark Rutland
2015-11-26 13:59 ` Russell King - ARM Linux
2015-11-26 13:59 ` Russell King - ARM Linux
2015-11-26 14:44 ` Mason [this message]
2015-11-26 14:44 ` Mason
2015-11-26 16:23 ` Geert Uytterhoeven
2015-11-26 16:23 ` Geert Uytterhoeven
2015-11-26 17:51 ` Robin Murphy
2015-11-26 17:51 ` Robin Murphy
2015-12-02 22:14 ` Mason
2015-12-02 22:14 ` Mason
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