[PATCH] amba: consolidate PrimeCell magic

[Russell King - ARM Linux]

On Tue, Aug 16, 2011 at 01:57:08PM +0530, Jassi Brar wrote:
> On Mon, Aug 15, 2011 at 3:25 PM, Linus Walleij
> <linus.walleij at stericsson.com> wrote:
> > +static inline u32 amba_get_magic(void __iomem *base, u32 size, u8 offset)
> > +{
> > +       u32 magic;
> > +       int i;
> > +
> > +       for (magic = 0, i = 0; i < 4; i++)
> > +               magic |= (readl(base + size - offset + 4 * i) & 255)
> > +                       << (i * 8);
> 0xff looks much better than 255, esp when we play with bits.
> Also you might simply use readb and drop the sieve ?

You're making the assumption that using byte reads are permitted.  Given
that these are described as 32-bit registers, and some primecells require
reads of certain sizes, I believe the code to be the most correct solution.