audio - BeagleBoneBlack-在ALSA上注册I2S ADC

Question

我正在尝试将音频ADC(wm8782 / pcm1803a)与Beagle Black连接。我已经对文件 davinci-evm ， wm8782.c 和BB-BONE-AUDI-01设备树覆盖文件进行了一些更改(请参见下面的代码)。
我的问题是，在加载dtbo文件时，dmesg返回:

"...Codec DAI wm8782-hifi not found"

我假设我的编解码器(wm8782)没有被alsa core注册，但是我必须在哪里做？
我正在运行Ubuntu 13.10，内核:3.8.13-bone39

谢谢!

davinci-evm.c

/*
 * ASoC Driver.
 *
 * 
 *      
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/module.h>
#include <linux/platform_device.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/jack.h>

static int evm_wm8782_init(struct snd_soc_pcm_runtime *rtd)
{
    return 0;
}

static int evm_wm8782_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;

        /*return snd_soc_dai_set_bclk_ratio(cpu_dai, 32*2);*/
        return 0;
}

/* machine stream operations */
static struct snd_soc_ops evm_wm8782_ops = {
    .hw_params = evm_wm8782_hw_params,
};

static struct snd_soc_dai_link evm_wm8782_dai[] = {
{
    .name       = "PCM1803 board",
    .stream_name    = "PCM1803 board",
    .cpu_dai_name   = "davinci-mcasp.0",
    .codec_dai_name = "wm8782-hifi",
    .platform_name  = "davinci-pcm-audio",
    .codec_name = "wm8782-codec",
    .dai_fmt    = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
                SND_SOC_DAIFMT_CBS_CFS,
    .ops        = &evm_wm8782_ops,
    .init       = evm_wm8782_init,
},
};

/* audio machine driver */
static struct snd_soc_card snd_wm8782_adc = {
    .name         = "snd_wm8782_adc",
    .dai_link     = evm_wm8782_dai,
    .num_links    = ARRAY_SIZE(evm_wm8782_dai),
};

static int snd_wm8782_probe(struct platform_device *pdev)
{
    int ret = 0;

    snd_wm8782_adc.dev = &pdev->dev;
    ret = snd_soc_register_card(&snd_wm8782_adc);
    if (ret)
        dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n", ret);

    return ret;
}

static int snd_wm8782_remove(struct platform_device *pdev)
{
    return snd_soc_unregister_card(&snd_wm8782_adc);
}

static struct platform_driver snd_wm8782_driver = {
        .driver = {
                .name   = "snd-wm8782-adc",
                .owner  = THIS_MODULE,
        },
        .probe          = snd_wm8782_probe,
        .remove         = snd_wm8782_remove,
};

module_platform_driver(snd_wm8782_driver);

MODULE_AUTHOR("E.E.R");
MODULE_DESCRIPTION("ASoC Driver for pcm1803 ADC");
MODULE_LICENSE("GPL v2");

wm8782.c

/*
 * sound/soc/codecs/wm8782.c
 * simple, strap-pin configured 24bit 2ch ADC
 *
 * Copyright: 2011 Raumfeld GmbH
 * Author: Johannes Stezenbach <js@sig21.net>
 *
 * based on ad73311.c
 * Copyright:   Analog Device Inc.
 * Author:  Cliff Cai <cliff.cai@analog.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>
#include <sound/soc.h>

static struct snd_soc_dai_driver wm8782_dai = {
    .name = "wm8782-hifi",
    .capture = {
        .stream_name = "Capture",
        .channels_min = 1,
        .channels_max = 2,
        .rates = SNDRV_PCM_RATE_8000_192000,
        .formats = SNDRV_PCM_FMTBIT_S16_LE |
               SNDRV_PCM_FMTBIT_S24_LE,
    },
};

static struct snd_soc_codec_driver soc_codec_dev_wm8782;

static int wm8782_probe(struct platform_device *pdev)
{
    return snd_soc_register_codec(&pdev->dev,
            &soc_codec_dev_wm8782, &wm8782_dai, 1);
}

static int wm8782_remove(struct platform_device *pdev)
{
    snd_soc_unregister_codec(&pdev->dev);
    return 0;
}

static struct platform_driver wm8782_codec_driver = {
    .driver = {
        .name = "wm8782",
        .owner = THIS_MODULE,
    },
    .probe = wm8782_probe,
    .remove = wm8782_remove,
};

module_platform_driver(wm8782_codec_driver);

