net: stmmac: dwmac-rk: keep the PHY up for WoL

When suspending the machine, do not shutdown the external PHY by cutting
its regulator in the mac platform driver suspend code if Wake-on-Lan is enabled,
else it cannot wake us up.
In order to do this, split the suspend/resume callbacks from the
init/exit callbacks, so we can condition the power-down on the lack of
need to wake-up from the LAN but do it unconditionally when unloading the
module.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -46,6 +46,7 @@ struct rk_priv_data {
 	struct platform_device *pdev;
 	int phy_iface;
 	struct regulator *regulator;
+	bool suspended;
 	const struct rk_gmac_ops *ops;
 
 	bool clk_enabled;
@@ -529,9 +530,8 @@ static struct rk_priv_data *rk_gmac_setup(struct platform_device *pdev,
 	return bsp_priv;
 }
 
-static int rk_gmac_init(struct platform_device *pdev, void *priv)
+static int rk_gmac_powerup(struct rk_priv_data *bsp_priv)
 {
-	struct rk_priv_data *bsp_priv = priv;
 	int ret;
 
 	ret = phy_power_on(bsp_priv, true);
@@ -545,14 +545,50 @@ static int rk_gmac_init(struct platform_device *pdev, void *priv)
 	return 0;
 }
 
-static void rk_gmac_exit(struct platform_device *pdev, void *priv)
+static void rk_gmac_powerdown(struct rk_priv_data *gmac)
 {
-	struct rk_priv_data *gmac = priv;
-
 	phy_power_on(gmac, false);
 	gmac_clk_enable(gmac, false);
 }
 
+static int rk_gmac_init(struct platform_device *pdev, void *priv)
+{
+	struct rk_priv_data *bsp_priv = priv;
+
+	return rk_gmac_powerup(bsp_priv);
+}
+
+static void rk_gmac_exit(struct platform_device *pdev, void *priv)
+{
+	struct rk_priv_data *bsp_priv = priv;
+
+	rk_gmac_powerdown(bsp_priv);
+}
+
+static void rk_gmac_suspend(struct platform_device *pdev, void *priv)
+{
+	struct rk_priv_data *bsp_priv = priv;
+
+	/* Keep the PHY up if we use Wake-on-Lan. */
+	if (device_may_wakeup(&pdev->dev))
+		return;
+
+	rk_gmac_powerdown(bsp_priv);
+	bsp_priv->suspended = true;
+}
+
+static void rk_gmac_resume(struct platform_device *pdev, void *priv)
+{
+	struct rk_priv_data *bsp_priv = priv;
+
+	/* The PHY was up for Wake-on-Lan. */
+	if (!bsp_priv->suspended)
+		return;
+
+	rk_gmac_powerup(bsp_priv);
+	bsp_priv->suspended = false;
+}
+
 static void rk_fix_speed(void *priv, unsigned int speed)
 {
 	struct rk_priv_data *bsp_priv = priv;
@@ -591,6 +627,8 @@ static int rk_gmac_probe(struct platform_device *pdev)
 	plat_dat->init = rk_gmac_init;
 	plat_dat->exit = rk_gmac_exit;
 	plat_dat->fix_mac_speed = rk_fix_speed;
+	plat_dat->suspend = rk_gmac_suspend;
+	plat_dat->resume = rk_gmac_resume;
 
 	plat_dat->bsp_priv = rk_gmac_setup(pdev, data);
 	if (IS_ERR(plat_dat->bsp_priv))