[PATCH 02/14] clk: sunxi: factors: Implement clock min and max frequencies

Emilio López emilio at elopez.com.ar
Thu Jul 17 09:09:35 PDT 2014


Hi Maxime,

El 17/07/14 06:08, Maxime Ripard escribió:
> In the A13, the out of reset frequency for the PLL6 is too high to be actually
> working.
>
> Hence, we need to be able to lower down its frequency whenever we need to use
> the clock to some acceptable frequency.
>
> This patch adds two new properties in the clock-nodes, clk-min-frequency and
> clk-max-frequency, to specify acceptable boundaries for proper clock
> operations.

This paragraph looks out of place

>
> It also adds supports in the sunxi factor clocks driver to use these
> boundaries, enforce them at prepare time to make sure that the drivers will
> have a decent frequency, even though it never called set_rate, but also make
> sure we never cross these boundaries.
>
> Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> ---
(...)
>
> @@ -123,6 +147,9 @@ static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
>
>   	factors->get_factors((u32 *)&rate, (u32)parent_rate, &n, &k, &m, &p);
>
> +	if ((rate > factors->max_rate) || (rate < factors->min_rate))
> +		return -EINVAL;

Printing an error message here may come in handy in the future, what do 
you think?

Thanks for working on this!

Emilio



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