From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Trumtrar Subject: Re: [PATCH v2 2/3] ARM: dts: socfpga: fpga bridges bindings docs Date: Fri, 24 Oct 2014 09:00:42 +0200 Message-ID: <20141024070042.GL10262@pengutronix.de> References: <1414108267-22058-1-git-send-email-atull@opensource.altera.com> <1414108267-22058-3-git-send-email-atull@opensource.altera.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1414108267-22058-3-git-send-email-atull@opensource.altera.com> Sender: linux-kernel-owner@vger.kernel.org To: atull@opensource.altera.com Cc: jgunthorpe@obsidianresearch.com, hpa@zytor.com, monstr@monstr.eu, michal.simek@xilinx.com, rdunlap@infradead.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, pantelis.antoniou@konsulko.com, robh+dt@kernel.org, grant.likely@linaro.org, iws@ovro.caltech.edu, linux-doc@vger.kernel.org, pavel@denx.de, broonie@kernel.org, philip@balister.org, rubini@gnudd.com, jason@lakedaemon.net, kyle.teske@ni.com, nico@linaro.org, balbi@ti.com, m.chehab@samsung.com, davidb@codeaurora.org, rob@landley.net, davem@davemloft.net, cesarb@cesarb.net, sameo@linux.intel.com, akpm@linux-foundation.org, linus.walleij@linaro.org, mgerlach@opensource.altera.com, delicious.quinoa@gmail.com, dinguyen@opensource.altera.com, yvanderv@opensource.altera.com List-Id: devicetree@vger.kernel.org Hi! On Thu, Oct 23, 2014 at 06:51:06PM -0500, atull@opensource.altera.com wrote: > From: Alan Tull (...) > diff --git a/Documentation/devicetree/bindings/fpga/altera-hps2fpga-bridge.txt b/Documentation/devicetree/bindings/fpga/altera-hps2fpga-bridge.txt > new file mode 100644 > index 0000000..bc24a2e > --- /dev/null > +++ b/Documentation/devicetree/bindings/fpga/altera-hps2fpga-bridge.txt > @@ -0,0 +1,53 @@ > +Altera FPGA/HPS Bridge Driver > + > +This driver manages a bridge between a FPGA and a host processor system (HPS). > +User space can enable or disable the bridge by writing a "1" or a "0", > +respectively, to its enable file under bridge's entry in > +/sys/class/fpga-bridge. Typically, one disables the bridges before > +reprogramming the FPGA. Once the FPGA is reprogrammed, the bridges are > +reenabled. > + NAK. This is all linux specific and doesn't belong here. > +Required properties: > + > + - compatible : should contain one of: > + "altr,socfpga-hps2fpga-bridge" > + "altr,socfpga-lwhps2fpga-bridge" > + "altr,socfpga-fpga2hps-bridge" > + > + - clocks : clocks used by this module > + > + - altr,l3-syscon : phandle of the l3 interconnect module > + L3 shouldn't be a syscon. Have you tried dumping the regmap in the debugfs if L3 is a syscon? Doesn't work. > +Optional properties: > + - label : name that you want this bridge to show up as under > + /sys/class/fpga-bridge. Default is br if this is > + not specified. > + Why? Linux-specific. > + - init-val : 0 if driver should disable bridge at startup > + 1 if driver should enable bridge at startup > + driver leaves bridge in current state if property not > + specified. > + Configuration in the DT? Really? > +Example: > + hps_fpgabridge0: fpgabridge@0 { > + compatible = "altr,socfpga-hps2fpga-bridge"; > + label = "hps2fpga"; > + altr,l3-syscon = <&l3regs>; > + clocks = <&l4_main_clk>; > + init-val = <1>; > + }; > + > + hps_fpgabridge1: fpgabridge@1 { > + compatible = "altr,socfpga-lwhps2fpga-bridge"; > + label = "lwhps2fpga"; > + altr,l3-syscon = <&l3regs>; > + clocks = <&l4_main_clk>; > + init-val = <0>; > + }; > + > + hps_fpgabridge2: fpgabridge@2 { > + compatible = "altr,socfpga-fpga2hps-bridge"; > + label = "fpga2hps"; > + altr,l3-syscon = <&l3regs>; > + clocks = <&l4_main_clk>; > + }; The bridges are the buses into the FPGA. This has to be accomodated. The bridges have two specified memory ranges: one the address space of the bus, the second the register space for configuration. This binding does NOT correctly describe the hardware. Sorry. Regards, Steffen -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |