diff options
| author | Emilio López <emilio@elopez.com.ar> | 2014-05-02 17:57:15 +0200 |
|---|---|---|
| committer | Mike Turquette <mturquette@linaro.org> | 2014-05-05 15:55:56 -0700 |
| commit | 862b728387aef3a3776ad2a261e484aff36c5e67 (patch) | |
| tree | 2a6cf568537a30530a5ca554376759b2d565b22d /drivers/clk/sunxi | |
| parent | 2c07e3c7dd487fa40983aa20704b2755c9aac477 (diff) | |
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>
Diffstat (limited to 'drivers/clk/sunxi')
| -rw-r--r-- | drivers/clk/sunxi/clk-factors.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c index 9e232644f07e..3806d97e529b 100644 --- a/drivers/clk/sunxi/clk-factors.c +++ b/drivers/clk/sunxi/clk-factors.c @@ -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, |