Subject: [PATCH RFC net-next 09/23] net: phy: add configuration of rx clock stop mode

From: "Russell King (Oracle)" <[email-masked]>
Date: Tue, 26 Nov 2024 12:52:57 +0000

Add a function to allow configuration of the PCS's clock stop enable
bit, used to configure whether the xMII receive clock can be stopped
during LPI mode.

Signed-off-by: Russell King (Oracle) <[email-masked]>
---
 drivers/net/phy/phy.c | 25 ++++++++++++++++++++-----
 include/linux/phy.h   |  1 +
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 21e0fc9a6f09..d0a9d807d48f 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1607,6 +1607,25 @@ int phy_eee_tx_clock_stop_capable(struct phy_device *phydev)
 }
 EXPORT_SYMBOL_GPL(phy_eee_tx_clock_stop_capable);
 
+/**
+ * phy_eee_rx_clock_stop() - configure PHY receive clock in LPI
+ * phydev: target phy_device struct
+ *
+ * Configure whether the PHY may disable its receive clock during LPI mode,
+ * See IEEE 802.3 sections 22.2.2.2, 35.2.2.10, and 45.2.3.1.4. Returns 0 or
+ * negative error.
+ */
+int phy_eee_rx_clock_stop(struct phy_device *phydev, bool clk_stop_enable)
+{
+	/* Configure the PHY to stop receiving xMII
+	 * clock while it is signaling LPI.
+	 */
+	return phy_modify_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
+			      MDIO_PCS_CTRL1_CLKSTOP_EN,
+			      clk_stop_enable ? MDIO_PCS_CTRL1_CLKSTOP_EN : 0);
+}
+EXPORT_SYMBOL_GPL(phy_eee_rx_clock_stop);
+
 /**
  * phy_init_eee - init and check the EEE feature
  * @phydev: target phy_device struct
@@ -1631,11 +1650,7 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 		return -EPROTONOSUPPORT;
 
 	if (clk_stop_enable)
-		/* Configure the PHY to stop receiving xMII
-		 * clock while it is signaling LPI.
-		 */
-		ret = phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
-				       MDIO_PCS_CTRL1_CLKSTOP_EN);
+		ret = phy_eee_rx_clock_stop(phydev, true);
 
 	return ret < 0 ? ret : 0;
 }
diff --git a/include/linux/phy.h b/include/linux/phy.h
index d0491cdf54b6..467149b44a8e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -2039,6 +2039,7 @@ int phy_unregister_fixup_for_id(const char *bus_id);
 int phy_unregister_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask);
 
 int phy_eee_tx_clock_stop_capable(struct phy_device *phydev);
+int phy_eee_rx_clock_stop(struct phy_device *phydev, bool clk_stop_enable);
 int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable);
 int phy_get_eee_err(struct phy_device *phydev);
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_keee *data);
-- 
2.30.2