ASoC: soc-utils: Transition to the faux device interface

The ASoC soc-utils driver does not require the creation of a platform
device. Originally, this approach was chosen for simplicity when the
driver was first implemented.

With the introduction of the lightweight faux device interface, we now
have a more appropriate alternative. Migrate the driver to utilize the
faux bus, given that the platform device it previously created was not
a real one anyway. This will simplify the code, reducing its footprint
while maintaining functionality.

Cc: Mark Brown <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: [email protected]
Signed-off-by: Sudeep Holla <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: sudeep-holla

sound/soc/soc-utils.c

@@ -7,7 +7,7 @@
 // Author: Mark Brown <[email protected]>
 //         Liam Girdwood <[email protected]>
 
-#include <linux/platform_device.h>
+#include <linux/device/faux.h>
 #include <linux/export.h>
 #include <linux/math.h>
 #include <sound/core.h>
@@ -262,48 +262,38 @@ struct snd_soc_dai_link_component snd_soc_dummy_dlc = {
 };
 EXPORT_SYMBOL_GPL(snd_soc_dummy_dlc);
 
-static int snd_soc_dummy_probe(struct platform_device *pdev)
+static int snd_soc_dummy_probe(struct faux_device *fdev)
 {
 	int ret;
 
-	ret = devm_snd_soc_register_component(&pdev->dev,
+	ret = devm_snd_soc_register_component(&fdev->dev,
 					      &dummy_codec, &dummy_dai, 1);
 	if (ret < 0)
 		return ret;
 
-	ret = devm_snd_soc_register_component(&pdev->dev, &dummy_platform,
+	ret = devm_snd_soc_register_component(&fdev->dev, &dummy_platform,
 					      NULL, 0);
 
 	return ret;
 }
 
-static struct platform_driver soc_dummy_driver = {
-	.driver = {
-		.name = "snd-soc-dummy",
-	},
+static struct faux_device_ops soc_dummy_ops = {
 	.probe = snd_soc_dummy_probe,
 };
 
-static struct platform_device *soc_dummy_dev;
+static struct faux_device *soc_dummy_dev;
 
 int __init snd_soc_util_init(void)
 {
-	int ret;
-
-	soc_dummy_dev =
-		platform_device_register_simple("snd-soc-dummy", -1, NULL, 0);
-	if (IS_ERR(soc_dummy_dev))
-		return PTR_ERR(soc_dummy_dev);
+	soc_dummy_dev = faux_device_create("snd-soc-dummy", NULL,
+					   &soc_dummy_ops);
+	if (!soc_dummy_dev)
+		return -ENODEV;
 
-	ret = platform_driver_register(&soc_dummy_driver);
-	if (ret != 0)
-		platform_device_unregister(soc_dummy_dev);
-
-	return ret;
+	return 0;
 }
 
 void snd_soc_util_exit(void)
 {
-	platform_driver_unregister(&soc_dummy_driver);
-	platform_device_unregister(soc_dummy_dev);
+	faux_device_destroy(soc_dummy_dev);
 }