Re: [PATCH 1/3] fpga: Add Efinix Trion & Titanium serial SPI programming driver

[Xu Yilun <yilun.xu@linux.intel.com>]

On Fri, Sep 27, 2024 at 04:14:42PM +0200, iansdannapel@gmail.com wrote:
> From: Ian Dannapel <iansdannapel@gmail.com>
> 
> Add a new driver for loading binary firmware to volatile
> configuration RAM using "SPI passive programming" on Efinix FPGAs.
> 
> Signed-off-by: Ian Dannapel <iansdannapel@gmail.com>
> ---
>  drivers/fpga/Kconfig                    |  10 ++
>  drivers/fpga/Makefile                   |   1 +
>  drivers/fpga/efinix-trion-spi-passive.c | 211 ++++++++++++++++++++++++
>  3 files changed, 222 insertions(+)
>  create mode 100644 drivers/fpga/efinix-trion-spi-passive.c
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 37b35f58f0df..eb1e44c4e3e0 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -83,6 +83,16 @@ config FPGA_MGR_XILINX_SPI
>  	  FPGA manager driver support for Xilinx FPGA configuration
>  	  over slave serial interface.
>  
> +config FPGA_MGR_EFINIX_SPI
> +	tristate "Efinix FPGA configuration over SPI passive"
> +	depends on SPI
> +	help
> +	  This option enables support for the FPGA manager driver to
> +	  configure Efinix Trion and Titanium Series FPGAs over SPI
> +	  using passive serial mode.
> +	  Warning: Do not activate this if there are other SPI devices
> +	  on the same bus as it might interfere with the transmission.

Sorry, this won't work. As you can see, the conflict usage of CS causes
several concerns. Just a text here is far from enough.

You need to actively work with SPI core/controller drivers to find a
solution that coordinate the usage of this pin.

Thanks
Yilun