[PATCH net-next v2 2/2] net: phy: adin: add support for setting link-status-pin polarity

[Josua Mayer <josua@solid-run.com>]

ADIN1300/1200 support software control over pin polarity for LINK_ST
(link-status) pin.

Configure the polarity during config_init based on device-tree property.

Polarity is only set if specified in device-tree, otherwise the phy
defaults to active-high during reset.

Signed-off-by: Josua Mayer <josua@solid-run.com>
---
 drivers/net/phy/adin.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/net/phy/adin.c b/drivers/net/phy/adin.c
index 2e1a46e121d9..a533932afcb8 100644
--- a/drivers/net/phy/adin.c
+++ b/drivers/net/phy/adin.c
@@ -158,6 +158,9 @@
 #define ADIN1300_RMII_20_BITS			0x0004
 #define ADIN1300_RMII_24_BITS			0x0005
 
+#define ADIN1300_GE_LNK_STAT_INV_EN_REG		0xff3c
+#define   ADIN1300_GE_LNK_STAT_INV_EN		BIT(0)
+
 /**
  * struct adin_cfg_reg_map - map a config value to aregister value
  * @cfg:	value in device configuration
@@ -522,6 +525,28 @@ static int adin_config_clk_out(struct phy_device *phydev)
 			      ADIN1300_GE_CLK_CFG_MASK, sel);
 }
 
+static int adin_config_link_status_pin_polarity(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	int ret;
+	u32 val;
+
+	if (!device_property_present(dev, "adi,link-st-polarity"))
+		return 0;
+
+	ret = device_property_read_u32(dev, "adi,link-st-polarity", &val);
+	if (ret) {
+		return ret;
+	} else if (val > 1) {
+		phydev_err(phydev, "invalid adi,link-st-polarity\n");
+		return -EINVAL;
+	}
+
+	return phy_modify_mmd(phydev, MDIO_MMD_VEND1,
+			     ADIN1300_GE_LNK_STAT_INV_EN_REG,
+			     ADIN1300_GE_LNK_STAT_INV_EN, val);
+}
+
 static int adin_config_init(struct phy_device *phydev)
 {
 	int rc;
@@ -548,6 +573,10 @@ static int adin_config_init(struct phy_device *phydev)
 	if (rc < 0)
 		return rc;
 
+	rc = adin_config_link_status_pin_polarity(phydev);
+	if (rc < 0)
+		return rc;
+
 	phydev_dbg(phydev, "PHY is using mode '%s'\n",
 		   phy_modes(phydev->interface));
 

-- 
2.35.3