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ramips: fix reboot with W25Q256 with 4-address-mode enabled

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Some board vendors actually changed the loader to expect the chip
to come up in 4-address-mode and flipped the ADP bit in the flash
chip's configuration register which makes it come up in 4-address-mode.
Hence it doesn't make sense to avoid switching to 4-address-mode on
those boards but the opposite as otherwise reboot hangs eg. on the
WrtNode2 boards. Fix this by checking the ADP register and only using
SPI_NOR_4B_READ_OP on chips which have ADP==0 (come up in 3-byte mode).

See also datasheet section 7.1.11 Power Up Address Mode (ADP)

Fixes: 22d982ea0 ("ramips: add support for switching between 3-byte and 4-byte addressing on w25q256 flash")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
This commit is contained in:
Daniel Golle 2018-06-07 01:51:58 +02:00
parent 1bbe813db0
commit 8796680277
1 changed files with 73 additions and 0 deletions
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73
target/linux/ramips/patches-4.14/0054-mtd-spi-nor-w25q256-respect-default-mode.patch Normal file
View file

@ -0,0 +1,73 @@
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -142,20 +142,29 @@ static int read_fsr(struct spi_nor *nor)
* location. Return the configuration register value.
* Returns negative if error occurred.
*/
-static int read_cr(struct spi_nor *nor)
+static int _read_cr(struct spi_nor *nor, u8 reg)
{
int ret;
u8 val;
- ret = nor->read_reg(nor, SPINOR_OP_RDCR, &val, 1);
+ ret = nor->read_reg(nor, reg, &val, 1);
if (ret < 0) {
- dev_err(nor->dev, "error %d reading CR\n", ret);
+ dev_err(nor->dev, "error %d reading %s\n", ret,
+ (reg==SPINOR_OP_RDCR)?"CR":"XCR");
return ret;
}
return val;
}
+static inline int read_cr(struct spi_nor *nor) {
+ return _read_cr(nor, SPINOR_OP_RDCR);
+}
+
+static inline int read_xcr(struct spi_nor *nor) {
+ return _read_cr(nor, SPINOR_OP_RDXCR);
+}
+
/*
* Write status register 1 byte
* Returns negative if error occurred.
@@ -2878,9 +2887,16 @@ int spi_nor_scan(struct spi_nor *nor, co
} else if (mtd->size > 0x1000000) {
/* enable 4-byte addressing if the device exceeds 16MiB */
nor->addr_width = 4;
- if (info->flags & SPI_NOR_4B_READ_OP)
- spi_nor_set_4byte_read(nor, info);
- else if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
+ if (info->flags & SPI_NOR_4B_READ_OP) {
+ if (JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
+ ret = read_xcr(nor);
+ if (!(ret > 0 && (ret & XCR_DEF_4B_ADDR_MODE)))
+ spi_nor_set_4byte_read(nor, info);
+ else
+ set_4byte(nor, info, 1);
+ } else
+ spi_nor_set_4byte_read(nor, info);
+ } else if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
info->flags & SPI_NOR_4B_OPCODES)
spi_nor_set_4byte_opcodes(nor, info);
else
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -103,6 +103,7 @@
#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
#define SPINOR_OP_WREAR 0xc5 /* Write extended address register */
+#define SPINOR_OP_RDXCR 0x15 /* Read extended configuration register */
/* Used for Spansion flashes only. */
#define SPINOR_OP_BRWR 0x17 /* Bank register write */
@@ -135,6 +136,7 @@
/* Configuration Register bits. */
#define CR_QUAD_EN_SPAN BIT(1) /* Spansion Quad I/O */
+#define XCR_DEF_4B_ADDR_MODE BIT(1) /* Winbond 4B mode default */
/* Status Register 2 bits. */
#define SR2_QUAD_EN_BIT7 BIT(7)