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>

3 files changed, 166 insertions, 0 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 40faec9f3b0b..075a4cc175b1 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -196,6 +196,17 @@ config MDIO_OCTEON
           buses. It is required by the Octeon and ThunderX ethernet device
           drivers on some systems.
 
+config MDIO_THUNDER
+        tristate "Support for MDIO buses on on ThunderX SOCs"
+        depends on 64BIT
+        depends on PCI
+        select MDIO_CAVIUM
+        help
+          This driver supports the MDIO interfaces found on Cavium
+          ThunderX SoCs when the MDIO bus device appears on as a PCI
+          device.
+
+
 config MDIO_SUN4I
         tristate "Allwinner sun4i MDIO interface support"
         depends on ARCH_SUNXI
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 041b3d977d31..fcdbb9299fab 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_DP83867_PHY)	+= dp83867.o
 obj-$(CONFIG_STE10XP)           += ste10Xp.o
 obj-$(CONFIG_MICREL_PHY)        += micrel.o
 obj-$(CONFIG_MDIO_OCTEON)       += mdio-octeon.o
+obj-$(CONFIG_MDIO_THUNDER)      += mdio-thunder.o
 obj-$(CONFIG_MDIO_CAVIUM)       += mdio-cavium.o
 obj-$(CONFIG_MICREL_KS8995MA)   += spi_ks8995.o
 obj-$(CONFIG_AT803X_PHY)        += at803x.o
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");