[U-Boot] [PATCH 1/1] sunxi: Fix pll1 clock calculation

[Stefan Mavrodiev]

Can someone review this patch?

Best regards,
Stefan

On 7/31/19 4:15 PM, Stefan Mavrodiev wrote:
> clock_sun6i.c is used for sun6i, sun8i and sun50i SoC families.
> PLL1 clock sets the default system clock, defined as:
>    sun6i: 1008000000
>    sun8i: 1008000000
>    sun50i: 816000000
>
> With the current calculation, m = 2 and k = 3. Solving for n,
> this results 28. Solving back:
>    (24MHz * 28 * 3) / 2 = 1008MHz
>
> However if the requested clock is 816, n is 22.66 rounded
> to 22, which results:
>    (24MHz * 28 * 3) / 2 = 792MHz
>
> Changing k to 4 satisfies both system clocks:
>    (24E6 * 21 * 4) / 2 = 1008MHz
>    (24E6 * 17 * 4) / 2 = 816MHz
>
> Signed-off-by: Stefan Mavrodiev <stefan at olimex.com>
> ---
>   arch/arm/mach-sunxi/clock_sun6i.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-sunxi/clock_sun6i.c b/arch/arm/mach-sunxi/clock_sun6i.c
> index 1628f3a7b6..6ca38f73d9 100644
> --- a/arch/arm/mach-sunxi/clock_sun6i.c
> +++ b/arch/arm/mach-sunxi/clock_sun6i.c
> @@ -118,7 +118,7 @@ void clock_set_pll1(unsigned int clk)
>   	if (clk > 1152000000) {
>   		k = 2;
>   	} else if (clk > 768000000) {
> -		k = 3;
> +		k = 4;
>   		m = 2;
>   	}
>