[PATCH 0/3] fpga: xilinx-selectmap: add new driver

[Charles Perry <charles.perry@savoirfairelinux.com>]

Hello,

This patchset adds a new driver for the 7 series FPGA's SelectMAP
interface.

The SelectMAP interface shares a common GPIO protocol with the SPI
interface which is already in the kernel (drivers/fpga/xilinx-spi.c).
The approach proposed in this patchset is to refactor xilinx-spi.c into
xilinx-core.c which would handle the common GPIO protocol. This is then
used to build two drivers, the already existing xilinx-spi.c driver and
a newly added xilinx-selectmap.c driver.

The SelectMAP driver proposed only supports 8 bit mode. This is because
the 16 and 32 bits mode have limitations with regards to compressed
bitstream support as well as introducing endianness considerations.

I'm testing xilinx-selectmap.c on a custom i.MX6 board connected to an
Artix 7 FPGA. Flashing a 913K bitstream takes 0.44 seconds.

v2: From Krzysztof Kozlowski review's:
  * Use more conventional names for gpio DT bindings
  * fix example in DT bindings
  * add mc-peripheral-props.yaml to DT bindings
  * fix various formatting mistakes
  * Remove all occurences of the "slave" word.

Charles Perry (3):
  fpga: xilinx-spi: extract a common driver core
  dt-bindings: fpga: xlnx,fpga-slave-selectmap: add DT schema
  fpga: xilinx-selectmap: add new driver

 .../bindings/fpga/xlnx,fpga-selectmap.yaml    |  83 +++++++
 drivers/fpga/Kconfig                          |  12 +
 drivers/fpga/Makefile                         |   2 +
 drivers/fpga/xilinx-core.c                    | 215 ++++++++++++++++++
 drivers/fpga/xilinx-core.h                    |  28 +++
 drivers/fpga/xilinx-selectmap.c               | 106 +++++++++
 drivers/fpga/xilinx-spi.c                     | 205 ++---------------
 7 files changed, 462 insertions(+), 189 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/fpga/xlnx,fpga-selectmap.yaml
 create mode 100644 drivers/fpga/xilinx-core.c
 create mode 100644 drivers/fpga/xilinx-core.h
 create mode 100644 drivers/fpga/xilinx-selectmap.c

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2.43.0