net: mvneta: get optional bus clk

Some platforms may provide more than one clk for the mvneta IP, for
example Marvell BG4CT provides one clk for the mac core, and one
clk for the AXI bus logic. Obviously this bus clk also need to
be enabled. This patch adds this optional "bus" clk support.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 4067055..662c2ee 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -373,6 +373,8 @@
 
 	/* Core clock */
 	struct clk *clk;
+	/* AXI clock */
+	struct clk *clk_bus;
 	u8 mcast_count[256];
 	u16 tx_ring_size;
 	u16 rx_ring_size;
@@ -3614,6 +3616,10 @@
 
 	clk_prepare_enable(pp->clk);
 
+	pp->clk_bus = devm_clk_get(&pdev->dev, "bus");
+	if (!IS_ERR(pp->clk_bus))
+		clk_prepare_enable(pp->clk_bus);
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pp->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(pp->base)) {
@@ -3725,6 +3731,7 @@
 err_free_ports:
 	free_percpu(pp->ports);
 err_clk:
+	clk_disable_unprepare(pp->clk_bus);
 	clk_disable_unprepare(pp->clk);
 err_put_phy_node:
 	of_node_put(phy_node);
@@ -3742,6 +3749,7 @@
 	struct mvneta_port *pp = netdev_priv(dev);
 
 	unregister_netdev(dev);
+	clk_disable_unprepare(pp->clk_bus);
 	clk_disable_unprepare(pp->clk);
 	free_percpu(pp->ports);
 	free_percpu(pp->stats);