netdev - [PATCH net-next 2/4] net: stmmac: visconti: reorganise visconti_eth_set_clk_tx

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Message-Id: <E1uRH26-004UyM-9G@rmk-PC.armlinux.org.uk>
Date: Mon, 16 Jun 2025 22:06:22 +0100
From: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
To: Andrew Lunn <andrew@...n.ch>,
	Heiner Kallweit <hkallweit1@...il.com>
Cc: Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-stm32@...md-mailman.stormreply.com,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	netdev@...r.kernel.org,
	Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@...hiba.co.jp>,
	Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH net-next 2/4] net: stmmac: visconti: reorganise
 visconti_eth_set_clk_tx_rate()

Rather than testing dwmac->phy_intf_sel several times for the same
values in this function, group the code together. The only part
which was common was stopping the internal clock before programming
the clock setting.

This further improves the readability of this function.

Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
---
 .../ethernet/stmicro/stmmac/dwmac-visconti.c  | 51 +++++++++++--------
 1 file changed, 29 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
index ef86f9dce791..c2aaac4a5ac1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c
@@ -76,6 +76,22 @@ static int visconti_eth_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
 		default:
 			return -EINVAL;
 		}
+
+		/* Stop internal clock */
+		val = readl(dwmac->reg + REG_ETHER_CLOCK_SEL);
+		val &= ~(ETHER_CLK_SEL_RMII_CLK_EN | ETHER_CLK_SEL_RX_TX_CLK_EN);
+		val |= ETHER_CLK_SEL_TX_O_E_N_IN;
+		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
+
+		/* Set Clock-Mux, Start clock, Set TX_O direction */
+		val = clk_sel_val | ETHER_CLK_SEL_RX_CLK_EXT_SEL_RXC;
+		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
+
+		val |= ETHER_CLK_SEL_RX_TX_CLK_EN;
+		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
+
+		val &= ~ETHER_CLK_SEL_TX_O_E_N_IN;
+		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
 	} else if (dwmac->phy_intf_sel == ETHER_CONFIG_INTF_RMII) {
 		switch (speed) {
 		case SPEED_100:
@@ -89,27 +105,14 @@ static int visconti_eth_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
 		default:
 			return -EINVAL;
 		}
-	}
-
-	/* Stop internal clock */
-	val = readl(dwmac->reg + REG_ETHER_CLOCK_SEL);
-	val &= ~(ETHER_CLK_SEL_RMII_CLK_EN | ETHER_CLK_SEL_RX_TX_CLK_EN);
-	val |= ETHER_CLK_SEL_TX_O_E_N_IN;
-	writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
 
-	/* Set Clock-Mux, Start clock, Set TX_O direction */
-	switch (dwmac->phy_intf_sel) {
-	case ETHER_CONFIG_INTF_RGMII:
-		val = clk_sel_val | ETHER_CLK_SEL_RX_CLK_EXT_SEL_RXC;
-		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
-
-		val |= ETHER_CLK_SEL_RX_TX_CLK_EN;
+		/* Stop internal clock */
+		val = readl(dwmac->reg + REG_ETHER_CLOCK_SEL);
+		val &= ~(ETHER_CLK_SEL_RMII_CLK_EN | ETHER_CLK_SEL_RX_TX_CLK_EN);
+		val |= ETHER_CLK_SEL_TX_O_E_N_IN;
 		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
 
-		val &= ~ETHER_CLK_SEL_TX_O_E_N_IN;
-		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
-		break;
-	case ETHER_CONFIG_INTF_RMII:
+		/* Set Clock-Mux, Start clock, Set TX_O direction */
 		val = clk_sel_val | ETHER_CLK_SEL_RX_CLK_EXT_SEL_DIV |
 			ETHER_CLK_SEL_TX_CLK_EXT_SEL_DIV | ETHER_CLK_SEL_TX_O_E_N_IN |
 			ETHER_CLK_SEL_RMII_CLK_SEL_RX_C;
@@ -120,16 +123,20 @@ static int visconti_eth_set_clk_tx_rate(void *bsp_priv, struct clk *clk_tx_i,
 
 		val |= ETHER_CLK_SEL_RMII_CLK_EN | ETHER_CLK_SEL_RX_TX_CLK_EN;
 		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
-		break;
-	case ETHER_CONFIG_INTF_MII:
-	default:
+	} else {
+		/* Stop internal clock */
+		val = readl(dwmac->reg + REG_ETHER_CLOCK_SEL);
+		val &= ~(ETHER_CLK_SEL_RMII_CLK_EN | ETHER_CLK_SEL_RX_TX_CLK_EN);
+		val |= ETHER_CLK_SEL_TX_O_E_N_IN;
+		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
+
+		/* Set Clock-Mux, Start clock, Set TX_O direction */
 		val = clk_sel_val | ETHER_CLK_SEL_RX_CLK_EXT_SEL_RXC |
 			ETHER_CLK_SEL_TX_CLK_EXT_SEL_TXC | ETHER_CLK_SEL_TX_O_E_N_IN;
 		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
 
 		val |= ETHER_CLK_SEL_RX_TX_CLK_EN;
 		writel(val, dwmac->reg + REG_ETHER_CLOCK_SEL);
-		break;
 	}
 
 	return 0;
-- 
2.30.2