[PATCH v7 0/3] spi: support the SpacemiT K1 SPI controller

[Alex Elder]

This series adds support for the SPI controller found in the SpacemiT
K1 SoC.  The driver currently supports only master mode.  The controller
has two 32-entry FIFOs and supports PIO and DMA for transfers.

Version 7 fixes two bugs, and now builds the driver as a kernel module
by default.

(Note, this is a distinct series from the QSPI driver, which was
merged recently.)

                                        -Alex

This series is available here:
  https://github.com/riscstar/linux/tree/outgoing/spi-v7

Between version 6 and version 7:
  - DIV_ROUND_UP_ULL() is now used when setting the speed, to address
    two errors reported by the Intel kernel test robot on 32-bit builds
  - Fixed a bug interpreting the resource pointer in k1_spi_dma_cleanup()
  - The driver is now built as a module by default, if ARCH_SPACEMIT
    is defined

Here is version 6 of this series:
  https://lore.kernel.org/lkml/20251027125504.297033-1-elder@riscstar.com/

Between version 5 and version 6:
  - Rebase only

Here is version 5 of this series:
  https://lore.kernel.org/lkml/20251013123309.2252042-1-elder@riscstar.com/

Between version 4 and version 5:
  - Added Yixun's Reviewed-by tag on patch 3

Here is version 4 of this series:
  https://lore.kernel.org/lkml/20250925121714.2514932-1-elder@riscstar.com/

Between version 3 and version 4 (all suggested by Yixun):
  - Fixed an underrun/overrun comment error
  - Renamed a pinctrl node
  - Formatted dmas and dma-names properties on one line

Here is version 3 of this series:
  https://lore.kernel.org/lkml/20250922161717.1590690-1-elder@riscstar.com/

Between version 2 and version 3:
  - Add Conor's Acked-by to patch 1
  - Add Rob's Reviewed-by to patch 1
  - Added imply_PDMA to the SPI_SPACEMIT_K1 Kconfig option
  - Fixed a bug pointed out by Vivian (and Troy) in word-sized reads
  - Added a comment stating we use 1, 2, or 4 bytes per word
  - Cleaned up DMA channels properly in case of failure setting up
  - No longer use devm_*() for allocating DMA channels or buffer
  - Moved the SPI controller into the dma-bus memory region

Here is version 2 of this series:
  https://lore.kernel.org/lkml/20250919155914.935608-1-elder@riscstar.com/

Between version 1 and version 2:
  - Use enum rather than const for the binding compatible string
  - Omit the label and status property in the binding example
  - The spi-spacemit-k1.o make target is now added in sorted order
  - The SPI_SPACEMIT_K1 config option is added in sorted order
  - The SPI_SPACEMIT_K1 config does *not* depend on MMP_PDMA,
    however MMP_PDMA is checked at runtime, and if not enabled,
    DMA will not be used
  - Read/modify/writes of registers no longer use an additional
    "virt" variable to hold the address accessed
  - The k1_spi_driver_data->ioaddr field has been renamed base
  - The DMA address for the base address is maintained, rather than
    saving the DMA address of the data register
  - The spi-max-frequency property value is now bounds checked
  - A local variable is now initialized to 0 in k1_spi_write_word()
  - The driver name is now "k1-spi"
  - DT aliases are used rather than spacemit,k1-ssp-id for bus number
  - The order of two pin control properties was changed as requested
  - Clock names and DMA names are now on one line in the "k1.dtsi"
  - The interrupts property is used rather than interrupts-extended
  - The order of two pin control properties was changed as requested
  - Clock names and DMA names are now on one line in the "k1.dtsi"
  - The interrupts property is used rather than interrupts-extended

Here is version 1 of this series:
  https://lore.kernel.org/lkml/20250917220724.288127-1-elder@riscstar.com/


Alex Elder (3):
  dt-bindings: spi: add SpacemiT K1 SPI support
  spi: spacemit: introduce SpacemiT K1 SPI controller driver
  riscv: dts: spacemit: define a SPI controller node

 .../bindings/spi/spacemit,k1-spi.yaml         |  84 ++
 .../boot/dts/spacemit/k1-bananapi-f3.dts      |   7 +
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |  20 +
 arch/riscv/boot/dts/spacemit/k1.dtsi          |  15 +
 drivers/spi/Kconfig                           |   9 +
 drivers/spi/Makefile                          |   1 +
 drivers/spi/spi-spacemit-k1.c                 | 966 ++++++++++++++++++
 7 files changed, 1102 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml
 create mode 100644 drivers/spi/spi-spacemit-k1.c


base-commit: 0f2995693867bfb26197b117cd55624ddc57582f
-- 
2.48.1