From 4d7cb45ee823541632a3d50f57031ce9fd60e13f Mon Sep 17 00:00:00 2001 From: Rajendra Nayak Date: Sat, 22 Sep 2012 02:24:16 -0600 Subject: ARM: omap: clk: add clk_prepare and clk_unprepare As part of Common Clk Framework (CCF) the clk_enable() operation was split into a clk_prepare() which could sleep, and a clk_enable() which should never sleep. Similarly the clk_disable() was split into clk_disable() and clk_unprepare(). This was needed to handle complex cases where in a clk gate/ungate would require a slow and a fast part to be implemented. None of the clocks below seem to be in the 'complex' clocks category and are just simple clocks which are enabled/disabled through simple register writes. Most of the instances also seem to be called in non-atomic context which means its safe to move all of those from using a clk_enable() to clk_prepare_enable() and clk_disable() to clk_disable_unprepare(). For some others, mainly the ones handled through the hwmod framework there is a possibility that they get called in either an atomic or a non-atomic context. The way these get handled below work only as long as clk_prepare is implemented as a no-op (which is the case today) since this gets called very early at boot while most subsystems are unavailable. Hence these are marked with a *HACK* comment, which says we need to re-visit these once we start doing something meaningful with clk_prepare/clk_unprepare like doing voltage scaling or something that involves i2c. This is in preparation of OMAP moving to CCF. Based on initial changes from Mike Turquette. Signed-off-by: Rajendra Nayak Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/omap_hwmod.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'arch/arm/mach-omap2/omap_hwmod.c') diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 6504f0e8d96e..99fd3bb3c432 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -685,6 +685,15 @@ static int _init_main_clk(struct omap_hwmod *oh) oh->name, oh->main_clk); return -EINVAL; } + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(oh->_clk); if (!oh->_clk->clkdm) pr_warning("omap_hwmod: %s: missing clockdomain for %s.\n", @@ -722,6 +731,15 @@ static int _init_interface_clks(struct omap_hwmod *oh) ret = -EINVAL; } os->_clk = c; + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(os->_clk); } return ret; @@ -749,6 +767,15 @@ static int _init_opt_clks(struct omap_hwmod *oh) ret = -EINVAL; } oc->_clk = c; + /* + * HACK: This needs a re-visit once clk_prepare() is implemented + * to do something meaningful. Today its just a no-op. + * If clk_prepare() is used at some point to do things like + * voltage scaling etc, then this would have to be moved to + * some point where subsystems like i2c and pmic become + * available. + */ + clk_prepare(oc->_clk); } return ret; -- cgit v1.2.3