net: phy: realtek: Add functions to read PHY's extended registers

According to the datasheet to access the extended registers we have to:

1. Write Register 31 Data = 0x0XYZ (Page 0xXYZ)
2. Read/Write the target Register Data
3. Write Register 31 Data = 0x0000 or 0xa42 (switch back to IEEE
   Standard Registers)

Hook the missing functions so that we can use the `mdio rx/wx` command to
easily access the extended registers.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index b3e6578df9acbf26878dd00ba9a95cebc3c7ce86..dd45e11b3ad9852ef2cf9afada767dce6ab7a9bd 100644 (file)
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -57,6 +57,33 @@
 #define MIIM_RTL8211F_TX_DELAY         0x100
 #define MIIM_RTL8211F_LCR              0x10
 
+static int rtl8211f_phy_extread(struct phy_device *phydev, int addr,
+                               int devaddr, int regnum)
+{
+       int oldpage = phy_read(phydev, MDIO_DEVAD_NONE,
+                              MIIM_RTL8211F_PAGE_SELECT);
+       int val;
+
+       phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, devaddr);
+       val = phy_read(phydev, MDIO_DEVAD_NONE, regnum);
+       phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, oldpage);
+
+       return val;
+}
+
+static int rtl8211f_phy_extwrite(struct phy_device *phydev, int addr,
+                                int devaddr, int regnum, u16 val)
+{
+       int oldpage = phy_read(phydev, MDIO_DEVAD_NONE,
+                              MIIM_RTL8211F_PAGE_SELECT);
+
+       phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, devaddr);
+       phy_write(phydev, MDIO_DEVAD_NONE, regnum, val);
+       phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, oldpage);
+
+       return 0;
+}
+
 static int rtl8211b_probe(struct phy_device *phydev)
 {
 #ifdef CONFIG_RTL8211X_PHY_FORCE_MASTER
@@ -336,6 +363,8 @@ static struct phy_driver RTL8211F_driver = {
        .config = &rtl8211f_config,
        .startup = &rtl8211f_startup,
        .shutdown = &genphy_shutdown,
+       .readext = &rtl8211f_phy_extread,
+       .writeext = &rtl8211f_phy_extwrite,
 };
 
 int phy_realtek_init(void)