davinci: enable easy top down traversal of clock tree
Achieve easy top down traversal of clock tree by keeping
track of each clock's list of children.
This is useful in supporting DVFS where clock rates of
all children need to be updated in an efficient manner.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index 83d54d5..f8c4ef08 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -123,8 +123,12 @@
clk->name, clk->parent->name))
return -EINVAL;
+ INIT_LIST_HEAD(&clk->children);
+
mutex_lock(&clocks_mutex);
list_add_tail(&clk->node, &clocks);
+ if (clk->parent)
+ list_add_tail(&clk->childnode, &clk->parent->children);
mutex_unlock(&clocks_mutex);
/* If rate is already set, use it */
@@ -146,6 +150,7 @@
mutex_lock(&clocks_mutex);
list_del(&clk->node);
+ list_del(&clk->childnode);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unregister);
@@ -352,9 +357,8 @@
/* REVISIT show device associations too */
/* cost is now small, but not linear... */
- list_for_each_entry(clk, &clocks, node) {
- if (clk->parent == parent)
- dump_clock(s, nest + NEST_DELTA, clk);
+ list_for_each_entry(clk, &parent->children, childnode) {
+ dump_clock(s, nest + NEST_DELTA, clk);
}
}
diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h
index 27233cb..f88794d 100644
--- a/arch/arm/mach-davinci/clock.h
+++ b/arch/arm/mach-davinci/clock.h
@@ -69,6 +69,8 @@
u8 lpsc;
u8 psc_ctlr;
struct clk *parent;
+ struct list_head children; /* list of children */
+ struct list_head childnode; /* parent's child list node */
struct pll_data *pll_data;
u32 div_reg;
};