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

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>
hifive-unleashed-5.1
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