[PATCH V2] clk: Add composite clock type

Hiroshi Doyu
2013-02-06T06:10:48Z

Prashant Gaikwad <pgaikwad@nvidia.com> wrote @ Wed, 6 Feb 2013 03:55:00 +0100:

> >> No, clk_ops depends on the clocks you are using. There could be a clock
> >> with mux and gate while another one with mux and div.
> > You are right. What about the following? We don't have to have similar
> > copy of clk_composite_ops for each instances.
>
> Clock framework takes decision depending on the ops availability and it
> does not know if the clock is mux or gate.
>
> For example,
>
> if (clk->ops->enable) {
> ret = clk->ops->enable(clk->hw);
> if (ret) {
> __clk_disable(clk->parent);
> return ret;
> }
> }
>
> in above case if clk_composite does not have gate clock then as per your
> suggestion if it returns error value then it will fail and it is wrong.

Ok, now I understand. Thank you for explanation.

We always need to allocate clk_composite_ops for each clk_composite,
right? If so what about having "struct clk_ops ops" in "struct
clk_composite"?

diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
index f30fb4b..5240e24 100644
--- a/drivers/clk/clk-composite.c
+++ b/drivers/clk/clk-composite.c
@@ -129,20 +129,13 @@ struct clk *clk_register_composite(struct device *dev, const char *name,
pr_err("%s: could not allocate composite clk\n", __func__);
return ERR_PTR(-ENOMEM);
}
+ clk_composite_ops = &composite->ops;

init.name = name;
init.flags = flags | CLK_IS_BASIC;
init.parent_names = parent_names;
init.num_parents = num_parents;

- /* allocate the clock ops */
- clk_composite_ops = kzalloc(sizeof(*clk_composite_ops), GFP_KERNEL);
- if (!clk_composite_ops) {
- pr_err("%s: could not allocate clk ops\n", __func__);
- kfree(composite);
- return ERR_PTR(-ENOMEM);
- }
-
if (mux_hw && mux_ops) {
if (!mux_ops->get_parent || !mux_ops->set_parent) {
clk = ERR_PTR(-EINVAL);
@@ -202,7 +195,6 @@ struct clk *clk_register_composite(struct device *dev, const char *name,
return clk;

err:
- kfree(clk_composite_ops);
kfree(composite);
return clk;
}
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index f0ac818..bb5d36a 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -346,6 +346,8 @@ struct clk_composite {
const struct clk_ops *mux_ops;
const struct clk_ops *div_ops;
const struct clk_ops *gate_ops;
+
+ const struct clk_ops ops;
};

struct clk *clk_register_composite(struct device *dev, const char *name,

> > diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
> > index f30fb4b..8f88805 100644
> > --- a/drivers/clk/clk-composite.c
> > +++ b/drivers/clk/clk-composite.c
> > @@ -27,6 +27,9 @@ static u8 clk_composite_get_parent(struct clk_hw *hw)
> > const struct clk_ops *mux_ops = composite->mux_ops;
> > struct clk_hw *mux_hw = composite->mux_hw;
> >
> > + if (!mux_hw->clk)
> > + return -EINVAL;
> > +
> > mux_hw->clk = hw->clk;
>
> It is wrong.

Will the above "mux_hw->clk = hw->clk" be removed from the original?