I2S fsl_ssi_set_dai_fmt() has no effect

[christian_fisch]

Using an I2S driver without an audio codec initialization we were able to create a soundcard that can be used with alsa (both aplay/arecord are working, audio is transmitted, the sound is "off" though) but are unable to influence the format of the I2S interface.

Using debug output I could verify that fsl_ssi_set_dai_fmt() is called during driver initialization with the format parameter I  configured (SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_NB_NF |  SND_SOC_DAIFMT_CBM_CFM) but that doesnt seem to have any effect on the I2S interface of the iMX6.

Even if the format parameter isnt configured at all or I switch to Master Mode the I2S interface doesnt change its operation and is still working the same as always.

Are there any other steps necessary to ensure that a format change applies properly?

[christian_fisch]

We are still using an older kernel (3.10.17) without a SAI implementation. The machine driver is derived from imx-sgtl5000.c just without a full codec implenentation.

#include <linux/module.h>
#include <linux/of_platform.h>
#include <sound/soc.h>
#include <linux/of.h>


#include <../sound/soc/fsl/imx-audmux.h>


struct imx_phone_data {
    struct snd_soc_dai_link dai;
    struct snd_soc_card card;
    struct platform_device *pdev;
};


static int imx_phone_audio_probe(struct platform_device *pdev)
{
    struct device_node *ssi_np, *np = pdev->dev.of_node;
    struct imx_phone_data *data;
    struct platform_device *ssi_pdev;
    int ret = 0, int_port, ext_port;


    /*
      Get the int and ext port from the dtb
    */
    ret = of_property_read_u32(np, "mux-int-port", &int_port);
    if (ret) {
        dev_err(&pdev->dev, "mux-int-port missing or invalid\n");
        return ret;
    }
    ret = of_property_read_u32(np, "mux-ext-port", &ext_port);
    if (ret) {
        dev_err(&pdev->dev, "mux-ext-port missing or invalid\n");
        return ret;
    }
    /*
     * The port numbering in the hardware manual starts at 1, while
     * the audmux API expects it starts at 0.
     */
    int_port--;
    ext_port--;


    /*Configure the audmux*/
    ret = imx_audmux_v2_configure_port(int_port,
                       IMX_AUDMUX_V2_PTCR_SYN |
                       IMX_AUDMUX_V2_PTCR_TFSEL(ext_port) |
                       IMX_AUDMUX_V2_PTCR_TCSEL(ext_port) |
                       IMX_AUDMUX_V2_PTCR_TFSDIR |
                       IMX_AUDMUX_V2_PTCR_TCLKDIR,
                       IMX_AUDMUX_V2_PDCR_RXDSEL(ext_port));
    if (ret) {
        dev_err(&pdev->dev, "audmux internal port setup failed\n");
        return ret;
    }
    ret = imx_audmux_v2_configure_port(ext_port,
                       IMX_AUDMUX_V2_PTCR_SYN,
                       IMX_AUDMUX_V2_PDCR_RXDSEL(int_port));
    if (ret) {
        dev_err(&pdev->dev, "audmux external port setup failed\n");
        return ret;
    }


    //Get the i2s controller from dtb
    ssi_np = of_parse_phandle(pdev->dev.of_node, "ssi-controller", 0);
    if (!ssi_np) {
        dev_err(&pdev->dev, "phandle missing or invalid\n");
        ret = -EINVAL;
        goto fail;
    }


    //find the i2s node and get its pdev struct
    ssi_pdev = of_find_device_by_node(ssi_np);
    if (!ssi_pdev) {
        dev_err(&pdev->dev, "failed to find SSI platform device\n");
        ret = -EINVAL;
        goto fail;
    }


    data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
    if (!data) {
        dev_err(&pdev->dev, "failed to allocate memory\n");
        ret = -ENOMEM;
        goto fail;
    }


    data->dai.name = "Phone HiFi";
    data->dai.stream_name = "Phone Audio";
    data->dai.codec_dai_name = "snd-soc-dummy-dai";
    data->dai.codec_name = "snd-soc-dummy";
    data->dai.cpu_of_node = ssi_np;
    data->dai.platform_of_node = ssi_np;
    data->dai.dai_fmt = SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_NB_NF |
        SND_SOC_DAIFMT_CBM_CFM;


    data->card.dev = &pdev->dev;
    data->card.num_links = 1;
    data->card.dai_link = &data->dai;


    data->pdev = platform_device_register_simple("phone", -1, NULL, 0);
    if (IS_ERR(data->pdev)) {
        ret = PTR_ERR(data->pdev);
        dev_err(&pdev->dev, "register failed: %d\n", ret);
        goto fail;
    }


