From 7c045a55c97fb83a2e5e9c6c857162c4866cc602 Mon Sep 17 00:00:00 2001 From: Mike Turquette Date: Tue, 4 Dec 2012 11:00:35 -0800 Subject: clk: introduce optional disable_unused callback Some gate clocks have special needs which must be handled during the disable-unused clocks sequence. These needs might be driven by software due to the fact that we're disabling a clock outside of the normal clk_disable path and a clk's enable_count will not be accurate. On the other hand a specific hardware programming sequence might need to be followed for this corner case. This change is needed for the upcoming OMAP port to the common clock framework. Specifically, it is undesirable to treat the disable-unused path identically to the normal clk_disable path since other software layers are involved. In this case OMAP's clockdomain code throws WARNs and bails early due to the clock's enable_count being set to zero. A custom callback mitigates this problem nicely. Cc: Paul Walmsley Acked-by: Ulf Hansson Acked-by: Linus Walleij Signed-off-by: Mike Turquette --- drivers/clk/clk.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'drivers/clk') diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 9955ad7e786e..251e45d6024d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -219,8 +219,17 @@ static void clk_disable_unused_subtree(struct clk *clk) if (clk->flags & CLK_IGNORE_UNUSED) goto unlock_out; - if (__clk_is_enabled(clk) && clk->ops->disable) - clk->ops->disable(clk->hw); + /* + * some gate clocks have special needs during the disable-unused + * sequence. call .disable_unused if available, otherwise fall + * back to .disable + */ + if (__clk_is_enabled(clk)) { + if (clk->ops->disable_unused) + clk->ops->disable_unused(clk->hw); + else if (clk->ops->disable) + clk->ops->disable(clk->hw); + } unlock_out: spin_unlock_irqrestore(&enable_lock, flags); -- cgit v1.2.1