diff -uprN linux-3.16.1-org/drivers/platform/x86/apple-gmux.c linux-3.16.1-patched/drivers/platform/x86/apple-gmux.c
--- a/drivers/platform/x86/apple-gmux.c	2014-08-14 04:36:35.000000000 +0200
+++ b/drivers/platform/x86/apple-gmux.c	2014-09-10 17:12:47.000000000 +0200
@@ -22,6 +22,10 @@
 #include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/vga_switcheroo.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
 #include <acpi/video.h>
 #include <asm/io.h>
 
@@ -39,10 +43,17 @@ struct apple_gmux_data {
 	enum vga_switcheroo_client_id resume_client_id;
 	enum vga_switcheroo_state power_state;
 	struct completion powerchange_done;
+	
+	/*debugfs data*/
+	struct dentry *debugfs_root;
+	struct dentry *switch_file;
 };
 
 static struct apple_gmux_data *apple_gmux_data;
 
+static int apple_gmux_debugfs_init(struct apple_gmux_data *gmux_data);
+static void apple_gmux_debugfs_fini(struct apple_gmux_data *gmux_data);
+
 /*
  * gmux port offsets. Many of these are not yet used, but may be in the
  * future, and it's useful to have them documented here anyhow.
@@ -560,6 +571,7 @@ static int gmux_probe(struct pnp_dev *pn
 	init_completion(&gmux_data->powerchange_done);
 	apple_gmux_data = gmux_data;
 	gmux_enable_interrupts(gmux_data);
+	apple_gmux_debugfs_init(gmux_data);
 
 	return 0;
 
@@ -584,6 +596,8 @@ static void gmux_remove(struct pnp_dev *
 {
 	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 
+	apple_gmux_debugfs_fini(gmux_data);
+	
 	vga_switcheroo_unregister_handler();
 	gmux_disable_interrupts(gmux_data);
 	if (gmux_data->gpe >= 0) {
@@ -604,6 +618,94 @@ static void gmux_remove(struct pnp_dev *
 	apple_bl_register();
 }
 
+static int apple_gmux_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "Active Device: %s\nDiscrete Powered: %s\n",
+		gmux_active_client(apple_gmux_data) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
+		apple_gmux_data->power_state == VGA_SWITCHEROO_ON ? "ON" : "OFF"
+	);
+	return 0;
+}
+
+static int apple_gmux_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, apple_gmux_show, NULL);
+}
+
+static ssize_t
+apple_gmux_debugfs_write(struct file *filp, const char __user *ubuf,
+			 size_t cnt, loff_t *ppos)
+{
+	char usercmd[64];
+	if (cnt > 63)
+		cnt = 63;
+	
+	if (copy_from_user(usercmd, ubuf, cnt))
+		return -EFAULT;
+	
+	/*switch to IGD*/
+	if (strncmp(usercmd, "IGD", 3) == 0)
+		gmux_switchto(VGA_SWITCHEROO_IGD);
+	
+	/*switch to DIS*/
+	if (strncmp(usercmd, "DIS", 3) == 0)
+		gmux_switchto(VGA_SWITCHEROO_DIS);
+	
+	/*change power state*/
+	if (strncmp(usercmd, "OFF", 3) == 0)
+		gmux_set_discrete_state(apple_gmux_data, VGA_SWITCHEROO_OFF);
+	
+	if (strncmp(usercmd, "ON", 2) == 0)
+		gmux_set_discrete_state(apple_gmux_data, VGA_SWITCHEROO_ON);
+	
+	return cnt;
+}
+
+static const struct file_operations apple_gmux_debugfs_fops = {
+    .owner = THIS_MODULE,
+    .open = apple_gmux_debugfs_open,
+    .write = apple_gmux_debugfs_write,
+    .read = seq_read,
+    .llseek = seq_lseek,
+    .release = single_release,
+};
+
+static void apple_gmux_debugfs_fini(struct apple_gmux_data *gmux_data)
+{
+	if (gmux_data->switch_file) {
+		debugfs_remove(gmux_data->switch_file);
+		gmux_data->switch_file = NULL;
+	}
+	if (gmux_data->debugfs_root) {
+		debugfs_remove(gmux_data->debugfs_root);
+		gmux_data->debugfs_root = NULL;
+	}
+}
+
+static int apple_gmux_debugfs_init(struct apple_gmux_data *gmux_data)
+{
+	/* already initialised */
+	if (gmux_data->debugfs_root)
+		return 0;
+	gmux_data->debugfs_root = debugfs_create_dir("applegmux", NULL);
+	
+	if (!gmux_data->debugfs_root) {
+		printk(KERN_ERR "apple_gmux: Cannot create /sys/kernel/debug/applegmux\n");
+		goto fail;
+	}
+	
+	gmux_data->switch_file = debugfs_create_file("switch", 0644,
+					gmux_data->debugfs_root, NULL, &apple_gmux_debugfs_fops);
+	if (!gmux_data->switch_file) {
+		printk(KERN_ERR "apple_gmux: cannot create /sys/kernel/debug/applegmux/switch\n");
+		goto fail;
+	}
+	return 0;
+fail:
+	apple_gmux_debugfs_fini(gmux_data);
+	return -1;
+}
+
 static const struct pnp_device_id gmux_device_ids[] = {
 	{"APP000B", 0},
 	{"", 0}