From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Stultz Subject: Re: [PATCH 6/8 v2] arm64: dts: hi3660: Add dma to uart nodes Date: Fri, 4 Jan 2019 21:37:23 -0800 Message-ID: References: <1546635388-13795-1-git-send-email-john.stultz@linaro.org> <1546635388-13795-7-git-send-email-john.stultz@linaro.org> <20190105034904.GD2477@Mani-XPS-13-9360> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Manivannan Sadhasivam Cc: Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Ryan Grachek , Zhuangluan Su , Tanglei Han , lkml , Wei Xu , Rob Herring , linux-arm-kernel List-Id: devicetree@vger.kernel.org On Fri, Jan 4, 2019 at 8:34 PM John Stultz wrote: > > On Fri, Jan 4, 2019 at 7:49 PM Manivannan Sadhasivam > wrote: > > > > Hi John, > > > > On Fri, Jan 04, 2019 at 12:56:26PM -0800, John Stultz wrote: > > > Try to add DMA support to the uart nodes following > > > the assignments made in the dts from the victoria vendor kernel > > > here: > > > https://consumer.huawei.com/en/opensource/detail/?siteCode=worldwide&keywords=p10&fileType=openSourceSoftware&pageSize=10&curPage=1 > > > > > > Cc: Tanglei Han > > > Cc: Zhuangluan Su > > > Cc: Ryan Grachek > > > Cc: Manivannan Sadhasivam > > > Cc: Wei Xu > > > Cc: Rob Herring > > > Cc: Mark Rutland > > > Cc: linux-arm-kernel@lists.infradead.org > > > Cc: devicetree@vger.kernel.org > > > Signed-off-by: John Stultz > > > --- > > > arch/arm64/boot/dts/hisilicon/hi3660.dtsi | 10 ++++++++++ > > > 1 file changed, 10 insertions(+) > > > > > > diff --git a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi > > > index 20ae40d..aaa2b04 100644 > > > --- a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi > > > +++ b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi > > > @@ -466,6 +466,8 @@ > > > compatible = "arm,pl011", "arm,primecell"; > > > reg = <0x0 0xfdf02000 0x0 0x1000>; > > > interrupts = ; > > > + dma-names = "rx", "tx"; > > > + dmas = <&dma0 0 &dma0 1>; > > > > Usage of DMA channel 0 contradicts with the description provided in > > patch, "dma: k3dma: Add support to dma_avail_chan". > > Hrm. Good point. I'll double check w/ Dr Su on this, I'm not sure if > that inconsistency is due to the the vendor kernel (where these came > from) having different reserved channels or just something overlooked > if the uart0 is not actually being used (as we find on hikey960 as > well). Hrm. So it seems like uart0 is mapped to the dma0 chan0, but the device specific files in the vendor tree overwite the dma values: serial0: uart@fdf02000 { pinctrl-names = "default", "idle"; pinctrl-0 = <&gpio053_pmx_func &gpio054_pmx_func &gpio053_cfg_func &gpio054_cfg_func>; pinctrl-1 = <&gpio053_pmx_idle &gpio054_pmx_idle &gpio053_cfg_idle &gpio054_cfg_idle>; dma-names = "", ""; dmas = <>; clock-rate = <0 19200000>; status = "ok"; }; But I went ahead and pulled the dma values on uart0. thaks -john