Messages in this thread | | | Date | Tue, 29 Sep 2020 18:38:40 +0530 | From | Pratyush Yadav <> | Subject | Re: [PATCH v13 11/15] mtd: spi-nor: core: perform a Soft Reset on shutdown |
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On 16/09/20 06:14PM, Pratyush Yadav wrote: > 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> > --- > drivers/mtd/spi-nor/core.c | 41 +++++++++++++++++++++++++++++++++++++ > include/linux/mtd/spi-nor.h | 2 ++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 6ee93544d72f..853dfa02f0de 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 +3177,41 @@ 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, 8),
The buswidth used here should be 1 instead of 8. It makes no difference in practice because the call to spi_nor_spimem_setup_op() immediately after will over-write it to the correct value anyway, but let's follow the style followed throughout the rest of the codebase. Will fix in the next version.
> + 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, 8),
Same here.
> + 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) > {
-- Regards, Pratyush Yadav Texas Instruments India
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