[PATCH v4 00/16] mtd: spi-nor: add xSPI Octal DTR support

Pratyush Yadav
2020-04-24T18:46:58Z

Hi,

This series adds support for octal DTR flashes in the spi-nor framework,
and then adds hooks for the Cypress Semper and Mircom Xcella flashes to
allow running them in octal DTR mode. This series assumes that the flash is handed to the kernel in Legacy SPI
mode.

Tested on TI J721e EVM with 1-bit ECC on the Cypress flash.

Changes in v4:
- Refactor the series to use the new spi-nor framework with the
manufacturer-specific bits separated from the core.

- Add support for Micron MT35XU512ABA.

- Use cmd.nbytes as the criteria of whether the data phase exists or not
instead of cmd.buf.in || cmd.buf.out in spi_nor_spimem_setup_op().

- Update Read FSR to use the same dummy cycles and address width as Read
SR.

- Fix BFPT parsing stopping too early for JESD216 rev B flashes.

- Use 2 byte reads for Read SR and FSR commands in DTR mode.

Changes in v3:
- Drop the DT properties "spi-rx-dtr" and "spi-tx-dtr". Instead, if
later a need is felt to disable DTR in case someone has a board with
Octal DTR capable flash but does not support DTR transactions for some
reason, a property like "spi-no-dtr" can be added.

- Remove mode bits SPI_RX_DTR and SPI_TX_DTR.

- Remove the Cadence Quadspi controller patch to un-block this series. I
will submit it as a separate patch.

- Rebase on latest 'master' and fix merge conflicts.

- Update read and write dirmap templates to use DTR.

- Rename 'is_dtr' to 'dtr'.

- Make 'dtr' a bitfield.

- Reject DTR ops in spi_mem_default_supports_op().

- Update atmel-quadspi to reject DTR ops. All other controller drivers
call spi_mem_default_supports_op() so they will automatically reject
DTR ops.

- Add support for both enabling and disabling DTR modes.

- Perform a Software Reset on flashes that support it when shutting
down.

- Disable Octal DTR mode on suspend, and re-enable it on resume.

- Drop enum 'spi_mem_cmd_ext' and make command opcode u16 instead.
Update spi-nor to use the 2-byte command instead of the command
extension. Since we still need a "extension type", mode that enum to
spi-nor and name it 'spi_nor_cmd_ext'.

- Default variable address width to 3 to fix SMPT parsing.

- Drop non-volatile change to uniform sector mode and rely on parsing
SMPT.

Changes in v2:
- Add DT properties "spi-rx-dtr" and "spi-tx-dtr" to allow expressing
DTR capabilities.

- Set the mode bits SPI_RX_DTR and SPI_TX_DTR when we discover the DT
properties "spi-rx-dtr" and spi-tx-dtr".

- spi_nor_cypress_octal_enable() was updating nor->params.read[] with
the intention of setting the correct number of dummy cycles. But this
function is called _after_ selecting the read so setting
nor->params.read[] will have no effect. So, update nor->read_dummy
directly.

- Fix spi_nor_spimem_check_readop() and spi_nor_spimem_check_pp()
passing nor->read_proto and nor->write_proto to
spi_nor_spimem_setup_op() instead of read->proto and pp->proto
respectively.

- Move the call to cqspi_setup_opcode_ext() inside cqspi_enable_dtr().
This avoids repeating the 'if (f_pdata->is_dtr)
cqspi_setup_opcode_ext()...` snippet multiple times.

- Call the default 'supports_op()' from cqspi_supports_mem_op(). This
makes sure the buswidth requirements are also enforced along with the
DTR requirements.

- Drop the 'is_dtr' argument from spi_check_dtr_req(). We only call it
when a phase is DTR so it is redundant.

Pratyush Yadav (16):
spi: spi-mem: allow specifying whether an op is DTR or not
spi: atmel-quadspi: reject DTR ops
spi: spi-mem: allow specifying a command's extension
mtd: spi-nor: add support for DTR protocol
mtd: spi-nor: default to address width of 3 for configurable widths
mtd: spi-nor: prepare BFPT parsing for JESD216 rev D
mtd: spi-nor: get command opcode extension type from BFPT
mtd: spi-nor: parse xSPI Profile 1.0 table
mtd: spi-nor: use dummy cycle and address width info from SFDP
mtd: spi-nor: do 2 byte reads for SR and FSR in DTR mode
mtd: spi-nor: enable octal DTR mode when possible
mtd: spi-nor: perform a Soft Reset on shutdown
mtd: spi-nor: Disable Octal DTR mode on suspend.
mtd: spi-nor: expose spi_nor_default_setup() in core.h
mtd: spi-nor: add support for Cypress Semper flash
mtd: spi-nor: allow using MT35XU512ABA in Octal DTR mode

drivers/mtd/spi-nor/core.c | 439 +++++++++++++++++++++++++++-----
drivers/mtd/spi-nor/core.h | 23 ++
drivers/mtd/spi-nor/micron-st.c | 113 +++++++-
drivers/mtd/spi-nor/sfdp.c | 114 ++++++++-
drivers/mtd/spi-nor/sfdp.h | 11 +-
drivers/mtd/spi-nor/spansion.c | 167 ++++++++++++
drivers/spi/atmel-quadspi.c | 4 +
drivers/spi/spi-mem.c | 3 +
include/linux/mtd/spi-nor.h | 50 +++-
include/linux/spi/spi-mem.h | 13 +-
10 files changed, 848 insertions(+), 89 deletions(-)