drivers/fsi: Add master unscan

Allow a master to undo a previous scan.  Should a master scan a bus
twice it will need to ensure it doesn't double register any
previously detected device.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
----
v7 - Unscan when unregistering master
   - Remove leading '__'s from function names
   - Return fail state for sysfs rescan file
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index d7a6e762527f6fb4dd0ffbd675a86b1228191f05..fcb0c818524f60ba2cd137dbcb071b581eecec04 100644 (file)
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -71,6 +71,7 @@ struct fsi_slave {
        uint32_t                size;   /* size of slave address space */
 };
 
+#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
 
 static int fsi_master_read(struct fsi_master *master, int link,
@@ -488,6 +489,40 @@ static int fsi_master_scan(struct fsi_master *master)
        return 0;
 }
 
+static int fsi_slave_remove_device(struct device *dev, void *arg)
+{
+       device_unregister(dev);
+       return 0;
+}
+
+static int fsi_master_remove_slave(struct device *dev, void *arg)
+{
+       device_for_each_child(dev, NULL, fsi_slave_remove_device);
+       device_unregister(dev);
+       return 0;
+}
+
+static void fsi_master_unscan(struct fsi_master *master)
+{
+       device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
+}
+
+static ssize_t master_rescan_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t count)
+{
+       struct fsi_master *master = to_fsi_master(dev);
+       int rc;
+
+       fsi_master_unscan(master);
+       rc = fsi_master_scan(master);
+       if (rc < 0)
+               return rc;
+
+       return count;
+}
+
+static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
+
 int fsi_master_register(struct fsi_master *master)
 {
        int rc;
@@ -504,7 +539,15 @@ int fsi_master_register(struct fsi_master *master)
                return rc;
        }
 
+       rc = device_create_file(&master->dev, &dev_attr_rescan);
+       if (rc) {
+               device_unregister(&master->dev);
+               ida_simple_remove(&master_ida, master->idx);
+               return rc;
+       }
+
        fsi_master_scan(master);
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(fsi_master_register);
@@ -516,6 +559,7 @@ void fsi_master_unregister(struct fsi_master *master)
                master->idx = -1;
        }
 
+       fsi_master_unscan(master);
        device_unregister(&master->dev);
 }
 EXPORT_SYMBOL_GPL(fsi_master_unregister);