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. > + > 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. 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. > + 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