On 05/23/2014 07:53 PM, Mike Turquette wrote: > Quoting Alex Elder (2014-05-20 05:52:39) >> @@ -743,11 +746,16 @@ struct clk *kona_clk_setup(struct kona_clk *bcm_clk) >> clk = clk_register(NULL, &bcm_clk->hw); >> if (IS_ERR(clk)) { >> pr_err("%s: error registering clock %s (%ld)\n", __func__, >> - init_data->name, PTR_ERR(clk)); >> + name, PTR_ERR(clk)); >> goto out_teardown; >> } >> BUG_ON(!clk); >> >> + /* Make it so we can look the clock up using clk_find() */ > > s/clk_find/clk_get/ ? > >> + bcm_clk->cl.con_id = name; >> + bcm_clk->cl.clk = clk; >> + clkdev_add(&bcm_clk->cl); > > This is not so nice. I'll explain more below. OK, despite what I said before, I do need this, or something like it, so I can look up clocks by name. (Continued below.) > >> + >> return clk; >> out_teardown: >> bcm_clk_teardown(bcm_clk); >> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c >> index d8a7f38..fd070d6 100644 >> --- a/drivers/clk/bcm/clk-kona.c >> +++ b/drivers/clk/bcm/clk-kona.c >> @@ -1195,6 +1195,48 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) >> return true; >> } >> >> +static bool __kona_clk_init(struct kona_clk *bcm_clk); >> +static bool __kona_prereq_init(struct kona_clk *bcm_clk) >> +{ >> + struct clk *clk; >> + struct clk_hw *hw; >> + struct kona_clk *prereq; >> + >> + BUG_ON(clk_is_initialized(bcm_clk)); >> + >> + if (!bcm_clk->p.prereq) >> + return true; >> + >> + clk = clk_get(NULL, bcm_clk->p.prereq); > > The clkdev global namespace is getting polluted with all of these new > prereq clocks. If there was an associated struct device *dev with them > then it wouldn't be a problem, but you might get collisions with other > clock drivers that also use NULL for the device. Yes I recognize this. Ideally a CCU would have a device struct associated with it that I could use, because the name of a clock is unique within that context. But I have no such device available. (Please correct me if I'm wrong. I don't want to make one up, and I would like to use it if it exists.) > It would be a lot nicer for the clocks that require a prereq clock to > just use clk_get(dev, "well_known_name"); in the same way that drivers > use it, without considering it a special case. I can do something like that if I can get a meaningful device structure. Do you have any suggestions? Other than this issue, I've implemented all of the previous initialization routines using ->prepare() instead, and it works fine. I'm going to send an updated series out tomorrow. I want to look it over again after a good night's sleep... -Alex >> + if (IS_ERR(clk)) { >> + pr_err("%s: unable to get prereq clock %s for %s\n", >> + __func__, bcm_clk->p.prereq, bcm_clk->init_data.name); >> + return false; >> + } >> + hw = __clk_get_hw(clk); >> + if (!hw) { >> + pr_err("%s: null hw pointer for clock %s\n", __func__, >> + bcm_clk->init_data.name); >> + return false; >> + } >> + prereq = to_kona_clk(hw); >> + if (prereq->ccu != bcm_clk->ccu) { >> + pr_err("%s: prereq clock %s CCU different for clock %s\n", >> + __func__, bcm_clk->p.prereq, bcm_clk->init_data.name); >> + return false; >> + } >> + >> + /* Initialize the prerequisite clock first */ >> + if (!__kona_clk_init(prereq)) { >> + pr_err("%s: failed to init prereq %s for clock %s\n", >> + __func__, bcm_clk->p.prereq, bcm_clk->init_data.name); >> + return false; >> + } >> + bcm_clk->p.prereq_clk = clk; > > The above seems like a lot effort to go to. Why not skip all of this and > just implement the prerequisite logic in the .enable & .disable > callbacks? E.g. your kona clk .enable callback would look like: > > diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c > index d603c4e..51f35b4 100644 > --- a/drivers/clk/bcm/clk-kona.c > +++ b/drivers/clk/bcm/clk-kona.c > @@ -987,6 +987,12 @@ static int kona_peri_clk_enable(struct clk_hw *hw) > { > struct kona_clk *bcm_clk = to_kona_clk(hw); > struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate; > + int ret; > + > + hw->prereq_bus_clk = clk_get(hw->ccu, hw->prereq); > + ret = clk_enable(prereq_bus_clk); > + if (ret) > + return ret; > > return clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, true); > } > @@ -997,6 +1003,9 @@ static void kona_peri_clk_disable(struct clk_hw *hw) > struct bcm_clk_gate *gate = &bcm_clk->u.peri->gate; > > (void)clk_gate(bcm_clk->ccu, bcm_clk->init_data.name, gate, false); > + > + clk_disable(hw->prereq_bus_clk); > + clk_put(hw->prereq_bus_clk); > } > > static int kona_peri_clk_is_enabled(struct clk_hw *hw) > > > I guess it might take some trickery to get clk_get to work like that. > Let me know if I've completely lost the plot. > > Regards, > Mike > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html