[U-Boot] [RFC PATCH 3/6] clk: add function to get peripheral ID

[Masahiro Yamada <yamada.masahiro@socionext.com>]

Currently, this framework does not provide the systematic way
to get the peripheral ID (clock index).

I assume that the functions added by this commit are mainly used to
get the ID from "clocks" properties in device trees although they are
not limited to that use.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/clk/clk-uclass.c | 10 ++++++++++
 include/clk.h            | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 73dfd7d..8078b0f 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -52,6 +52,16 @@ ulong clk_set_periph_rate(struct udevice *dev, int periph, ulong rate)
 	return ops->set_periph_rate(dev, periph, rate);
 }
 
+int clk_get_id(struct udevice *dev, int args_count, uint32_t *args)
+{
+	struct clk_ops *ops = clk_get_ops(dev);
+
+	if (!ops->get_id)
+		return -ENOSYS;
+
+	return ops->get_id(dev, args_count, args);
+}
+
 UCLASS_DRIVER(clk) = {
 	.id		= UCLASS_CLK,
 	.name		= "clk",
diff --git a/include/clk.h b/include/clk.h
index 371784a..1efbaf2 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -49,6 +49,16 @@ struct clk_ops {
 	 * @return new clock rate in Hz, or -ve error code
 	 */
 	ulong (*set_periph_rate)(struct udevice *dev, int periph, ulong rate);
+
+	/**
+	 * get_id() - Get peripheral ID
+	 *
+	 * @dev:	clock provider
+	 * @args_count:	number of arguments
+	 * @args:	arguments.  The meaning is driver specific.
+	 * @return peripheral ID, or -ve error code
+	 */
+	int (*get_id)(struct udevice *dev, int args_count, uint32_t *args);
 };
 
 #define clk_get_ops(dev)	((struct clk_ops *)(dev)->driver->ops)
@@ -87,4 +97,28 @@ ulong clk_get_periph_rate(struct udevice *dev, int periph);
  */
 ulong clk_set_periph_rate(struct udevice *dev, int periph, ulong rate);
 
+/**
+ * clk_get_id() - Get peripheral ID
+ *
+ * @dev:	clock provider
+ * @args_count:	number of arguments
+ * @args:	arguments.  The meaning is driver specific.
+ * @return peripheral ID, or -ve error code
+ */
+int clk_get_id(struct udevice *dev, int args_count, uint32_t *args);
+
+/**
+ * clk_get_id_simple() - Simple implementation of get_id() callback
+ *
+ * @dev:	clock provider
+ * @args_count:	number of arguments
+ * @args:	arguments.
+ * @return peripheral ID, or -ve error code
+ */
+static inline int clk_get_id_simple(struct udevice *dev, int args_count,
+				    uint32_t *args)
+{
+	return args_count > 0 ? args[0] : 0;
+}
+
 #endif /* _CLK_H_ */
-- 
1.9.1