[PATCH 0/4] mtd: spi-nor: Add support for Octal 8D-8D-8D mode

Mason Yang masonccyang at mxic.com.tw
Fri Nov 15 00:58:04 PST 2019


This is repost of patchset from Boris Brezillon's
[RFC,00/18] mtd: spi-nor: Proposal for 8-8-8 mode support [1].

Background from cover letter for RFC[1].

The trend has been around Octal NOR Flash lately and the latest mainline
already supports 1-1-8 and 1-8-8 modes.

Boris opened a discussion on how we should support stateful modes (X-X-X
and XD-XD-XD, where X is the bus width and D means Double Transfer Rate).

JESD216C has defined specification for Octal 8-8-8 and 8D-8D-8D.
It defined command and command extension in
JEDEC Basic Flash Parameter Table(18th DWORD) as well as how to
enable 8-8-8/8D-8D-8D mode sequences (Write CFG Reg 2).

The first set of patches is according to JESD216C adding Double Transfer
Rate(DTR) fields, extension command and command bytes number to the
spi_mem_op struct.

The second set of patches define the relevant macrons and enum in spi-nor
layer for Octal 8-8-8 and 8D-8D-8D mode operation.

The last set of patches in the series are modifying spi_nor_fixups hook to
tweak flash parameters for spi_nor_read/pp_setting() and then in a
chip-specific way to enter 8-8-8 or 8D-8D-8D modes on a Macronix chip.

Also patched spi-mxic driver for testing on Macronix's Zynq PicoZed board
with Macronix's SPI controller (spi-mxic.c) and mx25uw51245g Octal flash.

[1] https://patchwork.ozlabs.org/cover/982926/

thnaks for your time and review.
best regards,

Mason Yang (4):
  spi: spi-mem: Add support for Octal 8D-8D-8D mode
  mtd: spi-nor: Add support for Octal 8D-8D-8D mode
  mtd: spi-nor: Add Octal 8D-8D-8D mode support for Macronix
  spi: mxic: Add support for Octal 8D-8D-8D mode

 drivers/mtd/spi-nor/spi-nor.c | 273 +++++++++++++++++++++++++++++++++++++++++-
 drivers/spi/spi-mem.c         |   8 +-
 drivers/spi/spi-mxic.c        |  98 ++++++++++-----
 include/linux/mtd/spi-nor.h   |  61 +++++++++-
 include/linux/spi/spi-mem.h   |  13 ++
 5 files changed, 410 insertions(+), 43 deletions(-)


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