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

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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@xxxxxxxxxxxxxxxxxx>
---
(...)

@@ -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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