clk: pass parent_rate into .set_rate

For most of .set_rate implementation, parent_rate will be used, so just
like passing parent_rate into .recalc_rate, let's pass parent_rate into
.set_rate too.

It also updates the kernel doc for .set_rate ops.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

3 files changed, 11 insertions, 17 deletions

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 03b127c0313b..90627e4069af 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -111,14 +111,15 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
         return *prate / div;
 }
 
-static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate)
+static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+                                unsigned long parent_rate)
 {
         struct clk_divider *divider = to_clk_divider(hw);
         unsigned int div;
         unsigned long flags = 0;
         u32 val;
 
-        div = __clk_get_rate(__clk_get_parent(hw->clk)) / rate;
+        div = parent_rate / rate;
 
         if (!(divider->flags & CLK_DIVIDER_ONE_BASED))
                 div--;
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 1ab4f7e5c7ef..62ecac53b0a2 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -848,7 +848,7 @@ static void clk_change_rate(struct clk *clk)
         old_rate = clk->rate;
 
         if (clk->ops->set_rate)
-                clk->ops->set_rate(clk->hw, clk->new_rate);
+                clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);
 
         if (clk->ops->recalc_rate)
                 clk->rate = clk->ops->recalc_rate(clk->hw,
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 3323d24a7be4..cb82918d8fe0 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -88,19 +88,11 @@ struct clk_hw {
  *              array index into the value programmed into the hardware.
  *              Returns 0 on success, -EERROR otherwise.
  *
- * @set_rate:   Change the rate of this clock. If this callback returns
- *              CLK_SET_RATE_PARENT, the rate change will be propagated to the
- *              parent clock (which may propagate again if the parent clock
- *              also sets this flag). The requested rate of the parent is
- *              passed back from the callback in the second 'unsigned long *'
- *              argument.  Note that it is up to the hardware clock's set_rate
- *              implementation to insure that clocks do not run out of spec
- *              when propgating the call to set_rate up to the parent.  One way
- *              to do this is to gate the clock (via clk_disable and/or
- *              clk_unprepare) before calling clk_set_rate, then ungating it
- *              afterward.  If your clock also has the CLK_GATE_SET_RATE flag
- *              set then this will insure safety.  Returns 0 on success,
- *              -EERROR otherwise.
+ * @set_rate:   Change the rate of this clock. The requested rate is specified
+ *              by the second argument, which should typically be the return
+ *              of .round_rate call.  The third argument gives the parent rate
+ *              which is likely helpful for most .set_rate implementation.
+ *              Returns 0 on success, -EERROR otherwise.
  *
  * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow
  * implementations to split any work between atomic (enable) and sleepable
@@ -125,7 +117,8 @@ struct clk_ops {
                                         unsigned long *);
         int             (*set_parent)(struct clk_hw *hw, u8 index);
         u8              (*get_parent)(struct clk_hw *hw);
-        int             (*set_rate)(struct clk_hw *hw, unsigned long);
+        int             (*set_rate)(struct clk_hw *hw, unsigned long,
+                                    unsigned long);
         void            (*init)(struct clk_hw *hw);
 };