本文共 5825 字，大约阅读时间需要 19 分钟。

一. device 部分注册流程

1. arch/x86/platform/intel-mid/Board.c

   struct devs_id __initconst device_ids[] = {... ...	{"mrfld_sst", SFI_DEV_TYPE_IPC, 1, &mrfld_sst_audio_platform_data,						&ipc_device_handler},
2. arch/x86/platform/intel-mid/device_libs/Platform_mrfld_audio.c

   void *mrfld_sst_audio_platform_data(void *info){	struct platform_device *pdev;	int ret;	ret = add_sst_platform_device();	if (ret < 0) {		pr_err("%s failed to sst_platform device\n", __func__);		return NULL;	}	if(!audio_codec || !strcmp(audio_codec, "dummy")) {		pdev = platform_device_register_simple("merr_dpcm_dummy",					0, NULL, 0);		if (!pdev) {			pr_err("failed to register merr_dpcm_dummy platform device\n");			return NULL;		}	} else if (!strcmp(audio_codec, "wm8958")) {
3. arch/x86/platform/intel-mid/device_libs/Platform_sst_audio.c

   int add_sst_platform_device(void){	struct platform_device *pdev = NULL;	int ret;	populate_platform_data();	pdev = platform_device_alloc("sst-platform", -1);	if (!pdev) {		pr_err("failed to allocate audio platform device\n");		return -EINVAL;	}	ret = platform_device_add_data(pdev, &sst_platform_pdata,					sizeof(sst_platform_pdata));	if (ret) {		pr_err("failed to add sst platform data\n");		platform_device_put(pdev);		return  -EINVAL;	}	ret = platform_device_add(pdev);	if (ret) {		pr_err("failed to add audio platform device\n");		platform_device_put(pdev);		return  -EINVAL;	}	return ret;}

   // 注册device "sst-platform"    和 "merr_dpcm_dummy" 完成。

二.  驱动匹配：   //  匹配  "sst-platform"  流程

1. sound/soc/intel/pcm.c

   static struct platform_driver sst_platform_driver = {	.driver		= {		.name		= "sst-platform“,		.owner		= THIS_MODULE,	},	.probe		= sst_platform_probe,	.remove		= sst_platform_remove,};module_platform_driver(sst_platform_driver);
2. sound/soc/intel/pcm.c

   static int sst_platform_probe(struct platform_device *pdev){	struct sst_data *sst;	int ret;	struct sst_platform_data *pdata = pdev->dev.platform_data;	pr_debug("sst_platform_probe called\n");	sst = devm_kzalloc(&pdev->dev, sizeof(*sst), GFP_KERNEL);	if (sst == NULL) {		pr_err("kzalloc failed\n");		return -ENOMEM;	}	sst_pdev = &pdev->dev;	sst->pdata = pdata;	mutex_init(&sst->lock);	dev_set_drvdata(&pdev->dev, sst);	ret = snd_soc_register_platform(&pdev->dev,					 &sst_soc_platform_drv);	if (ret) {		pr_err("registering soc platform failed\n");		return ret;	}	ret = snd_soc_register_component(&pdev->dev, &pcm_component,				sst_platform_dai, ARRAY_SIZE(sst_platform_dai));	if (ret) {		pr_err("registering cpu dais failed\n");		snd_soc_unregister_platform(&pdev->dev);	}	return ret;}
3. sound/soc/intel/pcm.c

   static struct snd_soc_platform_driver sst_soc_platform_drv  = {	.probe		= sst_soc_probe,	.remove		= sst_soc_remove,	.ops		= &sst_platform_ops,	.compr_ops	= &sst_platform_compr_ops,	.pcm_new	= sst_pcm_new,	.pcm_free	= sst_pcm_free,	.read		= sst_soc_read,	.write		= sst_soc_write,};
4. sound/soc/intel/pcm.c

