linux-kernel - [RFC v2 1/1] clk: Add notifier support in clk_prepare/clk

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 14 Mar 2013 02:31:04 -0700
From:	Bill Huang <bilhuang@...dia.com>
To:	<mturquette@...aro.org>, <patches@...aro.org>,
	<linux-kernel@...r.kernel.org>, <linaro-dev@...ts.linaro.org>,
	<linux-arm-kernel@...ts.infradead.org>
CC:	Bill Huang <bilhuang@...dia.com>
Subject: [RFC v2 1/1] clk: Add notifier support in clk_prepare/clk_unprepare

Add the below two notifier events so drivers which are interested in
knowing the clock status can act accordingly. This is extremely useful
in some of the DVFS (Dynamic Voltage Frequency Scaling) design.

CLK_PREPARED
CLK_UNPREPARED

Signed-off-by: Bill Huang <bilhuang@...dia.com>
---
 drivers/clk/clk.c   |    3 +++
 include/linux/clk.h |    2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ed87b24..3292cec 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -550,6 +550,7 @@ void clk_unprepare(struct clk *clk)
 {
 	mutex_lock(&prepare_lock);
 	__clk_unprepare(clk);
+	__clk_notify(clk, CLK_UNPREPARED, clk->rate, clk->rate);
 	mutex_unlock(&prepare_lock);
 }
 EXPORT_SYMBOL_GPL(clk_unprepare);
@@ -598,6 +599,8 @@ int clk_prepare(struct clk *clk)
 
 	mutex_lock(&prepare_lock);
 	ret = __clk_prepare(clk);
+	if (!ret)
+		__clk_notify(clk, CLK_PREPARED, clk->rate, clk->rate);
 	mutex_unlock(&prepare_lock);
 
 	return ret;
diff --git a/include/linux/clk.h b/include/linux/clk.h
index b3ac22d..16c1d92 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -43,6 +43,8 @@ struct clk;
 #define PRE_RATE_CHANGE			BIT(0)
 #define POST_RATE_CHANGE		BIT(1)
 #define ABORT_RATE_CHANGE		BIT(2)
+#define CLK_PREPARED			BIT(3)
+#define CLK_UNPREPARED			BIT(4)
 
 /**
  * struct clk_notifier - associate a clk with a notifier
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/