Re: [PATCH v1 0/6] PolarFire SoC Auto Update Support

[Xu Yilun]

On 2023-02-17 at 16:40:17 +0000, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> 
> Hey all,
> 
> This patchset adds support for the "Auto Update" feature on PolarFire
> SoC that allows for writing an FPGA bistream to the SPI flash connected
> to the system controller.

I haven't fully checked the patches yet, just some quick comments:

Since this feature is just to R/W the flash, and would not affect the
runtime FPGA region, I don't think an FPGA manager is actually needed.
Why not just use the MTD uAPI? There is a set of exsiting MTD uAPI &
MTD tool if I remember correctly.

Thanks,
Yilun

> On powercycle (or reboot depending on how the firmware implements the
> openSBI SRST extension) "Auto Update" will take place, and program the
> FPGA with the contents of the SPI flash - provided that that image is
> valid and an actual upgrade from that already programmed!
> 
> Unfortunately, this series is not really testable yet - the Engineering
> Sample silicon on most dev boards has a bug in the QSPI controller
> connected to the system controller's flash and cannot access it.
> Pre-production and later silicon has this bug fixed.
> 
> I previously posted an RFC about my approach in this driver, since as a
> flash-based FPGA we are somewhat different to the existing
> self-reprogramming drivers here. That RFC is here:
> https://lore.kernel.org/linux-fpga/20221121225748.124900-1-conor@xxxxxxxxxx/
> 
> This series depends on the following fixes:
> https://patchwork.kernel.org/project/linux-riscv/list/?series=714160
> 
> The patch adding the driver depends on the soc patches earlier in the
> series, so taking both through the same tree makes sense. Depending on
> sequencing with the dependencies, me taking it through the soc tree
> (with Acks etc of course) may make the most sense.
> 
> The other caveat here I guess is that this uses debugfs to trigger the
> write, as we do not yet have a userspace for this yet!
> 
> Cheers,
> Conor.
> 
> CC: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> CC: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
> CC: Rob Herring <robh+dt@xxxxxxxxxx>
> CC: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>
> CC: Moritz Fischer <mdf@xxxxxxxxxx>
> CC: Wu Hao <hao.wu@xxxxxxxxx>
> CC: Xu Yilun <yilun.xu@xxxxxxxxx>
> CC: Tom Rix <trix@xxxxxxxxxx>
> CC: linux-riscv@xxxxxxxxxxxxxxxxxxx
> CC: devicetree@xxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> CC: linux-fpga@xxxxxxxxxxxxxxx
> 
> Conor Dooley (6):
>   soc: microchip: mpfs: add a prefix to rx_callback()
>   dt-bindings: soc: microchip: add a property for system controller
>     flash
>   soc: microchip: mpfs: enable access to the system controller's flash
>   soc: microchip: mpfs: add auto-update subdev to system controller
>   fpga: add PolarFire SoC Auto Update support
>   riscv: dts: microchip: add the mpfs' system controller qspi &
>     associated flash
> 
>  .../microchip,mpfs-sys-controller.yaml        |  10 +
>  .../boot/dts/microchip/mpfs-icicle-kit.dts    |  21 +
>  arch/riscv/boot/dts/microchip/mpfs.dtsi       |  24 +-
>  drivers/fpga/Kconfig                          |   9 +
>  drivers/fpga/Makefile                         |   1 +
>  drivers/fpga/microchip-auto-update.c          | 495 ++++++++++++++++++
>  drivers/soc/microchip/Kconfig                 |   1 +
>  drivers/soc/microchip/mpfs-sys-controller.c   |  33 +-
>  include/soc/microchip/mpfs.h                  |   2 +
>  9 files changed, 586 insertions(+), 10 deletions(-)
>  create mode 100644 drivers/fpga/microchip-auto-update.c
> 
> -- 
> 2.39.1
>