net: dsa: bcm_sf2: request and handle clocks

Fetch the corresponding clock resource and enable/disable it during
suspend/resume if and only if we have no ports defined for Wake-on-LAN.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -14,6 +14,7 @@
 #include <linux/phy_fixed.h>
 #include <linux/phylink.h>
 #include <linux/mii.h>
+#include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
@@ -750,6 +751,9 @@ static int bcm_sf2_sw_suspend(struct dsa_switch *ds)
 			bcm_sf2_port_disable(ds, port);
 	}
 
+	if (!priv->wol_ports_mask)
+		clk_disable_unprepare(priv->clk);
+
 	return 0;
 }
 
@@ -758,6 +762,9 @@ static int bcm_sf2_sw_resume(struct dsa_switch *ds)
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
 	int ret;
 
+	if (!priv->wol_ports_mask)
+		clk_prepare_enable(priv->clk);
+
 	ret = bcm_sf2_sw_rst(priv);
 	if (ret) {
 		pr_err("%s: failed to software reset switch\n", __func__);
@@ -1189,10 +1196,16 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 		base++;
 	}
 
+	priv->clk = devm_clk_get_optional(&pdev->dev, "sw_switch");
+	if (IS_ERR(priv->clk))
+		return PTR_ERR(priv->clk);
+
+	clk_prepare_enable(priv->clk);
+
 	ret = bcm_sf2_sw_rst(priv);
 	if (ret) {
 		pr_err("unable to software reset switch: %d\n", ret);
-		return ret;
+		goto out_clk;
 	}
 
 	bcm_sf2_gphy_enable_set(priv->dev->ds, true);
@@ -1200,7 +1213,7 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 	ret = bcm_sf2_mdio_register(ds);
 	if (ret) {
 		pr_err("failed to register MDIO bus\n");
-		return ret;
+		goto out_clk;
 	}
 
 	bcm_sf2_gphy_enable_set(priv->dev->ds, false);
@@ -1267,6 +1280,8 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 
 out_mdio:
 	bcm_sf2_mdio_unregister(priv);
+out_clk:
+	clk_disable_unprepare(priv->clk);
 	return ret;
 }
 
@@ -1280,6 +1295,7 @@ static int bcm_sf2_sw_remove(struct platform_device *pdev)
 	dsa_unregister_switch(priv->dev->ds);
 	bcm_sf2_cfp_exit(priv->dev->ds);
 	bcm_sf2_mdio_unregister(priv);
+	clk_disable_unprepare(priv->clk);
 	if (priv->type == BCM7278_DEVICE_ID && !IS_ERR(priv->rcdev))
 		reset_control_assert(priv->rcdev);
 

drivers/net/dsa/bcm_sf2.h

@@ -93,6 +93,8 @@ struct bcm_sf2_priv {
 	/* Mask of ports enabled for Wake-on-LAN */
 	u32				wol_ports_mask;
 
+	struct clk			*clk;
+
 	/* MoCA port location */
 	int				moca_port;