diff --git a/include/asm-arm/hardware/clock.h b/include/asm-arm/hardware/clock.h index 19da861e523d8dbbfe327e4b07d166c61544a623..5c5689409a4b59ad3bb508fbcbdf35c83036da67 100644 --- a/include/asm-arm/hardware/clock.h +++ b/include/asm-arm/hardware/clock.h @@ -33,6 +33,8 @@ struct clk; * uses @dev and @id to determine the clock consumer, and thereby * the clock producer. (IOW, @id may be identical strings, but * clk_get may return different clock producers depending on @dev.) + * + * Drivers must assume that the clock source is not enabled. */ struct clk *clk_get(struct device *dev, const char *id); @@ -49,6 +51,14 @@ int clk_enable(struct clk *clk); /** * clk_disable - inform the system when the clock source is no longer required. * @clk: clock source + * + * Inform the system that a clock source is no longer required by + * a driver and may be shut down. + * + * Implementation detail: if the clock source is shared between + * multiple drivers, clk_enable() calls must be balanced by the + * same number of clk_disable() calls for the clock source to be + * disabled. */ void clk_disable(struct clk *clk); @@ -76,6 +86,10 @@ unsigned long clk_get_rate(struct clk *clk); /** * clk_put - "free" the clock source * @clk: clock source + * + * Note: drivers must ensure that all clk_enable calls made on this + * clock source are balanced by clk_disable calls prior to calling + * this function. */ void clk_put(struct clk *clk);