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authorSekhar Nori <nsekhar@ti.com>2009-08-31 15:48:04 +0530
committerKevin Hilman <khilman@deeprootsystems.com>2009-11-25 10:21:21 -0800
commitb82a51e8ce560fece675b8e3ca652eee26a47789 (patch)
tree876329e082954426fce0d63619816e573fd4a3ea /arch/arm/mach-davinci/clock.c
parentd6a61563f9e934ef20a1338780082f63802c8908 (diff)
downloadop-kernel-dev-b82a51e8ce560fece675b8e3ca652eee26a47789.zip
op-kernel-dev-b82a51e8ce560fece675b8e3ca652eee26a47789.tar.gz
davinci: support re-parenting a clock in the clock framework
The clk_set_parent() API is implemented to enable re-parenting clocks in the clock tree. This is useful in DVFS and helps by shifting clocks to an asynchronous domain where supported by hardware Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Diffstat (limited to 'arch/arm/mach-davinci/clock.c')
-rw-r--r--arch/arm/mach-davinci/clock.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index 09e0e1c..e7696fc 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -141,6 +141,33 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
}
EXPORT_SYMBOL(clk_set_rate);
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ unsigned long flags;
+
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ /* Cannot change parent on enabled clock */
+ if (WARN_ON(clk->usecount))
+ return -EINVAL;
+
+ mutex_lock(&clocks_mutex);
+ clk->parent = parent;
+ list_del_init(&clk->childnode);
+ list_add(&clk->childnode, &clk->parent->children);
+ mutex_unlock(&clocks_mutex);
+
+ spin_lock_irqsave(&clockfw_lock, flags);
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+ propagate_rate(clk);
+ spin_unlock_irqrestore(&clockfw_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
int clk_register(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
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