phy: mdio-thunder: Add driver for Cavium Thunder SoC MDIO buses.

The Cavium Thunder SoCs have multiple MIDO buses that are part of a
single PCI device.  To model this in the device tree we call the PCI
parent device a "cavium,thunder-8890-mdio-nexus", it has several
children, one for each MDIO bus.

The MDIO bus hardware is identical to that found in the OCTEON SoCs,
so we use that code for things that are not part of the PCI driver
probe/remove

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 154 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio-thunder.c b/drivers/net/phy/mdio-thunder.c
new file mode 100644
index 000000000000..564616968cad
--- /dev/null
+++ b/drivers/net/phy/mdio-thunder.c
@@ -0,0 +1,154 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2009-2016 Cavium, Inc.
+ */
+
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/phy.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+
+#include "mdio-cavium.h"
+
+struct thunder_mdiobus_nexus {
+	void __iomem *bar0;
+	struct cavium_mdiobus *buses[4];
+};
+
+static int thunder_mdiobus_pci_probe(struct pci_dev *pdev,
+				     const struct pci_device_id *ent)
+{
+	struct device_node *node;
+	struct fwnode_handle *fwn;
+	struct thunder_mdiobus_nexus *nexus;
+	int err;
+	int i;
+
+	nexus = devm_kzalloc(&pdev->dev, sizeof(*nexus), GFP_KERNEL);
+	if (!nexus)
+		return -ENOMEM;
+
+	pci_set_drvdata(pdev, nexus);
+
+	err = pcim_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to enable PCI device\n");
+		pci_set_drvdata(pdev, NULL);
+		return err;
+	}
+
+	err = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (err) {
+		dev_err(&pdev->dev, "pci_request_regions failed\n");
+		goto err_disable_device;
+	}
+
+	nexus->bar0 = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
+	if (!nexus->bar0) {
+		err = -ENOMEM;
+		goto err_release_regions;
+	}
+
+	i = 0;
+	device_for_each_child_node(&pdev->dev, fwn) {
+		struct resource r;
+		struct mii_bus *mii_bus;
+		struct cavium_mdiobus *bus;
+		union cvmx_smix_en smi_en;
+
+		/* If it is not an OF node we cannot handle it yet, so
+		 * exit the loop.
+		 */
+		node = to_of_node(fwn);
+		if (!node)
+			break;
+
+		err = of_address_to_resource(node, 0, &r);
+		if (err) {
+			dev_err(&pdev->dev,
+				"Couldn't translate address for \"%s\"\n",
+				node->name);
+			break;
+		}
+
+		mii_bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*bus));
+		if (!mii_bus)
+			break;
+		bus = mii_bus->priv;
+		bus->mii_bus = mii_bus;
+
+		nexus->buses[i] = bus;
+		i++;
+
+		bus->register_base = (u64)nexus->bar0 +
+			r.start - pci_resource_start(pdev, 0);
+
+		smi_en.u64 = 0;
+		smi_en.s.en = 1;
+		oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
+		bus->mii_bus->name = KBUILD_MODNAME;
+		snprintf(bus->mii_bus->id, MII_BUS_ID_SIZE, "%llx", r.start);
+		bus->mii_bus->parent = &pdev->dev;
+		bus->mii_bus->read = cavium_mdiobus_read;
+		bus->mii_bus->write = cavium_mdiobus_write;
+
+		err = of_mdiobus_register(bus->mii_bus, node);
+		if (err)
+			dev_err(&pdev->dev, "of_mdiobus_register failed\n");
+
+		dev_info(&pdev->dev, "Added bus at %llx\n", r.start);
+		if (i >= ARRAY_SIZE(nexus->buses))
+			break;
+	}
+	return 0;
+
+err_release_regions:
+	pci_release_regions(pdev);
+
+err_disable_device:
+	pci_set_drvdata(pdev, NULL);
+	return err;
+}
+
+static void thunder_mdiobus_pci_remove(struct pci_dev *pdev)
+{
+	int i;
+	struct thunder_mdiobus_nexus *nexus = pci_get_drvdata(pdev);
+
+	for (i = 0; i < ARRAY_SIZE(nexus->buses); i++) {
+		struct cavium_mdiobus *bus = nexus->buses[i];
+
+		if (!bus)
+			continue;
+
+		mdiobus_unregister(bus->mii_bus);
+		mdiobus_free(bus->mii_bus);
+		oct_mdio_writeq(0, bus->register_base + SMI_EN);
+	}
+	pci_set_drvdata(pdev, NULL);
+}
+
+static const struct pci_device_id thunder_mdiobus_id_table[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa02b) },
+	{ 0, } /* End of table. */
+};
+MODULE_DEVICE_TABLE(pci, thunder_mdiobus_id_table);
+
+static struct pci_driver thunder_mdiobus_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = thunder_mdiobus_id_table,
+	.probe = thunder_mdiobus_pci_probe,
+	.remove = thunder_mdiobus_pci_remove,
+};
+
+module_pci_driver(thunder_mdiobus_driver);
+
+MODULE_DESCRIPTION("Cavium ThunderX MDIO bus driver");
+MODULE_LICENSE("GPL");