Quoting Phil Edworthy (2018-07-27 08:38:12) > On 25 July 2018 23:37, Stephen Boyd wrote: > > Short answer is they don't. I'd still prefer we have this API though. > > > > Can you rework this patch to be a little more invasive into the > > clk_get() path, perhaps by reworking __of_clk_get_by_name() a little to > > take an 'optional' argument, so that it only returns NULL when the clk is > > looked up from DT? The fallback path in clkdev where we have a DT based > > system looking up a clk through clkdev lookups doesn't seem to be a real > > scenario that we should worry about here. I think sometimes people use > > clkdev lookups when they're migrating to DT systems and things aren't wired > > up properly in DT, but that isn't the norm. > Do you mean something like this: > [...] > diff --git a/include/linux/clk.h b/include/linux/clk.h > index 907202b..830209a 100644 > --- a/include/linux/clk.h > +++ b/include/linux/clk.h > @@ -771,6 +771,7 @@ static inline void clk_bulk_disable_unprepare(int > num_clks, > #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) > struct clk *of_clk_get(struct device_node *np, int index); > struct clk *of_clk_get_by_name(struct device_node *np, const char *name); > +struct clk *of_clk_get_by_name_optional(struct device_node *np, const char > *name); > struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec); > #else > static inline struct clk *of_clk_get(struct device_node *np, int index) > > --- > A lot of drivers use devm_clk_get() so I think a devm_clk_get_optional() > version would be useful. That would probably need an additional > clk_get_optional() function. >
Yes, this would be the first patch, and then the second patch would add clk_get_optional() and devm_clk_get_optional(). We shouldn't encourage consumers to move from device based to DT node based clk_get() for the optional clk API.
