diff options
| author | Pratyush Yadav <p.yadav@ti.com> | 2020-10-05 21:01:30 +0530 |
|---|---|---|
| committer | Vignesh Raghavendra <vigneshr@ti.com> | 2020-11-09 11:56:16 +0530 |
| commit | 354b412967016e2f99fb2d5113e7b92b539f33b6 (patch) | |
| tree | 1cf7a23c5db9609205c1b9b19d30e0c0b8cd173d /drivers/mtd/spi-nor | |
| parent | 6c6a2b2b8ed6dd1ad1a318afd1035777a73936e0 (diff) | |
| download | linux-354b412967016e2f99fb2d5113e7b92b539f33b6.tar.bz2 | |
mtd: spi-nor: core: do 2 byte reads for SR and FSR in DTR mode
Some controllers, like the cadence qspi controller, have trouble reading
only 1 byte in DTR mode. So, do 2 byte reads for SR and FSR commands in
DTR mode, and then discard the second byte.
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/20201005153138.6437-8-p.yadav@ti.com
Diffstat (limited to 'drivers/mtd/spi-nor')
| -rw-r--r-- | drivers/mtd/spi-nor/core.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index d63dfd7d4b31..518d16511dee 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -370,7 +370,7 @@ int spi_nor_write_disable(struct spi_nor *nor) * spi_nor_read_sr() - Read the Status Register. * @nor: pointer to 'struct spi_nor'. * @sr: pointer to a DMA-able buffer where the value of the - * Status Register will be written. + * Status Register will be written. Should be at least 2 bytes. * * Return: 0 on success, -errno otherwise. */ @@ -388,6 +388,11 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr) if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) { op.addr.nbytes = nor->params->rdsr_addr_nbytes; op.dummy.nbytes = nor->params->rdsr_dummy; + /* + * We don't want to read only one byte in DTR mode. So, + * read 2 and then discard the second byte. + */ + op.data.nbytes = 2; } spi_nor_spimem_setup_op(nor, &op, nor->reg_proto); @@ -408,7 +413,8 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr) * spi_nor_read_fsr() - Read the Flag Status Register. * @nor: pointer to 'struct spi_nor' * @fsr: pointer to a DMA-able buffer where the value of the - * Flag Status Register will be written. + * Flag Status Register will be written. Should be at least 2 + * bytes. * * Return: 0 on success, -errno otherwise. */ @@ -426,6 +432,11 @@ static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr) if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) { op.addr.nbytes = nor->params->rdsr_addr_nbytes; op.dummy.nbytes = nor->params->rdsr_dummy; + /* + * We don't want to read only one byte in DTR mode. So, + * read 2 and then discard the second byte. + */ + op.data.nbytes = 2; } spi_nor_spimem_setup_op(nor, &op, nor->reg_proto); |