   static int sst_soc_probe(struct snd_soc_platform *platform){	struct sst_data *ctx = snd_soc_platform_get_drvdata(platform);	struct soft_platform_id spid;	int ret = 0;	memcpy(&spid, ctx->pdata->spid, sizeof(spid));	pr_err("Enter:%s\n", __func__);#if IS_BUILTIN(CONFIG_SST_MRFLD_DPCM)    ret = sst_dsp_init_v2_dpcm(platform);#else    ret = sst_dsp_init(platform);#endif//    if (ret)//        return ret;//    ret = snd_soc_register_effect(platform->card, &effects_ops);	return ret;}
5. sound/soc/intel/platform-libs/Controls_v2_dpcm.c

   int sst_dsp_init_v2_dpcm(struct snd_soc_platform *platform){	int i, ret = 0;	struct sst_data *sst = snd_soc_platform_get_drvdata(platform);	sst->byte_stream = devm_kzalloc(platform->dev,					SST_MAX_BIN_BYTES, GFP_KERNEL);	if (!sst->byte_stream) {		pr_err("%s: kzalloc failed\n", __func__);		return -ENOMEM;	}	sst->widget = devm_kzalloc(platform->dev,				   SST_NUM_WIDGETS * sizeof(*sst->widget),				   GFP_KERNEL);	if (!sst->widget) {		pr_err("%s: kzalloc failed\n", __func__);		return -ENOMEM;	}	snd_soc_dapm_new_controls(&platform->dapm, sst_dapm_widgets,			ARRAY_SIZE(sst_dapm_widgets));	snd_soc_dapm_add_routes(&platform->dapm, intercon,			ARRAY_SIZE(intercon));	snd_soc_dapm_new_widgets(&platform->dapm);	for (i = 0; i < SST_NUM_GAINS; i++) {		sst_gains[i].mute = SST_GAIN_MUTE_DEFAULT;		sst_gains[i].l_gain = SST_GAIN_VOLUME_DEFAULT;		sst_gains[i].r_gain = SST_GAIN_VOLUME_DEFAULT;		sst_gains[i].ramp_duration = SST_GAIN_RAMP_DURATION_DEFAULT;	}	snd_soc_add_platform_controls(platform, sst_gain_controls,			ARRAY_SIZE(sst_gain_controls));	snd_soc_add_platform_controls(platform, sst_algo_controls,			ARRAY_SIZE(sst_algo_controls));	snd_soc_add_platform_controls(platform, sst_slot_controls,			ARRAY_SIZE(sst_slot_controls));	snd_soc_add_platform_controls(platform, sst_mux_controls,			ARRAY_SIZE(sst_mux_controls));	/* initialize the names of the probe points */	for (i = 0; i < SST_NUM_PROBE_CONNECTION_PTS; i++)		sst_probe_enum_texts[i] = sst_probes[i].name;	snd_soc_add_platform_controls(platform, sst_probe_controls,			ARRAY_SIZE(sst_probe_controls));	ret = sst_map_modules_to_pipe(platform);	return ret;}

   // 继续向下执行驱动代码。

三.  驱动匹配： //  匹配 “merr_dpcm_dummy”  流程

1. sound/soc/intel/board/merr_dpcm_dummy.c

   static struct platform_driver snd_merr_dpcm_drv = {	.driver = {			.owner = THIS_MODULE,			.name = "merr_dpcm_dummy",			.pm = &snd_merr_dpcm_mc_pm_ops,	},	.probe = snd_merr_dpcm_probe,	.remove = snd_merr_dpcm_remove,};module_platform_driver(snd_merr_dpcm_drv);
2. sound/soc/intel/board/merr_dpcm_dummy.c

   static int snd_merr_dpcm_probe(struct platform_device *pdev){	int ret_val = 0;	pr_debug("%s enter\n", __func__);	/* register the soc card */	snd_soc_card_merr.dev = &pdev->dev;	ret_val = snd_soc_register_card(&snd_soc_card_merr);	if (ret_val) {		pr_err("snd_soc_register_card failed %d\n", ret_val);		return ret_val;	}	platform_set_drvdata(pdev, &snd_soc_card_merr);	pr_info("%s successful\n", __func__);	return ret_val;}

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