From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753289AbbIKR4B (ORCPT ); Fri, 11 Sep 2015 13:56:01 -0400 Received: from mail-wi0-f181.google.com ([209.85.212.181]:33447 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752849AbbIKR4A (ORCPT ); Fri, 11 Sep 2015 13:56:00 -0400 Date: Fri, 11 Sep 2015 18:55:55 +0100 From: Lee Jones To: Peter Griffin Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, srinivas.kandagatla@gmail.com, maxime.coquelin@st.com, patrice.chotard@st.com, vinod.koul@intel.com, robh+dt@kernel.org, dmaengine@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2 7/9] ARM: STi: DT: STiH407: Add FDMA driver dt nodes. Message-ID: <20150911175555.GF18779@x1> References: <1441980871-24475-1-git-send-email-peter.griffin@linaro.org> <1441980871-24475-8-git-send-email-peter.griffin@linaro.org> <20150911162749.GD18779@x1> <20150911164822.GA1150@griffinp-ThinkPad-X1-Carbon-2nd> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20150911164822.GA1150@griffinp-ThinkPad-X1-Carbon-2nd> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 11 Sep 2015, Peter Griffin wrote: > On Fri, 11 Sep 2015, Lee Jones wrote: > > On Fri, 11 Sep 2015, Peter Griffin wrote: > > > > > These nodes are required to get the fdma driver working > > > on STiH407 based silicon. > > > > > > Signed-off-by: Peter Griffin > > > --- > > > arch/arm/boot/dts/stih407-family.dtsi | 51 +++++++++++++++++++++++++++++++++++ > > > 1 file changed, 51 insertions(+) > > > > > > diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi > > > index 838b812..da07474b 100644 > > > --- a/arch/arm/boot/dts/stih407-family.dtsi > > > +++ b/arch/arm/boot/dts/stih407-family.dtsi > > > @@ -565,5 +565,56 @@ > > > <&phy_port2 PHY_TYPE_USB3>; > > > }; > > > }; > > > + > > > + fdma0: fdma0-audio@8e20000 { > > > > I'm not familiar with the FDMA driver, so can't comment knowledgeably, > > but the part of @ should only describe the > > type of hardware. I believe in this case it should just be > > dma@08e20000. Also notice the leading zero in the address, which I > > believe mitigates possible confusion. Then you be more specific with > > the label, so something like 'fdma-audio' seems appropriate here. > > Ok, can change to that format in v3. > > > > > > + compatible = "st,stih407-fdma-mpe31"; > > > + reg = <0x8e20000 0x20000>; > > > > I personally find padding up to 32bits helpful in the addresses. > > None of the stih407-family nodes I can see have this padding, including > the ones merged by you. Nither of these two facts mean it's correct. I'm happy to write a patch to correct them all. Bear in mind that this isn't a hard and fast rule. Both work and are legal. I just think the padding is more consistent. > > > + interrupts = ; > > > + dma-channels = <16>; > > > + #dma-cells = <3>; > > > + st,fdma-id = <0>; > > > > We usually shy away from ID properties. What is it required for in > > this case? > > Yes Rob did already mention that over here, see my reply at the bottom > http://www.spinics.net/lists/devicetree/msg92529.html. > > However I can't think of any other useful properties we could add > to derive this information. The fdma controller number is used > by the driver to generate a unique firmware filename. Who chooses the naming scheme of the firmware binary? Is there any reason they can't be: fdma_STiH407_audio.elf fdma_STiH407_app.elf fdma_STiH407_free_running.elf Then you can have a different compatible for each. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog