wm831x_backup: Support multiple instances

If there are multiple wm831x devices in the system we need to assign
different names to the power supply devices in order to ensure we can
create the sysfs entries for them.

Signed-off-by: Mark Brown <[e-mail]>
Signed-off-by: Anton Vorontsov <[e-mail]>

drivers/power/wm831x_backup.c

···
 struct wm831x_backup {
 	struct wm831x *wm831x;
 	struct power_supply backup;
+	char name[20];
 };
 
 static int wm831x_backup_read_voltage(struct wm831x *wm831x,
···
 static __devinit int wm831x_backup_probe(struct platform_device *pdev)
 {
 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
 	struct wm831x_backup *devdata;
 	struct power_supply *backup;
 	int ret;
···
 	 */
 	wm831x_config_backup(wm831x);
 
-	backup->name = "wm831x-backup";
+	if (wm831x_pdata && wm831x_pdata->wm831x_num)
+		snprintf(devdata->name, sizeof(devdata->name),
+			 "wm831x-backup.%d", wm831x_pdata->wm831x_num);
+	else
+		snprintf(devdata->name, sizeof(devdata->name),
+			 "wm831x-backup");
+
+	backup->name = devdata->name;
 	backup->type = POWER_SUPPLY_TYPE_BATTERY;
 	backup->properties = wm831x_backup_props;
 	backup->num_properties = ARRAY_SIZE(wm831x_backup_props);
···
 	struct wm831x_backup *devdata = platform_get_drvdata(pdev);
 
 	power_supply_unregister(&devdata->backup);
+	kfree(devdata->backup.name);
 	kfree(devdata);
 
 	return 0;