pch_gbe: Add MinnowBoard support

The MinnowBoard uses an AR803x PHY with the PCH GBE which requires
special handling. Use the MinnowBoard PCI Subsystem ID to detect this
and add a pci_device_id.driver_data structure and functions to handle
platform setup.

The AR803x does not implement the RGMII 2ns TX clock delay in the trace
routing nor via strapping. Add a detection method for the board and the
PHY and enable the TX clock delay via the registers.

This PHY will hibernate without link for 10 seconds. Ensure the PHY is
awake for probe and then disable hibernation. A future improvement would
be to convert pch_gbe to using PHYLIB and making sure we can wake the
PHY at the necessary times rather than permanently disabling it.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Waskiewicz <peter.p.waskiewicz.jr@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: netdev@vger.kernel.org

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c
index da079073a6c6..8b7ff75fc8e0 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_phy.c
@@ -74,6 +74,15 @@
 #define MII_SR_100X_FD_CAPS      0x4000	/* 100X  Full Duplex Capable */
 #define MII_SR_100T4_CAPS        0x8000	/* 100T4 Capable */
 
+/* AR8031 PHY Debug Registers */
+#define PHY_AR803X_ID           0x00001374
+#define PHY_AR8031_DBG_OFF      0x1D
+#define PHY_AR8031_DBG_DAT      0x1E
+#define PHY_AR8031_SERDES       0x05
+#define PHY_AR8031_HIBERNATE    0x0B
+#define PHY_AR8031_SERDES_TX_CLK_DLY   0x0100 /* TX clock delay of 2.0ns */
+#define PHY_AR8031_PS_HIB_EN           0x8000 /* Hibernate enable */
+
 /* Phy Id Register (word 2) */
 #define PHY_REVISION_MASK        0x000F
 
@@ -249,6 +258,51 @@ void pch_gbe_phy_set_rgmii(struct pch_gbe_hw *hw)
 }
 
 /**
+ * pch_gbe_phy_tx_clk_delay - Setup TX clock delay via the PHY
+ * @hw:	            Pointer to the HW structure
+ * Returns
+ *	0:		Successful.
+ *	-EINVAL:	Invalid argument.
+ */
+static int pch_gbe_phy_tx_clk_delay(struct pch_gbe_hw *hw)
+{
+	/* The RGMII interface requires a ~2ns TX clock delay. This is typically
+	 * done in layout with a longer trace or via PHY strapping, but can also
+	 * be done via PHY configuration registers.
+	 */
+	struct pch_gbe_adapter *adapter = pch_gbe_hw_to_adapter(hw);
+	u16 mii_reg;
+	int ret = 0;
+
+	switch (hw->phy.id) {
+	case PHY_AR803X_ID:
+		netdev_dbg(adapter->netdev,
+			   "Configuring AR803X PHY for 2ns TX clock delay\n");
+		pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_OFF, &mii_reg);
+		ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_OFF,
+						 PHY_AR8031_SERDES);
+		if (ret)
+			break;
+
+		pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_DAT, &mii_reg);
+		mii_reg |= PHY_AR8031_SERDES_TX_CLK_DLY;
+		ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_DAT,
+						 mii_reg);
+		break;
+	default:
+		netdev_err(adapter->netdev,
+			   "Unknown PHY (%x), could not set TX clock delay\n",
+			   hw->phy.id);
+		return -EINVAL;
+	}
+
+	if (ret)
+		netdev_err(adapter->netdev,
+			   "Could not configure tx clock delay for PHY\n");
+	return ret;
+}
+
+/**
  * pch_gbe_phy_init_setting - PHY initial setting
  * @hw:	            Pointer to the HW structure
  */
@@ -277,4 +331,48 @@ void pch_gbe_phy_init_setting(struct pch_gbe_hw *hw)
 	pch_gbe_phy_read_reg_miic(hw, PHY_PHYSP_CONTROL, &mii_reg);
 	mii_reg |= PHYSP_CTRL_ASSERT_CRS_TX;
 	pch_gbe_phy_write_reg_miic(hw, PHY_PHYSP_CONTROL, mii_reg);
+
+	/* Setup a TX clock delay on certain platforms */
+	if (adapter->pdata && adapter->pdata->phy_tx_clk_delay)
+		pch_gbe_phy_tx_clk_delay(hw);
+}
+
+/**
+ * pch_gbe_phy_disable_hibernate - Disable the PHY low power state
+ * @hw:	            Pointer to the HW structure
+ * Returns
+ *	0:		Successful.
+ *	-EINVAL:	Invalid argument.
+ */
+int pch_gbe_phy_disable_hibernate(struct pch_gbe_hw *hw)
+{
+	struct pch_gbe_adapter *adapter = pch_gbe_hw_to_adapter(hw);
+	u16 mii_reg;
+	int ret = 0;
+
+	switch (hw->phy.id) {
+	case PHY_AR803X_ID:
+		netdev_dbg(adapter->netdev,
+			   "Disabling hibernation for AR803X PHY\n");
+		ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_OFF,
+						 PHY_AR8031_HIBERNATE);
+		if (ret)
+			break;
+
+		pch_gbe_phy_read_reg_miic(hw, PHY_AR8031_DBG_DAT, &mii_reg);
+		mii_reg &= ~PHY_AR8031_PS_HIB_EN;
+		ret = pch_gbe_phy_write_reg_miic(hw, PHY_AR8031_DBG_DAT,
+						 mii_reg);
+		break;
+	default:
+		netdev_err(adapter->netdev,
+			   "Unknown PHY (%x), could not disable hibernation\n",
+			   hw->phy.id);
+		return -EINVAL;
+	}
+
+	if (ret)
+		netdev_err(adapter->netdev,
+			   "Could not disable PHY hibernation\n");
+	return ret;
 }