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clk: sunxi: factors: automatic reparenting support 

This commit implements .determine_rate, so that our factor clocks can be
reparented when needed.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit is contained in:
Emilio López 2014-05-02 17:57:15 +02:00 committed by Mike Turquette
parent 2c07e3c7dd
commit 862b728387
1 changed files with 36 additions and 0 deletions
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36
drivers/clk/sunxi/clk-factors.c
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@ -77,6 +77,41 @@ static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
return rate;
}
static long clk_factors_determine_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate,
struct clk **best_parent_p)
{
struct clk *clk = hw->clk, *parent, *best_parent = NULL;
int i, num_parents;
unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0;
/* find the parent that can help provide the fastest rate <= rate */
num_parents = __clk_get_num_parents(clk);
for (i = 0; i < num_parents; i++) {
parent = clk_get_parent_by_index(clk, i);
if (!parent)
continue;
if (__clk_get_flags(clk) & CLK_SET_RATE_PARENT)
parent_rate = __clk_round_rate(parent, rate);
else
parent_rate = __clk_get_rate(parent);
child_rate = clk_factors_round_rate(hw, rate, &parent_rate);
if (child_rate <= rate && child_rate > best_child_rate) {
best_parent = parent;
best = parent_rate;
best_child_rate = child_rate;
}
}
if (best_parent)
*best_parent_p = best_parent;
*best_parent_rate = best;
return best_child_rate;
}
static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
@ -113,6 +148,7 @@ static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
}
const struct clk_ops clk_factors_ops = {
.determine_rate = clk_factors_determine_rate,
.recalc_rate = clk_factors_recalc_rate,
.round_rate = clk_factors_round_rate,
.set_rate = clk_factors_set_rate,