ASoC: SOF: Add Nocodec machine driver support

Add a simple "fallback" machine driver that can be used to enable SOF
on boards with no codec device. This machine driver can also be forced
for debug/development.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/sof.h

@@ -12,6 +12,7 @@
 #define __INCLUDE_SOUND_SOF_H
 
 #include <linux/pci.h>
+#include <sound/soc.h>
 #include <sound/soc-acpi.h>
 
 struct snd_sof_dsp_ops;
@@ -91,4 +92,9 @@ struct sof_dev_desc {
 	const struct sof_arch_ops *arch_ops;
 };
 
+int sof_nocodec_setup(struct device *dev,
+		      struct snd_sof_pdata *sof_pdata,
+		      struct snd_soc_acpi_mach *mach,
+		      const struct sof_dev_desc *desc,
+		      const struct snd_sof_dsp_ops *ops);
 #endif

sound/soc/sof/nocodec.c

@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018 Intel Corporation. All rights reserved.
+//
+// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
+//
+
+#include <linux/module.h>
+#include <sound/sof.h>
+#include "sof-priv.h"
+
+static struct snd_soc_card sof_nocodec_card = {
+	.name = "nocodec", /* the sof- prefix is added by the core */
+};
+
+static int sof_nocodec_bes_setup(struct device *dev,
+				 const struct snd_sof_dsp_ops *ops,
+				 struct snd_soc_dai_link *links,
+				 int link_num, struct snd_soc_card *card)
+{
+	int i;
+
+	if (!ops || !links || !card)
+		return -EINVAL;
+
+	/* set up BE dai_links */
+	for (i = 0; i < link_num; i++) {
+		links[i].name = devm_kasprintf(dev, GFP_KERNEL,
+					       "NoCodec-%d", i);
+		if (!links[i].name)
+			return -ENOMEM;
+
+		links[i].id = i;
+		links[i].no_pcm = 1;
+		links[i].cpu_dai_name = ops->drv[i].name;
+		links[i].platform_name = dev_name(dev);
+		links[i].codec_dai_name = "snd-soc-dummy-dai";
+		links[i].codec_name = "snd-soc-dummy";
+		links[i].dpcm_playback = 1;
+		links[i].dpcm_capture = 1;
+	}
+
+	card->dai_link = links;
+	card->num_links = link_num;
+
+	return 0;
+}
+
+int sof_nocodec_setup(struct device *dev,
+		      struct snd_sof_pdata *sof_pdata,
+		      struct snd_soc_acpi_mach *mach,
+		      const struct sof_dev_desc *desc,
+		      const struct snd_sof_dsp_ops *ops)
+{
+	struct snd_soc_dai_link *links;
+	int ret;
+
+	if (!mach)
+		return -EINVAL;
+
+	sof_pdata->drv_name = "sof-nocodec";
+
+	mach->drv_name = "sof-nocodec";
+	sof_pdata->fw_filename = desc->nocodec_fw_filename;
+	sof_pdata->tplg_filename = desc->nocodec_tplg_filename;
+
+	/* create dummy BE dai_links */
+	links = devm_kzalloc(dev, sizeof(struct snd_soc_dai_link) *
+			     ops->num_drv, GFP_KERNEL);
+	if (!links)
+		return -ENOMEM;
+
+	ret = sof_nocodec_bes_setup(dev, ops, links, ops->num_drv,
+				    &sof_nocodec_card);
+	return ret;
+}
+EXPORT_SYMBOL(sof_nocodec_setup);
+
+static int sof_nocodec_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = &sof_nocodec_card;
+
+	card->dev = &pdev->dev;
+
+	return devm_snd_soc_register_card(&pdev->dev, card);
+}
+
+static int sof_nocodec_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver sof_nocodec_audio = {
+	.probe = sof_nocodec_probe,
+	.remove = sof_nocodec_remove,
+	.driver = {
+		.name = "sof-nocodec",
+		.pm = &snd_soc_pm_ops,
+	},
+};
+module_platform_driver(sof_nocodec_audio)
+
+MODULE_DESCRIPTION("ASoC sof nocodec");
+MODULE_AUTHOR("Liam Girdwood");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:sof-nocodec");