s390/ccwgroup: add get_ccwgroupdev_by_busid()
Provide function to find a ccwgroup device by its busid.
Acked-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/ccwgroup.h b/arch/s390/include/asm/ccwgroup.h
index 860cab7..7293c13 100644
--- a/arch/s390/include/asm/ccwgroup.h
+++ b/arch/s390/include/asm/ccwgroup.h
@@ -64,6 +64,8 @@ extern int ccwgroup_driver_register (struct ccwgroup_driver *cdriver);
extern void ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver);
int ccwgroup_create_dev(struct device *root, struct ccwgroup_driver *gdrv,
int num_devices, const char *buf);
+struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
+ char *bus_id);
extern int ccwgroup_set_online(struct ccwgroup_device *gdev);
extern int ccwgroup_set_offline(struct ccwgroup_device *gdev);
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 93b2862..4ebf6d4 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -608,6 +608,36 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
}
EXPORT_SYMBOL(ccwgroup_driver_unregister);
+static int __ccwgroupdev_check_busid(struct device *dev, void *id)
+{
+ char *bus_id = id;
+
+ return (strcmp(bus_id, dev_name(dev)) == 0);
+}
+
+/**
+ * get_ccwgroupdev_by_busid() - obtain device from a bus id
+ * @gdrv: driver the device is owned by
+ * @bus_id: bus id of the device to be searched
+ *
+ * This function searches all devices owned by @gdrv for a device with a bus
+ * id matching @bus_id.
+ * Returns:
+ * If a match is found, its reference count of the found device is increased
+ * and it is returned; else %NULL is returned.
+ */
+struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
+ char *bus_id)
+{
+ struct device *dev;
+
+ dev = driver_find_device(&gdrv->driver, NULL, bus_id,
+ __ccwgroupdev_check_busid);
+
+ return dev ? to_ccwgroupdev(dev) : NULL;
+}
+EXPORT_SYMBOL_GPL(get_ccwgroupdev_by_busid);
+
/**
* ccwgroup_probe_ccwdev() - probe function for slave devices
* @cdev: ccw device to be probed