mediatek: support non standard trx magic values

Buffalo uses the TRX format with a different magic, add support for
this.

It is planned to send these patches upstream.

Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

1 files changed, 75 insertions, 0 deletions

diff --git a/target/linux/mediatek/patches-5.4/0350-mtd-parsers-trx-Allow-to-specify-trx-magic-in-DT.patch b/target/linux/mediatek/patches-5.4/0350-mtd-parsers-trx-Allow-to-specify-trx-magic-in-DT.patch
new file mode 100644
index 0000000000..4db51a88ad
--- /dev/null
+++ b/target/linux/mediatek/patches-5.4/0350-mtd-parsers-trx-Allow-to-specify-trx-magic-in-DT.patch
@@ -0,0 +1,75 @@
+From 0600e3d81628002a5cd80cf83ee454851b0063c0 Mon Sep 17 00:00:00 2001
+From: Hauke Mehrtens <hauke@hauke-m.de>
+Date: Sun, 7 Mar 2021 18:19:26 +0100
+Subject: mtd: parsers: trx: Allow to specify trx-magic in DT
+
+Buffalo uses a different TRX magic for every device, to be able to use
+this trx parser, make it possible to specify the TRX magic in device
+tree. If no TRX magic is specified in device tree, the standard value
+will be used. This value should only be specified if a vendor chooses to
+use a non standard TRX magic.
+
+Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
+---
+ .../bindings/mtd/partitions/brcm,trx.txt      |  5 +++++
+ drivers/mtd/parsers/parser_trx.c              | 21 ++++++++++++++++++-
+ 2 files changed, 25 insertions(+), 1 deletion(-)
+
+--- a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
++++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
+@@ -28,6 +28,11 @@ detected by a software parsing TRX heade
+ Required properties:
+ - compatible : (required) must be "brcm,trx"
+ 
++Optional properties:
++
++- trx-magic: TRX magic, if it is different from the default magic
++	     0x30524448 as a u32.
++
+ Example:
+ 
+ flash@0 {
+--- a/drivers/mtd/parsers/parser_trx.c
++++ b/drivers/mtd/parsers/parser_trx.c
+@@ -74,6 +74,24 @@ out_default:
+ 	return "rootfs";
+ }
+ 
++static uint32_t parser_trx_get_magic(struct mtd_info *mtd)
++{
++	uint32_t trx_magic = TRX_MAGIC;
++	struct device_node *np;
++	int err;
++
++	np = mtd_get_of_node(mtd);
++	if (!np)
++		return trx_magic;
++
++	/* Get different magic from device tree if specified */
++	err = of_property_read_u32(np, "trx-magic", &trx_magic);
++	if (err != 0 && err != -EINVAL)
++		pr_err("failed to parse \"trx-magic\" DT attribute, use default: %d\n", err);
++
++	return trx_magic;
++}
++
+ static int parser_trx_parse(struct mtd_info *mtd,
+ 			    const struct mtd_partition **pparts,
+ 			    struct mtd_part_parser_data *data)
+@@ -83,6 +101,7 @@ static int parser_trx_parse(struct mtd_i
+ 	struct trx_header trx;
+ 	size_t bytes_read;
+ 	uint8_t curr_part = 0, i = 0;
++	uint32_t trx_magic = parser_trx_get_magic(mtd);
+ 	int err;
+ 
+ 	parts = kcalloc(TRX_PARSER_MAX_PARTS, sizeof(struct mtd_partition),
+@@ -97,7 +116,7 @@ static int parser_trx_parse(struct mtd_i
+ 		return err;
+ 	}
+ 
+-	if (trx.magic != TRX_MAGIC) {
++	if (trx.magic != trx_magic) {
+ 		kfree(parts);
+ 		return -ENOENT;
+ 	}