Thread (41 messages) read the whole thread 41 messages, 6 authors, 2013-08-16

[PATCH v1 04/14] clk: Add set_rate_and_parent() op

From: James Hogan <hidden>
Date: 2013-08-09 09:12:09
Also in: linux-arm-msm, lkml

Hi Stephen,

On 25/07/13 01:43, Stephen Boyd wrote:
Some of Qualcomm's clocks can change their parent and rate at the
same time with a single register write. Add support for this
hardware to the common clock framework by adding a new
set_rate_and_parent() op. When the clock framework determines
that both the parent and the rate are going to change during
clk_set_rate() it will call the .set_rate_and_parent() op if
available and fall back to calling .set_parent() followed by
.set_rate() otherwise.

Cc: James Hogan <redacted>
Signed-off-by: Stephen Boyd <redacted>
Aside from the nit below, I can't see anything wrong with this patch.
Reviewed-by: James Hogan <redacted>
quoted hunk ↗ jump to hunk
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 484f8ad..1f7eabb 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -108,6 +108,18 @@ struct clk_hw;
  *		which is likely helpful for most .set_rate implementation.
  *		Returns 0 on success, -EERROR otherwise.
  *
+ * @set_rate_and_parent: Change the rate and the parent 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_and_parent implementation. The fourth
+ *		argument gives the parent index. It is optional (and
nit: s/It/This callback/ or add newline or something - I completely
misread it the first time, thinking you were referring to the parent
index argument :)
+ *		unnecessary) for clocks with 0 or 1 parents as well as
+ *		for clocks that can tolerate switching the rate and the parent
+ *		separately via calls to .set_parent and .set_rate.
+ *		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
  * (prepare) contexts.  If enabling a clock requires code that might sleep,
Thanks
James
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