[RFC/PATCHv1 0/2] clk: of: add helper function to fill parent clock array

[RFC/PATCHv1 0/2] clk: of: add helper function to fill parent clock array

[dinguyen]

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Hi,

As suggested by Stephen Boyd, this patch adds a helper function that will fill
the parent clock array.

Since this kind of code is sprinkled all over the platform clock drivers:

for (i = 0; i < num_parents; ++i)
	parent_names[i] = of_clk_get_parent_name(np, i);

The above code can be replace by of_clk_parent_fill(). And since the logic
of the of_clk_parent_fill is to walk the clock node to find the parent, it is
easy to just return the number of parents as well.

The second patch makes use of the new helper function in the SoCFPGA platform.
If this patch is accepted, I can go through and replace the other platforms
after that.

Thanks,

Dinh Nguyen (2):
  clk: of: helper for filling parent clock array and return num of
    parents
  clk: socfpga: make use of of_clk_parent_fill helper function

 drivers/clk/clk.c              | 20 ++++++++++++++++++++
 drivers/clk/socfpga/clk-gate.c |  6 +-----
 drivers/clk/socfpga/clk-pll.c  |  7 +------
 include/linux/clk-provider.h   |  1 +
 4 files changed, 23 insertions(+), 11 deletions(-)

-- 
2.2.1

[RFC/PATCHv1 1/2] clk: of: helper for filling parent clock array and return num of parents

[dinguyen]

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Sprinkled all through the platform clock drivers are code like this to
fill the clock parent array:

for (i = 0; i < num_parents; ++i)
	parent_names[i] = of_clk_get_parent_name(np, i);

The of_clk_parent_fill() will do the same as the code above, and while
at it, return the number of parents as well since the logic of the
function is to the walk the clock node to look for the parent.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
 drivers/clk/clk.c            | 20 ++++++++++++++++++++
 include/linux/clk-provider.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 459ce9d..b75616f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3060,6 +3060,26 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
 }
 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
 
+/*
+ * of_clk_parent_fill(): Helper clock function that will fill the parent
+ * clock's array and return the number of parents it found.
+ * @np: Device node pointer associated with clock provider
+ * @parents: pointer to char array that hold the parent's name
+ * @size: size of the parents array
+ *
+ * Returns number of parents for the clock node.
+ */
+int of_clk_parent_fill(struct device_node *np, const char **parents, int size)
+{
+	int i = 0;
+
+	while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
+		i++;
+
+	return i;
+}
+EXPORT_SYMBOL(of_clk_parent_fill);
+
 struct clock_provider {
 	of_clk_init_cb_t clk_init_cb;
 	struct device_node *np;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index df69531..36e56c4 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -624,6 +624,7 @@ struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
 				  void *data);
 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data);
 int of_clk_get_parent_count(struct device_node *np);
+int of_clk_parent_fill(struct device_node *np, const char **parents, int size);
 const char *of_clk_get_parent_name(struct device_node *np, int index);
 
 void of_clk_init(const struct of_device_id *matches);
-- 
2.2.1

Re: [RFC/PATCHv1 1/2] clk: of: helper for filling parent clock array and return num of parents

[Geert Uytterhoeven]

On Mon, Jun 1, 2015 at 11:46 PM,  <dinguyen@opensource.altera.com> wrote:
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3060,6 +3060,26 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
>  }
>  EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
>
> +/*
> + * of_clk_parent_fill(): Helper clock function that will fill the parent
> + * clock's array and return the number of parents it found.
> + * @np: Device node pointer associated with clock provider
> + * @parents: pointer to char array that hold the parent's name
> + * @size: size of the parents array
> + *
> + * Returns number of parents for the clock node.
> + */
> +int of_clk_parent_fill(struct device_node *np, const char **parents, int size)

I'd say "unsigned int size", but of_clk_get_parent_name(),
of_parse_phandle_with_args(), and of_property_read_string_index() also take
"int" :-(

> +{
> +       int i = 0;

If "size" becomes "unsigned int", "i" should be "unsigned int", too.

> +
> +       while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
> +               i++;
> +
> +       return i;

Return type "int" is OK, though...

> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[RFC/PATCHv1 2/2] clk: socfpga: make use of of_clk_parent_fill helper function

[dinguyen]

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Use of_clk_parent_fill to fill in the parent clock's array.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
 drivers/clk/socfpga/clk-gate.c | 6 +-----
 drivers/clk/socfpga/clk-pll.c  | 7 +------
 2 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/socfpga/clk-gate.c b/drivers/clk/socfpga/clk-gate.c
index dd3a78c..fb5a5d7 100644
--- a/drivers/clk/socfpga/clk-gate.c
+++ b/drivers/clk/socfpga/clk-gate.c
@@ -194,7 +194,6 @@ static void __init __socfpga_gate_init(struct device_node *node,
 	const char *parent_name[SOCFPGA_MAX_PARENTS];
 	struct clk_init_data init;
 	int rc;
-	int i = 0;
 
 	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 	if (WARN_ON(!socfpga_clk))
@@ -238,12 +237,9 @@ static void __init __socfpga_gate_init(struct device_node *node,
 	init.name = clk_name;
 	init.ops = ops;
 	init.flags = 0;
-	while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] =
-			of_clk_get_parent_name(node, i)) != NULL)
-		i++;
 
+	init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 	init.parent_names = parent_name;
-	init.num_parents = i;
 	socfpga_clk->hw.hw.init = &init;
 
 	clk = clk_register(NULL, &socfpga_clk->hw.hw);
diff --git a/drivers/clk/socfpga/clk-pll.c b/drivers/clk/socfpga/clk-pll.c
index de6da95..8f26b52 100644
--- a/drivers/clk/socfpga/clk-pll.c
+++ b/drivers/clk/socfpga/clk-pll.c
@@ -92,7 +92,6 @@ static __init struct clk *__socfpga_pll_init(struct device_node *node,
 	struct clk_init_data init;
 	struct device_node *clkmgr_np;
 	int rc;
-	int i = 0;
 
 	of_property_read_u32(node, "reg", &reg);
 
@@ -111,11 +110,7 @@ static __init struct clk *__socfpga_pll_init(struct device_node *node,
 	init.ops = ops;
 	init.flags = 0;
 
-	while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] =
-			of_clk_get_parent_name(node, i)) != NULL)
-		i++;
-
-	init.num_parents = i;
+	init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 	init.parent_names = parent_name;
 	pll_clk->hw.hw.init = &init;
 
-- 
2.2.1