ppc32: Update PowerMac laptop backlight control core

arch/ppc/kernel/ppc_ksyms.c

@@ -237,12 +237,6 @@ EXPORT_SYMBOL(adb_try_handler_change);
 EXPORT_SYMBOL(cuda_request);
 EXPORT_SYMBOL(cuda_poll);
 #endif /* CONFIG_ADB_CUDA */
-#ifdef CONFIG_PMAC_BACKLIGHT
-EXPORT_SYMBOL(get_backlight_level);
-EXPORT_SYMBOL(set_backlight_level);
-EXPORT_SYMBOL(set_backlight_enable);
-EXPORT_SYMBOL(register_backlight_controller);
-#endif /* CONFIG_PMAC_BACKLIGHT */
 #ifdef CONFIG_PPC_MULTIPLATFORM
 EXPORT_SYMBOL(_machine);
 #endif

arch/ppc/platforms/pmac_backlight.c

@@ -8,6 +8,7 @@
 
 #include <linux/config.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/stddef.h>
 #include <linux/reboot.h>
 #include <linux/nvram.h>
@@ -37,6 +38,10 @@ register_backlight_controller(struct backlight_controller *ctrler, void *data, c
 	char *prop;
 	int valid = 0;
 
+	/* There's already a matching controller, bail out */
+	if (backlighter != NULL)
+		return;
+
 	bk_node = find_devices("backlight");
 
 #ifdef CONFIG_ADB_PMU
@@ -84,6 +89,7 @@ register_backlight_controller(struct backlight_controller *ctrler, void *data, c
 	printk(KERN_INFO "Registered \"%s\" backlight controller, level: %d/15\n",
 		type, backlight_level);
 }
+EXPORT_SYMBOL(register_backlight_controller);
 
 void __pmac
 unregister_backlight_controller(struct backlight_controller *ctrler, void *data)
@@ -92,6 +98,7 @@ unregister_backlight_controller(struct backlight_controller *ctrler, void *data)
 	if (ctrler == backlighter && data == backlighter_data)
 		backlighter = NULL;
 }
+EXPORT_SYMBOL(unregister_backlight_controller);
 
 int __pmac
 set_backlight_enable(int enable)
@@ -105,6 +112,7 @@ set_backlight_enable(int enable)
 		backlight_enabled = enable;
 	return rc;
 }
+EXPORT_SYMBOL(set_backlight_enable);
 
 int __pmac
 get_backlight_enable(void)
@@ -113,6 +121,7 @@ get_backlight_enable(void)
 		return -ENODEV;
 	return backlight_enabled;
 }
+EXPORT_SYMBOL(get_backlight_enable);
 
 int __pmac
 set_backlight_level(int level)
@@ -137,6 +146,7 @@ set_backlight_level(int level)
 	}
 	return rc;
 }
+EXPORT_SYMBOL(set_backlight_level);
 
 int __pmac
 get_backlight_level(void)
@@ -145,3 +155,4 @@ get_backlight_level(void)
 		return -ENODEV;
 	return backlight_level;
 }
+EXPORT_SYMBOL(get_backlight_level);