[U-Boot] [PATCH 01/14] powerpc, 8xx: Simplify brgclk calculation and remove get_brgclk()

[Wolfgang Denk]

Dear Christophe,

In message <59ac182501e89d3b9ee1dc7c31ce358ff33c0877.1499629706.git.christophe.leroy at c-s.fr> you wrote:
> divider is calculated based on SCCR_DFBRG, with:
> SCCR_DFBRG 00 => divider 1  = 1 << 0
> SCCR_DFBRG 01 => divider 4  = 1 << 2
> SCCR_DFBRG 10 => divider 16 = 1 << 4
> SCCR_DFBRG 11 => divider 64 = 1 << 6
> 
> This can be easily converted to a single shift operation:
> divider = 1 << (SCCR_DFBRG * 2)

Agreed, but...

> -	switch ((sccr & SCCR_DFBRG11) >> 11) {
...
> +	uint divider = 1 << ((sccr & SCCR_DFBRG11) >> 10);

The code would be easier to read / understand if you made the
calculation obvious, i. e.

	uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2);

The compiler generates the same code, so there is no size effect.

Reviewed-by: Wolfgang Denk <wd at denx.de>


Best regards,

Wolfgang Denk

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