[PATCH v2 4/4] mtd:spi_nor: Disable Micron flash HW protection
From: Yunhui Cui <hidden>
Date: 2016-02-01 11:38:59
Also in:
lkml
Subsystem:
memory technology devices (mtd), spi nor subsystem, the rest · Maintainers:
Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Pratyush Yadav, Michael Walle, Linus Torvalds
For Micron family ,The status register write enable/disable bit, provides hardware data protection for the device. When the enable/disable bit is set to 1, the status register nonvolatile bits become read-only and the WRITE STATUS REGISTER operation will not execute. Signed-off-by: Yunhui Cui <redacted> --- drivers/mtd/spi-nor/spi-nor.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index ed0c19c..917f814 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c@@ -39,6 +39,7 @@ #define SPI_NOR_MAX_ID_LEN 6 #define SPI_NOR_MAX_ADDR_WIDTH 4 +#define SPI_NOR_MICRON_WRITE_ENABLE 0x7f struct flash_info { char *name;
@@ -1238,6 +1239,14 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) write_sr(nor, 0); } + if (JEDEC_MFR(info) == SNOR_MFR_MICRON) { + ret = read_sr(nor); + ret &= SPI_NOR_MICRON_WRITE_ENABLE; + + write_enable(nor); + write_sr(nor, ret); + } + if (!mtd->name) mtd->name = dev_name(dev); mtd->priv = nor;
--
2.1.0.27.g96db324