x86: mrccache: Allow use before driver model is active

The change to avoid searching the device tree does not work on boards
wich don't have driver model set up this early, for example minnowmax.
Put back the old code (converted to livetree) as a fallback for these
devices. Also update the documentation.

This is tested on minnowmax, link, samus and coral.

Fixes: 87f1084a630 (x86: Adjust mrccache_get_region() to use livetree)
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com> (on Intel minnowmax)

1 files changed, 25 insertions, 10 deletions

diff --git a/arch/x86/lib/mrccache.c b/arch/x86/lib/mrccache.c
index 21c71e036e..f181e8100c 100644
--- a/arch/x86/lib/mrccache.c
+++ b/arch/x86/lib/mrccache.c
@@ -233,6 +233,7 @@ int mrccache_get_region(enum mrc_type_t type, struct udevice **devp,
 	ulong map_base;
 	uint map_size;
 	uint offset;
+	ofnode node;
 	u32 reg[2];
 	int ret;
 
@@ -242,23 +243,36 @@ int mrccache_get_region(enum mrc_type_t type, struct udevice **devp,
 	 * memory map cannot be read.
 	 */
 	ret = uclass_find_first_device(UCLASS_SPI_FLASH, &dev);
-	if (!ret && !dev)
+	if (ret || !dev) {
+		/*
+		 * Fall back to searching the device tree since driver model
+		 * may not be ready yet (e.g. with FSPv1)
+		 */
+		node = ofnode_by_compatible(ofnode_null(), "jedec,spi-nor");
+		if (!ofnode_valid(node))
+			return log_msg_ret("Cannot find SPI flash\n", -ENOENT);
 		ret = -ENODEV;
-	if (ret)
-		return log_msg_ret("Cannot find SPI flash\n", ret);
-	ret = dm_spi_get_mmap(dev, &map_base, &map_size, &offset);
-	if (!ret) {
-		entry->base = map_base;
 	} else {
-		ret = dev_read_u32_array(dev, "memory-map", reg, 2);
+		ret = dm_spi_get_mmap(dev, &map_base, &map_size, &offset);
+		if (!ret)
+			entry->base = map_base;
+		node = dev_ofnode(dev);
+	}
+
+	/*
+	 * At this point we have entry->base if ret == 0. If not, then we have
+	 * the node and can look for memory-map
+	 */
+	if (ret) {
+		ret = ofnode_read_u32_array(node, "memory-map", reg, 2);
 		if (ret)
 			return log_msg_ret("Cannot find memory map\n", ret);
 		entry->base = reg[0];
 	}
 
 	/* Find the place where we put the MRC cache */
-	mrc_node = dev_read_subnode(dev, type == MRC_TYPE_NORMAL ?
-				    "rw-mrc-cache" : "rw-var-mrc-cache");
+	mrc_node = ofnode_find_subnode(node, type == MRC_TYPE_NORMAL ?
+				       "rw-mrc-cache" : "rw-var-mrc-cache");
 	if (!ofnode_valid(mrc_node))
 		return log_msg_ret("Cannot find node", -EPERM);
 
@@ -271,7 +285,8 @@ int mrccache_get_region(enum mrc_type_t type, struct udevice **devp,
 	if (devp)
 		*devp = dev;
 	debug("MRC cache type %d in '%s', offset %x, len %x, base %x\n",
-	      type, dev->name, entry->offset, entry->length, entry->base);
+	      type, dev ? dev->name : ofnode_get_name(node), entry->offset,
+	      entry->length, entry->base);
 
 	return 0;
 }