+++ /dev/null
-From 15a02c1f6dd7c2bb150c61d00ffb33f584ff2288 Mon Sep 17 00:00:00 2001
-From: Stephen Boyd <sboyd@codeaurora.org>
-Date: Mon, 19 Jan 2015 18:05:28 -0800
-Subject: [PATCH] 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>
----
- drivers/clk/clk.c | 47 +++++++++++++++++++++++++++++++++++---------
- include/linux/clk-provider.h | 8 +++++++-
- 2 files changed, 45 insertions(+), 10 deletions(-)
-
---- a/drivers/clk/clk.c
-+++ b/drivers/clk/clk.c
-@@ -695,14 +695,20 @@ struct clk *__clk_lookup(const char *nam
- 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 **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 **best_parent_p,
-+ unsigned long flags)
- {
- struct clk *clk = hw->clk, *parent, *best_parent = NULL;
- int i, num_parents;
-@@ -730,7 +736,7 @@ long __clk_mux_determine_rate(struct clk
- 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;
- }
-@@ -743,8 +749,31 @@ 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 **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 **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)
---- a/include/linux/clk-provider.h
-+++ b/include/linux/clk-provider.h
-@@ -382,6 +382,8 @@ struct clk *clk_register_divider_table(s
- * register, and mask of mux bits are in higher 16-bit of this register.
- * While setting the mux bits, higher 16-bit should also be updated to
- * indicate changing mux bits.
-+ * CLK_MUX_ROUND_CLOSEST - Use the parent rate that is closest to the desired
-+ * frequency.
- */
- struct clk_mux {
- struct clk_hw hw;
-@@ -396,7 +398,8 @@ struct clk_mux {
- #define CLK_MUX_INDEX_ONE BIT(0)
- #define CLK_MUX_INDEX_BIT BIT(1)
- #define CLK_MUX_HIWORD_MASK BIT(2)
--#define CLK_MUX_READ_ONLY BIT(3) /* mux setting cannot be changed */
-+#define CLK_MUX_READ_ONLY BIT(3) /* mux can't be changed */
-+#define CLK_MUX_ROUND_CLOSEST BIT(4)
-
- extern const struct clk_ops clk_mux_ops;
- extern const struct clk_ops clk_mux_ro_ops;
-@@ -554,6 +557,9 @@ struct clk *__clk_lookup(const char *nam
- long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *best_parent_rate,
- struct clk **best_parent_p);
-+long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
-+ unsigned long *best_parent_rate,
-+ struct clk **best_parent_p);
-
- /*
- * FIXME clock api without lock protection
projects / openwrt / staging / lynxis / omap.git / blobdiff