[PATCH v7 1/8] clk: sunxi: factors: automatic reparenting support
From: David Lanzendörfer <hidden>
Date: 2014-02-17 10:06:57
Also in:
linux-arm-kernel, linux-mmc, lkml
Subsystem:
arm/allwinner soc clock support, common clk framework, the rest · Maintainers:
Emilio López, Michael Turquette, Stephen Boyd, Linus Torvalds
From: Emilio López <redacted> This commit implements .determine_rate, so that our factor clocks can be reparented when needed. Signed-off-by: Emilio López <redacted> --- drivers/clk/sunxi/clk-factors.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index 9e23264..3806d97 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,
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