[PATCH] clk: Update comment for clk_round_rate()
viresh kumar
viresh.linux at gmail.com
Wed Apr 4 13:27:59 EDT 2012
From: Viresh Kumar <viresh.kumar at st.com>
clk_round_rate() must not provide rate greater than requested rate, as hardware
may not work at it. This wasn't clear from documentation of clk_round_rate().
This patch updates documentation for this.
Signed-off-by: Viresh Kumar <viresh.kumar at st.com>
---
Mike,
I don't know if this holds true for common clock framework or not?
But it looks more logical to me and this is how it was implemented for SPEAr.
drivers/clk/clk.c | 6 +++---
include/linux/clk.h | 3 ++-
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 9cf6f59..2f58455 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -603,9 +603,9 @@ unsigned long __clk_round_rate(struct clk *clk,
unsigned long rate)
* @clk: the clk for which we are rounding a rate
* @rate: the rate which is to be rounded
*
- * Takes in a rate as input and rounds it to a rate that the clk can actually
- * use which is then returned. If clk doesn't support round_rate operation
- * then the parent rate is returned.
+ * Takes in a rate as input and rounds it to a rate <= input rate that the clk
+ * can actually use which is then returned. If clk doesn't support round_rate
+ * operation then the parent rate is returned.
*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
diff --git a/include/linux/clk.h b/include/linux/clk.h
index b025272..19d31ef 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -213,7 +213,8 @@ void clk_put(struct clk *clk);
/**
- * clk_round_rate - adjust a rate to the exact rate a clock can provide
+ * clk_round_rate - adjust a rate to the exact rate a clock can provide. Output
+ * clock rate should be <= requested rate
* @clk: clock source
* @rate: desired clock rate in Hz
*
--
1.7.9
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