[PATCH RFC net-next v2 03/12] net: mdio: mdiobus_register: update validation test

[Michael Walle <michael@walle.cc>]

From: Andrew Lunn <andrew@lunn.ch>

Now that C45 uses its own read/write methods, the validation performed
when a bus is registers needs updating. All combinations of C22 and
C45 are supported, but both read and write methods must be provided,
read only busses are not supported etc.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
---
v2:
 - [al] be consistent with other checks
 - [mw] make the test a bit easier to read
---
 drivers/net/phy/mdio_bus.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index bde195864c17..d14d7704e895 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -526,8 +526,18 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 	int i, err;
 	struct gpio_desc *gpiod;
 
-	if (NULL == bus || NULL == bus->name ||
-	    NULL == bus->read || NULL == bus->write)
+	if (!bus || !bus->name)
+		return -EINVAL;
+
+	/* An access method always needs both read and write operations */
+	if ((bus->read && !bus->write) ||
+	    (!bus->read && bus->write) ||
+	    (bus->read_c45 && !bus->write_c45) ||
+	    (!bus->read_c45 && bus->write_c45))
+		return -EINVAL;
+
+	/* At least one method is mandatory */
+	if (!bus->read && !bus->read_c45)
 		return -EINVAL;
 
 	if (bus->parent && bus->parent->of_node)

-- 
2.30.2