From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v2 1/4] net: dt-bindings: Document the new Meson8b and GXBB DWMAC bindings Date: Mon, 22 Aug 2016 17:25:30 +0200 Message-ID: <4041259.IszN4229Cj@wuerfel> References: <20160815164100.27766-1-martin.blumenstingl@googlemail.com> <7308700.atIMKyMFZU@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: Sender: netdev-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Martin Blumenstingl , mark.rutland@arm.com, devicetree@vger.kernel.org, sboyd@codeaurora.org, catalin.marinas@arm.com, alexandre.torgue@st.com, khilman@baylibre.com, mturquette@baylibre.com, will.deacon@arm.com, robh+dt@kernel.org, peppe.cavallaro@st.com, carlo@caione.org, linux-amlogic@lists.infradead.org, netdev@vger.kernel.org List-Id: devicetree@vger.kernel.org On Monday, August 22, 2016 2:04:49 PM CEST Martin Blumenstingl wrote: > On Mon, Aug 22, 2016 at 1:55 PM, Arnd Bergmann wrote: > > On Saturday, August 20, 2016 11:35:35 AM CEST Martin Blumenstingl wrote: > >> +- reg: The first register range should be the one of the DWMAC > >> + controller. The second range is is for the Amlogic specific > >> + configuration (for example the PRG_ETHERNET register range > >> + on Meson8b and newer) > >> > > ... > > > >> +Example for GXBB: > >> + ethmac: ethernet@c9410000 { > >> + compatible = "amlogic,meson-gxbb-dwmac", "snps,dwmac"; > >> + reg = <0x0 0xc9410000 0x0 0x10000>, > >> + <0x0 0xc8834540 0x0 0x8>; > >> > > > > The address "0xc8834540" suggests that this is part of a larger register > > range that is used for various things, i.e. a "syscon" type of device. > You are right, these are part of the cbus range (which is already > defined in meson-gxbb.dtsi) > > > How about making this a syscon reference rather than a "reg" address? > The first version of my patch ([0]) used > syscon_regmap_lookup_by_phandle. Maybe I did it wrong (and I should > have passed the cbus syscon-node instead of defining a new one just > for the 2x32bit PRG_ETHERNET registers). > I am perfectly fine with either way - however it seems that some other > dwmac glue implementations are also using a second set of resources > (that doesn't automatically make it "correct" though). It really depends on the kind of SoC. Some may have a suboptimal binding, on some others there may be a distinct register area that just contains a few additional registers for the dwmac. Arnd