[PATCH v3 00/12] mtd: spi-nor: add xSPI Octal DTR support

[Pratyush Yadav]

Hi,

This series adds support for octal DTR flashes in the spi-nor framework,
and then adds hooks for the Cypress Semper flash which is an xSPI
compliant Octal DTR flash.

This series assumes that the flash is handed to the kernel in Legacy SPI
mode. That is why there is no tracking of the state the flash is in.
Ability to detect the flash mode and then run the SFDP procedure in that
mode will be added as a follow up series.

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

v1 can be found at [0]. v2 can be found at [1].

[0] https://lore.kernel.org/linux-mtd/20200211133348.15558-1-p.yadav@xxxxxx/
[1] https://lore.kernel.org/linux-mtd/20200226093703.19765-1-p.yadav@xxxxxx/

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.

Pratyush Yadav (12):
  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: 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: 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: add support for Cypress Semper flash

 drivers/mtd/spi-nor/spi-nor.c | 692 ++++++++++++++++++++++++++++++----
 drivers/spi/atmel-quadspi.c   |   4 +
 drivers/spi/spi-mem.c         |   3 +
 include/linux/mtd/spi-nor.h   |  73 +++-
 include/linux/spi/spi-mem.h   |  13 +-
 5 files changed, 702 insertions(+), 83 deletions(-)

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2.25.0