From: Hou Zhiqiang <zhiqiang....@nxp.com> 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....@nxp.com> --- V3: - no change. Documentation/mtd/spi-nor.txt | 3 +++ drivers/mtd/spi-nor/spi-nor.c | 10 ++++++++++ include/linux/mtd/spi-nor.h | 6 ++++++ 3 files changed, 19 insertions(+) diff --git a/Documentation/mtd/spi-nor.txt b/Documentation/mtd/spi-nor.txt index 548d6306ebca..da1fbff5a24c 100644 --- a/Documentation/mtd/spi-nor.txt +++ b/Documentation/mtd/spi-nor.txt @@ -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. diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index bc266f70a15b..4a925378d434 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -2713,6 +2713,16 @@ 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) { diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index d0c66a0975cf..0a182c3d0884 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -399,4 +399,10 @@ 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 -- 2.14.1