[PATCH net-next v3 6/7] net: dsa: microchip: use wakeup-source DT property to enable PME output

[Oleksij Rempel <o.rempel@pengutronix.de>]

KSZ switches with WoL support signals wake event over PME pin. If this
pin is attached to some external PMIC or System Controller can't be
described as GPIO, the only way to describe it in the devicetree is to
use wakeup-source property. So, add support for this property and enable
PME switch output if this property is present.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/dsa/microchip/ksz9477.c    | 3 +++
 drivers/net/dsa/microchip/ksz_common.c | 3 +++
 drivers/net/dsa/microchip/ksz_common.h | 1 +
 3 files changed, 7 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index 8d51ec629d76..8035e14ac372 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -1241,6 +1241,9 @@ int ksz9477_setup(struct dsa_switch *ds)
 	/* enable global MIB counter freeze function */
 	ksz_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true);
 
+	if (dev->wakeup_source)
+		ksz_write8(dev, REG_SW_PME_CTRL, PME_ENABLE);
+
 	return 0;
 }
 
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index bef1951fe6f2..820edda82cea 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -4240,6 +4240,9 @@ int ksz_switch_register(struct ksz_device *dev)
 			dev_err(dev->dev, "inconsistent synclko settings\n");
 			return -EINVAL;
 		}
+
+		dev->wakeup_source = of_property_read_bool(dev->dev->of_node,
+							   "wakeup-source");
 	}
 
 	ret = dsa_register_switch(dev->ds);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 43d0d8717eaa..80679f38ee12 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -163,6 +163,7 @@ struct ksz_device {
 	phy_interface_t compat_interface;
 	bool synclko_125;
 	bool synclko_disable;
+	bool wakeup_source;
 
 	struct vlan_table *vlan_cache;
 
-- 
2.39.2