[PATCH] net: mdio-octeon: Add PCI driver binding.

[David Daney]

From: David Daney <david.daney@xxxxxxxxxx>

When the Cavium mdio-octeon devices appear in the Thunder family of
arm64 based SoCs, they show up as PCI devices.  Add PCI driver
wrapping so the driver is bound in the standard PCI device scan.

When in this form, a single PCI device may have more than a single
bus, we call this a "nexus" of buses.  The standard firmware
device_for_each_child_node() iterator is used to find the individual
buses underneath the "nexus".

Update the device tree binding documentation for the new PCI driver
binding.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---
 .../devicetree/bindings/net/cavium-mdio.txt        |  61 +++++++-
 drivers/net/phy/mdio-octeon.c                      | 159 +++++++++++++++++++--
 2 files changed, 209 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/cavium-mdio.txt b/Documentation/devicetree/bindings/net/cavium-mdio.txt
index 04cb749..020df08 100644
--- a/Documentation/devicetree/bindings/net/cavium-mdio.txt
+++ b/Documentation/devicetree/bindings/net/cavium-mdio.txt
@@ -1,9 +1,12 @@
 * System Management Interface (SMI) / MDIO
 
 Properties:
-- compatible: "cavium,octeon-3860-mdio"
+- compatible: One of:
 
-  Compatibility with all cn3XXX, cn5XXX and cn6XXX SOCs.
+   "cavium,octeon-3860-mdio": Compatibility with all cn3XXX, cn5XXX
+                       and cn6XXX SOCs.
+
+   "cavium,thunder-8890-mdio": Compatibility with all cn8XXX SOCs.
 
 - reg: The base address of the MDIO bus controller register bank.
 
@@ -25,3 +28,57 @@ Example:
 			reg = <0>;
 		};
 	};
+
+
+* System Management Interface (SMI) / MDIO Nexus
+
+  Several mdio buses may be gathered as children of a single PCI
+  device, this PCI device is the nexus of the buses.
+
+Properties:
+
+- compatible: "cavium,thunder-8890-mdio-nexus";
+
+- reg: The PCI device and function numbers of the nexus device.
+
+- #address-cells: Must be <2>.
+
+- #size-cells: Must be <2>.
+
+- ranges: As needed for mapping of the MDIO bus device registers.
+
+- assigned-addresses: As needed for mapping of the MDIO bus device registers.
+
+Example:
+
+        mdio-nexus@1,3 {
+                compatible = "cavium,thunder-8890-mdio-nexus";
+                #address-cells = <2>;
+                #size-cells = <2>;
+                reg = <0x0b00 0 0 0 0>; /* DEVFN = 0x0b (1:3) */
+                assigned-addresses = <0x03000000 0x87e0 0x05000000 0x0 0x800000>;
+                ranges = <0x87e0 0x05000000 0x03000000 0x87e0 0x05000000 0x0 0x800000>;
+
+                mdio0@87e0,05003800 {
+                        compatible = "cavium,thunder-8890-mdio";
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+                        reg = <0x87e0 0x05003800 0x0 0x30>;
+
+                        ethernet-phy@0 {
+                                ...
+                                reg = <0>;
+                        };
+                };
+                mdio0@87e0,05003880 {
+                        compatible = "cavium,thunder-8890-mdio";
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+                        reg = <0x87e0 0x05003880 0x0 0x30>;
+
+                        ethernet-phy@0 {
+                                ...
+                                reg = <0>;
+                        };
+                };
+        };
diff --git a/drivers/net/phy/mdio-octeon.c b/drivers/net/phy/mdio-octeon.c
index fcf4e4d..21eca35 100644
--- a/drivers/net/phy/mdio-octeon.c
+++ b/drivers/net/phy/mdio-octeon.c
@@ -3,7 +3,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2009-2012 Cavium, Inc.
+ * Copyright (C) 2009-2015 Cavium, Inc.
  */
 
 #include <linux/platform_device.h>
@@ -14,6 +14,7 @@
 #include <linux/gfp.h>
 #include <linux/phy.h>
 #include <linux/io.h>
+#include <linux/pci.h>
 
