kernel: mtd: backport extended dynamic partitions support

This gets rid of "nvmem-cells" limitation. Dynamic partitions can be
defined for any (sub)partitions layout.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 65 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.15/406-v6.2-0001-mtd-core-simplify-a-bit-code-find-partition-matching.patch b/target/linux/generic/backport-5.15/406-v6.2-0001-mtd-core-simplify-a-bit-code-find-partition-matching.patch
new file mode 100644
index 0000000000..7e9645ea98
--- /dev/null
+++ b/target/linux/generic/backport-5.15/406-v6.2-0001-mtd-core-simplify-a-bit-code-find-partition-matching.patch
@@ -0,0 +1,65 @@
+From 63db0cb35e1cb3b3c134906d1062f65513fdda2d Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Tue, 4 Oct 2022 10:37:09 +0200
+Subject: [PATCH] mtd: core: simplify (a bit) code find partition-matching
+ dynamic OF node
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+1. Don't hardcode "partition-" string twice
+2. Use simpler logic & use ->name to avoid of_property_read_string()
+3. Use mtd_get_of_node() helper
+
+Cc: Christian Marangi <ansuelsmth@gmail.com>
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
+Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-1-zajec5@gmail.com
+---
+ drivers/mtd/mtdcore.c | 16 +++++++---------
+ 1 file changed, 7 insertions(+), 9 deletions(-)
+
+--- a/drivers/mtd/mtdcore.c
++++ b/drivers/mtd/mtdcore.c
+@@ -569,18 +569,16 @@ static void mtd_check_of_node(struct mtd
+ 	struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
+ 	const char *pname, *prefix = "partition-";
+ 	int plen, mtd_name_len, offset, prefix_len;
+-	struct mtd_info *parent;
+ 	bool found = false;
+ 
+ 	/* Check if MTD already has a device node */
+-	if (dev_of_node(&mtd->dev))
++	if (mtd_get_of_node(mtd))
+ 		return;
+ 
+ 	/* Check if a partitions node exist */
+ 	if (!mtd_is_partition(mtd))
+ 		return;
+-	parent = mtd->parent;
+-	parent_dn = of_node_get(dev_of_node(&parent->dev));
++	parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
+ 	if (!parent_dn)
+ 		return;
+ 
+@@ -593,15 +591,15 @@ static void mtd_check_of_node(struct mtd
+ 
+ 	/* Search if a partition is defined with the same name */
+ 	for_each_child_of_node(partitions, mtd_dn) {
+-		offset = 0;
+-
+ 		/* Skip partition with no/wrong prefix */
+-		if (!of_node_name_prefix(mtd_dn, "partition-"))
++		if (!of_node_name_prefix(mtd_dn, prefix))
+ 			continue;
+ 
+ 		/* Label have priority. Check that first */
+-		if (of_property_read_string(mtd_dn, "label", &pname)) {
+-			of_property_read_string(mtd_dn, "name", &pname);
++		if (!of_property_read_string(mtd_dn, "label", &pname)) {
++			offset = 0;
++		} else {
++			pname = mtd_dn->name;
+ 			offset = prefix_len;
+ 		}
+