[PATCH 2/4] [RFC] ram: stm32mp1: Add support for multiple configs

[Marek Vasut]

Add support for multiple DRAM configuration subnodes, while retaining
the support for a single flat DRAM configuration node. This is useful
on systems which can be manufactured in multiple configurations and
where the DRAM configuration can be determined at runtime.

The code is augmented by a function which can be overridden on board
level, allowing a match on the configuration node name, very much like
the fitImage configuration node name matching works. The default match
is on the single top-level DRAM configuration, if matching on subnodes
is required, then this board_stm32mp1_ddr_config_name_match() must be
overridden.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
Cc: Patrick Delaunay <patrick.delaunay at st.com>
Cc: Patrice Chotard <patrice.chotard at st.com>
---
 drivers/ram/stm32mp1/stm32mp1_ram.c | 36 +++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/ram/stm32mp1/stm32mp1_ram.c b/drivers/ram/stm32mp1/stm32mp1_ram.c
index eb78f1198d..d6821eacd7 100644
--- a/drivers/ram/stm32mp1/stm32mp1_ram.c
+++ b/drivers/ram/stm32mp1/stm32mp1_ram.c
@@ -57,6 +57,33 @@ int stm32mp1_ddr_clk_enable(struct ddr_info *priv, uint32_t mem_speed)
 	return 0;
 }
 
+__weak int board_stm32mp1_ddr_config_name_match(struct udevice *dev,
+						const char *name)
+{
+	return 0;	/* Always match */
+}
+
+static ofnode stm32mp1_ddr_get_ofnode(struct udevice *dev)
+{
+	const char *name;
+	ofnode node;
+
+	node = dev_ofnode(dev);
+	name = ofnode_get_name(node);
+
+	if (!board_stm32mp1_ddr_config_name_match(dev, name))
+		return node;
+
+	dev_for_each_subnode(node, dev) {
+		name = ofnode_get_name(node);
+
+		if (!board_stm32mp1_ddr_config_name_match(dev, name))
+			return node;
+	}
+
+	return ofnode_null();
+}
+
 static __maybe_unused int stm32mp1_ddr_setup(struct udevice *dev)
 {
 	struct ddr_info *priv = dev_get_priv(dev);
@@ -64,6 +91,7 @@ static __maybe_unused int stm32mp1_ddr_setup(struct udevice *dev)
 	unsigned int idx;
 	struct clk axidcg;
 	struct stm32mp1_ddr_config config;
+	ofnode node = stm32mp1_ddr_get_ofnode(dev);
 
 #define PARAM(x, y) \
 	{ x,\
@@ -87,9 +115,9 @@ static __maybe_unused int stm32mp1_ddr_setup(struct udevice *dev)
 		PHY_PARAM(cal)
 	};
 
-	config.info.speed = dev_read_u32_default(dev, "st,mem-speed", 0);
-	config.info.size = dev_read_u32_default(dev, "st,mem-size", 0);
-	config.info.name = dev_read_string(dev, "st,mem-name");
+	config.info.speed = ofnode_read_u32_default(node, "st,mem-speed", 0);
+	config.info.size = ofnode_read_u32_default(node, "st,mem-size", 0);
+	config.info.name = ofnode_read_string(node, "st,mem-name");
 	if (!config.info.name) {
 		debug("%s: no st,mem-name\n", __func__);
 		return -EINVAL;
@@ -97,7 +125,7 @@ static __maybe_unused int stm32mp1_ddr_setup(struct udevice *dev)
 	printf("RAM: %s\n", config.info.name);
 
 	for (idx = 0; idx < ARRAY_SIZE(param); idx++) {
-		ret = dev_read_u32_array(dev, param[idx].name,
+		ret = ofnode_read_u32_array(node, param[idx].name,
 					 (void *)((u32)&config +
 						  param[idx].offset),
 					 param[idx].size);
-- 
2.25.1