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From:   Michael Walle <michael@walle.cc>
Date:   Wed, 28 Dec 2022 00:07:19 +0100
Subject: [PATCH RFC net-next v2 03/12] net: mdio: mdiobus_register: update
 validation test
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Message-Id: <20221227-v6-2-rc1-c45-seperation-v2-3-ddb37710e5a7@walle.cc>
References: <20221227-v6-2-rc1-c45-seperation-v2-0-ddb37710e5a7@walle.cc>
In-Reply-To: <20221227-v6-2-rc1-c45-seperation-v2-0-ddb37710e5a7@walle.cc>
To:     Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jose Abreu <Jose.Abreu@synopsys.com>,
        Sergey Shtylyov <s.shtylyov@omp.ru>,
        Wei Fang <wei.fang@nxp.com>,
        Shenwei Wang <shenwei.wang@nxp.com>,
        Clark Wang <xiaoning.wang@nxp.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Sean Wang <sean.wang@mediatek.com>,
        Landen Chao <Landen.Chao@mediatek.com>,
        DENG Qingfang <dqfext@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, Andrew Lunn <andrew@lunn.ch>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Michael Walle <michael@walle.cc>
Precedence: bulk

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