mediatek: add patch allowing 1-byte wide access to efuse

Allow byte-wise access to mtk-efuse as some drivers require that.
Patch imported from mtk-openwrt-feeds (MTK SDK).

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/target/linux/mediatek/patches-5.15/815-nvmem-mtk-efuse-support-minimum-one-byte-access-stri.patch b/target/linux/mediatek/patches-5.15/815-nvmem-mtk-efuse-support-minimum-one-byte-access-stri.patch
new file mode 100644
index 0000000000..e57f742fc8
--- /dev/null
+++ b/target/linux/mediatek/patches-5.15/815-nvmem-mtk-efuse-support-minimum-one-byte-access-stri.patch
@@ -0,0 +1,46 @@
+From 44ae4ed142265a6d50a9d3e6f4c395f97b6849ab Mon Sep 17 00:00:00 2001
+From: Zhanyong Wang <zhanyong.wang@mediatek.com>
+Date: Sat, 6 Nov 2021 20:06:30 +0800
+Subject: [PATCH 2/5] nvmem: mtk-efuse: support minimum one byte access stride
+ and granularity
+
+In order to support nvmem bits property, should support minimum 1 byte
+read stride and minimum 1 byte read granularity at the same time.
+
+Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
+Signed-off-by: Zhanyong Wang <zhanyong.wang@mediatek.com>
+Change-Id: Iafe1ebf195d58a3e9e3518913f795d14a01dfd3b
+---
+ drivers/nvmem/mtk-efuse.c | 13 +++++++------
+ 1 file changed, 7 insertions(+), 6 deletions(-)
+
+--- a/drivers/nvmem/mtk-efuse.c
++++ b/drivers/nvmem/mtk-efuse.c
+@@ -19,11 +19,12 @@ static int mtk_reg_read(void *context,
+ 			unsigned int reg, void *_val, size_t bytes)
+ {
+ 	struct mtk_efuse_priv *priv = context;
+-	u32 *val = _val;
+-	int i = 0, words = bytes / 4;
++	void __iomem *addr = priv->base + reg;
++	u8 *val = _val;
++	int i;
+ 
+-	while (words--)
+-		*val++ = readl(priv->base + reg + (i++ * 4));
++	for (i = 0; i < bytes; i++, val++)
++		*val = readb(addr + i);
+ 
+ 	return 0;
+ }
+@@ -45,8 +46,8 @@ static int mtk_efuse_probe(struct platfo
+ 	if (IS_ERR(priv->base))
+ 		return PTR_ERR(priv->base);
+ 
+-	econfig.stride = 4;
+-	econfig.word_size = 4;
++	econfig.stride = 1;
++	econfig.word_size = 1;
+ 	econfig.reg_read = mtk_reg_read;
+ 	econfig.size = resource_size(res);
+ 	econfig.priv = priv;