Re: [PATCH v1 02/14] clk: Add of_init_clk_data() to parse commonclock bindings

From: Stephen Boyd
Date: Thu Jul 25 2013 - 12:37:09 EST


On 07/25, Tomasz Figa wrote:
> On Wednesday 24 of July 2013 17:43:30 Stephen Boyd wrote:
> > Consolidate DT parsing for the common bits of a clock binding in
> > one place to simplify clock drivers. This also has the added
> > benefit of standardizing how the clock names used by the common
> > clock framework are generated from the DT bindings. We always use
> > the first clock-output-names string if it exists, otherwise we
> > fall back to the node name.
> >
> > To be slightly more efficient and make the caller's life easier,
> > we introduce a shallow copy flag so that the clock core knows to
> > just copy the pointers to the strings and not the string
> > contents. Otherwise the callers of this function would have to
> > free the strings allocated here which could be cumbersome.
> >
> > Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
> > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> > ---
> > drivers/clk/clk.c | 59
> > +++++++++++++++++++++++++++++++++++++++++++-
> > include/linux/clk-provider.h | 7 ++++++
> > 2 files changed, 65 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> > index 1ed9bdd..ea8e951b 100644
> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -1809,6 +1809,10 @@ static int _clk_register(struct device *dev,
> > struct clk_hw *hw, struct clk *clk) {
> > int i, ret;
> >
> > + hw->clk = clk;
> > + if (hw->init->flags & CLK_SHALLOW_COPY)
> > + return PTR_RET(__clk_register(dev, hw));
> > +
> > clk->name = kstrdup(hw->init->name, GFP_KERNEL);
> > if (!clk->name) {
> > pr_err("%s: could not allocate clk->name\n", __func__);
> > @@ -1819,7 +1823,6 @@ static int _clk_register(struct device *dev,
> > struct clk_hw *hw, struct clk *clk) clk->hw = hw;
> > clk->flags = hw->init->flags;
> > clk->num_parents = hw->init->num_parents;
> > - hw->clk = clk;
> >
> > /* allocate local copy in case parent_names is __initdata */
> > clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents),
> > @@ -2232,4 +2235,58 @@ void __init of_clk_init(const struct of_device_id
> > *matches) clk_init_cb(np);
> > }
> > }
> > +
> > +/**
> > + * of_init_clk_data() - Initialize a clk_init_data struct from a DT
> > node + * @np: node to initialize struct from
> > + * @init: struct to initialize
> > + *
> > + * Populates the clk_init_data struct by parsing the device node for
> > + * properties matching the common clock binding. Returns 0 on success
> > + * and a negative error code on failure.
> > + */
> > +int of_init_clk_data(struct device_node *np, struct clk_init_data
> > *init) +{
> > + struct of_phandle_args s;
> > + const char **names = NULL, **p;
> > + const char *name;
> > + int i;
> > +
> > + if (of_property_read_string(np, "clock-output-names", &name) < 0)
> > + name = np->name;
> > + init->name = kstrdup(name, GFP_KERNEL);
> > + if (!init->name)
> > + return -ENOMEM;
> > +
> > + for (i = 0; of_parse_phandle_with_args(np, "clocks", "#clock-
> cells",
> > + i, &s) == 0; i++) {
> > + p = krealloc(names, sizeof(*names) * (i + 1), GFP_KERNEL);
> > + if (!p)
> > + goto err;
>
> What about using of_count_phandle_with_args() first to get the parent
> count?

Sure that simplifies things.

>
> > + names = p;
> > +
> > + if (of_property_read_string(s.np, "clock-output-names",
> > + &name) < 0)
> > + name = s.np->name;
>
> You should be able to use of_clk_get_parent_name() here, instead of
> parsing the properties directly.

This must be new too. Will do in v2.

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