    //Fill in the card details
    ret = snd_soc_of_parse_card_name(&data->card, "model");
    if (ret)
        goto fail;



    data->card.num_links = 1;
    data->card.owner = THIS_MODULE;
    data->card.dai_link = &data->dai;


    platform_set_drvdata(pdev, &data->card);
    snd_soc_card_set_drvdata(&data->card, data);


    ret = snd_soc_register_card(&data->card);
    if (ret) {
        dev_err(&pdev->dev, "snd_soc_register_card failed: %d\n", ret);
        goto fail;
    }


    of_node_put(ssi_np);


    return 0;


fail:
    if (ssi_np)
        of_node_put(ssi_np);


    return ret;
}


static int imx_phone_audio_remove(struct platform_device *pdev)
{
    struct snd_soc_card *card = platform_get_drvdata(pdev);
    struct imx_phone_data *data = snd_soc_card_get_drvdata(card);
    snd_soc_unregister_card(card);
    platform_device_unregister(data->pdev);


    return 0;
}


static const struct of_device_id imx_phone_dt_ids[] = {
    { .compatible = "fsl,imx-audio-phone", },
    { }
};


MODULE_DEVICE_TABLE(of, imx_phone_dt_ids);


static struct platform_driver imx_phone_driver = {
    .driver = {
        .name = "imx-audio-phone",
        .owner = THIS_MODULE,
        .pm = &snd_soc_pm_ops,
        .of_match_table = imx_phone_dt_ids,
    },
    .probe = imx_phone_audio_probe,
    .remove = imx_phone_audio_remove,
};


module_platform_driver(imx_phone_driver);‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

As said in my intro post the main problem I could detect seems to be that the call to fsl_ssi_set_dai_fmt() doesnt do anything when it should set the i2s format.

[weidong_sun]

hello Christian,

sorry! probably there is something wrong with my understanding your audio application.

On your board, are you using  "IMX6ULL SAI + SGTL5000" ?  

if not, which i.MX processor are you using?

Have a nice day!

B.R,

Weidong

[christian_fisch]

Hello Weidong,

we use an i.MX 6DualPlus (with Kernel 3.10.17).

The audio application looks the following basically:

SIMCOM7600 (snd-soc-dummy) + I2S (ssi1, fsl_ssi).

The code I posted above is from our own machine driver which is based upon the SGTL5000 machine driver.

The Kernel we use doesn't offer any implementation/code for SAI or simple-card.c.

The problem with our driver seems to be that the fsl_ssi side isn't set up properly, the format parameters are set (verified through debbuging) but don't seem to have any effect.

Regards

Christian

[weidong_sun]

Hello Christian

   OK, understood.

Your audio application is like this:

i.MX6DP SSI + DUMMY CODEC -- > Dummy Sound card.

platform driver should be : imx-ssi.c.

I tried to change some code on the basis of yours, see attachment, please!

probably it is not complete, your can try and debug it.

Have a nice day!

B.R,

Weidong

[christian_fisch · Accepted solution]

Hello Weidong,

the code you provided helped me in tracking down the main problem and finally fixing it.

The plattform driver used is still fsl_ssi (imx-ssi doesn't work with a device tree configuration as far as I know) but now it is setup correctly.

What was missing was the call to snd_soc_dai_set_fmt() in imx_hifi_hw_params(). This seems necessary because after the initialziation phase fsl_ssi reverts its fmt parameters every time audio data transfer resumes on the I2S device.

#include <linux/module.h>
#include <linux/of_platform.h>
#include <sound/soc.h>
#include <linux/of.h>

#include <../sound/soc/fsl/imx-audmux.h>

struct imx_phone_data {
    struct snd_soc_dai_link dai;
    struct snd_soc_card card;
    struct platform_device *pdev;
};

struct imx_phone_data *data;

static int imx_hifi_startup(struct snd_pcm_substream *substream)
{
 return 0;
}

static int imx_hifi_hw_params(struct snd_pcm_substream *substream,
   struct snd_pcm_hw_params *params)
{
 struct snd_soc_pcm_runtime *rtd = substream->private_data;
 struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 struct device *dev = data->card.dev;

 int ret = 0;

 ret = snd_soc_dai_set_fmt(cpu_dai, data->dai.dai_fmt);
  if (ret) {
    dev_err(dev, "setting format for cpu dai failed\n");
    return ret;
  }

 return 0;
}

static int imx_hifi_hw_free(struct snd_pcm_substream *substream)
{
 return 0;
}

static struct snd_soc_ops imx_hifi_ops = {
 .startup = imx_hifi_startup,
 .hw_params = imx_hifi_hw_params,
 .hw_free = imx_hifi_hw_free,
};

static int imx_phone_audio_probe(struct platform_device *pdev)
{
    struct device_node *ssi_np, *np = pdev->dev.of_node;
    struct platform_device *ssi_pdev;
    int ret = 0, int_port, ext_port;
    //struct platform_device *cpu_pdev;

    /*
      Get the int and ext port from the dtb
    */
    ret = of_property_read_u32(np, "mux-int-port", &int_port);
    if (ret) {
        dev_err(&pdev->dev, "mux-int-port missing or invalid\n");
        return ret;
    }
    ret = of_property_read_u32(np, "mux-ext-port", &ext_port);
    if (ret) {
        dev_err(&pdev->dev, "mux-ext-port missing or invalid\n");
        return ret;
    }
    /*
     * The port numbering in the hardware manual starts at 1, while
     * the audmux API expects it starts at 0.
     */
    int_port--;
    ext_port--;

