[PATCH net-next] net: phy: add flag PHY_QUIRK_NO_ESTATEN

[Heiner Kallweit <hkallweit1@gmail.com>]

We have a Xilinx GBit PHY that doesn't have BMSR_ESTATEN set
(what violates the Clause 22 standard). Instead of having the PHY
driver to implement almost identical copies of few generic functions
let's add a flag for this quirk to phylib.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/phy/phy_device.c |  6 +++---
 include/linux/phy.h          | 16 +++++++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2c879ba01..7593ebebf 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1595,7 +1595,7 @@ static int genphy_config_advert(struct phy_device *phydev)
 	 * 1000Mbits/sec capable PHYs shall have the BMSR_ESTATEN bit set to a
 	 * logical 1.
 	 */
-	if (!(bmsr & BMSR_ESTATEN))
+	if (!(bmsr & BMSR_ESTATEN) && !phy_quirk_no_estaten(phydev))
 		return changed;
 
 	/* Configure gigabit if it's supported */
@@ -1919,7 +1919,7 @@ int genphy_config_init(struct phy_device *phydev)
 	if (val & BMSR_10HALF)
 		linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, features);
 
-	if (val & BMSR_ESTATEN) {
+	if (val & BMSR_ESTATEN || phy_quirk_no_estaten(phydev)) {
 		val = phy_read(phydev, MII_ESTATUS);
 		if (val < 0)
 			return val;
@@ -1972,7 +1972,7 @@ int genphy_read_abilities(struct phy_device *phydev)
 	linkmode_mod_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, phydev->supported,
 			 val & BMSR_10HALF);
 
-	if (val & BMSR_ESTATEN) {
+	if (val & BMSR_ESTATEN || phy_quirk_no_estaten(phydev)) {
 		val = phy_read(phydev, MII_ESTATUS);
 		if (val < 0)
 			return val;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index dc4b51060..b2ffd82b1 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -73,9 +73,10 @@ extern const int phy_10gbit_features_array[1];
 #define PHY_POLL		-1
 #define PHY_IGNORE_INTERRUPT	-2
 
-#define PHY_IS_INTERNAL		0x00000001
-#define PHY_RST_AFTER_CLK_EN	0x00000002
-#define MDIO_DEVICE_IS_PHY	0x80000000
+#define PHY_IS_INTERNAL		BIT(0)
+#define PHY_RST_AFTER_CLK_EN	BIT(1)
+#define PHY_QUIRK_NO_ESTATEN	BIT(2)
+#define MDIO_DEVICE_IS_PHY	BIT(31)
 
 /* Interface Mode definitions */
 typedef enum {
@@ -677,6 +678,15 @@ size_t phy_speeds(unsigned int *speeds, size_t size,
 void of_set_phy_supported(struct phy_device *phydev);
 void of_set_phy_eee_broken(struct phy_device *phydev);
 
+/**
+ * phy_quirk_no_estaten - Helper to check for flag PHY_QUIRK_NO_ESTATEN
+ * @phydev: The phy_device struct
+ */
+static inline bool phy_quirk_no_estaten(struct phy_device *phydev)
+{
+	return phydev->drv && phydev->drv->flags & PHY_QUIRK_NO_ESTATEN;
+}
+
 /**
  * phy_is_started - Convenience function to check whether PHY is started
  * @phydev: The phy_device struct
-- 
2.21.0