 #ifdef CONFIG_CAVIUM_OCTEON_SOC
 #include <asm/octeon/octeon.h>
@@ -110,8 +111,6 @@ enum octeon_mdiobus_mode {
 struct octeon_mdiobus {
 	struct mii_bus *mii_bus;
 	u64 register_base;
-	resource_size_t mdio_phys;
-	resource_size_t regsize;
 	enum octeon_mdiobus_mode mode;
 	int phy_irq[PHY_MAX_ADDR];
 };
@@ -269,6 +268,8 @@ static int octeon_mdiobus_probe(struct platform_device *pdev)
 {
 	struct octeon_mdiobus *bus;
 	struct resource *res_mem;
+	resource_size_t mdio_phys;
+	resource_size_t regsize;
 	union cvmx_smix_en smi_en;
 	int err = -ENOENT;
 
@@ -282,17 +283,17 @@ static int octeon_mdiobus_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
-	bus->mdio_phys = res_mem->start;
-	bus->regsize = resource_size(res_mem);
+	mdio_phys = res_mem->start;
+	regsize = resource_size(res_mem);
 
-	if (!devm_request_mem_region(&pdev->dev, bus->mdio_phys, bus->regsize,
+	if (!devm_request_mem_region(&pdev->dev, mdio_phys, regsize,
 				     res_mem->name)) {
 		dev_err(&pdev->dev, "request_mem_region failed\n");
 		return -ENXIO;
 	}
 
 	bus->register_base =
-		(u64)devm_ioremap(&pdev->dev, bus->mdio_phys, bus->regsize);
+		(u64)devm_ioremap(&pdev->dev, mdio_phys, regsize);
 	if (!bus->register_base) {
 		dev_err(&pdev->dev, "dev_ioremap failed\n");
 		return -ENOMEM;
@@ -308,7 +309,7 @@ static int octeon_mdiobus_probe(struct platform_device *pdev)
 
 	bus->mii_bus->priv = bus;
 	bus->mii_bus->irq = bus->phy_irq;
-	bus->mii_bus->name = "mdio-octeon";
+	bus->mii_bus->name = KBUILD_MODNAME;
 	snprintf(bus->mii_bus->id, MII_BUS_ID_SIZE, "%llx", bus->register_base);
 	bus->mii_bus->parent = &pdev->dev;
 
@@ -356,7 +357,7 @@ MODULE_DEVICE_TABLE(of, octeon_mdiobus_match);
 
 static struct platform_driver octeon_mdiobus_driver = {
 	.driver = {
-		.name		= "mdio-octeon",
+		.name		= KBUILD_MODNAME,
 		.of_match_table = octeon_mdiobus_match,
 	},
 	.probe		= octeon_mdiobus_probe,
@@ -371,6 +372,146 @@ EXPORT_SYMBOL(octeon_mdiobus_force_mod_depencency);
 
 module_platform_driver(octeon_mdiobus_driver);
 
+#ifdef CONFIG_PCI
+
+struct thunder_mdiobus_nexus {
+	void __iomem *bar0;
+	struct octeon_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 octeon_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;
+		}
+		bus = devm_kzalloc(&pdev->dev, sizeof(struct octeon_mdiobus),
+				   GFP_KERNEL);
+
+		if (!bus)
+			break;
+
+		nexus->buses[i] = bus;
+		i++;
+
+		bus->register_base = (u64)nexus->bar0 +
+			r.start - pci_resource_start(pdev, 0);
+
+		bus->mii_bus = mdiobus_alloc();
+		if (!bus->mii_bus)
+			break;
+
+		smi_en.u64 = 0;
+		smi_en.s.en = 1;
+		oct_mdio_writeq(smi_en.u64, bus->register_base + SMI_EN);
+		bus->mii_bus->priv = bus;
+		bus->mii_bus->irq = bus->phy_irq;
+		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 = octeon_mdiobus_read;
+		bus->mii_bus->write = octeon_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;
+	union cvmx_smix_en smi_en;
+	struct thunder_mdiobus_nexus *nexus = pci_get_drvdata(pdev);
+
+	for (i = 0; i < ARRAY_SIZE(nexus->buses); i++) {
+		struct octeon_mdiobus *bus = nexus->buses[i];
+
+		if (!bus)
+			continue;
+
+		mdiobus_unregister(bus->mii_bus);
+		mdiobus_free(bus->mii_bus);
+		smi_en.u64 = 0;
+		oct_mdio_writeq(smi_en.u64, 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);
+#endif /* CONFIG_PCI */
 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 MODULE_VERSION(DRV_VERSION);
 MODULE_AUTHOR("David Daney");
-- 
1.9.1

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