    /*Configure the audmux*/
    ret = imx_audmux_v2_configure_port(int_port,
                       IMX_AUDMUX_V2_PTCR_SYN |
                       IMX_AUDMUX_V2_PTCR_TFSEL(ext_port) |
                       IMX_AUDMUX_V2_PTCR_TCSEL(ext_port) |
                       IMX_AUDMUX_V2_PTCR_TFSDIR |
                       IMX_AUDMUX_V2_PTCR_TCLKDIR,
                       IMX_AUDMUX_V2_PDCR_RXDSEL(ext_port));
    if (ret) {
        dev_err(&pdev->dev, "audmux internal port setup failed\n");
        return ret;
    }
    ret = imx_audmux_v2_configure_port(ext_port,
                       IMX_AUDMUX_V2_PTCR_SYN,
                       IMX_AUDMUX_V2_PDCR_RXDSEL(int_port));
    if (ret) {
        dev_err(&pdev->dev, "audmux external port setup failed\n");
        return ret;
    }

    //Get the i2s controller from dtb
    ssi_np = of_parse_phandle(pdev->dev.of_node, "ssi-controller", 0);
    if (!ssi_np) {
        dev_err(&pdev->dev, "phandle missing or invalid\n");
        ret = -EINVAL;
        goto fail;
    }

    //find the i2s node and get its pdev struct
    ssi_pdev = of_find_device_by_node(ssi_np);
    if (!ssi_pdev) {
        dev_err(&pdev->dev, "failed to find SSI platform device\n");
        ret = -EINVAL;
        goto fail;
    }

    data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
    if (!data) {
        dev_err(&pdev->dev, "failed to allocate memory\n");
        ret = -ENOMEM;
        goto fail;
    }

    data->dai.name = "Phone HiFi";
    data->dai.stream_name = "Phone Audio";
    data->dai.codec_dai_name = "snd-soc-dummy-dai";
    data->dai.codec_name = "snd-soc-dummy";
    data->dai.cpu_dai_name = dev_name(&ssi_pdev->dev);
    data->dai.ops = &imx_hifi_ops;
    data->dai.cpu_of_node = ssi_np;
    data->dai.platform_of_node = ssi_np;
    data->dai.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_IB_NF |
        SND_SOC_DAIFMT_CBM_CFM;

    data->card.dev = &pdev->dev;
    data->card.num_links = 1;
    data->card.dai_link = &data->dai;

    data->pdev = platform_device_register_simple("phone", -1, NULL, 0);
    if (IS_ERR(data->pdev)) {
        ret = PTR_ERR(data->pdev);
        dev_err(&pdev->dev, "register failed: %d\n", ret);
        goto fail;
    }

    //Fill in the card details
    ret = snd_soc_of_parse_card_name(&data->card, "model");
    if (ret)
        goto fail;

    data->card.num_links = 1;
    data->card.owner = THIS_MODULE;
    data->card.dai_link = &data->dai;

    platform_set_drvdata(pdev, &data->card);
    snd_soc_card_set_drvdata(&data->card, data);

    ret = snd_soc_register_card(&data->card);
    if (ret) {
        dev_err(&pdev->dev, "snd_soc_register_card failed: %d\n", ret);
        goto fail;
    }

    of_node_put(ssi_np);

    return 0;

fail:
    if (ssi_np)
        of_node_put(ssi_np);

    return ret;
}

static int imx_phone_audio_remove(struct platform_device *pdev)
{
    struct snd_soc_card *card = platform_get_drvdata(pdev);
    struct imx_phone_data *data = snd_soc_card_get_drvdata(card);
    snd_soc_unregister_card(card);
    platform_device_unregister(data->pdev);

    return 0;
}

static const struct of_device_id imx_phone_dt_ids[] = {
    { .compatible = "fsl,imx-audio-phone", },
    { }
};

MODULE_DEVICE_TABLE(of, imx_phone_dt_ids);

static struct platform_driver imx_phone_driver = {
    .driver = {
        .name = "imx-audio-phone",
        .owner = THIS_MODULE,
        .pm = &snd_soc_pm_ops,
        .of_match_table = imx_phone_dt_ids,
    },
    .probe = imx_phone_audio_probe,
    .remove = imx_phone_audio_remove,
};

module_platform_driver(imx_phone_driver);‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Regards

Christian

[weidong_sun]

That's great!

Have a nice day!

Weidong

[weidong_sun]

Hi Christian,

   No matter whether you use real audio codec, your sound card driver must meet architecture Linux ALSA SoC driver:
1. platform driver(CPU side: SAI driver)
2. codec driver (codec driver)
3. machine driver. ( SAI + codec ---> sound card)

Otherwise, sai can't normally work.

According to your application, you don't use audio codec, but also need a dummy codec.
1. sai driver (fsl_sai.c)
2. dummy codec driver( soc-utils.c)
2. machine driver
sai + dummy-codec--->dummy sound card.
For the machine driver, you can use simple-card.c, or write one by yourself.

Hope above information is helpful for you.

Have a nice day!
B.R,
Weidong