diff options
| author | Stephen Boyd <sboyd@codeaurora.org> | 2015-01-19 18:05:28 -0800 |
|---|---|---|
| committer | Michael Turquette <mturquette@linaro.org> | 2015-01-27 11:48:39 -0800 |
| commit | 15a02c1f6dd7c2bb150c61d00ffb33f584ff2288 (patch) | |
| tree | 803aecc489bac86074b95d25cbdb2bbc426ffb38 /drivers/clk/clk.c | |
| parent | 52bba9809a954d72bc77773bd560b9724b495eb7 (diff) | |
clk: Add __clk_mux_determine_rate_closest
Some clock drivers want to find the closest rate on the input of
a mux instead of a rate that's less than or equal to the desired
rate. Add a generic mux function to support this.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 30fff56e1f15..9fc209abcb48 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -690,14 +690,20 @@ struct clk *__clk_lookup(const char *name) return NULL; } -/* - * Helper for finding best parent to provide a given frequency. This can be used - * directly as a determine_rate callback (e.g. for a mux), or from a more - * complex clock that may combine a mux with other operations. - */ -long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, - unsigned long *best_parent_rate, - struct clk_hw **best_parent_p) +static bool mux_is_better_rate(unsigned long rate, unsigned long now, + unsigned long best, unsigned long flags) +{ + if (flags & CLK_MUX_ROUND_CLOSEST) + return abs(now - rate) < abs(best - rate); + + return now <= rate && now > best; +} + +static long +clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk_hw **best_parent_p, + unsigned long flags) { struct clk *clk = hw->clk, *parent, *best_parent = NULL; int i, num_parents; @@ -725,7 +731,7 @@ long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, parent_rate = __clk_round_rate(parent, rate); else parent_rate = __clk_get_rate(parent); - if (parent_rate <= rate && parent_rate > best) { + if (mux_is_better_rate(rate, parent_rate, best, flags)) { best_parent = parent; best = parent_rate; } @@ -738,8 +744,31 @@ out: return best; } + +/* + * Helper for finding best parent to provide a given frequency. This can be used + * directly as a determine_rate callback (e.g. for a mux), or from a more + * complex clock that may combine a mux with other operations. + */ +long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk_hw **best_parent_p) +{ + return clk_mux_determine_rate_flags(hw, rate, best_parent_rate, + best_parent_p, 0); +} EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); +long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk_hw **best_parent_p) +{ + return clk_mux_determine_rate_flags(hw, rate, best_parent_rate, + best_parent_p, + CLK_MUX_ROUND_CLOSEST); +} +EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest); + /*** clk api ***/ void __clk_unprepare(struct clk *clk) |