net: stmmac: qcom-ethqos: use rgmii_clock() to set the link clock

The link clock operates at twice the RGMII clock rate. Therefore, we
can use the rgmii_clock() helper to set this clock rate.

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

drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c

···
 		rgmii_readl(ethqos, EMAC_SYSTEM_LOW_POWER_DEBUG));
 }
 
-/* Clock rates */
-#define RGMII_1000_NOM_CLK_FREQ			(250 * 1000 * 1000UL)
-#define RGMII_ID_MODE_100_LOW_SVS_CLK_FREQ	 (50 * 1000 * 1000UL)
-#define RGMII_ID_MODE_10_LOW_SVS_CLK_FREQ	  (5 * 1000 * 1000UL)
-
 static void
 ethqos_update_link_clk(struct qcom_ethqos *ethqos, int speed)
 {
+	long rate;
+
 	if (!phy_interface_mode_is_rgmii(ethqos->phy_mode))
 		return;
 
-	switch (speed) {
-	case SPEED_1000:
-		ethqos->link_clk_rate =  RGMII_1000_NOM_CLK_FREQ;
-		break;
-
-	case SPEED_100:
-		ethqos->link_clk_rate =  RGMII_ID_MODE_100_LOW_SVS_CLK_FREQ;
-		break;
-
-	case SPEED_10:
-		ethqos->link_clk_rate =  RGMII_ID_MODE_10_LOW_SVS_CLK_FREQ;
-		break;
-	}
+	rate = rgmii_clock(speed);
+	if (rate > 0)
+		ethqos->link_clk_rate = rate * 2;
 
 	clk_set_rate(ethqos->link_clk, ethqos->link_clk_rate);
 }