From 145436ae01193c0a379fd3ea9c4fbdf32863db1f Mon Sep 17 00:00:00 2001 From: Dimitri Fedrau Date: Wed, 16 Apr 2025 19:14:49 +0200 Subject: [PATCH] net: phy: Add helper for getting MAC termination resistance Add helper which returns the MAC termination resistance value. Modifying the resistance to an appropriate value can reduce signal reflections and therefore improve signal quality. Reviewed-by: Russell King (Oracle) Signed-off-by: Dimitri Fedrau Link: https://patch.msgid.link/20250416-dp83822-mac-impedance-v3-3-028ac426cddb@liebherr.com Signed-off-by: Jakub Kicinski --- drivers/net/phy/phy_device.c | 15 +++++++++++++++ include/linux/phy.h | 3 +++ 2 files changed, 18 insertions(+) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index cc6c209fe702..f85c172c446c 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -2975,6 +2975,21 @@ int phy_get_tx_amplitude_gain(struct phy_device *phydev, struct device *dev, } EXPORT_SYMBOL_GPL(phy_get_tx_amplitude_gain); +/** + * phy_get_mac_termination - stores MAC termination in @val + * @phydev: phy_device struct + * @dev: pointer to the devices device struct + * @val: MAC termination + * + * Returns: 0 on success, < 0 on failure + */ +int phy_get_mac_termination(struct phy_device *phydev, struct device *dev, + u32 *val) +{ + return phy_get_u32_property(dev, "mac-termination-ohms", val); +} +EXPORT_SYMBOL_GPL(phy_get_mac_termination); + static int phy_led_set_brightness(struct led_classdev *led_cdev, enum led_brightness value) { diff --git a/include/linux/phy.h b/include/linux/phy.h index fb755358d965..066a28a4b64b 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -2040,6 +2040,9 @@ int phy_get_tx_amplitude_gain(struct phy_device *phydev, struct device *dev, enum ethtool_link_mode_bit_indices linkmode, u32 *val); +int phy_get_mac_termination(struct phy_device *phydev, struct device *dev, + u32 *val); + void phy_resolve_pause(unsigned long *local_adv, unsigned long *partner_adv, bool *tx_pause, bool *rx_pause); -- 2.50.1