[PATCH net-next] rswitch: Add PM ops

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

Add PM ops for Suspend to Idle. When the system suspended,
the Ethernet Serdes's clock will be stopped. So, this driver needs
to re-initialize the Ethernet Serdes by phy_init() in
renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 This patch is based on the latest net-next.git / next branch.
 After applied this patch with the following patches, the system can
 enter/exit Suspend to Idle without any error:

https://lore.kernel.org/netdev/20230201131454.1928136-1-yoshihiro.shimoda.uh@renesas.com/
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=510b18cf23b9bd8a982ef7f1fb19f3968a2bf787
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=053f13f67be6d02781730c9ac71abde6e9140610

 drivers/net/ethernet/renesas/rswitch.c | 43 ++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
index 0023ff254915..301053db61ac 100644
--- a/drivers/net/ethernet/renesas/rswitch.c
+++ b/drivers/net/ethernet/renesas/rswitch.c
@@ -17,6 +17,7 @@
 #include <linux/of_net.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/rtnetlink.h>
 #include <linux/slab.h>
@@ -1315,6 +1316,7 @@ static int rswitch_phy_device_init(struct rswitch_device *rdev)
 	if (!phydev)
 		goto out;
 	__set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
+	phydev->mac_managed_pm = true;
 
 	phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
 				rdev->etha->phy_interface);
@@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
 	platform_set_drvdata(pdev, NULL);
 }
 
+static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
+{
+	struct rswitch_private *priv = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i;
+
+	rswitch_for_each_enabled_port(priv, i) {
+		ndev = priv->rdev[i]->ndev;
+		if (netif_running(ndev)) {
+			netif_device_detach(ndev);
+			rswitch_stop(ndev);
+		}
+		if (priv->rdev[i]->serdes->init_count)
+			phy_exit(priv->rdev[i]->serdes);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused renesas_eth_sw_resume(struct device *dev)
+{
+	struct rswitch_private *priv = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i;
+
+	rswitch_for_each_enabled_port(priv, i) {
+		phy_init(priv->rdev[i]->serdes);
+		ndev = priv->rdev[i]->ndev;
+		if (netif_running(ndev)) {
+			rswitch_open(ndev);
+			netif_device_attach(ndev);
+		}
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(renesas_eth_sw_pm_ops, renesas_eth_sw_suspend,
+			 renesas_eth_sw_resume);
+
 static struct platform_driver renesas_eth_sw_driver_platform = {
 	.probe = renesas_eth_sw_probe,
 	.remove_new = renesas_eth_sw_remove,
 	.driver = {
 		.name = "renesas_eth_sw",
+		.pm = &renesas_eth_sw_pm_ops,
 		.of_match_table = renesas_eth_sw_of_table,
 	}
 };
-- 
2.25.1