Great, I'll integrate this into my testing setup so I don't need an external codec.

BTW, I have a github fork at https://github.com/ccrome/linux-caleb-dev/tree/linux-mx6-working-branch, which has my patches in it. Some patches are generic SSI related stuff, and others are specific hacks (like in the tms320aic3x.c file) for my hardware. I'll separate those out at some point to I have a clean set of patches that may be applied.

-Caleb

On Mon, Nov 23, 2015 at 1:58 AM, arnaud.mouiche@invoxia.com arnaud.mouiche@invoxia.com wrote:

To answer to myself:

• there are some "virtual" codecs available : "bt-sco", "linux,spdif-dit" and "linux,spdif-dir". but none of them is fully generic.
• a "snd-soc-dummy-dai" codec is implemented in soc-utils.c. yet, no device-tree bindings are available, except if a patch like the following one is applied

--- a/sound/soc/soc-utils.c +++ b/sound/soc/soc-utils.c @@ -19,6 +19,7 @@ #include <sound/pcm.h> #include <sound/pcm_params.h> #include <sound/soc.h> +#include <linux/module.h>

int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots) { @@ -151,9 +152,18 @@ static int snd_soc_dummy_remove(struct platform_device *pdev) return 0; }

+#ifdef CONFIG_OF +static const struct of_device_id soc_dummy_ids[] = {

• { .compatible = "linux,snd-soc-dummy", },
• { }

+}; +MODULE_DEVICE_TABLE(of, soc_dummy_ids); +#endif

static struct platform_driver soc_dummy_driver = { .driver = { .name = "snd-soc-dummy",

•    .of_match_table = of_match_ptr(soc_dummy_ids),
  

  }, .probe = snd_soc_dummy_probe, .remove = snd_soc_dummy_remove,

Once done, here is a DTS example for imx6sl:

&audmux { ssi3 { fsl,audmux-port = <6>; fsl,port-config = < #ifdef SSI_TEST_MASTER 0x00000000 #else (IMX_AUDMUX_V2_PTCR_TFSDIR | IMX_AUDMUX_V2_PTCR_TFSEL(4) | IMX_AUDMUX_V2_PTCR_TCLKDIR | IMX_AUDMUX_V2_PTCR_TCSEL(4)) #endif IMX_AUDMUX_V2_PDCR_RXDSEL(4) >; };

port5 {
    fsl,audmux-port = <4>;
    fsl,port-config = <

#ifdef SSI_TEST_MASTER (IMX_AUDMUX_V2_PTCR_TFSDIR | IMX_AUDMUX_V2_PTCR_TFSEL(6) | IMX_AUDMUX_V2_PTCR_TCLKDIR | IMX_AUDMUX_V2_PTCR_TCSEL(6)) #else 0x00000000 #endif IMX_AUDMUX_V2_PDCR_RXDSEL(6) >; }; };

&ssi3 { status = "okay";

// select the a clock parent suitable for 48000 Hz sampling rate
assigned-clocks = <&clks IMX6SL_CLK_SSI3_SEL>, <&clks IMX6SL_CLK_SSI3>;
assigned-clock-parents = <&clks IMX6SL_CLK_PLL4_AUDIO_DIV>;
assigned-clock-rates = <0>, <49152000>;

};

/ { codec_test: codec_test { compatible = "linux,snd-soc-dummy"; #sound-dai-cells = <0>; };

sound@2 {
    compatible = "simple-audio-card";
    simple-audio-card,name = "test";
    simple-audio-card,format="dsp_a";

#ifdef SSI_TEST_MASTER simple-audio-card,frame-master = <&sound2_ssi>; simple-audio-card,bitclock-master = <&sound2_ssi>; #else simple-audio-card,frame-master = <&codec_test>; simple-audio-card,bitclock-master = <&codec_test>; #endif sound2_ssi: simple-audio-card,cpu { sound-dai = <&ssi3>; system-clock-frequency = <1536000>; dai-tdm-slot-num = <2>; dai-tdm-slot-width = <16>; }; sound2codec: simple-audio-card,codec { sound-dai = <&codec_test>; }; };

};

Le 20/11/2015 02:24, Caleb Crome a écrit :

...

I've been wondering about that too. I don't know how to do it easily.

-Caleb

On Thu, Nov 19, 2015 at 9:26 AM, arnaud.mouiche@invoxia.com arnaud.mouiche@invoxia.com wrote:

...

Hello,

I'm starting debugging / testing all the fsl_ssi issues (see Caleb's previous post).

First step I just need to setup a DTS entry for "simple-card" + fake codec to generate arbitrary PCM bus output (1 to 16 channels, various TDM, various sampling rate and format and master/slave role) I will then plug my logical analyser, or do some loopback, or plug a FPGA to generate/check some patterns.

Is there such "fake codec" somewhere. Indeed, something that look like the bt-sco codec, but without rate/format/channel limitations ? Or does the "simple-card" even needs one ?

Regards, Arnaud