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[ARM] omap: create a proper tree of clocks

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Traditionally, we've tracked the parent/child relationships between
clk structures by setting the child's parent member to point at the
upstream clock.  As a result, when decending the tree, we have had
to scan all clocks to find the children.

Avoid this wasteful scanning by keeping a list of the clock's children.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
2009-01-31 10:05:51 +00:00
committed by Russell King
parent b5088c0d90
commit 3f0a820c4c
9 changed files with 74 additions and 128 deletions
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51
arch/arm/plat-omap/clock.c
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@ -143,8 +143,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
if (ret == 0) {
if (clk->recalc)
clk->recalc(clk);
if (clk->flags & RATE_PROPAGATES)
propagate_rate(clk);
propagate_rate(clk);
}
spin_unlock_irqrestore(&clockfw_lock, flags);
@ -166,8 +165,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
if (ret == 0) {
if (clk->recalc)
clk->recalc(clk);
if (clk->flags & RATE_PROPAGATES)
propagate_rate(clk);
propagate_rate(clk);
}
spin_unlock_irqrestore(&clockfw_lock, flags);
@ -214,24 +212,31 @@ void followparent_recalc(struct clk *clk)
clk->rate = clk->parent->rate;
}
void clk_reparent(struct clk *child, struct clk *parent)
{
list_del_init(&child->sibling);
if (parent)
list_add(&child->sibling, &parent->children);
child->parent = parent;
/* now do the debugfs renaming to reattach the child
to the proper parent */
}
/* Propagate rate to children */
void propagate_rate(struct clk * tclk)
{
struct clk *clkp;
if (tclk == NULL || IS_ERR(tclk))
return;
list_for_each_entry(clkp, &clocks, node) {
if (likely(clkp->parent != tclk))
continue;
list_for_each_entry(clkp, &tclk->children, sibling) {
if (clkp->recalc)
clkp->recalc(clkp);
if (clkp->flags & RATE_PROPAGATES)
propagate_rate(clkp);
propagate_rate(clkp);
}
}
static LIST_HEAD(root_clks);
/**
* recalculate_root_clocks - recalculate and propagate all root clocks
*
@ -243,16 +248,18 @@ void recalculate_root_clocks(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &clocks, node) {
if (!clkp->parent) {
if (clkp->recalc)
clkp->recalc(clkp);
if (clkp->flags & RATE_PROPAGATES)
propagate_rate(clkp);
}
list_for_each_entry(clkp, &root_clks, sibling) {
if (clkp->recalc)
clkp->recalc(clkp);
propagate_rate(clkp);
}
}
void clk_init_one(struct clk *clk)
{
INIT_LIST_HEAD(&clk->children);
}
int clk_register(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
@ -265,6 +272,11 @@ int clk_register(struct clk *clk)
return 0;
mutex_lock(&clocks_mutex);
if (clk->parent)
list_add(&clk->sibling, &clk->parent->children);
else
list_add(&clk->sibling, &root_clks);
list_add(&clk->node, &clocks);
if (clk->init)
clk->init(clk);
@ -280,6 +292,7 @@ void clk_unregister(struct clk *clk)
return;
mutex_lock(&clocks_mutex);
list_del(&clk->sibling);
list_del(&clk->node);
mutex_unlock(&clocks_mutex);
}