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Commit aa87aa34 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: clkfwk: Improve the generic clk_set_parent() implementation. 



This causes the generic clk_set_parent() implementation to be a bit more
intelligent. A clk_reparent() is added to move the clock over to the new
parent's sibling list, which then allows the generic rate propagation
code to succeed. This also becomes a nop if the new and old parents are
unchanged.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent ae891a42

arch/sh/include/asm/clock.h

+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ int clk_init(void); 
unsigned long followparent_recalc(struct clk *);

void recalculate_root_clocks(void);

void propagate_rate(struct clk *);

int clk_reparent(struct clk *child, struct clk *parent);

void clk_recalc_rate(struct clk *);

int clk_register(struct clk *);

void clk_unregister(struct clk *);

arch/sh/kernel/cpu/clock.c

+20 −0
Original line number Diff line number Diff line
@@ -81,6 +81,19 @@ unsigned long followparent_recalc(struct clk *clk) 
	return clk->parent->rate;

}



int 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 */



	return 0;

}



/* Propagate rate to children */

void propagate_rate(struct clk *tclk)

{
@@ -288,12 +301,19 @@ int clk_set_parent(struct clk *clk, struct clk *parent) 


	if (!parent || !clk)

		return ret;

	if (clk->parent == parent)

		return 0;



	spin_lock_irqsave(&clock_lock, flags);

	if (clk->usecount == 0) {

		if (clk->ops->set_parent)

			ret = clk->ops->set_parent(clk, parent);

		else

			ret = clk_reparent(clk, parent);



		if (ret == 0) {

			pr_debug("clock: set parent of %s to %s (new rate %ld)\n",

				 clk->name, clk->parent->name, clk->rate);

			if (clk->ops->recalc)

				clk->rate = clk->ops->recalc(clk);

			propagate_rate(clk);