[PATCH] phy: adin: add readext and writeext support for mdio cmd

[Nate Drude]

The adin phy has extended registers that can be accessed using
adin_ext_read and adin_ext_write. These registers can be read directly
using the mdio command using readext and writext. For example:
    => mdio rx ethernet@428a0000 0xff23
    Reading from bus ethernet@428a0000
    PHY at address 0:
    65315 - 0xe01

Signed-off-by: Nate Drude <nat...@variscite.com>
---
 drivers/net/phy/adin.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/phy/adin.c b/drivers/net/phy/adin.c
index fb9f1e4c70d..d29210adffc 100644
--- a/drivers/net/phy/adin.c
+++ b/drivers/net/phy/adin.c
@@ -155,6 +155,18 @@ static int adin_ext_write(struct phy_device 
*phydev, const u32 regnum, const u16
        return phy_write(phydev, MDIO_DEVAD_NONE, ADIN1300_EXT_REG_DATA, val);
 }

+static int adin_extread(struct phy_device *phydev, int addr, int devaddr,
+                              int regnum)
+{
+       return adin_ext_read(phydev, regnum);
+}
+
+static int adin_extwrite(struct phy_device *phydev, int addr,
+                               int devaddr, int regnum, u16 val)
+{
+       return adin_ext_write(phydev, regnum, val);
+}
+
 static int adin_config_clk_out(struct phy_device *phydev)
 {
        ofnode node = phy_get_ofnode(phydev);
@@ -260,4 +272,6 @@ U_BOOT_PHY_DRIVER(ADIN1300) = {
        .config = adin1300_config,
        .startup = genphy_startup,
        .shutdown = genphy_shutdown,
+       .readext = adin_extread,
+       .writeext = adin_extwrite,
 };
--
2.40.1