On Fri, 2013-07-12 at 17:58 -0700, Darren Hart wrote: 

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.

Few comments below.

I don't like the platform_init() approach here. 
I think here should be plain GPIO line number.

I'll explain below why.

Missed colon.

Here perhaps you check pdata and GPIO line number (let's say != -1) and
call GPIO request helper.

First of all, who is going to release gpio? Perhaps
devm_gpio_request_one?

Next is the name of the function, since you are resetting PHY, what if
you call it like pch_gbe_reset_by_gpio ?

+
+	return ret;
+}

And most important one is the ACPI case. As far as I understand Minnow
board supports / will support ACPI5 variant of device enumeration. In
such case the GPIO line will come in the ACPI resources. Moreover, you
will have no struct pci_dev. I highly recommend to rewrite this as a
generic helper, which takes GPIO line number as an input parameter and
does the job.

+
+static struct pch_gbe_privdata pch_gbe_minnow_privdata = {
+	.phy_tx_clk_delay = true,
+	.phy_disable_hibernate = true,
+	.platform_init = pch_gbe_minnow_platform_init,
+};
+
 static DEFINE_PCI_DEVICE_TABLE(pch_gbe_pcidev_id) = {
 	{.vendor = PCI_VENDOR_ID_INTEL,
 	 .device = PCI_DEVICE_ID_INTEL_IOH1_GBE,
+	 .subvendor = PCI_VENDOR_ID_CIRCUITCO,
+	 .subdevice = PCI_SUBSYSTEM_ID_CIRCUITCO_MINNOWBOARD,
+	 .class = (PCI_CLASS_NETWORK_ETHERNET << 8),
+	 .class_mask = (0xFFFF00),
+	 .driver_data = (unsigned long) &pch_gbe_minnow_privdata
+	 },
+	{.vendor = PCI_VENDOR_ID_INTEL,
+	 .device = PCI_DEVICE_ID_INTEL_IOH1_GBE,
 	 .subvendor = PCI_ANY_ID,
 	 .subdevice = PCI_ANY_ID,
 	 .class = (PCI_CLASS_NETWORK_ETHERNET << 8),

No need to assign. Are you trying to shut (sparse?) warning?

+
+	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_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;

Ditto.

+	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;
 }

-- 
Andy Shevchenko [off-list ref]
Intel Finland Oy