[PATCH v2 3/5] verdin-imx8mm: Change board phy skew values for our ksz9031

[Philippe Schenker]

This patches uses the existing functions for interacting with the
KSZ9031 and uses the values appropriate for our board.

Signed-off-by: Philippe Schenker <philippe.schenker at toradex.com>
Tested-by: Igor Opaniuk <igor.opaniuk at toradex.com>
Acked-by: Igor Opaniuk <igor.opaniuk at toradex.com>
---

 board/toradex/verdin-imx8mm/verdin-imx8mm.c | 32 +++++++++++++++------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/board/toradex/verdin-imx8mm/verdin-imx8mm.c b/board/toradex/verdin-imx8mm/verdin-imx8mm.c
index 16b9fa1ec18..3177ba53907 100644
--- a/board/toradex/verdin-imx8mm/verdin-imx8mm.c
+++ b/board/toradex/verdin-imx8mm/verdin-imx8mm.c
@@ -8,6 +8,7 @@
 #include <asm/io.h>
 #include <miiphy.h>
 #include <netdev.h>
+#include <micrel.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -32,14 +33,29 @@ static int setup_fec(void)
 
 int board_phy_config(struct phy_device *phydev)
 {
-	/* enable rgmii rxc skew and phy mode select to RGMII copper */
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1d, 0x1f);
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1e, 0x8);
-
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1d, 0x00);
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1e, 0x82ee);
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1d, 0x05);
-	phy_write(phydev, MDIO_DEVAD_NONE, 0x1e, 0x100);
+	/*
+	 * The PHY adds 1.2ns for the RXC and 0ns for TXC clock by
+	 * default. The MAC and the layout don't add a skew between
+	 * clock and data.
+	 * Add 0.3ns for the RXC path and 0.96 + 0.42 ns (1.38 ns) for
+	 * the TXC path to get the required clock skews.
+	 */
+	/* control data pad skew - devaddr = 0x02, register = 0x04 */
+	ksz9031_phy_extended_write(phydev, 0x02,
+				MII_KSZ9031_EXT_RGMII_CTRL_SIG_SKEW,
+				MII_KSZ9031_MOD_DATA_NO_POST_INC, 0x0070);
+	/* rx data pad skew - devaddr = 0x02, register = 0x05 */
+	ksz9031_phy_extended_write(phydev, 0x02,
+				MII_KSZ9031_EXT_RGMII_RX_DATA_SKEW,
+				MII_KSZ9031_MOD_DATA_NO_POST_INC, 0x7777);
+	/* tx data pad skew - devaddr = 0x02, register = 0x06 */
+	ksz9031_phy_extended_write(phydev, 0x02,
+				MII_KSZ9031_EXT_RGMII_TX_DATA_SKEW,
+				MII_KSZ9031_MOD_DATA_NO_POST_INC, 0x0000);
+	/* gtx and rx clock pad skew - devaddr = 0x02, register = 0x08 */
+	ksz9031_phy_extended_write(phydev, 0x02,
+				MII_KSZ9031_EXT_RGMII_CLOCK_SKEW,
+				MII_KSZ9031_MOD_DATA_NO_POST_INC, 0x03f4);
 
 	if (phydev->drv->config)
 		phydev->drv->config(phydev);
-- 
2.25.1