Re: [PATCH v9 3/3] fpga: Add support for Lattice iCE40 FPGAs
From: Marek Vasut
Date: Fri Dec 09 2016 - 08:11:50 EST
On 12/09/2016 06:35 AM, Joel Holdsworth wrote:
> The Lattice iCE40 is a family of FPGAs with a minimalistic architecture
> and very regular structure, designed for low-cost, high-volume consumer
> and system applications.
> This patch adds support to the FPGA manager for configuring the SRAM of
> iCE40LM, iCE40LP, iCE40HX, iCE40 Ultra, iCE40 UltraLite and iCE40
> UltraPlus devices, through slave SPI.
> The iCE40 family is notable because it is the first FPGA family to have
> complete reverse engineered bit-stream documentation for the iCE40LP and
> iCE40HX devices. Furthermore, there is now a Free Software Verilog
> synthesis tool-chain: the "IceStorm" tool-chain.
> This project is the work of Clifford Wolf, who is the maintainer of
> Yosys Verilog RTL synthesis framework, and Mathias Lasser, with notable
> contributions from "Cotton Seed", the main author of "arachne-pnr"; a
> place-and-route tool for iCE40 FPGAs.
> Having a Free Software synthesis tool-chain offers interesting
> opportunities for embedded devices that are able reconfigure themselves
> with open firmware that is generated on the device itself. For example
> a mobile device might have an application processor with an iCE40 FPGA
> attached, which implements slave devices, or through which the processor
> communicates with other devices through the FPGA fabric.
> A kernel driver for the iCE40 is useful, because in some cases, the FPGA
> may need to be configured before other devices can be accessed.
> An example of such a device is the icoBoard; a RaspberryPI HAT which
> features an iCE40HX8K with a 1 or 8 MBit SRAM and ports for
> Digilent-compatible PMOD modules. A PMOD module may contain a device
> with which the kernel communicates, via the FPGA.
> Signed-off-by: Joel Holdsworth <joel@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Marek Vasut <marex@xxxxxxx>