clk: add CONFIG_CLK_AUTO_ID

Add a new config CONFIG_CLK_AUTO_ID to support a unique clk id
for all the clock providers, managed by clk uclass, when the clock
reference arg[0] is the same.

When the CONFIG is activated, the clock id is limited to the lower
CLK_ID_SZ = 24 bits in default clock xlate function
and the sequence number + 1 of the clk provider device is
added for the 8 higher bits.

We use sequence number + 1 to avoid the "dummy" clock id = 0,
used for invalid clock when CCF is activated.

When this config is activated, the new function clk_get_id()
should be used to get back the internal reference to clock
for the each clock provider.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/clk.h b/include/clk.h
index a6ef4e02692..f94135ff778 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -13,6 +13,15 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 
+#ifdef CONFIG_CLK_AUTO_ID
+#define CLK_ID_SZ	24
+#define CLK_ID_MSK	GENMASK(23, 0)
+#define CLK_ID(dev, id)	(((dev_seq(dev) + 1) << CLK_ID_SZ) | ((id) & CLK_ID_MSK))
+#else
+#define CLK_ID_MSK	(~0UL)
+#define CLK_ID(dev, id)	id
+#endif
+
 /**
  * DOC: Overview
  *
@@ -570,6 +579,16 @@ int clk_get_by_id(ulong id, struct clk **clkp);
  */
 bool clk_dev_binded(struct clk *clk);
 
+/**
+ * clk_get_id - get clk id
+ *
+ * @clk:	A clock struct
+ *
+ * Return: the clock identifier as it is defined by the clock provider in
+ * device tree or in platdata
+ */
+ulong clk_get_id(const struct clk *clk);
+
 #else /* CONFIG_IS_ENABLED(CLK) */
 
 static inline int clk_request(struct udevice *dev, struct clk *clk)
@@ -641,6 +660,11 @@ static inline bool clk_dev_binded(struct clk *clk)
 {
 	return false;
 }
+
+static inline ulong clk_get_id(const struct clk *clk)
+{
+	return 0;
+}
 #endif /* CONFIG_IS_ENABLED(CLK) */
 
 /**