net: dwmac-sti: Use helper rgmii_clock

Utilize a new helper function rgmii_clock().

Reviewed-by: Andrew Lunn <[e-mail]>
Reviewed-by: Russell King (Oracle) <[e-mail]>
Signed-off-by: Jan Petrous (OSS) <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c

···
 
 #include "stmmac_platform.h"
 
-#define DWMAC_125MHZ	125000000
 #define DWMAC_50MHZ	50000000
-#define DWMAC_25MHZ	25000000
-#define DWMAC_2_5MHZ	2500000
 
 #define IS_PHY_IF_MODE_RGMII(iface)	(iface == PHY_INTERFACE_MODE_RGMII || \
 			iface == PHY_INTERFACE_MODE_RGMII_ID || \
···
 	struct sti_dwmac *dwmac = priv;
 	u32 src = dwmac->tx_retime_src;
 	u32 reg = dwmac->ctrl_reg;
-	u32 freq = 0;
+	long freq = 0;
 
 	if (dwmac->interface == PHY_INTERFACE_MODE_MII) {
 		src = TX_RETIME_SRC_TXCLK;
···
 		}
 	} else if (IS_PHY_IF_MODE_RGMII(dwmac->interface)) {
 		/* On GiGa clk source can be either ext or from clkgen */
-		if (spd == SPEED_1000) {
-			freq = DWMAC_125MHZ;
-		} else {
+		freq = rgmii_clock(spd);
+
+		if (spd != SPEED_1000 && freq > 0)
 			/* Switch to clkgen for these speeds */
 			src = TX_RETIME_SRC_CLKGEN;
-			if (spd == SPEED_100)
-				freq = DWMAC_25MHZ;
-			else if (spd == SPEED_10)
-				freq = DWMAC_2_5MHZ;
-		}
 	}
 
-	if (src == TX_RETIME_SRC_CLKGEN && freq)
+	if (src == TX_RETIME_SRC_CLKGEN && freq > 0)
 		clk_set_rate(dwmac->clk, freq);
 
 	regmap_update_bits(dwmac->regmap, reg, STIH4XX_RETIME_SRC_MASK,