Re: [PATCH 1/2] clk: rockchip: add 400MHz and 500MHz for rk3288 clock rate

From: Doug Anderson
Date: Tue Oct 07 2014 - 12:56:39 EST


Kever,

On Tue, Oct 7, 2014 at 2:33 AM, Kever Yang <kever.yang@xxxxxxxxxxxxxx> wrote:
> This patch add 400MHz and 500MHz to clock rate table for rk3288.
>
> Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>
> ---
>
> drivers/clk/rockchip/clk-rk3288.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
> index d053529..f6ea9c6 100644
> --- a/drivers/clk/rockchip/clk-rk3288.c
> +++ b/drivers/clk/rockchip/clk-rk3288.c
> @@ -86,8 +86,10 @@ struct rockchip_pll_rate_table rk3288_pll_rates[] = {
> RK3066_PLL_RATE( 594000000, 2, 198, 4),
> RK3066_PLL_RATE( 552000000, 1, 46, 2),
> RK3066_PLL_RATE( 504000000, 1, 84, 4),
> + RK3066_PLL_RATE( 500000000, 3, 125, 2),
> RK3066_PLL_RATE( 456000000, 1, 76, 4),
> RK3066_PLL_RATE( 408000000, 1, 68, 4),
> + RK3066_PLL_RATE( 400000000, 3, 50, 1),

This violates the constraints in the TRM. That says:

Fvco = (Fin/NR)*NF value range requirement: 440MHz â 2200MHz

I believe you end up with 400Mhz, not 440. Are you aware of this? Is
there some reason it's OK to violate the TRM in this case?

-Doug
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/