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>
This commit is contained in:
Christopher Bostic 2017-06-06 16:08:46 -05:00 committed by Greg Kroah-Hartman
parent 4efe37f4c4
commit cd0fdb5c07
1 changed files with 44 additions and 0 deletions

View File

@ -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);