1 files changed, 123 insertions, 0 deletions
diff --git a/target/linux/ramips/patches-4.4/0054-mtd-add-chunked-read-io-to-m25p80.patch b/target/linux/ramips/patches-4.4/0054-mtd-add-chunked-read-io-to-m25p80.patch
new file mode 100644
index 0000000000..227cc96099
--- /dev/null
+++ b/target/linux/ramips/patches-4.4/0054-mtd-add-chunked-read-io-to-m25p80.patch
@@ -0,0 +1,123 @@
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -1011,6 +1011,66 @@ write_err:
+ 	return ret;
+ }
+ 
++static int spi_nor_chunked_write(struct mtd_info *mtd, loff_t _to, size_t _len,
++				 size_t *_retlen, const u_char *_buf)
++{
++	struct spi_nor *nor = mtd_to_spi_nor(mtd);
++	int chunk_size;
++	int retlen = 0;
++	int ret;
++
++	chunk_size = nor->chunk_size;
++	if (!chunk_size)
++		chunk_size = _len;
++
++	if (nor->addr_width > 3)
++		chunk_size -= nor->addr_width - 3;
++
++	while (retlen < _len) {
++		size_t len = min_t(int, chunk_size, _len - retlen);
++		const u_char *buf = _buf + retlen;
++		loff_t to = _to + retlen;
++
++		if (nor->flags & SNOR_F_SST)
++			ret = sst_write(mtd, to, len, &retlen, buf);
++		else
++			ret = spi_nor_write(mtd, to, len, &retlen, buf);
++		if (ret)
++			return ret;
++	}
++
++	*_retlen += retlen;
++	return 0;
++}
++
++static int spi_nor_chunked_read(struct mtd_info *mtd, loff_t _from, size_t _len,
++				size_t *_retlen, u_char *_buf)
++{
++	struct spi_nor *nor = mtd_to_spi_nor(mtd);
++	int chunk_size;
++	int ret;
++
++	chunk_size = nor->chunk_size;
++	if (!chunk_size)
++		chunk_size = _len;
++
++	*_retlen = 0;
++	while (*_retlen < _len) {
++		size_t len = min_t(int, chunk_size, _len - *_retlen);
++		u_char *buf = _buf + *_retlen;
++		loff_t from = _from + *_retlen;
++		int retlen = 0;
++
++		ret = spi_nor_read(mtd, from, len, &retlen, buf);
++		if (ret)
++			return ret;
++
++		*_retlen += retlen;
++	}
++
++	return 0;
++}
++
+ static int macronix_quad_enable(struct spi_nor *nor)
+ {
+ 	int ret, val;
+@@ -1232,10 +1292,12 @@ int spi_nor_scan(struct spi_nor *nor, co
+ 	}
+ 
+ 	/* sst nor chips use AAI word program */
+-	if (info->flags & SST_WRITE)
++	if (info->flags & SST_WRITE) {
+ 		mtd->_write = sst_write;
+-	else
++		nor->flags |= SNOR_F_SST;
++	} else {
+ 		mtd->_write = spi_nor_write;
++	}
+ 
+ 	if (info->flags & USE_FSR)
+ 		nor->flags |= SNOR_F_USE_FSR;
+@@ -1263,11 +1325,20 @@ int spi_nor_scan(struct spi_nor *nor, co
+ 	mtd->writebufsize = nor->page_size;
+ 
+ 	if (np) {
++		u32 val;
++
+ 		/* If we were instantiated by DT, use it */
+ 		if (of_property_read_bool(np, "m25p,fast-read"))
+ 			nor->flash_read = SPI_NOR_FAST;
+ 		else
+ 			nor->flash_read = SPI_NOR_NORMAL;
++
++		if (!of_property_read_u32(np, "m25p,chunked-io", &val)) {
++			dev_info(dev, "using chunked io (size=%d)\n", val);
++			mtd->_read = spi_nor_chunked_read;
++			mtd->_write = spi_nor_chunked_write;
++			nor->chunk_size = val;
++		}
+ 	} else {
+ 		/* If we weren't instantiated by DT, default to fast-read */
+ 		nor->flash_read = SPI_NOR_FAST;
+--- a/include/linux/mtd/spi-nor.h
++++ b/include/linux/mtd/spi-nor.h
+@@ -116,6 +116,7 @@ enum spi_nor_ops {
+ 
+ enum spi_nor_option_flags {
+ 	SNOR_F_USE_FSR		= BIT(0),
++	SNOR_F_SST		= BIT(1),
+ };
+ 
+ /**
+@@ -156,6 +157,7 @@ struct spi_nor {
+ 	struct device		*dev;
+ 	struct device_node	*flash_node;
+ 	u32			page_size;
++	u16			chunk_size;
+ 	u8			addr_width;
+ 	u8			erase_opcode;
+ 	u8			read_opcode;