net: phy: dp83867: add support for MAC impedance configuration

Add support for programmable MAC impedance configuration

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 91177a4a32ad21c1cbea044424659f5604cef7de..1b639242f9e23170e69f7b7669ba82d8d4263fb5 100644 (file)
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -33,6 +33,7 @@
 /* Extended Registers */
 #define DP83867_RGMIICTL       0x0032
 #define DP83867_RGMIIDCTL      0x0086
+#define DP83867_IO_MUX_CFG     0x0170
 
 #define DP83867_SW_RESET       BIT(15)
 #define DP83867_SW_RESTART     BIT(14)
@@ -62,10 +63,17 @@
 /* RGMIIDCTL bits */
 #define DP83867_RGMII_TX_CLK_DELAY_SHIFT       4
 
+/* IO_MUX_CFG bits */
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL   0x1f
+
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX    0x0
+#define DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN    0x1f
+
 struct dp83867_private {
        int rx_id_delay;
        int tx_id_delay;
        int fifo_depth;
+       int io_impedance;
 };
 
 static int dp83867_ack_interrupt(struct phy_device *phydev)
@@ -111,6 +119,14 @@ static int dp83867_of_init(struct phy_device *phydev)
        if (!of_node)
                return -ENODEV;
 
+       dp83867->io_impedance = -EINVAL;
+
+       /* Optional configuration */
+       if (of_property_read_bool(of_node, "ti,max-output-impedance"))
+               dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MAX;
+       else if (of_property_read_bool(of_node, "ti,min-output-impedance"))
+               dp83867->io_impedance = DP83867_IO_MUX_CFG_IO_IMPEDANCE_MIN;
+
        ret = of_property_read_u32(of_node, "ti,rx-internal-delay",
                                   &dp83867->rx_id_delay);
        if (ret)
@@ -184,6 +200,18 @@ static int dp83867_config_init(struct phy_device *phydev)
 
                phy_write_mmd_indirect(phydev, DP83867_RGMIIDCTL,
                                       DP83867_DEVADDR, delay);
+
+               if (dp83867->io_impedance >= 0) {
+                       val = phy_read_mmd_indirect(phydev, DP83867_IO_MUX_CFG,
+                                                   DP83867_DEVADDR);
+
+                       val &= ~DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL;
+                       val |= dp83867->io_impedance &
+                              DP83867_IO_MUX_CFG_IO_IMPEDANCE_CTRL;
+
+                       phy_write_mmd_indirect(phydev, DP83867_IO_MUX_CFG,
+                                              DP83867_DEVADDR, val);
+               }
        }
 
        return 0;