From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH 1/4] dt-bindings: Document the dmas and dma-names properties for bcm2835-analog-audio Date: Mon, 20 Mar 2017 11:50:09 -0500 Message-ID: <20170320165009.ylrohjwettdy2lgf@rob-hp-laptop> References: <20170312063820.19313-1-mzoran@crowfest.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20170312063820.19313-1-mzoran@crowfest.net> 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: Michael Zoran Cc: mark.rutland@arm.co, stefan.wahren@i2se.com, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, tiwai@suse.com, eric@anholt.net, linux-rpi-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Sat, Mar 11, 2017 at 10:38:17PM -0800, Michael Zoran wrote: > Add documentation for the DMA properties required when using the > PWM controller of the bcm2835 for analog audio output. > > Signed-off-by: Michael Zoran > --- > Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt > index cf573e85b11d..08fc06fc083a 100644 > --- a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt > +++ b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt > @@ -1,14 +1,21 @@ > BCM2835 PWM controller (Raspberry Pi controller) > > Required properties: > -- compatible: should be "brcm,bcm2835-pwm" > +- compatible: should be "brcm,bcm2835-pwm" or "brcm,bcm2835-analog-audio" Compatibles are not for selecting usage modes. You should describe the connection to the pwm that makes it an audio output rather than change the compatible. > - reg: physical base address and length of the controller's registers > - clocks: This clock defines the base clock frequency of the PWM hardware > system, the period and the duty_cycle of the PWM signal is a multiple of > the base period. > + > +Required properties(PWM Output): > - #pwm-cells: Should be 2. See pwm.txt in this directory for a description of > the cells format. > > +Required properties(Audio Output): > +- dmas: Should contain one entry pointing to the DMA channel used to > + transfer audio data > +- dma-names: Should contain "tx" > + > Examples: > > pwm@2020c000 { > -- > 2.11.0 >