From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: Re: [PATCH v4 2/3] ASoC: add fsl_audmix DT binding documentation Date: Fri, 25 Jan 2019 11:43:16 -0800 Message-ID: <20190125194315.GA21222@Asurada-Nvidia.nvidia.com> References: <1548155654-12985-1-git-send-email-viorel.suman@nxp.com> <1548155654-12985-3-git-send-email-viorel.suman@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1548155654-12985-3-git-send-email-viorel.suman@nxp.com> Sender: linux-kernel-owner@vger.kernel.org To: Viorel Suman Cc: Liam Girdwood , Mark Brown , Rob Herring , Mark Rutland , Jaroslav Kysela , Takashi Iwai , Timur Tabi , Xiubo Li , Fabio Estevam , "S.j. Wang" , Daniel Baluta , Cosmin Samoila , "alsa-devel@alsa-project.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , dl-linux-imx , Viorel Suman List-Id: devicetree@vger.kernel.org On Tue, Jan 22, 2019 at 11:14:27AM +0000, Viorel Suman wrote: > Add the DT binding documentation for NXP Audio Mixer > CPU DAI driver. > > Signed-off-by: Viorel Suman > --- > .../devicetree/bindings/sound/fsl,audmix.txt | 54 ++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > create mode 100644 Documentation/devicetree/bindings/sound/fsl,audmix.txt > > diff --git a/Documentation/devicetree/bindings/sound/fsl,audmix.txt b/Documentation/devicetree/bindings/sound/fsl,audmix.txt > new file mode 100644 > index 0000000..45f807e > --- /dev/null > +++ b/Documentation/devicetree/bindings/sound/fsl,audmix.txt > @@ -0,0 +1,54 @@ > +NXP Audio Mixer (AUDMIX). > + > +The Audio Mixer is a on-chip functional module that allows mixing of two > +audio streams into a single audio stream. Audio Mixer has two input serial > +audio interfaces. These are driven by two Synchronous Audio interface > +modules (SAI). Each input serial interface carries 8 audio channels in its > +frame in TDM manner. Mixer mixes audio samples of corresponding channels > +from two interfaces into a single sample. Before mixing, audio samples of > +two inputs can be attenuated based on configuration. The output of the > +Audio Mixer is also a serial audio interface. Like input interfaces it has > +the same TDM frame format. This output is used to drive the serial DAC TDM > +interface of audio codec and also sent to the external pins along with the > +receive path of normal audio SAI module for readback by the CPU. > + > +The output of Audio Mixer can be selected from any of the three streams > + - serial audio input 1 > + - serial audio input 2 > + - mixed audio > + > +Mixing operation is independent of audio sample rate but the two audio > +input streams must have same audio sample rate with same number of channels > +in TDM frame to be eligible for mixing. > + > +Device driver required properties: > +================================= > + - compatible : Compatible list, contains "fsl,imx8qm-audmix" > + > + - reg : Offset and length of the register set for the device. > + > + - clocks : Must contain an entry for each entry in clock-names. > + > + - clock-names : Must include the "ipg" for register access. > + > + - power-domains : Must contain the phandle to AUDMIX power domain node > + > + - dais : Must contain a list of phandles to AUDMIX connected > + DAIs. The current implementation requires two phandles > + to SAI interfaces to be provided, the first SAI in the > + list being used to route the AUDMIX output. > + > + - model : Must contain machine driver name which will configure > + and instantiate the appropriate audio card. I don't feel this is necessary for DT node. The driver should be able to figure out a proper name for the machine driver: it could use the compatible string to get "imx8qm-audmix" as the name like fsl_ssi; Or it could have built-in "imx-audmix" of_device_id data corresponding to "fsl,imx8qm-audmix" compatible string -- for any non-imx compatible in the future, use something else. Thanks Nic > + > +Device driver configuration example: > +====================================== > + audmix: audmix@59840000 { > + compatible = "fsl,imx8qm-audmix"; > + reg = <0x0 0x59840000 0x0 0x10000>; > + clocks = <&clk IMX8QXP_AUD_AUDMIX_IPG>; > + clock-names = "ipg"; > + power-domains = <&pd_audmix>; > + dais = <&sai4>, <&sai5>; > + model = "imx-audmix"; > + }; > -- > 2.7.4 >