net: ethernet: mtk_eth_soc: fix return values and refactor MDIO ops

[ Upstream commit eda80b249df7bbc7b3dd13907343a3e59bfc57fd ]

Instead of returning -1 (-EPERM) when MDIO bus is stuck busy
while writing or 0xffff if it happens while reading, return the
appropriate -ETIMEDOUT. Also fix return type to int instead of u32.
Refactor functions to use bitfield helpers instead of having various
masking and shifting constants in the code, which also results in the
register definitions in the header file being more obviously related
to what is stated in the MediaTek's Reference Manual.

Fixes: 656e705243fd0 ("net-next: mediatek: add support for MT7623 ethernet")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 398c23c..9e7a872 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -91,46 +91,53 @@ static int mtk_mdio_busy_wait(struct mtk_eth *eth)
        }
 
        dev_err(eth->dev, "mdio: MDIO timeout\n");
-       return -1;
+       return -ETIMEDOUT;
 }
 
-static u32 _mtk_mdio_write(struct mtk_eth *eth, u32 phy_addr,
-                          u32 phy_register, u32 write_data)
+static int _mtk_mdio_write(struct mtk_eth *eth, u32 phy_addr, u32 phy_reg,
+                          u32 write_data)
 {
-       if (mtk_mdio_busy_wait(eth))
-               return -1;
+       int ret;
 
-       write_data &= 0xffff;
+       ret = mtk_mdio_busy_wait(eth);
+       if (ret < 0)
+               return ret;
 
-       mtk_w32(eth, PHY_IAC_ACCESS | PHY_IAC_START | PHY_IAC_WRITE |
-               (phy_register << PHY_IAC_REG_SHIFT) |
-               (phy_addr << PHY_IAC_ADDR_SHIFT) | write_data,
+       mtk_w32(eth, PHY_IAC_ACCESS |
+                    PHY_IAC_START_C22 |
+                    PHY_IAC_CMD_WRITE |
+                    PHY_IAC_REG(phy_reg) |
+                    PHY_IAC_ADDR(phy_addr) |
+                    PHY_IAC_DATA(write_data),
                MTK_PHY_IAC);
 
-       if (mtk_mdio_busy_wait(eth))
-               return -1;
+       ret = mtk_mdio_busy_wait(eth);
+       if (ret < 0)
+               return ret;
 
        return 0;
 }
 
-static u32 _mtk_mdio_read(struct mtk_eth *eth, int phy_addr, int phy_reg)
+static int _mtk_mdio_read(struct mtk_eth *eth, u32 phy_addr, u32 phy_reg)
 {
-       u32 d;
+       int ret;
 
-       if (mtk_mdio_busy_wait(eth))
-               return 0xffff;
+       ret = mtk_mdio_busy_wait(eth);
+       if (ret < 0)
+               return ret;
 
-       mtk_w32(eth, PHY_IAC_ACCESS | PHY_IAC_START | PHY_IAC_READ |
-               (phy_reg << PHY_IAC_REG_SHIFT) |
-               (phy_addr << PHY_IAC_ADDR_SHIFT),
+       mtk_w32(eth, PHY_IAC_ACCESS |
+                    PHY_IAC_START_C22 |
+                    PHY_IAC_CMD_C22_READ |
+                    PHY_IAC_REG(phy_reg) |
+                    PHY_IAC_ADDR(phy_addr),
                MTK_PHY_IAC);
 
-       if (mtk_mdio_busy_wait(eth))
-               return 0xffff;
-
-       d = mtk_r32(eth, MTK_PHY_IAC) & 0xffff;
+       ret = mtk_mdio_busy_wait(eth);
+       if (ret < 0)
+               return ret;
 
-       return d;
+       return mtk_r32(eth, MTK_PHY_IAC) & PHY_IAC_DATA_MASK;
 }
 
 static int mtk_mdio_write(struct mii_bus *bus, int phy_addr,

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 5ef70dd..f2d9063 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -341,11 +341,17 @@
 /* PHY Indirect Access Control registers */
 #define MTK_PHY_IAC            0x10004
 #define PHY_IAC_ACCESS         BIT(31)
-#define PHY_IAC_READ           BIT(19)
-#define PHY_IAC_WRITE          BIT(18)
-#define PHY_IAC_START          BIT(16)
-#define PHY_IAC_ADDR_SHIFT     20
-#define PHY_IAC_REG_SHIFT      25
+#define PHY_IAC_REG_MASK       GENMASK(29, 25)
+#define PHY_IAC_REG(x)         FIELD_PREP(PHY_IAC_REG_MASK, (x))
+#define PHY_IAC_ADDR_MASK      GENMASK(24, 20)
+#define PHY_IAC_ADDR(x)                FIELD_PREP(PHY_IAC_ADDR_MASK, (x))
+#define PHY_IAC_CMD_MASK       GENMASK(19, 18)
+#define PHY_IAC_CMD_WRITE      FIELD_PREP(PHY_IAC_CMD_MASK, 1)
+#define PHY_IAC_CMD_C22_READ   FIELD_PREP(PHY_IAC_CMD_MASK, 2)
+#define PHY_IAC_START_MASK     GENMASK(17, 16)
+#define PHY_IAC_START_C22      FIELD_PREP(PHY_IAC_START_MASK, 1)
+#define PHY_IAC_DATA_MASK      GENMASK(15, 0)
+#define PHY_IAC_DATA(x)                FIELD_PREP(PHY_IAC_DATA_MASK, (x))
 #define PHY_IAC_TIMEOUT                HZ
 
 #define MTK_MAC_MISC           0x1000c