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mtd: spi-nor: add an API to restore the status of SPI flash chip

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Add this API to restore the status of SPI flash chip to the default
such as addressing mode, whenever detach the driver from device or
reboot the system.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
This commit is contained in:
Hou Zhiqiang 2017-12-06 10:53:41 +08:00 committed by Cyrille Pitchen
parent 2666067fdb
commit 8dee1d971a
3 changed files with 19 additions and 0 deletions
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3
Documentation/mtd/spi-nor.txt
View File

@ -60,3 +60,6 @@ The main API is spi_nor_scan(). Before you call the hook, a driver should
initialize the necessary fields for spi_nor{}. Please see
drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to fsl-quadspi.c
when you want to write a new driver for a SPI NOR controller.
Another API is spi_nor_restore(), this is used to restore the status of SPI
flash chip such as addressing mode. Call it whenever detach the driver from
device or reboot the system.

10
drivers/mtd/spi-nor/spi-nor.c
View File

@ -2740,6 +2740,16 @@ static void spi_nor_resume(struct mtd_info *mtd)
dev_err(dev, "resume() failed\n");
}
void spi_nor_restore(struct spi_nor *nor)
{
/* restore the addressing mode */
if ((nor->addr_width == 4) &&
(JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
!(nor->info->flags & SPI_NOR_4B_OPCODES))
set_4byte(nor, nor->info, 0);
}
EXPORT_SYMBOL_GPL(spi_nor_restore);
int spi_nor_scan(struct spi_nor *nor, const char *name,
const struct spi_nor_hwcaps *hwcaps)
{

6
include/linux/mtd/spi-nor.h
View File

@ -403,4 +403,10 @@ struct spi_nor_hwcaps {
int spi_nor_scan(struct spi_nor *nor, const char *name,
const struct spi_nor_hwcaps *hwcaps);
/**
* spi_nor_restore_addr_mode() - restore the status of SPI NOR
* @nor: the spi_nor structure
*/
void spi_nor_restore(struct spi_nor *nor);
#endif