MODULE_DESCRIPTION("ASoC WM8782 driver");
MODULE_AUTHOR("Johannes Stezenbach <js@sig21.net>");
MODULE_LICENSE("GPL");

BB-BONE-AUDI-01-00A0.dts

/*
 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
/dts-v1/;
/plugin/;

/ {
    compatible = "ti,beaglebone", "ti,beaglebone-black";

    /* identification */
    part-number = "BB-BONE-AUDI-01";
    version = "00A0", "A0";

    /* state the resources this cape uses */
    exclusive-use =
        /* the pin header uses */
        "P9.14",    /* leds:   gpio1_18 */
        "P9.16",    /* leds:   gpio1_19 */
        "P9.31",    /* mcasp0: mcasp0_aclkx */
        "P9.29",    /* mcasp0: mcasp0_fsx */
        "P9.28",    /* mcasp0: mcasp0_axr2 */
        "P9.25",    /* mcasp0: mcasp0_ahclkx */
        /* the hardware ip uses */
        "gpio1_18", "gpio1_19",
        "mcasp0";

    fragment@0 {
        target = <&am33xx_pinmux>;
        __overlay__ {

            bone_audio_cape_led_pins: pinmux_bone_audio_cape_led_pins {
                pinctrl-single,pins = <
                    0x48 0x07   /* gpmc_a2.gpio1_18, OUTPUT | MODE7 */
                    0x4c 0x07   /* gpmc_a3.gpio1_19, OUTPUT | MODE7 */
                >;
            };

            bone_audio_cape_audio_pins: pinmux_bone_audio_cape_audio_pins {
                pinctrl-single,pins = <
                    0x190 0x20  /* mcasp0_aclkx.mcasp0_aclkx, INPUT | MODE0 */
                    0x194 0x20  /* mcasp0_fsx.mcasp0_fsx, INPUT | MODE0 */
                    0x19c 0x22  /* mcasp0_ahclkr.mcasp0_axr2, INPUT | MODE2 */
                    0x1ac 0x22  /* mcasp0_ahclkx.mcasp0_axr3, INPUT | MODE2 */

                >;
            };
        };
    };

    fragment@1 {
        target = <&ocp>;
        __overlay__ {

            /* avoid stupid warning */
            #address-cells = <1>;
            #size-cells = <1>;

            gpio-leds-cape-audio {
                compatible = "gpio-leds";
                pinctrl-names = "default";
                pinctrl-0 = <&bone_audio_cape_led_pins>;

                audio-led0 {
                    label = "audio:green:usr0";
                    gpios = <&gpio2 18 0>;
                    linux,default-trigger = "heartbeat";
                    default-state = "off";
                };

                audio-led1 {
                    label = "audio:green:usr1";
                    gpios = <&gpio2 19 0>;
                    linux,default-trigger = "mmc0";
                    default-state = "off";
                };
            };
        };
    };


    fragment@2 {
        target = <&mcasp0>;
        __overlay__ {
            pinctrl-names = "default";
            pinctrl-0 = <&bone_audio_cape_audio_pins>;

            status = "okay";

            op-mode = <0>;          /* MCASP_IIS_MODE */
            tdm-slots = <2>;
            num-serializer = <16>;
            serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
                0 0 2 1
                0 0 0 0
                0 0 0 0
                0 0 0 0
            >;
            tx-num-evt = <1>;
            rx-num-evt = <1>;
        };
    };


};

Answer 1

您可以使编解码器驱动程序与设备树兼容，并进行加载，只需在dts文件中为编解码器添加一个节点即可。

根据您的情况，将此部分添加到编解码器驱动程序中:

.
.
.
#ifdef CONFIG_OF
static const struct of_device_id wm8782_dt_ids[] = {
    { .compatible = "ti,wm8782", },
    { }
};
MODULE_DEVICE_TABLE(of, wm8782_dt_ids);
#endif

static struct platform_driver wm8782_codec_driver = {
    .driver = {
        .name = "wm8782",
        .owner = THIS_MODULE,
        .of_match_table = of_match_ptr(wm8782_dt_ids),
    },
.
.
.

然后，将此节点添加到您的dts文件中:

wm8782: wm8782 {
        wm8782 = "ti,wm8782";
    };