diff options
| author | Pratyush Yadav <p.yadav@ti.com> | 2021-06-25 22:17:24 +0300 |
|---|---|---|
| committer | Jagan Teki <jagan@amarulasolutions.com> | 2021-06-28 09:34:53 +0300 |
| commit | 575caf45004fb9be983db33f86425c95d4619213 (patch) | |
| tree | 1b78fa1eb8f1498f250055ff30ee66db7ae2cc47 /include/linux | |
| parent | a1122a3d98430754626547eb0acba11645039881 (diff) | |
| download | u-boot-575caf45004fb9be983db33f86425c95d4619213.tar.xz | |
mtd: spi-nor-core: Perform a Soft Reset on shutdown
On probe, the SPI NOR core will put a flash in 8D-8D-8D mode if it
supports it. But Linux as of now expects to get the flash in 1S-1S-1S
mode. Handing the flash to Linux in Octal DTR mode means the kernel will
fail to detect the flash.
So, we need to reset to Power-on-Reset (POR) state before handing off
the flash. A Software Reset command can be used to do this.
One limitation of the soft reset is that it will restore state from
non-volatile registers in some flashes. This means that if the flash was
set to 8D mode in a non-volatile configuration, a soft reset won't help.
This commit assumes that we don't set any non-volatile bits anywhere,
and the flash doesn't have any non-volatile Octal DTR mode
configuration.
Since spi-nor-tiny doesn't (and likely shouldn't) have
spi_nor_soft_reset(), add a dummy spi_nor_remove() for it that does
nothing.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mtd/spi-nor.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index b2159f6319..29ce175156 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -67,6 +67,8 @@ #define SPINOR_OP_CLFSR 0x50 /* Clear flag status register */ #define SPINOR_OP_RDEAR 0xc8 /* Read Extended Address Register */ #define SPINOR_OP_WREAR 0xc5 /* Write Extended Address Register */ +#define SPINOR_OP_SRSTEN 0x66 /* Software Reset Enable */ +#define SPINOR_OP_SRST 0x99 /* Software Reset */ /* 4-byte address opcodes - used on Spansion and some Macronix flashes. */ #define SPINOR_OP_READ_4B 0x13 /* Read data bytes (low frequency) */ @@ -562,4 +564,19 @@ device_node *spi_nor_get_flash_node(struct spi_nor *nor) */ int spi_nor_scan(struct spi_nor *nor); +#if CONFIG_IS_ENABLED(SPI_FLASH_TINY) +static inline int spi_nor_remove(struct spi_nor *nor) +{ + return 0; +} +#else +/** + * spi_nor_remove() - perform cleanup before booting to the next stage + * @nor: the spi_nor structure + * + * Return: 0 for success, -errno for failure. + */ +int spi_nor_remove(struct spi_nor *nor); +#endif + #endif |