[PATCH v2 1/3] net: sun8i-emac: Always clear syscon EPHY register

[Andre Przywara <andre.przywara@arm.com>]

At the moment we only consider the EPHY register for those SoCs were
we actually have an internal PHY to configure. However even other SoCs
have this register, an expect the EPHY select bit to be cleared for
proper operation with an external PHY.

Rework sun8i_emac_set_syscon_ephy() to be called regardless of the EMAC
model, and clear the H3_EPHY_SELECT bit if no internal PHY is used.

We get away without it so far because SoCs like the A64 clear this bit
on reset, but we need to explicitly clear it on the H616, for instance.
The Linux driver does so as well.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/net/sun8i_emac.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
index 9f91a20d1d1..2344525bf52 100644
--- a/drivers/net/sun8i_emac.c
+++ b/drivers/net/sun8i_emac.c
@@ -297,30 +297,29 @@ static void sun8i_adjust_link(struct emac_eth_dev *priv,
 	writel(v, priv->mac_reg + EMAC_CTL0);
 }
 
-static int sun8i_emac_set_syscon_ephy(struct emac_eth_dev *priv, u32 *reg)
+static u32 sun8i_emac_set_syscon_ephy(struct emac_eth_dev *priv, u32 reg)
 {
 	if (priv->use_internal_phy) {
 		/* H3 based SoC's that has an Internal 100MBit PHY
 		 * needs to be configured and powered up before use
 		*/
-		*reg &= ~H3_EPHY_DEFAULT_MASK;
-		*reg |=  H3_EPHY_DEFAULT_VALUE;
-		*reg |= priv->phyaddr << H3_EPHY_ADDR_SHIFT;
-		*reg &= ~H3_EPHY_SHUTDOWN;
-		*reg |= H3_EPHY_SELECT;
-	} else
-		/* This is to select External Gigabit PHY on
-		 * the boards with H3 SoC.
-		*/
-		*reg &= ~H3_EPHY_SELECT;
+		reg &= ~H3_EPHY_DEFAULT_MASK;
+		reg |=  H3_EPHY_DEFAULT_VALUE;
+		reg |= priv->phyaddr << H3_EPHY_ADDR_SHIFT;
+		reg &= ~H3_EPHY_SHUTDOWN;
+		return reg | H3_EPHY_SELECT;
+	}
 
-	return 0;
+	/* This is to select External Gigabit PHY on those boards with
+	 * an internal PHY. Does not hurt on other SoCs. Linux does
+	 * it as well.
+	 */
+	return reg & ~H3_EPHY_SELECT;
 }
 
 static int sun8i_emac_set_syscon(struct sun8i_eth_pdata *pdata,
 				 struct emac_eth_dev *priv)
 {
-	int ret;
 	u32 reg;
 
 	if (priv->variant == R40_GMAC) {
@@ -336,11 +335,7 @@ static int sun8i_emac_set_syscon(struct sun8i_eth_pdata *pdata,
 
 	reg = readl(priv->sysctl_reg + 0x30);
 
-	if (priv->variant == H3_EMAC || priv->variant == H6_EMAC) {
-		ret = sun8i_emac_set_syscon_ephy(priv, &reg);
-		if (ret)
-			return ret;
-	}
+	reg = sun8i_emac_set_syscon_ephy(priv, reg);
 
 	reg &= ~(SC_ETCS_MASK | SC_EPIT);
 	if (priv->variant == H3_EMAC ||
-- 
2.17.5