Re: [PATCHv7 1/4] pwm: Add Freescale FTM PWM driver support

From: Russell King - ARM Linux
Date: Tue Dec 17 2013 - 08:05:56 EST


On Tue, Dec 17, 2013 at 01:54:35PM +0100, Tomasz Figa wrote:
> On Tuesday 17 of December 2013 13:45:06 Thierry Reding wrote:
> > I fail to see how that would eliminate the problem with the types. That
> > said I don't actually see sparse complaining about any type mismatches.
> > That's probably because the various macros implicitly cast to u32.
>
> Well, in BE variant you would read the register using __raw_readl() into
> a __be32 and then get an u32 from be32_to_cpu() and return it. Similarly
> for writes

__raw_readl() returns a u32, so you'll get a warning trying to assign a
u32 to a __be32.

We do have ioread32() and ioread32be() which do the appropriate conversion,
as well as the write versions too. They both include the barrier if you're
overly concerned about that.
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