From: Daniel Golle <daniel@makrotopia.org>
Subject: [PATCH] LEGACY block: partitions: populate fwnode

Assign matching firmware nodes to block partitions in order to allow
them to be referenced e.g. as NVMEM providers.

REMOVE THIS PATCH ONCE ALL TARGETS ARE USING LINUX 6.12 AND ALL BOARDS
HAVE MIGRATED TO UPSTREAM DT BINDINGS.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -11,6 +11,8 @@
 #include <linux/vmalloc.h>
 #include <linux/device.h>
 #include <linux/raid/detect.h>
+#include <linux/property.h>
+
 #include "check.h"
 
 static int (*const check_part[])(struct parsed_partitions *) = {
@@ -285,6 +287,74 @@ static ssize_t whole_disk_show(struct de
 }
 static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
 
+static bool part_meta_match(const char *attr, const char *member, size_t length)
+{
+	/* check if length of attr exceeds specified maximum length */
+	if (strnlen(attr, length) == length)
+		return false;
+
+	/* return true if strings match */
+	return !strncmp(attr, member, length);
+}
+
+static struct fwnode_handle *find_partition_fwnode(struct block_device *bdev)
+{
+	struct fwnode_handle *fw_parts, *fw_part;
+	struct device *ddev = disk_to_dev(bdev->bd_disk);
+	const char *partname, *uuid;
+	u32 partno;
+	bool got_uuid, got_partname, got_partno;
+
+	fw_parts = device_get_named_child_node(ddev, "partitions");
+	if (!fw_parts)
+		return NULL;
+
+	fwnode_for_each_child_node(fw_parts, fw_part) {
+		got_uuid = false;
+		got_partname = false;
+		got_partno = false;
+		/*
+		 * In case 'uuid' is defined in the partitions firmware node
+		 * require partition meta info being present and the specified
+		 * uuid to match.
+		 */
+		got_uuid = !fwnode_property_read_string(fw_part, "uuid", &uuid);
+		if (got_uuid && (!bdev->bd_meta_info ||
+				 !part_meta_match(uuid, bdev->bd_meta_info->uuid,
+						  PARTITION_META_INFO_UUIDLTH)))
+			continue;
+
+		/*
+		 * In case 'partname' is defined in the partitions firmware node
+		 * require partition meta info being present and the specified
+		 * volname to match.
+		 */
+		got_partname = !fwnode_property_read_string(fw_part, "partname",
+							    &partname);
+		if (got_partname && (!bdev->bd_meta_info ||
+				     !part_meta_match(partname,
+						      bdev->bd_meta_info->volname,
+						      PARTITION_META_INFO_VOLNAMELTH)))
+			continue;
+
+		/*
+		 * In case 'partno' is defined in the partitions firmware node
+		 * the specified partno needs to match.
+		 */
+		got_partno = !fwnode_property_read_u32(fw_part, "partno", &partno);
+		if (got_partno && bdev_partno(bdev) != partno)
+			continue;
+
+		/* Skip if no matching criteria is present in firmware node */
+		if (!got_uuid && !got_partname && !got_partno)
+			continue;
+
+		return fw_part;
+	}
+
+	return NULL;
+}
+
 /*
  * Must be called either with open_mutex held, before a disk can be opened or
  * after all disk users are gone.
@@ -361,6 +431,9 @@ static struct block_device *add_partitio
 			goto out_put;
 	}
 
+	if (!pdev->fwnode && !pdev->of_node)
+		device_set_node(pdev, find_partition_fwnode(bdev));
+
 	/* delay uevent until 'holders' subdir is created */
 	dev_set_uevent_suppress(pdev, 1);
 	err = device_add(pdev);
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -368,6 +368,8 @@ int mmc_add_card(struct mmc_card *card)
 
 	mmc_add_card_debugfs(card);
 	card->dev.of_node = mmc_of_find_child_device(card->host, 0);
+	if (card->dev.of_node && !card->dev.fwnode)
+		card->dev.fwnode = &card->dev.of_node->fwnode;
 
 	device_enable_async_suspend(&card->dev);
 
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2679,6 +2679,10 @@ static struct mmc_blk_data *mmc_blk_allo
 	if (area_type == MMC_BLK_DATA_AREA_MAIN)
 		dev_set_drvdata(&card->dev, md);
 	disk_fwnode = mmc_blk_get_partitions_node(parent, subname);
+	if (!disk_fwnode)
+		disk_fwnode = device_get_named_child_node(subname ? md->parent->parent :
+							  md->parent,
+							  subname ? subname : "block");
 	ret = add_disk_fwnode(md->parent, md->disk, mmc_disk_attr_groups,
 			      disk_fwnode);
 	if (ret)