diff options
author | Pratyush Yadav <p.yadav@ti.com> | 2020-10-05 21:01:35 +0530 |
---|---|---|
committer | Vignesh Raghavendra <vigneshr@ti.com> | 2020-11-09 11:56:17 +0530 |
commit | d73ee7534cc537b98b61bfd83dbce5bb12aecb80 (patch) | |
tree | 09efa7e59d3bb003317b9762ab8645010b9dd623 /drivers/mtd/spi-nor | |
parent | 1131324aa53ad3465a36c4e58a56615e1bf52932 (diff) |
mtd: spi-nor: core: perform a Soft Reset on shutdown
Perform a Soft Reset on shutdown on flashes that support it so that the
flash can be reset to its initial state and any configurations made by
spi-nor (given that they're only done in volatile registers) will be
reset. This will hand back the flash in pristine state for any further
operations on it.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201005153138.6437-13-p.yadav@ti.com
Diffstat (limited to 'drivers/mtd/spi-nor')
-rw-r--r-- | drivers/mtd/spi-nor/core.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 7b9ec02734f2..633a1af8a0fe 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -40,6 +40,9 @@ #define SPI_NOR_MAX_ADDR_WIDTH 4 +#define SPI_NOR_SRST_SLEEP_MIN 200 +#define SPI_NOR_SRST_SLEEP_MAX 400 + /** * spi_nor_get_cmd_ext() - Get the command opcode extension based on the * extension type. @@ -3174,6 +3177,45 @@ static int spi_nor_init(struct spi_nor *nor) return 0; } +static void spi_nor_soft_reset(struct spi_nor *nor) +{ + struct spi_mem_op op; + int ret; + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_SRSTEN, 0), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DATA); + + spi_nor_spimem_setup_op(nor, &op, nor->reg_proto); + + ret = spi_mem_exec_op(nor->spimem, &op); + if (ret) { + dev_warn(nor->dev, "Software reset failed: %d\n", ret); + return; + } + + op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_SRST, 0), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DATA); + + spi_nor_spimem_setup_op(nor, &op, nor->reg_proto); + + ret = spi_mem_exec_op(nor->spimem, &op); + if (ret) { + dev_warn(nor->dev, "Software reset failed: %d\n", ret); + return; + } + + /* + * Software Reset is not instant, and the delay varies from flash to + * flash. Looking at a few flashes, most range somewhere below 100 + * microseconds. So, sleep for a range of 200-400 us. + */ + usleep_range(SPI_NOR_SRST_SLEEP_MIN, SPI_NOR_SRST_SLEEP_MAX); +} + /* mtd resume handler */ static void spi_nor_resume(struct mtd_info *mtd) { @@ -3193,6 +3235,9 @@ void spi_nor_restore(struct spi_nor *nor) if (nor->addr_width == 4 && !(nor->flags & SNOR_F_4B_OPCODES) && nor->flags & SNOR_F_BROKEN_RESET) nor->params->set_4byte_addr_mode(nor, false); + + if (nor->flags & SNOR_F_SOFT_RESET) + spi_nor_soft_reset(nor); } EXPORT_SYMBOL_GPL(spi_nor_restore); |