[PATCH 4/4] clk: scmi: Defer issue of SCMI_CLOCK_ATTRIBUTES

[Marek Vasut]

Instead of resolving clock control flags using SCMI_CLOCK_ATTRIBUTES
during probe for each and every clock, resolve the clock control
flags using SCMI_CLOCK_ATTRIBUTES when the clock control flags are
first used. Because most clock are never used by U-Boot, this allows
reducing the amount of SCMI_CLOCK_ATTRIBUTES considerably, and this
improve probe time of the scmi clock driver and U-Boot start up time.

On Renesas X5H, with 1700+ SCMI clock, the boot time improved by 1.7s .

Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
---
Cc: Alice Guo <alice.guo at nxp.com>
Cc: Patrice Chotard <patrice.chotard at foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Sean Anderson <seanga2 at gmail.com>
Cc: Tom Rini <trini at konsulko.com>
Cc: Valentin Caron <valentin.caron at foss.st.com>
Cc: Vinh Nguyen <vinh.nguyen.xz at renesas.com>
Cc: u-boot at lists.denx.de
---
 drivers/clk/clk_scmi.c | 50 ++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 19 deletions(-)

diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
index afaeb84e65d..005968e8b75 100644
--- a/drivers/clk/clk_scmi.c
+++ b/drivers/clk/clk_scmi.c
@@ -18,6 +18,7 @@ struct clk_scmi {
 	struct clk clk;
 	char name[SCMI_CLOCK_NAME_LENGTH_MAX];
 	u32 ctrl_flags;
+	bool attrs_resolved;
 };
 
 struct scmi_clock_priv {
@@ -85,7 +86,7 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
 	return 0;
 }
 
-static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name,
+static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char *name,
 				 u32 *attr)
 {
 	struct scmi_clock_priv *priv = dev_get_priv(dev);
@@ -109,7 +110,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name,
 		if (ret)
 			return ret;
 
-		*name = strdup(out.clock_name);
+		strncpy(name, out.clock_name, SCMI_CLOCK_NAME_LENGTH_MAX);
 		*attr = out.attributes;
 	} else {
 		struct scmi_clk_attribute_out out;
@@ -126,7 +127,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name,
 		if (ret)
 			return ret;
 
-		*name = strdup(out.clock_name);
+		strncpy(name, out.clock_name, SCMI_CLOCK_NAME_LENGTH_MAX);
 		*attr = out.attributes;
 	}
 
@@ -166,7 +167,9 @@ static int scmi_clk_gate(struct clk *clk, int enable)
 
 static int scmi_clk_get_ctrl_flags(struct clk *clk, u32 *ctrl_flags)
 {
+	struct udevice *dev = clk->dev->parent;
 	struct clk_scmi *clkscmi;
+	u32 attributes;
 	struct clk *c;
 	int ret;
 
@@ -176,6 +179,31 @@ static int scmi_clk_get_ctrl_flags(struct clk *clk, u32 *ctrl_flags)
 
 	clkscmi = container_of(c, struct clk_scmi, clk);
 
+	if (!clkscmi->attrs_resolved) {
+		char name[SCMI_CLOCK_NAME_LENGTH_MAX];
+		ret = scmi_clk_get_attibute(dev, clk->id & CLK_ID_MSK,
+					    name, &attributes);
+		if (ret)
+			return ret;
+
+		strncpy(clkscmi->name, name, SCMI_CLOCK_NAME_LENGTH_MAX);
+		if (CLK_HAS_RESTRICTIONS(attributes)) {
+			u32 perm;
+
+			ret = scmi_clk_get_permissions(dev, clk->id & CLK_ID_MSK, &perm);
+			if (ret < 0)
+				clkscmi->ctrl_flags = 0;
+			else
+				clkscmi->ctrl_flags = perm;
+		} else {
+			clkscmi->ctrl_flags = SUPPORT_CLK_STAT_CONTROL |
+					      SUPPORT_CLK_PARENT_CONTROL |
+					      SUPPORT_CLK_RATE_CONTROL;
+		}
+
+		clkscmi->attrs_resolved = true;
+	}
+
 	*ctrl_flags = clkscmi->ctrl_flags;
 
 	return 0;
@@ -328,7 +356,6 @@ static int scmi_clk_probe(struct udevice *dev)
 	for (i = 0; i < num_clocks; i++) {
 		clk_scmi = clk_scmi_bulk + i;
 		char *clock_name = clk_scmi->name;
-		u32 attributes;
 
 		snprintf(clock_name, SCMI_CLOCK_NAME_LENGTH_MAX, "scmi-%zu", i);
 
@@ -338,21 +365,6 @@ static int scmi_clk_probe(struct udevice *dev)
 			return ret;
 
 		dev_clk_dm(dev, i, &clk_scmi->clk);
-
-		if (!scmi_clk_get_attibute(dev, i, &clock_name, &attributes)) {
-			if (CLK_HAS_RESTRICTIONS(attributes)) {
-				u32 perm;
-
-				ret = scmi_clk_get_permissions(dev, i, &perm);
-				if (ret < 0)
-					clk_scmi->ctrl_flags = 0;
-				else
-					clk_scmi->ctrl_flags = perm;
-			} else {
-				clk_scmi->ctrl_flags = SUPPORT_CLK_STAT_CONTROL | SUPPORT_CLK_PARENT_CONTROL |
-						       SUPPORT_CLK_RATE_CONTROL;
-			}
-		}
 	}
 
 	return 0;
-- 
2.51.0