net: dsa: allow switch drivers to implement suspend/resume hooks

Add an abstraction layer to suspend/resume switch devices, doing the
following split:

- suspend/resume the slave network devices and their corresponding PHY
  devices
- suspend/resume the switch hardware using switch driver callbacks

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -210,6 +210,12 @@ struct dsa_switch_driver {
 	void	(*get_ethtool_stats)(struct dsa_switch *ds,
 				     int port, uint64_t *data);
 	int	(*get_sset_count)(struct dsa_switch *ds);
+
+	/*
+	 * Suspend and resume
+	 */
+	int	(*suspend)(struct dsa_switch *ds);
+	int	(*resume)(struct dsa_switch *ds);
 };
 
 void register_switch_driver(struct dsa_switch_driver *type);

net/dsa/dsa.c

@@ -238,6 +238,49 @@ static void dsa_switch_destroy(struct dsa_switch *ds)
 {
 }
 
+static int dsa_switch_suspend(struct dsa_switch *ds)
+{
+	int i, ret = 0;
+
+	/* Suspend slave network devices */
+	for (i = 0; i < DSA_MAX_PORTS; i++) {
+		if (!(ds->phys_port_mask & (1 << i)))
+			continue;
+
+		ret = dsa_slave_suspend(ds->ports[i]);
+		if (ret)
+			return ret;
+	}
+
+	if (ds->drv->suspend)
+		ret = ds->drv->suspend(ds);
+
+	return ret;
+}
+
+static int dsa_switch_resume(struct dsa_switch *ds)
+{
+	int i, ret = 0;
+
+	if (ds->drv->resume)
+		ret = ds->drv->resume(ds);
+
+	if (ret)
+		return ret;
+
+	/* Resume slave network devices */
+	for (i = 0; i < DSA_MAX_PORTS; i++) {
+		if (!(ds->phys_port_mask & (1 << i)))
+			continue;
+
+		ret = dsa_slave_resume(ds->ports[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 
 /* link polling *************************************************************/
 static void dsa_link_poll_work(struct work_struct *ugly)
@@ -650,6 +693,42 @@ static struct packet_type dsa_pack_type __read_mostly = {
 	.func	= dsa_switch_rcv,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static int dsa_suspend(struct device *d)
+{
+	struct platform_device *pdev = to_platform_device(d);
+	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
+	int i, ret = 0;
+
+	for (i = 0; i < dst->pd->nr_chips; i++) {
+		struct dsa_switch *ds = dst->ds[i];
+
+		if (ds != NULL)
+			ret = dsa_switch_suspend(ds);
+	}
+
+	return ret;
+}
+
+static int dsa_resume(struct device *d)
+{
+	struct platform_device *pdev = to_platform_device(d);
+	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
+	int i, ret = 0;
+
+	for (i = 0; i < dst->pd->nr_chips; i++) {
+		struct dsa_switch *ds = dst->ds[i];
+
+		if (ds != NULL)
+			ret = dsa_switch_resume(ds);
+	}
+
+	return ret;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(dsa_pm_ops, dsa_suspend, dsa_resume);
+
 static const struct of_device_id dsa_of_match_table[] = {
 	{ .compatible = "brcm,bcm7445-switch-v4.0" },
 	{ .compatible = "marvell,dsa", },
@@ -665,6 +744,7 @@ static struct platform_driver dsa_driver = {
 		.name	= "dsa",
 		.owner	= THIS_MODULE,
 		.of_match_table = dsa_of_match_table,
+		.pm	= &dsa_pm_ops,
 	},
 };
 

net/dsa/dsa_priv.h

@@ -56,6 +56,8 @@ void dsa_slave_mii_bus_init(struct dsa_switch *ds);
 struct net_device *dsa_slave_create(struct dsa_switch *ds,
 				    struct device *parent,
 				    int port, char *name);
+int dsa_slave_suspend(struct net_device *slave_dev);
+int dsa_slave_resume(struct net_device *slave_dev);
 
 /* tag_dsa.c */
 extern const struct dsa_device_ops dsa_netdev_ops;

net/dsa/slave.c

@@ -412,6 +412,37 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
 			p->phy->addr, p->phy->drv->name);
 }
 
+int dsa_slave_suspend(struct net_device *slave_dev)
+{
+	struct dsa_slave_priv *p = netdev_priv(slave_dev);
+
+	netif_device_detach(slave_dev);
+
+	if (p->phy) {
+		phy_stop(p->phy);
+		p->old_pause = -1;
+		p->old_link = -1;
+		p->old_duplex = -1;
+		phy_suspend(p->phy);
+	}
+
+	return 0;
+}
+
+int dsa_slave_resume(struct net_device *slave_dev)
+{
+	struct dsa_slave_priv *p = netdev_priv(slave_dev);
+
+	netif_device_attach(slave_dev);
+
+	if (p->phy) {
+		phy_resume(p->phy);
+		phy_start(p->phy);
+	}
+
+	return 0;
+}
+
 struct net_device *
 dsa_slave_create(struct dsa_switch *ds, struct device *parent,
 		 int port, char *name)