On Fri, 2019-03-15 at 10:16 -0700, Stephen Boyd wrote: > Quoting Jerome Brunet (2019-03-15 03:01:53) > > On Tue, 2019-02-26 at 14:34 -0800, Stephen Boyd wrote: > > > --- > > > drivers/clk/clk.c | 260 ++++++++++++++++++++++++++--------- > > > include/linux/clk-provider.h | 19 +++ > > > 2 files changed, 217 insertions(+), 62 deletions(-) > > > > Sorry for the delay. > > > > With the fix you sent to Jeffrey > > Tested by porting the aoclk controller of Amlogic g12a SoC. > > This allowed to test > > * hws only table > > * parent_data with a mix of hw pointers and fw_name (with different input > > controllers and also an input that is optional and never provided) > > > > Tested-by: Jerome Brunet <[email protected]> > > > > With the small comment below > > > > Reviewed-by Jerome Brunet <[email protected]> > > > > Awesome. Thanks! I need to Cc Rob H to hopefully get an ack on the > concept of relying on DT so I'll resend this series again next week. It > would also be nice if I can throw in a couple more patches to let > drivers specify a DT node when registering a clk if they don't have a > struct device on hand and let drivers lookup with clk_lookups somehow. > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > > index 937b8d092d17..3d01e8c56400 100644 > > > --- a/drivers/clk/clk.c > > > +++ b/drivers/clk/clk.c > > > @@ -39,6 +39,13 @@ static LIST_HEAD(clk_notifier_list); > > > > > > > [...] > > > > > > > > +static int clk_cpy_name(const char *dst, const char *src, bool > > > must_exist) > > > +{ > > > + if (!src) { > > > + if (must_exist) > > > + return -EINVAL; > > > + return 0; > > > + } > > > + > > > + dst = kstrdup_const(src, GFP_KERNEL); > > > + if (!dst) > > > + return -ENOMEM; > > > + > > > + return 0; > > > +} > > > + > > > +static int clk_core_populate_parent_map(struct clk_core *core) > > > +{ > > > + const struct clk_init_data *init = core->hw->init; > > > + u8 num_parents = init->num_parents; > > > + const char * const *parent_names = init->parent_names; > > > + const struct clk_hw **parent_hws = init->parent_hws; > > > + const struct clk_parent_data *parent_data = init->parent_data; > > > + int i, ret = 0; > > > + struct clk_parent_map *parents, *parent; > > > + > > > + if (!num_parents) > > > + return 0; > > > + > > > + /* > > > + * Avoid unnecessary string look-ups of clk_core's possible parents > > > by > > > + * having a cache of names/clk_hw pointers to clk_core pointers. > > > + */ > > > + parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL); > > > + core->parents = parents; > > > + if (!parents) > > > + return -ENOMEM; > > > + > > > + /* Copy everything over because it might be __initdata */ > > > + for (i = 0, parent = parents; i < num_parents; i++, parent++) { > > > + if (parent_names) { > > > + /* throw a WARN if any entries are NULL */ > > > + WARN(!parent_names[i], > > > + "%s: invalid NULL in %s's .parent_names\n", > > > + __func__, core->name); > > > + ret = clk_cpy_name(parent->name, parent_names[i], > > > + true); > > > + } else if (parent_data) { > > > > While testing, I mistakenly left both parent_names and parent_data. I was > > surprised that parent_data did not take precedence of parent_names. > > > > Maybe it should ? (... but I understand we are not supposed to provide both) > > I don't think we can. We have a problem where drivers don't initialize > the init structure properly, opting to just throw it on the stack and > leave junk in there that they overwrite. We'd have to go through all the > init structures and initialize them. I suppose we could make a macro for > that: > > DECLARE_CLK_INIT_DATA(init); > > or something like that that does this. We could bury a magic number in > there under some debug option too so that we can make sure drivers are > doing this properly. Otherwise we're left to doing these weird tricks > like I've done here. > > Regardless. I'll have to add a comment to this fact in the code. Thanks. > > > > + parent->hw = parent_data[i].hw; > > > + ret = clk_cpy_name(parent->fw_name, > > > + parent_data[i].fw_name, false); > > > + if (!ret) > > > + ret = clk_cpy_name(parent->name, > > > + parent_data[i].name, > > > + false); > > > + } else if (parent_hws) { > > > + parent->hw = parent_hws[i]; > > > + } else { > > > > Maybe there should also some kinda of check to verify if more than one > > option > > (among hws, parent_data and parent_names) was provided and throw a warn ? > > > > Could be useful with drivers move away from parent_names ? > > Same thing. It would be nice but we're sort of unable to do so unless we > do what I suggest above. Should we do it? >
I was not thinking about anything complicated: * Among the 3 pointers, just throw a warn if more than one is not NULL * In the if/elseif/else, I would have put parent_data before parent_names Nothing critical about that comment though
