From 2b9672ddb6f347467d7b33b86c5dfc4d5c0501a8 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Thu, 12 Jul 2018 21:32:53 +0200 Subject: [PATCH] net: phy: add phy_speed_down and phy_speed_up 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 Signed-off-by: David S. Miller --- 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 c4aa360dedff..d2baedc4ea91 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 + * + * WARNING: Setting sync to false may cause the system being unable to suspend + * in case the PHY generates an interrupt when finishing the autonegotiation. + * This interrupt may wake up the system immediately after suspend. + * Therefore use sync = false only if you're sure it's safe with the respective + * network chip. + */ +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 + * + * Description: Used to revert the effect of phy_speed_down + */ +int phy_speed_up(struct phy_device *phydev) +{ + u32 mask = PHY_10BT_FEATURES | PHY_100BT_FEATURES | PHY_1000BT_FEATURES; + u32 adv_old = phydev->advertising; + + if (phydev->autoneg != AUTONEG_ENABLE) + return 0; + + phydev->advertising = (adv_old & ~mask) | (phydev->supported & mask); + + if (phydev->advertising == adv_old) + return 0; + + return phy_config_aneg(phydev); +} +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 6cd09098427c..075c2f770d3e 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); int phy_stop_interrupts(struct phy_device *phydev); int phy_restart_aneg(struct phy_device *phydev); -- 2.30.2