Interesting, keep me on the cc list for stuff like this (though it's not my sphere). 2008/12/13 Wookey > This just appeared on linux-embedded list. Very relevant to us. If > anyone has any comments about how it should work from balloon's POV > then now is the time to say. > > ----- Forwarded message from Florian Fainelli ----- > > From: Florian Fainelli > Date: Sat, 13 Dec 2008 13:58:01 +0100 > To: Hugo Villeneuve > Cc: linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org > Subject: Re: FPGA programming driver architecture > List-ID: > X-Spam-Status: No, score=-6.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED > autolearn=ham version=3.2.3, No > > (CC'ing linux-embedded) > > Salut Hugo, > > Le Friday 12 December 2008 21:03:14 Hugo Villeneuve, vous avez écrit : > > Hi, > > I have written some code to program a FPGA in Linux, for two different > > types of boards: one uses a serial interface (SPI) and the second a > > parallel interface. I have been able to sucessfully program both boards. > > I'm now trying to clean my code and make it more generic, as well as > better > > in line with the Linux driver model. I would also like to include it in > the > > mainline kernel if there is interest. > > Is it a platform-driver ? What do you provide in platform_data ? > > > > > Here is a description of the current architecture (refer to diagrams > > below): The fpgaload module controls one output GPIOs (PROG), and two > input > > GPIOs (INIT and DONE). These GPIOs are specified in board setup code. > Both > > fpgaload_ser and fpgaload_par modules export a single function to write a > > byte. The fpgaload driver is a char device to which we can write > > (/dev/fpgaload) to program a bitstream (FPGA firmware) inside the FPGA. > > You should probably consider using request_firmware to load the bitstream > from > the userspace and possibly add a /sys interface to export some attributes > like : > > - GPIOs being used between the host and the FPGA > - status (i.e : programmed, not programmed ...) > - FPGA vendor, type ... > > > The > > fpgaload driver will toggle the GPIOs to initiate programming and the > then > > call the corresponding write_byte function based on the interface type > > specified in board setup code (serial or parallel, or any future > interface > > desired). > > > The problem with that approach is that when loading the fpgaload module > > with modprobe, it will automatically try to load the fpgaload_ser and > > fpgaload_par modules, even if only serial interface was specified in > board > > setup code for example. This is not good when building a kernel for > similar > > but different boards. > > What about something like that : > > - fpgaload-core which contains all the code that can be shared between the > drivers like requesting firmware, providing sysfs attributes, > - fpgaload-spi would handle the low-level SPI connection > - fpgaload-par would handle the low-level parallel connection > > fpgaload-ser and par would register with fpgaload-core and they could > register > a fpga loading callback which is low-level specific for instance. Platform > code would instantiate the core driver. That way, adding support for other > loading protocols like slave serial or master serial can be done easily. > > > > > Probably a better approach would be for the fpgaload_Ser and fpgaload_par > > modules to register themselves with the fpgaload module. Then, should the > > fpgaload module be built using a BUS driver structure? Or anyone having > any > > suggestions on how it should be implemented? > -- > Best regards, Florian Fainelli > Email : florian@openwrt.org > http://openwrt.org > ------------------------------- > -- > To unsubscribe from this list: send the line "unsubscribe linux-embedded" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > ----- End forwarded message ----- > Wookey > -- > Principal hats: Balloonz - Toby Churchill - Aleph One - Debian > http://wookware.org/ > > _______________________________________________ > Balloon mailing list > Balloon@balloonboard.org > http://balloonboard.org/mailman/listinfo/balloon >