net: hibmcge: support scenario without PHY

Currently, the driver uses phylib to operate PHY by default.

On some boards, the PHY device is separated from the MAC device.
As a result, the hibmcge driver cannot operate the PHY device.

In this patch, the driver determines whether a PHY is available
based on register configuration. If no PHY is available,
the driver will use fixed_phy to register fake phydev.

Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Link: https://patch.msgid.link/20250702125716.2875169-2-shaojijie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
index 42b0083c9193f23ae04d536484c61a66c274f0a3..8b7b476ed7fbfee38fe6807771513a0ba5c8cff2 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
@@ -2,6 +2,7 @@
 // Copyright (c) 2024 Hisilicon Limited.
 
 #include <linux/phy.h>
+#include <linux/phy_fixed.h>
 #include <linux/rtnetlink.h>
 #include "hbg_common.h"
 #include "hbg_hw.h"
@@ -19,6 +20,7 @@
 #define HBG_MDIO_OP_INTERVAL_US                (5 * 1000)
 
 #define HBG_NP_LINK_FAIL_RETRY_TIMES   5
+#define HBG_NO_PHY                     0xFF
 
 static void hbg_mdio_set_command(struct hbg_mac *mac, u32 cmd)
 {
@@ -229,6 +231,39 @@ void hbg_phy_stop(struct hbg_priv *priv)
        phy_stop(priv->mac.phydev);
 }
 
+static void hbg_fixed_phy_uninit(void *data)
+{
+       fixed_phy_unregister((struct phy_device *)data);
+}
+
+static int hbg_fixed_phy_init(struct hbg_priv *priv)
+{
+       struct fixed_phy_status hbg_fixed_phy_status = {
+               .link = 1,
+               .speed = SPEED_1000,
+               .duplex = DUPLEX_FULL,
+               .pause = 1,
+               .asym_pause = 1,
+       };
+       struct device *dev = &priv->pdev->dev;
+       struct phy_device *phydev;
+       int ret;
+
+       phydev = fixed_phy_register(&hbg_fixed_phy_status, NULL);
+       if (IS_ERR(phydev)) {
+               dev_err_probe(dev, PTR_ERR(phydev),
+                             "failed to register fixed PHY device\n");
+               return PTR_ERR(phydev);
+       }
+
+       ret = devm_add_action_or_reset(dev, hbg_fixed_phy_uninit, phydev);
+       if (ret)
+               return ret;
+
+       priv->mac.phydev = phydev;
+       return hbg_phy_connect(priv);
+}
+
 int hbg_mdio_init(struct hbg_priv *priv)
 {
        struct device *dev = &priv->pdev->dev;
@@ -238,6 +273,9 @@ int hbg_mdio_init(struct hbg_priv *priv)
        int ret;
 
        mac->phy_addr = priv->dev_specs.phy_addr;
+       if (mac->phy_addr == HBG_NO_PHY)
+               return hbg_fixed_phy_init(priv);
+
        mdio_bus = devm_mdiobus_alloc(dev);
        if (!mdio_bus)
                return dev_err_probe(dev, -ENOMEM,