Create symlink in /sys/devices/platform to mts-io node in case it is placed in other directory in sysfs4.9.3

2 files changed, 48 insertions, 1 deletions

diff --git a/io-module/mts-io.c b/io-module/mts-io.c
index ca7fdcb..a6e5204 100644
--- a/io-module/mts-io.c
+++ b/io-module/mts-io.c
@@ -93,16 +93,63 @@ EXPORT_SYMBOL(mts_get_hw_version);
 struct platform_device *mts_io_platform_device;
 EXPORT_SYMBOL(mts_io_platform_device);
 
+#ifdef PLATFORM_BUS_SYMLINK
+struct mts_io_drvdata {
+  bool f_platform_bus_symlink;
+};
+#endif // PLATFORM_BUS_SYMLINK
 
 static int mts_io_probe(struct platform_device *pdev)
 {
+#ifdef PLATFORM_BUS_SYMLINK
+	struct device *dev = &pdev->dev;
+	const char *symlink_name = kobject_name(&pdev->dev.kobj);
+	struct mts_io_drvdata *mts_io_dd;
+	int res;
+#endif // PLATFORM_BUS_SYMLINK
+
     mts_io_platform_device = pdev;
     dev_dbg(&pdev->dev,"%s: ENTER\n",__func__);
+
+#ifdef PLATFORM_BUS_SYMLINK
+	mts_io_dd = devm_kzalloc(dev, sizeof(*mts_io_dd), GFP_KERNEL);
+	if (!mts_io_dd) {
+		return -ENOMEM;
+	};
+	mts_io_dd->f_platform_bus_symlink = false;
+	platform_set_drvdata(pdev, mts_io_dd);
+
+	if (!dev->parent) {
+		log_warning("Parent device is not found");
+	} else if (dev->parent == &platform_bus) {
+		log_info("Parent device is platform_bus. No need to create symlink");
+		goto exit;
+	}
+	log_info("Creating symlink on platform_bus to %s", symlink_name);
+	
+	res = sysfs_create_link(&platform_bus.kobj, &dev->kobj, symlink_name);
+	if (!res) {
+		mts_io_dd->f_platform_bus_symlink = true;
+	} else {
+		log_warning("Failed to create symlink");
+	}
+
+exit:
+#endif // PLATFORM_BUS_SYMLINK
+
     return 0;
 }
 
 static int mts_io_remove(struct platform_device *pdev)
 {
+#ifdef PLATFORM_BUS_SYMLINK
+	struct mts_io_drvdata *mts_io_dd = platform_get_drvdata(pdev);
+	const char *symlink_name = kobject_name(&pdev->dev.kobj);
+	if (mts_io_dd && mts_io_dd->f_platform_bus_symlink) {
+		log_info("Removing %s symlink from platform_bus", symlink_name);
+		sysfs_remove_link(&platform_bus.kobj, symlink_name);
+	}
+#endif // PLATFORM_BUS_SYMLINK	
     return 0;
 }
 
diff --git a/io-module/version.h b/io-module/version.h
index e61e6ed..5b6304b 100644
--- a/io-module/version.h
+++ b/io-module/version.h
@@ -1,7 +1,7 @@
 #ifndef __VERSION_H
 #define __VERSION_H
 
-#define DRIVER_VERSION  "v4.9.2"
+#define DRIVER_VERSION  "v4.9.3"
 #define DRIVER_AUTHOR   "Multitech Systems"
 #define DRIVER_DESC "MTS-IO Controller"
 #define DRIVER_NAME "mts-io"