[PATCH v2 00/16] mtd: spi-nor-core: 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.

The Cadence QSPI controller driver is also updated to run in Octal DTR
mode.

Tested on TI J721e EVM with 1-bit ECC on the Cypress flash on top of
u-boot-ti/next.

This series depends on [0]. v1 can be found at [1].

[0] cf. <20200224071051.19331-1-p.yadav at ti.com>
[0] https://lists.denx.de/pipermail/u-boot/2020-February/401192.html
[1] cf. <20200226125606.22684-1-p.yadav at ti.com>
[1] https://lists.denx.de/pipermail/u-boot/2020-February/401414.html

Changes in v2:
- Update the series with comments received on the corresponding kernel
  series.
- 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.

- Rename 'is_dtr' to 'dtr'.

- Make 'dtr' a bitfield.

- Reject DTR ops in spi_mem_default_supports_op().

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

- Perform a Software Reset on boot if enabled.

- 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'.

- Rework hwcaps selection to use supports_op() instead of relying on
  mode bits.

- Fix a build failure when SFDP is not enabled.

- Read CFR3V instead of CFR3N in the s28hs setup hook. Reading CFR3N
  means we need to know beforehand how many dummy cycles are needed.
  Reading CFR3V doesn't need that because the dummy cycles are exactly
  the same as the Read ID cycles. So if we can Read ID we can read
  volatile registers.

Pratyush Yadav (16):
  spi: spi-mem: allow specifying whether an op is DTR or not
  spi: spi-mem: allow specifying a command's extension
  spi: cadence-qspi: Do not calibrate when device tree sets read delay
  spi: cadence-qspi: Add support for octal DTR flashes
  mtd: spi-nor-core: Add a ->setup() hook
  mtd: spi-nor-core: Move SFDP related declarations to top
  mtd: spi-nor-core: Introduce flash-specific fixup hooks
  mtd: spi-nor-core: Rework hwcaps selection
  mtd: spi-nor-core: Add support for DTR protocol
  mtd: spi-nor-core: Get command opcode extension type from BFPT
  mtd: spi-nor-core: Parse xSPI Profile 1.0 table
  mtd: spi-nor-core: Use Read SR dummy cycle and address width from SFDP
  mtd: spi-nor-core: Enable octal DTR mode when possible
  mtd: spi-nor-core: Perform a Soft Reset on shutdown
  mtd: spi-nor-core: Perform a Soft Reset on boot
  mtd: spi-nor-core: Add support for Cypress Semper flash

 drivers/mtd/spi/Kconfig        |   11 +
 drivers/mtd/spi/sf_internal.h  |    9 +
 drivers/mtd/spi/sf_probe.c     |    9 +
 drivers/mtd/spi/spi-nor-core.c | 1166 ++++++++++++++++++++++++--------
 drivers/mtd/spi/spi-nor-ids.c  |    1 +
 drivers/mtd/spi/spi-nor-tiny.c |   22 -
 drivers/spi/cadence_qspi.c     |   87 ++-
 drivers/spi/cadence_qspi.h     |   15 +-
 drivers/spi/cadence_qspi_apb.c |  286 +++++++-
 drivers/spi/spi-mem.c          |    3 +
 include/linux/mtd/spi-nor.h    |  261 +++++--
 include/spi-mem.h              |   16 +-
 12 files changed, 1497 insertions(+), 389 deletions(-)

--
2.25.0