Re: [PATCH 00/17] spi: dw: Add generic DW DMA controller support

[Andy Shevchenko]

On Fri, May 08, 2020 at 04:29:25PM +0300, Serge Semin wrote:
> Baikal-T1 SoC provides DW DMA controller to perform low-speed peripherals
> Mem-to-Dev and Dev-to-Mem transaction. This is also applicable to the DW
> APB SSI devices embedded into the SoC. Currently this type DMA device is
> supported by the DW APB SPI driver only as a middle layer code for Intel
> MID PCI devices. Seeing the same code can be used for normal platform
> DW DMAC device we introduced a set of patches to fix it within this
> patchset.
> 
> First of all traditionally we replaced the legacy plain text-based dt-binding
> file with yaml-based one. Then we unpinned the Intel MID specific code from
> the generic DMA one and placed it into the spi-dw-pci.c driver, which was a
> better place for it anyway. Then we introduced a set of naming cleanups since
> the code was going to be used for generic DW DMAC device and DMAC usage
> alterations to handle the controller functionality in a generic way by the
> DW APB SSI MMIO driver as well. See the individual patches commit messages
> for details.
> 
> In addition we fixed a problem in the native chip-select method, which despite
> of multiple attempts to be fixed doesn't correctly perceive the SPI_CS_HIGH
> flag and the enable-argument.
> 
> Finally as a cherry on a cake we replaced the manually written DebugFS
> registers read method with a ready-to-use for the same purpose regset32
> DebugFS interface usage.

Thanks! Appreciate the series (some of the things I would like to have done
myself, but lack of time and no specific request from our hardware).

Though, I will wait for v2 rebased on top of spi/for-next and I will review the
rest of the patches (mostly those I haven't commented out).

> This patchset is rebased and tested on the mainline Linux kernel 5.7-rc4:
> 0e698dfa2822 ("Linux 5.7-rc4")
> tag: v5.7-rc4

Perhaps --base will do the trick?

> 
> Co-developed-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
> Co-developed-by: Ramil Zaripov <Ramil.Zaripov@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ramil Zaripov <Ramil.Zaripov@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Maxim Kaurkin <Maxim.Kaurkin@xxxxxxxxxxxxxxxxxxxx>
> Cc: Pavel Parkhomenko <Pavel.Parkhomenko@xxxxxxxxxxxxxxxxxxxx>
> Cc: Ekaterina Skachko <Ekaterina.Skachko@xxxxxxxxxxxxxxxxxxxx>
> Cc: Vadim Vlasov <V.Vlasov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Alexey Kolotnikov <Alexey.Kolotnikov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Paul Burton <paulburton@xxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Allison Randal <allison@xxxxxxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Gareth Williams <gareth.williams.jx@xxxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxxx
> Cc: linux-spi@xxxxxxxxxxxxxxx
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> 
> Serge Semin (17):
>   dt-bindings: spi: Convert DW SPI binding to DT schema
>   dt-bindings: spi: dw: Add DMA properties bindings
>   spi: dw: Split up the generic DMA code and Intel MID driver
>   spi: dw: Cleanup generic DW DMA code namings
>   spi: dw: Discard static DW DMA slave structures
>   spi: dw: Add DW SPI DMA/PCI/MMIO dependency on DW SPI core
>   spi: dw: Add Tx/Rx finish wait methods to DMA
>   spi: dw: Clear DMAC register when done or stopped
>   spi: dw: Enable interrupts in accordance with DMA xfer mode
>   spi: dw: Parameterize the DMA Rx/Tx burst length
>   spi: dw: Fix native CS being unset
>   spi: dw: Fix dma_slave_config used partly uninitialized
>   spi: dw: Initialize paddr in DW SPI MMIO private data
>   spi: dw: Add DMA support to the DW SPI MMIO driver
>   spi: dw: Use DMA max burst to set the request thresholds
>   spi: dw: Fix Rx-only DMA transfers
>   spi: dw: Use regset32 DebugFS method to create a registers file
> 
>  .../bindings/spi/snps,dw-apb-ssi.txt          |  41 ---
>  .../bindings/spi/snps,dw-apb-ssi.yaml         | 123 +++++++++
>  .../devicetree/bindings/spi/spi-dw.txt        |  24 --
>  drivers/spi/Kconfig                           |  16 +-
>  drivers/spi/Makefile                          |   4 +-
>  drivers/spi/{spi-dw-mid.c => spi-dw-dma.c}    | 237 ++++++++++++------
>  drivers/spi/spi-dw-mmio.c                     |  15 +-
>  drivers/spi/spi-dw-pci.c                      |  38 ++-
>  drivers/spi/spi-dw.c                          |  89 +++----
>  drivers/spi/spi-dw.h                          |  27 +-
>  10 files changed, 402 insertions(+), 212 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
>  create mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
>  delete mode 100644 Documentation/devicetree/bindings/spi/spi-dw.txt
>  rename drivers/spi/{spi-dw-mid.c => spi-dw-dma.c} (53%)
> 
> -- 
> 2.25.1
> 

-- 
With Best Regards,
Andy Shevchenko