[PATCH net-next v2 3/8] net: stmmac: consolidate version reading and validation

[Russell King (Oracle)]

There is no need to read the version register twice, once in
stmmac_get_id() and then again in stmmac_get_dev_id(). Consolidate
this into stmmac_get_version() and pass each of these this value.

As both functions unnecessarily issue the same warning for a zero
register value, also move this into stmmac_get_version().

Reviewed-by: Andrew Lunn <andrew at lunn.ch>
Tested-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/hwif.c | 29 ++++++++--------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
index 6b001d3f57c6..699c94acfeff 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
@@ -18,30 +18,16 @@ struct stmmac_version {
 	u8 dev_id;
 };
 
-static u32 stmmac_get_id(struct stmmac_priv *priv, u32 id_reg)
+static u32 stmmac_get_id(struct stmmac_priv *priv, u32 reg)
 {
-	u32 reg = readl(priv->ioaddr + id_reg);
-
-	if (!reg) {
-		dev_info(priv->device, "Version ID not available\n");
-		return 0x0;
-	}
-
 	dev_info(priv->device, "User ID: 0x%x, Synopsys ID: 0x%x\n",
 			(unsigned int)(reg & GENMASK(15, 8)) >> 8,
 			(unsigned int)(reg & GENMASK(7, 0)));
 	return reg & GENMASK(7, 0);
 }
 
-static u32 stmmac_get_dev_id(struct stmmac_priv *priv, u32 id_reg)
+static u32 stmmac_get_dev_id(struct stmmac_priv *priv, u32 reg)
 {
-	u32 reg = readl(priv->ioaddr + id_reg);
-
-	if (!reg) {
-		dev_info(priv->device, "Version ID not available\n");
-		return 0x0;
-	}
-
 	return (reg & GENMASK(15, 8)) >> 8;
 }
 
@@ -50,6 +36,7 @@ static void stmmac_get_version(struct stmmac_priv *priv,
 {
 	enum dwmac_core_type core_type = priv->plat->core_type;
 	unsigned int version_offset;
+	u32 version;
 
 	ver->snpsver = 0;
 	ver->dev_id = 0;
@@ -62,9 +49,15 @@ static void stmmac_get_version(struct stmmac_priv *priv,
 	else
 		version_offset = GMAC4_VERSION;
 
-	ver->snpsver = stmmac_get_id(priv, version_offset);
+	version = readl(priv->ioaddr + version_offset);
+	if (version == 0) {
+		dev_info(priv->device, "Version ID not available\n");
+		return;
+	}
+
+	ver->snpsver = stmmac_get_id(priv, version);
 	if (core_type == DWMAC_CORE_XGMAC)
-		ver->dev_id = stmmac_get_dev_id(priv, version_offset);
+		ver->dev_id = stmmac_get_dev_id(priv, version);
 }
 
 static void stmmac_dwmac_mode_quirk(struct stmmac_priv *priv)
-- 
2.47.3