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>

drivers/clk/Kconfig

@@ -10,6 +10,16 @@ config CLK
 	  feed into other clocks in a tree structure, with multiplexers to
 	  choose the source for each clock.
 
+config CLK_AUTO_ID
+	bool "Enable support of an unique clock id with several provider"
+	depends on CLK
+	help
+	  Add the uclass sequence number of clock provider in the 8 higher bits
+	  of the clk id to guaranty an unique clock identifier in clk uclass
+	  when several clock providers are present on the device and when
+	  default xlate are used.
+	  This feature limit each identifier for each clock providers (24 bits).
+
 config SPL_CLK
 	bool "Enable clock support in SPL"
 	depends on CLK && SPL && SPL_DM

drivers/clk/clk-uclass.c

@@ -34,6 +34,11 @@ struct clk *dev_get_clk_ptr(struct udevice *dev)
 	return (struct clk *)dev_get_uclass_priv(dev);
 }
 
+ulong clk_get_id(const struct clk *clk)
+{
+	return (ulong)(clk->id & CLK_ID_MSK);
+}
+
 #if CONFIG_IS_ENABLED(OF_PLATDATA)
 int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
 		       struct clk *clk)
@@ -43,7 +48,7 @@ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
 	ret = device_get_by_ofplat_idx(cells->idx, &clk->dev);
 	if (ret)
 		return ret;
-	clk->id = cells->arg[0];
+	clk->id = CLK_ID(dev, cells->arg[0]);
 
 	return 0;
 }
@@ -61,7 +66,7 @@ static int clk_of_xlate_default(struct clk *clk,
 	}
 
 	if (args->args_count)
-		clk->id = args->args[0];
+		clk->id = CLK_ID(clk->dev, args->args[0]);
 	else
 		clk->id = 0;
 

drivers/clk/stm32/clk-stm32-core.c

@@ -46,7 +46,8 @@ int stm32_rcc_init(struct udevice *dev,
 
 		if (cfg->setup) {
 			clk = cfg->setup(dev, cfg);
-			clk->id = cfg->id;
+			/* set identifier of clock provider*/
+			dev_clk_dm(dev, cfg->id, clk);
 		} else {
 			dev_err(dev, "failed to register clock %s\n", cfg->name);
 			return -ENOENT;

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) */
 
 /**

include/linux/clk-provider.h

@@ -15,10 +15,17 @@
 
 struct udevice;
 
+/* update clock ID for the dev = clock provider, compatible with CLK_AUTO_ID */
+static inline void dev_clk_dm(const struct udevice *dev, ulong id, struct clk *clk)
+{
+	if (!IS_ERR(clk))
+		clk->id = CLK_ID(dev, id);
+}
+
 static inline void clk_dm(ulong id, struct clk *clk)
 {
 	if (!IS_ERR(clk))
-		clk->id = id;
+		clk->id = CLK_ID(clk->dev, id);
 }
 
 /*