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

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Dec 17 08:04:35 EST 2013


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.



More information about the linux-arm-kernel mailing list