From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jose Abreu Subject: Re: [PATCH 5/5 v4] ASoC: dwc: Update DOCUMENTATION for I2S Driver Date: Mon, 11 Apr 2016 10:24:54 +0100 Message-ID: <570B6D66.4080309@synopsys.com> References: <20160407175326.GX1924@sirena.org.uk> <570782BF.10402@synopsys.com> <5707D3AD.8030308@metafoo.de> <5707D780.4050406@synopsys.com> <570917E9.8020804@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtprelay.synopsys.com (smtprelay.synopsys.com [198.182.47.9]) by alsa0.perex.cz (Postfix) with ESMTP id B512126154C for ; Mon, 11 Apr 2016 11:25:32 +0200 (CEST) In-Reply-To: <570917E9.8020804@metafoo.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Lars-Peter Clausen , Jose Abreu , Mark Brown Cc: alsa-devel@alsa-project.org, Vineet.Gupta1@synopsys.com, Alexey.Brodkin@synopsys.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, lgirdwood@gmail.com, CARLOS.PALMINHA@synopsys.com, tiwai@suse.com, linux-snps-arc@lists.infradead.org List-Id: alsa-devel@alsa-project.org Hi Lars, On 09-04-2016 15:55, Lars-Peter Clausen wrote: > On 04/08/2016 06:08 PM, Jose Abreu wrote: >> Hi Lars, >> >> >> On 08-04-2016 16:52, Lars-Peter Clausen wrote: >>> On 04/08/2016 12:06 PM, Jose Abreu wrote: >>>> Hi Mark, >>>> >>>> >>>> On 07-04-2016 18:53, Mark Brown wrote: >>>>> On Thu, Apr 07, 2016 at 05:53:59PM +0100, Jose Abreu wrote: >>>>> >>>>>> + Optional properties: >>>>>> + - snps,use-dmaengine: If set the driver will use ALSA DMA engine. If set >>>>>> + it is required to use the properties 'dmas' and 'dma-names'. >>>>> This is not a good interface, it's describing Linux internal APIs. If >>>>> the device needs to operate in PIO mode it should just do that. >>>> I added this interface because there is no direct way to check if DMA is >>>> available on the I2S controller so it is not possible to automatically change >>>> between DMA and PIO mode. As the I2S controller can be built with or without DMA >>>> support it is necessary to somehow check if DMA is enabled or not and according >>>> to that use either ALSA DMA engine or the custom platform driver sent in these >>>> patches. I did not want to remove drivers functionality so I added this property >>>> to the DT. This way a user can select between DMA and PIO mode. >>> That's OK, but you need to describe the hardware, not the indented behavior >>> of the software driver. >>> >> Is this okay: "snps,use-dmaengine: Set this boolean paramater if I2S controller >> has DMA support. If set the properties 'dmas' and 'dma-names' must be also set" ? > The description is better. But the name of the property is still imperative > rather then descriptive. It tells the software what should be done rather > then describing what the hardware looks like. > > Since there is already the dmas property which is present if a DMA is > connected and is absent when no DMA is present it should be enough to just > check that property rather than requiring an additional one. Ok, will then use the DMA property to decide which mode to use: PIO or DMA. > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel Best regards, Jose Miguel Abreu