Some network drivers include functionality to speed down the PHY when
suspending and just waiting for a WoL packet because this saves energy.
This functionality is quite generic, therefore let's factor it out to
phylib.
Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
---
drivers/net/phy/phy.c | 78 +++++++++++++++++++++++++++++++++++++++++++
include/linux/phy.h | 2 ++
2 files changed, 80 insertions(+)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index c4aa360d..0547c603 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -551,6 +551,84 @@ int phy_start_aneg(struct phy_device *phydev)
}
EXPORT_SYMBOL(phy_start_aneg);
+static int phy_poll_aneg_done(struct phy_device *phydev)
+{
+ unsigned int retries = 100;
+ int ret;
+
+ do {
+ msleep(100);
+ ret = phy_aneg_done(phydev);
+ } while (!ret && --retries);
+
+ if (!ret)
+ return -ETIMEDOUT;
+
+ return ret < 0 ? ret : 0;
+}
+
+/**
+ * phy_speed_down - set speed to lowest speed supported by both link partners
+ * @phydev: the phy_device struct
+ * @sync: perform action synchronously
+ *
+ * Description: Typically used to save energy when waiting for a WoL packet
+ */
+int phy_speed_down(struct phy_device *phydev, bool sync)
+{
+ u32 adv = phydev->lp_advertising & phydev->supported;
+ u32 adv_old = phydev->advertising;
+ int ret;
+
+ if (phydev->autoneg != AUTONEG_ENABLE)
+ return 0;
+
+ if (adv & PHY_10BT_FEATURES)
+ phydev->advertising &= ~(PHY_100BT_FEATURES |
+ PHY_1000BT_FEATURES);
+ else if (adv & PHY_100BT_FEATURES)
+ phydev->advertising &= ~PHY_1000BT_FEATURES;
+
+ if (phydev->advertising == adv_old)
+ return 0;
+
+ ret = phy_config_aneg(phydev);
+ if (ret)
+ return ret;
+
+ return sync ? phy_poll_aneg_done(phydev) : 0;
+}
+EXPORT_SYMBOL_GPL(phy_speed_down);
+
+/**
+ * phy_speed_up - (re)set advertised speeds to all supported speeds
+ * @phydev: the phy_device struct
+ * @sync: perform action synchronously
+ *
+ * Description: Used to revert the effect of phy_speed_down
+ */
+int phy_speed_up(struct phy_device *phydev, bool sync)
+{
+ u32 mask = PHY_10BT_FEATURES | PHY_100BT_FEATURES | PHY_1000BT_FEATURES;
+ u32 adv_old = phydev->advertising;
+ int ret;
+
+ if (phydev->autoneg != AUTONEG_ENABLE)
+ return 0;
+
+ phydev->advertising = (adv_old & ~mask) | (phydev->supported & mask);
+
+ if (phydev->advertising == adv_old)
+ return 0;
+
+ ret = phy_config_aneg(phydev);
+ if (ret)
+ return ret;
+
+ return sync ? phy_poll_aneg_done(phydev) : 0;
+}
+EXPORT_SYMBOL_GPL(phy_speed_up);
+
/**
* phy_start_machine - start PHY state machine tracking
* @phydev: the phy_device struct
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 6cd09098..275f528e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -942,6 +942,8 @@ void phy_start(struct phy_device *phydev);
void phy_stop(struct phy_device *phydev);
int phy_start_aneg(struct phy_device *phydev);
int phy_aneg_done(struct phy_device *phydev);
+int phy_speed_down(struct phy_device *phydev, bool sync);
+int phy_speed_up(struct phy_device *phydev, bool sync);
int phy_stop_interrupts(struct phy_device *phydev);
int phy_restart_aneg(struct phy_device *phydev);
--
2.18.0
