[PATCH net-next 2/2] net: phy: dp83867: use 2ns delay if not specified in DTB

[Matthias Schiffer]

Most PHY drivers default to a 2ns delay if internal delay is requested
and no value is specified. Having a default value makes sense, as it
allows a Device Tree to only care about board design (whether there are
delays on the PCB or not), and not whether the delay is added on the MAC
or the PHY side when needed.

Whether the delays are actually applied is controlled by the
DP83867_RGMII_*_CLK_DELAY_EN flags, so the behavior is only changed in
configurations that would previously be rejected with -EINVAL.

Suggested-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
---
 drivers/net/phy/dp83867.c | 44 ++++-----------------------------------
 1 file changed, 4 insertions(+), 40 deletions(-)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index e5b0c1b7be13f..deeefb9625664 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -106,10 +106,8 @@
 /* RGMIIDCTL bits */
 #define DP83867_RGMII_TX_CLK_DELAY_MAX		0xf
 #define DP83867_RGMII_TX_CLK_DELAY_SHIFT	4
-#define DP83867_RGMII_TX_CLK_DELAY_INV	(DP83867_RGMII_TX_CLK_DELAY_MAX + 1)
 #define DP83867_RGMII_RX_CLK_DELAY_MAX		0xf
 #define DP83867_RGMII_RX_CLK_DELAY_SHIFT	0
-#define DP83867_RGMII_RX_CLK_DELAY_INV	(DP83867_RGMII_RX_CLK_DELAY_MAX + 1)
 
 /* IO_MUX_CFG bits */
 #define DP83867_IO_MUX_CFG_IO_IMPEDANCE_MASK	0x1f
@@ -501,29 +499,6 @@ static int dp83867_config_port_mirroring(struct phy_device *phydev)
 	return 0;
 }
 
-static int dp83867_verify_rgmii_cfg(struct phy_device *phydev)
-{
-	struct dp83867_private *dp83867 = phydev->priv;
-
-	/* RX delay *must* be specified if internal delay of RX is used. */
-	if ((phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-	     phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) &&
-	     dp83867->rx_id_delay == DP83867_RGMII_RX_CLK_DELAY_INV) {
-		phydev_err(phydev, "ti,rx-internal-delay must be specified\n");
-		return -EINVAL;
-	}
-
-	/* TX delay *must* be specified if internal delay of TX is used. */
-	if ((phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-	     phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) &&
-	     dp83867->tx_id_delay == DP83867_RGMII_TX_CLK_DELAY_INV) {
-		phydev_err(phydev, "ti,tx-internal-delay must be specified\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 #if IS_ENABLED(CONFIG_OF_MDIO)
 static int dp83867_of_init_io_impedance(struct phy_device *phydev)
 {
@@ -607,7 +582,7 @@ static int dp83867_of_init(struct phy_device *phydev)
 	dp83867->sgmii_ref_clk_en = of_property_read_bool(of_node,
 							  "ti,sgmii-ref-clock-output-enable");
 
-	dp83867->rx_id_delay = DP83867_RGMII_RX_CLK_DELAY_INV;
+	dp83867->rx_id_delay = DP83867_RGMIIDCTL_2_00_NS;
 	ret = of_property_read_u32(of_node, "ti,rx-internal-delay",
 				   &dp83867->rx_id_delay);
 	if (!ret && dp83867->rx_id_delay > DP83867_RGMII_RX_CLK_DELAY_MAX) {
@@ -617,7 +592,7 @@ static int dp83867_of_init(struct phy_device *phydev)
 		return -EINVAL;
 	}
 
-	dp83867->tx_id_delay = DP83867_RGMII_TX_CLK_DELAY_INV;
+	dp83867->tx_id_delay = DP83867_RGMIIDCTL_2_00_NS;
 	ret = of_property_read_u32(of_node, "ti,tx-internal-delay",
 				   &dp83867->tx_id_delay);
 	if (!ret && dp83867->tx_id_delay > DP83867_RGMII_TX_CLK_DELAY_MAX) {
@@ -737,7 +712,6 @@ static int dp83867_config_init(struct phy_device *phydev)
 {
 	struct dp83867_private *dp83867 = phydev->priv;
 	int ret, val, bs;
-	u16 delay;
 
 	/* Force speed optimization for the PHY even if it strapped */
 	ret = phy_modify(phydev, DP83867_CFG2, DP83867_DOWNSHIFT_EN,
@@ -745,10 +719,6 @@ static int dp83867_config_init(struct phy_device *phydev)
 	if (ret)
 		return ret;
 
-	ret = dp83867_verify_rgmii_cfg(phydev);
-	if (ret)
-		return ret;
-
 	/* RX_DV/RX_CTRL strapped in mode 1 or mode 2 workaround */
 	if (dp83867->rxctrl_strap_quirk)
 		phy_clear_bits_mmd(phydev, DP83867_DEVADDR, DP83867_CFG4,
@@ -827,15 +797,9 @@ static int dp83867_config_init(struct phy_device *phydev)
 
 		phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIICTL, val);
 
-		delay = 0;
-		if (dp83867->rx_id_delay != DP83867_RGMII_RX_CLK_DELAY_INV)
-			delay |= dp83867->rx_id_delay;
-		if (dp83867->tx_id_delay != DP83867_RGMII_TX_CLK_DELAY_INV)
-			delay |= dp83867->tx_id_delay <<
-				 DP83867_RGMII_TX_CLK_DELAY_SHIFT;
-
 		phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIIDCTL,
-			      delay);
+			      dp83867->rx_id_delay |
+			      (dp83867->tx_id_delay << DP83867_RGMII_TX_CLK_DELAY_SHIFT));
 	}
 
 	/* If specified, set io impedance */
-- 
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