ASoC: hdac_hda: add asoc extension for legacy HDA codec drivers

This patch adds a kernel module which is used by the legacy HDA
codec drivers as library. This implements hdac_ext_bus_ops to enable
the reuse of legacy HDA codec drivers with ASoC platform drivers.

Signed-off-by: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/pci/hda/hda_bind.c

@@ -81,6 +81,12 @@ static int hda_codec_driver_probe(struct device *dev)
 	hda_codec_patch_t patch;
 	int err;
 
+	if (codec->bus->core.ext_ops) {
+		if (WARN_ON(!codec->bus->core.ext_ops->hdev_attach))
+			return -EINVAL;
+		return codec->bus->core.ext_ops->hdev_attach(&codec->core);
+	}
+
 	if (WARN_ON(!codec->preset))
 		return -EINVAL;
 
@@ -134,6 +140,12 @@ static int hda_codec_driver_remove(struct device *dev)
 {
 	struct hda_codec *codec = dev_to_hda_codec(dev);
 
+	if (codec->bus->core.ext_ops) {
+		if (WARN_ON(!codec->bus->core.ext_ops->hdev_detach))
+			return -EINVAL;
+		return codec->bus->core.ext_ops->hdev_detach(&codec->core);
+	}
+
 	if (codec->patch_ops.free)
 		codec->patch_ops.free(codec);
 	snd_hda_codec_cleanup_for_unbind(codec);