From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [PATCH v1 2/3] ARM: dts: tegra20: Add DMA phandle to 'fuse' node Date: Tue, 26 Sep 2017 23:10:49 +0100 Message-ID: <59edd5b4-754a-93eb-8529-a5ff140c1a37@nvidia.com> References: <27dadd0335aac71c9d4d613c33a6a1d0a285afa4.1506378772.git.digetx@gmail.com> <8268404736bd3c254f8516109465bb8db4739c33.1506378772.git.digetx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dmitry Osipenko , Thierry Reding Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 26/09/17 22:54, Dmitry Osipenko wrote: > On 27.09.2017 00:25, Jon Hunter wrote: >> >> On 26/09/17 21:54, Jon Hunter wrote: >>> >>> On 25/09/17 23:35, Dmitry Osipenko wrote: >>>> Currently efuse driver requests DMA channel from an arbitrary DMA device, >>>> it is not a problem since there is only one DMA provider for Tegra20 yet, >>>> but it will become troublesome once another provider would be added. >>>> >>>> Signed-off-by: Dmitry Osipenko >>>> --- >>>> arch/arm/boot/dts/tegra20.dtsi | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi >>>> index fb485a5e63d7..f1579c9a7ef4 100644 >>>> --- a/arch/arm/boot/dts/tegra20.dtsi >>>> +++ b/arch/arm/boot/dts/tegra20.dtsi >>>> @@ -600,6 +600,8 @@ >>>> clock-names = "fuse"; >>>> resets = <&tegra_car 39>; >>>> reset-names = "fuse"; >>>> + dmas = <&apbdma 0>; >>>> + dma-names = "fuse"; >>>> }; >>>> >>>> pcie@80003000 { >>>> >>> >>> Acked-by: Jon Hunter >> >> Actually, request-id '0' is a valid request. Does this work ok? >> > > It works fine, I have verified that reading on CPU == reading by DMA. The > REQ_SEL 0 is "Not Assigned" and seems acts as DRQ=1. I know that it is not > entirely correct, but APB DMA driver is hardcoded to the master mode, while we > need slave mode. Looking at the TRM I see that it is 'CNTR_REQ' so I am not sure if this is a timer/counter that is driving this. Jon -- nvpublic