[PATCH v2 12/15] net: phy: adin: implement Energy Detect Powerdown mode

[Alexandru Ardelean]

The ADIN PHYs support Energy Detect Powerdown mode, which puts the PHY into
a low power mode when there is no signal on the wire (typically cable
unplugged).
This behavior is enabled by default, but can be disabled via device
property.

Signed-off-by: Alexandru Ardelean <alexandru.ardel...@analog.com>
---
 drivers/net/phy/adin.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/net/phy/adin.c b/drivers/net/phy/adin.c
index f276d692bdee..bc4393195de7 100644
--- a/drivers/net/phy/adin.c
+++ b/drivers/net/phy/adin.c
@@ -24,6 +24,11 @@
 #define   ADIN1300_AUTO_MDI_EN                 BIT(10)
 #define   ADIN1300_MAN_MDIX_EN                 BIT(9)
 
+#define ADIN1300_PHY_CTRL_STATUS2              0x0015
+#define   ADIN1300_NRG_PD_EN                   BIT(3)
+#define   ADIN1300_NRG_PD_TX_EN                        BIT(2)
+#define   ADIN1300_NRG_PD_STATUS               BIT(1)
+
 #define ADIN1300_INT_MASK_REG                  0x0018
 #define   ADIN1300_INT_MDIO_SYNC_EN            BIT(9)
 #define   ADIN1300_INT_ANEG_STAT_CHNG_EN       BIT(8)
@@ -138,6 +143,14 @@ static struct adin_clause45_mmd_map 
adin_clause45_mmd_map[] = {
        { MDIO_MMD_PCS, MDIO_PCS_EEE_WK_ERR,    ADIN1300_LPI_WAKE_ERR_CNT_REG },
 };
 
+/**
+ * struct adin_priv - ADIN PHY driver private data
+ * edpd_enabled                true if Energy Detect Powerdown mode is enabled
+ */
+struct adin_priv {
+       bool                    edpd_enabled;
+};
+
 static int adin_lookup_reg_value(const struct adin_cfg_reg_map *tbl, int cfg)
 {
        size_t i;
@@ -246,6 +259,18 @@ static int adin_config_rmii_mode(struct phy_device *phydev)
                             ADIN1300_GE_RMII_CFG_REG, reg);
 }
 
+static int adin_config_init_edpd(struct phy_device *phydev)
+{
+       struct adin_priv *priv = phydev->priv;
+
+       if (priv->edpd_enabled)
+               return phy_set_bits(phydev, ADIN1300_PHY_CTRL_STATUS2,
+                               (ADIN1300_NRG_PD_EN | ADIN1300_NRG_PD_TX_EN));
+
+       return phy_clear_bits(phydev, ADIN1300_PHY_CTRL_STATUS2,
+                       (ADIN1300_NRG_PD_EN | ADIN1300_NRG_PD_TX_EN));
+}
+
 static int adin_config_init(struct phy_device *phydev)
 {
        int rc;
@@ -264,6 +289,10 @@ static int adin_config_init(struct phy_device *phydev)
        if (rc < 0)
                return rc;
 
+       rc = adin_config_init_edpd(phydev);
+       if (rc < 0)
+               return rc;
+
        phydev_dbg(phydev, "PHY is using mode '%s'\n",
                   phy_modes(phydev->interface));
 
@@ -495,6 +524,17 @@ static int adin_reset(struct phy_device *phydev)
 
 static int adin_probe(struct phy_device *phydev)
 {
+       struct device *dev = &phydev->mdio.dev;
+       struct adin_priv *priv;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->edpd_enabled =
+               device_property_read_bool(dev, "adi,disable-energy-detect");
+       phydev->priv = priv;
+
        return adin_reset(phydev);
 }
 
-- 
2.20.1