From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kenneth Westfield Subject: Re: [Patch V7 02/10] ASoC: qcom: Document LPASS CPU bindings Date: Thu, 5 Mar 2015 17:51:31 -0800 Message-ID: <20150306015131.GA15850@kwestfie-linux.qualcomm.com> References: <1425428519-12224-1-git-send-email-kwestfie@codeaurora.org> <1425428519-12224-3-git-send-email-kwestfie@codeaurora.org> <7E5AFC65-1705-4BDC-B57F-0444E83A8987@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <7E5AFC65-1705-4BDC-B57F-0444E83A8987-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kumar Gala Cc: Kenneth Westfield , Mark Brown , Takashi Iwai , Liam Girdwood , Banajit Goswami , Patrick Lai , David Brown , Bryan Huntsman , Greg KH , ALSA Mailing List , MSM Mailing List , Device Tree Mailing List , Kernel Mailing List List-Id: linux-arm-msm@vger.kernel.org On Thu, Mar 05, 2015 at 12:52:30PM -0600, Kumar Gala wrote: > > On Mar 3, 2015, at 6:21 PM, Kenneth Westfield wrote: > > > +++ b/Documentation/devicetree/bindings/sound/qcom,lpass-cpu.txt > > @@ -0,0 +1,49 @@ > > +* Qualcomm Technologies LPASS CPU DAI > > + > > +Required subnodes: > > + > > +- qcom,adsp : Audio DSP sub-node > > + > > +Optional Audio DSP subnode properties: > > + > > +- status : "disabled" indicates the adsp is not available. > > + > > What is the intent of this subnode? > >>From the cover letter: Even though the ipq806x LPASS does not contain an audio DSP, other SOCs do have one. For those SOCs, the audio DSP typically controls the hardware blocks in the LPASS. Hence, different CPU DAI driver(s) would need to be used in order to facilitate audio with the DSP. As such, the LPASS DT contains an adsp subnode, which is disabled for this SOC. The same subnode should be enabled and populated for other SOCs that do contain an audio DSP. Not using the audio DSP would require different CPU DAI driver(s), in addition to possible bootloader and/or firmware changes. This was the result of a request from Mark. See here: http://thread.gmane.org/gmane.linux.drivers.devicetree/109331/focus=11633 -- Kenneth Westfield Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html