[PATCH v3 01/21] clk: divider: Make divider_round_rate take the parent clock

[Maxime Ripard]

So far, divider_round_rate only considers the parent clock returned by
clk_hw_get_parent.

This works fine on clocks that have a single parents, this doesn't work on
muxes, since we will only consider the first parent, while other parents
may totally be able to provide a better combination.

Clocks in that case cannot use divider_round_rate, so would have to come up
with a very similar logic to work around it. Instead of having to do
something like this, and duplicate that logic everywhere, create a
divider_round_rate parent to allow caller to give an additional parameter
for the parent clock to consider.

Reviewed-by: Chen-Yu Tsai <w...@csie.org>
Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com>
---
 drivers/clk/clk-divider.c    | 19 ++++++++++---------
 include/linux/clk-provider.h | 16 +++++++++++++---
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 96386ffc8483..9bb472cccca6 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -275,7 +275,8 @@ static int _next_div(const struct clk_div_table *table, int 
div,
        return div;
 }
 
-static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
+static int clk_divider_bestdiv(struct clk_hw *hw, struct clk_hw *parent,
+                              unsigned long rate,
                               unsigned long *best_parent_rate,
                               const struct clk_div_table *table, u8 width,
                               unsigned long flags)
@@ -314,8 +315,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned 
long rate,
                        *best_parent_rate = parent_rate_saved;
                        return i;
                }
-               parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
-                                              rate * i);
+               parent_rate = clk_hw_round_rate(parent, rate * i);
                now = DIV_ROUND_UP_ULL((u64)parent_rate, i);
                if (_is_best_div(rate, now, best, flags)) {
                        bestdiv = i;
@@ -326,23 +326,24 @@ static int clk_divider_bestdiv(struct clk_hw *hw, 
unsigned long rate,
 
        if (!bestdiv) {
                bestdiv = _get_maxdiv(table, width, flags);
-               *best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), 1);
+               *best_parent_rate = clk_hw_round_rate(parent, 1);
        }
 
        return bestdiv;
 }
 
-long divider_round_rate(struct clk_hw *hw, unsigned long rate,
-                       unsigned long *prate, const struct clk_div_table *table,
-                       u8 width, unsigned long flags)
+long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
+                              unsigned long rate, unsigned long *prate,
+                              const struct clk_div_table *table,
+                              u8 width, unsigned long flags)
 {
        int div;
 
-       div = clk_divider_bestdiv(hw, rate, prate, table, width, flags);
+       div = clk_divider_bestdiv(hw, parent, rate, prate, table, width, flags);
 
        return DIV_ROUND_UP_ULL((u64)*prate, div);
 }
-EXPORT_SYMBOL_GPL(divider_round_rate);
+EXPORT_SYMBOL_GPL(divider_round_rate_parent);
 
 static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
                                unsigned long *prate)
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index a428aec36ace..c59c62571e4f 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -412,9 +412,10 @@ extern const struct clk_ops clk_divider_ro_ops;
 unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
                unsigned int val, const struct clk_div_table *table,
                unsigned long flags);
-long divider_round_rate(struct clk_hw *hw, unsigned long rate,
-               unsigned long *prate, const struct clk_div_table *table,
-               u8 width, unsigned long flags);
+long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
+                              unsigned long rate, unsigned long *prate,
+                              const struct clk_div_table *table,
+                              u8 width, unsigned long flags);
 int divider_get_val(unsigned long rate, unsigned long parent_rate,
                const struct clk_div_table *table, u8 width,
                unsigned long flags);
@@ -757,6 +758,15 @@ static inline void __clk_hw_set_clk(struct clk_hw *dst, 
struct clk_hw *src)
        dst->core = src->core;
 }
 
+static inline long divider_round_rate(struct clk_hw *hw, unsigned long rate,
+                                     unsigned long *prate,
+                                     const struct clk_div_table *table,
+                                     u8 width, unsigned long flags)
+{
+       return divider_round_rate_parent(hw, clk_hw_get_parent(hw),
+                                        rate, prate, table, width, flags);
+}
+
 /*
  * FIXME clock api without lock protection
  */
-- 
git-series 0.9.1
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