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

Xu Yilun
2023-02-24T08:08:28Z

On 2023-02-17 at 16:40:17 +0000, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
>
> 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@kernel.org/
>
> 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@microchip.com>
> CC: Daire McNamara <daire.mcnamara@microchip.com>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> CC: Moritz Fischer <mdf@kernel.org>
> CC: Wu Hao <hao.wu@intel.com>
> CC: Xu Yilun <yilun.xu@intel.com>
> CC: Tom Rix <trix@redhat.com>
> CC: linux-riscv@lists.infradead.org
> CC: devicetree@vger.kernel.org
> CC: linux-kernel@vger.kernel.org
> CC: linux-fpga@vger.kernel.org
>
> 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
>