net: ti: prueth: Adds power management support for PRU-ICSS

Changes for supporting the sleep/resume feature for PRU-ICSS.

PRU-ICSS will be kept in IDLE mode for optimal power consumption by Linux
power management subsystem and will be resumed when it is required.

Signed-off-by: Roger Quadros <[email protected]>
Signed-off-by: Andrew F. Davis <[email protected]>
Signed-off-by: Basharath Hussain Khaja <[email protected]>
Signed-off-by: Parvathi Pudi <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: Roger Quadros

drivers/net/ethernet/ti/icssm/icssm_prueth.c

@@ -2324,6 +2324,63 @@ static void icssm_prueth_remove(struct platform_device *pdev)
 		pru_rproc_put(prueth->pru1);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int icssm_prueth_suspend(struct device *dev)
+{
+	struct prueth *prueth = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i, ret;
+
+	for (i = 0; i < PRUETH_NUM_MACS; i++) {
+		ndev = prueth->registered_netdevs[i];
+
+		if (!ndev)
+			continue;
+
+		if (netif_running(ndev)) {
+			netif_device_detach(ndev);
+			ret = icssm_emac_ndo_stop(ndev);
+			if (ret < 0) {
+				netdev_err(ndev, "failed to stop: %d", ret);
+				return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int icssm_prueth_resume(struct device *dev)
+{
+	struct prueth *prueth = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i, ret;
+
+	for (i = 0; i < PRUETH_NUM_MACS; i++) {
+		ndev = prueth->registered_netdevs[i];
+
+		if (!ndev)
+			continue;
+
+		if (netif_running(ndev)) {
+			ret = icssm_emac_ndo_open(ndev);
+			if (ret < 0) {
+				netdev_err(ndev, "failed to start: %d", ret);
+				return ret;
+			}
+			netif_device_attach(ndev);
+		}
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops prueth_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(icssm_prueth_suspend, icssm_prueth_resume)
+};
+
 /* AM57xx SoC-specific firmware data */
 static struct prueth_private_data am57xx_prueth_pdata = {
 	.driver_data = PRUSS_AM57XX,
@@ -2349,6 +2406,7 @@ static struct platform_driver prueth_driver = {
 	.driver = {
 		.name = "prueth",
 		.of_match_table = prueth_dt_match,
+		.pm = &prueth_dev_pm_ops,
 	},
 };
 module_platform_driver(prueth_driver);