[alsa-devel] ASoC: Using mxs-saif with simple-card

7 Jan 2017


      Hi,
I am trying to use the simple-card framework on a custom i.MX28 board.
There are two SAIF modules (saif0 and saif1) instantiated on the cpu. A
reference for the platform driver is mxs-sgtl5000. The two cpu dais
saif0 and saif1 are connected to the audio codec sgtl5000. saif0 is
used to playback and saif1 is used to capture.
Unfortunately, I do not have a sgtl5000 codec, but a pcm5102a, a wm8524
and wm8731 to play with.
For all those codec I copied the mxs-sgtl5000 driver, e.g. mxs-
pcm5102a, mxs-wm8524, mxs-wm8731. I will refer to these drivers as mxs-
<codec> later. The only difference was in setting the mclk. That's why
I'm interested in using the simple-card driver for this platform.
With the help of Mans Rullgard I came up with these parts of the device
tree node when using the wm8731 codec:
sound {
    compatible = "simple-audio-card";
    simple-audio-card,name = "hbm10-wm8731";
    simple-audio-card,widgets =
    			"Headphone", "Headphone Jack",
    			"Microphone", "Microphone Jack",
    			"Line", "Line Jack";
    simple-audio-card,routing =
    			"Headphone Jack", "RHPOUT",
    			"Headphone Jack", "LHPOUT",
    			"LLINEIN", "Line Jack",
    			"MICIN", "Mic Bias",
    			"Mic Bias", "Microphone Jack";
simple-audio-card,dai-link@0 {
    	format = "i2s";
    	bitclock-master = <&dai0_master>;
    	frame-master = <&dai0_master>;
    	mclk-fs = <256>;
dai0_master: cpu {
    		sound-dai = <&saif0>;
    	};
codec {
    		sound-dai = <&wm8731>;
    		clocks = <&saif0>;
    	};
    };
simple-audio-card,dai-link@1 {
    	format = "i2s";
    	bitclock-master = <&dai1_master>;
    	frame-master = <&dai1_master>;
    	mclk-fs = <256>;
dai1_master: cpu {
    		sound-dai = <&saif1>;
    	};
codec {
    		sound-dai = <&wm8731>;
    	};
    };
};
&saif0 {
    #sound-dai-cells = <0>;
    pinctrl-names = "default";
    pinctrl-0 = <&saif0_pins_a>;
    assigned-clocks = <&clks 53>;
    assigned-clock-rates = <12288000>;
    status = "okay";
};
&saif1 {
    #sound-dai-cells = <0>;
    pinctrl-names = "default";
    pinctrl-0 = <&saif1_pins_a>;
    fsl,saif-master = <&saif0>;
    status = "okay";
};
&i2c0 {
    pinctrl-names = "default";
    pinctrl-0 = <&i2c0_pins_a>;
    status = "okay";
wm8731: wm8731@1a {
    	#sound-dai-cells = <0>;
    	compatible = "wlf,wm8731";
    	reg = <0x1a>;
    };
};
...
From my understanding of the simple-card framework this should connect
saif0 (cpu dai) <-> wm8731 (codec) and saif1 (cpu dai) <-> wm8731
(codec) as it is done in the probe function of the mxs-<codec> driver,
right?
However, this gives me a warning while bringing up the board:
sysfs: cannot create duplicate filename '/devices/soc0/sound/mxs-saif-
wm8731-hifi'.
Note, that the simple-card framework works fine for mxs-saif if using
only the dai0 link (playback) and leaving the dai1 link (capture).
Am I doing something wrong here?
Is it possible to map the two dai links using the current simple-card
framework?
Is anyone using the simple-card framework on mxs-saif using both
playback and capture?
Best regards,
Jörg Krause