[PATCH] dp83867: fix speed 10 in sgmii mode

[Max Uvarov <muvarov@gmail.com>]

For support 10Mps sped in SGMII mode DP83867_10M_SGMII_RATE_ADAPT bit
of DP83867_10M_SGMII_CFG register has to be cleared by software.
That does not affect speeds 100 and 1000 so can be done on init.

Signed-off-by: Max Uvarov <muvarov@gmail.com>
---
 http://www.ti.com/lit/ds/symlink/dp83867e.pdf
 page 87 for register bits
 and
 page 23 last sentance that bit needs to be cleared.

 drivers/net/phy/dp83867.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index ab58224f897f..1df4da3f70a9 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -37,6 +37,7 @@
 #define DP83867_STRAP_STS1	0x006E
 #define DP83867_RGMIIDCTL	0x0086
 #define DP83867_IO_MUX_CFG	0x0170
+#define DP83867_10M_SGMII_CFG  0x016F
 
 #define DP83867_SW_RESET	BIT(15)
 #define DP83867_SW_RESTART	BIT(14)
@@ -79,6 +80,9 @@
 /* CFG4 bits */
 #define DP83867_CFG4_PORT_MIRROR_EN              BIT(0)
 
+/* 10M_SGMII_CFG bits */
+#define DP83867_10M_SGMII_RATE_ADAPT		 BIT(7)
+
 enum {
 	DP83867_PORT_MIRROING_KEEP,
 	DP83867_PORT_MIRROING_EN,
@@ -285,6 +289,24 @@ static int dp83867_config_init(struct phy_device *phydev)
 		}
 	}
 
+	if (phydev->interface == PHY_INTERFACE_MODE_SGMII) {
+		/* For support SPEED_10 in SGMII mode
+		 * DP83867_10M_SGMII_RATE_ADAPT bit
+		 * has to be cleared by software. That
+		 * does not affect SPEED_100 and
+		 * SPEED_1000.
+		 */
+		val = phy_read_mmd(phydev, DP83867_DEVADDR,
+				   DP83867_10M_SGMII_CFG);
+		val &= ~DP83867_10M_SGMII_RATE_ADAPT;
+		ret = phy_write_mmd(phydev, DP83867_DEVADDR,
+				    DP83867_10M_SGMII_CFG, val);
+		if (ret) {
+			WARN_ONCE(1, "dp83867: error DP83867_10M_SGMII_CFG read\n");
+			return ret;
+		}
+	}
+
 	/* Enable Interrupt output INT_OE in CFG3 register */
 	if (phy_interrupt_is_valid(phydev)) {
 		val = phy_read(phydev, DP83867_CFG3);
-- 
2.17.1