diff mbox series

[net-next,v2,4/4] net: usb: asix: suspend embedded PHY if external is used

Message ID 20220311085014.1210963-4-o.rempel@pengutronix.de (mailing list archive)
State Accepted
Commit 4d17d43de9d186150b3289ce99d7a79fcff202f9
Headers show
Series [net-next,v2,1/4] net: usb: asix: unify ax88772_resume code | expand

Commit Message

Oleksij Rempel March 11, 2022, 8:50 a.m. UTC
In case external PHY is used, we need to take care of embedded PHY.
Since there are no methods to disable this PHY from the MAC side and
keeping RMII reference clock, we need to suspend it.

This patch will reduce electrical noise (PHY is continuing to send FLPs)
and power consumption by 0,22W.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v2:
- rename internal to embedded PHY
- add note about refclock dependency
---
 drivers/net/usb/asix.h         |  3 +++
 drivers/net/usb/asix_devices.c | 18 +++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/usb/asix.h b/drivers/net/usb/asix.h
index 072760d76a72..2c81236c6c7c 100644
--- a/drivers/net/usb/asix.h
+++ b/drivers/net/usb/asix.h
@@ -158,6 +158,8 @@ 
 #define AX_EEPROM_MAGIC		0xdeadbeef
 #define AX_EEPROM_LEN		0x200
 
+#define AX_EMBD_PHY_ADDR	0x10
+
 /* This structure cannot exceed sizeof(unsigned long [5]) AKA 20 bytes */
 struct asix_data {
 	u8 multi_filter[AX_MCAST_FILTER_SIZE];
@@ -183,6 +185,7 @@  struct asix_common_private {
 	struct asix_rx_fixup_info rx_fixup_info;
 	struct mii_bus *mdio;
 	struct phy_device *phydev;
+	struct phy_device *phydev_int;
 	u16 phy_addr;
 	bool embd_phy;
 	u8 chipcode;
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 40046d23d986..4241852f392b 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -679,6 +679,22 @@  static int ax88772_init_phy(struct usbnet *dev)
 
 	phy_attached_info(priv->phydev);
 
+	if (priv->embd_phy)
+		return 0;
+
+	/* In case main PHY is not the embedded PHY and MAC is RMII clock
+	 * provider, we need to suspend embedded PHY by keeping PLL enabled
+	 * (AX_SWRESET_IPPD == 0).
+	 */
+	priv->phydev_int = mdiobus_get_phy(priv->mdio, AX_EMBD_PHY_ADDR);
+	if (!priv->phydev_int) {
+		netdev_err(dev->net, "Could not find internal PHY\n");
+		return -ENODEV;
+	}
+
+	priv->phydev_int->mac_managed_pm = 1;
+	phy_suspend(priv->phydev_int);
+
 	return 0;
 }
 
@@ -734,7 +750,7 @@  static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 		return ret;
 
 	priv->phy_addr = ret;
-	priv->embd_phy = ((priv->phy_addr & 0x1f) == 0x10);
+	priv->embd_phy = ((priv->phy_addr & 0x1f) == AX_EMBD_PHY_ADDR);
 
 	ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1,
 			    &priv->chipcode, 0);