diff options
author | Sekhar Nori <nsekhar@ti.com> | 2009-08-31 10:18:04 (GMT) |
---|---|---|
committer | Kevin Hilman <khilman@deeprootsystems.com> | 2009-11-25 18:21:21 (GMT) |
commit | b82a51e8ce560fece675b8e3ca652eee26a47789 (patch) | |
tree | 876329e082954426fce0d63619816e573fd4a3ea /arch | |
parent | d6a61563f9e934ef20a1338780082f63802c8908 (diff) | |
download | linux-fsl-qoriq-b82a51e8ce560fece675b8e3ca652eee26a47789.tar.xz |
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')
-rw-r--r-- | arch/arm/mach-davinci/clock.c | 27 |
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)) |