--- /dev/null
+/*
+ * Driver for the MDIO interface of Marvell network interfaces.
+ *
+ * Since the MDIO interface of Marvell network interfaces is shared
+ * between all network interfaces, having a single driver allows to
+ * handle concurrent accesses properly (you may have four Ethernet
+ * ports, but they in fact share the same SMI interface to access the
+ * MDIO bus). Moreover, this MDIO interface code is similar between
+ * the mv643xx_eth driver and the mvneta driver. For now, it is only
+ * used by the mvneta driver, but it could later be used by the
+ * mv643xx_eth driver as well.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/phy.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/platform_device.h>
+
+#include <asm/delay.h>
+
+#define MVMDIO_SMI_DATA_SHIFT 0
+#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
+#define MVMDIO_SMI_PHY_REG_SHIFT 21
+#define MVMDIO_SMI_READ_OPERATION BIT(26)
+#define MVMDIO_SMI_WRITE_OPERATION 0
+#define MVMDIO_SMI_READ_VALID BIT(27)
+#define MVMDIO_SMI_BUSY BIT(28)
+
+struct orion_mdio_dev {
+ struct mutex lock;
+ void __iomem *smireg;
+};
+
+/*
+ * Wait for the SMI unit to be ready for another operation
+ */
+static int orion_mdio_wait_ready(struct mii_bus *bus)
+{
+ struct orion_mdio_dev *dev = bus->priv;
+ int count;
+ u32 val;
+
+ count = 0;
+ while (1) {
+ val = readl(dev->smireg);
+ if (!(val & MVMDIO_SMI_BUSY))
+ break;
+
+ if (count > 100) {
+ dev_err(bus->parent, "Timeout: SMI busy for too long\n");
+ return -ETIMEDOUT;
+ }
+
+ udelay(10);
+ count++;
+ }
+
+ return 0;
+}
+
+static int orion_mdio_read(struct mii_bus *bus, int mii_id,
+ int regnum)
+{
+ struct orion_mdio_dev *dev = bus->priv;
+ int count;
+ u32 val;
+ int ret;
+
+ mutex_lock(&dev->lock);
+
+ ret = orion_mdio_wait_ready(bus);
+ if (ret < 0) {
+ mutex_unlock(&dev->lock);
+ return ret;
+ }
+
+ writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
+ (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
+ MVMDIO_SMI_READ_OPERATION),
+ dev->smireg);
+
+ /* Wait for the value to become available */
+ count = 0;
+ while (1) {
+ val = readl(dev->smireg);
+ if (val & MVMDIO_SMI_READ_VALID)
+ break;
+
+ if (count > 100) {
+ dev_err(bus->parent, "Timeout when reading PHY\n");
+ mutex_unlock(&dev->lock);
+ return -ETIMEDOUT;
+ }
+
+ udelay(10);
+ count++;
+ }
+
+ mutex_unlock(&dev->lock);
+
+ return val & 0xFFFF;
+}
+
+static int orion_mdio_write(struct mii_bus *bus, int mii_id,
+ int regnum, u16 value)
+{
+ struct orion_mdio_dev *dev = bus->priv;
+ int ret;
+
+ mutex_lock(&dev->lock);
+
+ ret = orion_mdio_wait_ready(bus);
+ if (ret < 0) {
+ mutex_unlock(&dev->lock);
+ return ret;
+ }
+
+ writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
+ (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
+ MVMDIO_SMI_WRITE_OPERATION |
+ (value << MVMDIO_SMI_DATA_SHIFT)),
+ dev->smireg);
+
+ mutex_unlock(&dev->lock);
+
+ return 0;
+}
+
+static int orion_mdio_reset(struct mii_bus *bus)
+{
+ return 0;
+}
+
+static int __devinit orion_mdio_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct mii_bus *bus;
+ struct orion_mdio_dev *dev;
+ int i, ret;
+
+ bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
+ if (!bus) {
+ dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
+ return -ENOMEM;
+ }
+
+ bus->name = "orion_mdio_bus";
+ bus->read = orion_mdio_read;
+ bus->write = orion_mdio_write;
+ bus->reset = orion_mdio_reset;
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
+ dev_name(&pdev->dev));
+ bus->parent = &pdev->dev;
+
+ bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+ if (!bus->irq) {
+ dev_err(&pdev->dev, "Cannot allocate PHY IRQ array\n");
+ mdiobus_free(bus);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < PHY_MAX_ADDR; i++)
+ bus->irq[i] = PHY_POLL;
+
+ dev = bus->priv;
+ dev->smireg = of_iomap(pdev->dev.of_node, 0);
+ if (!dev->smireg) {
+ dev_err(&pdev->dev, "No SMI register address given in DT\n");
+ kfree(bus->irq);
+ mdiobus_free(bus);
+ return -ENODEV;
+ }
+
+ mutex_init(&dev->lock);
+
+ ret = of_mdiobus_register(bus, np);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
+ iounmap(dev->smireg);
+ kfree(bus->irq);
+ mdiobus_free(bus);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, bus);
+
+ return 0;
+}
+
+static int __devexit orion_mdio_remove(struct platform_device *pdev)
+{
+ struct mii_bus *bus = platform_get_drvdata(pdev);
+ mdiobus_unregister(bus);
+ kfree(bus->irq);
+ mdiobus_free(bus);
+ return 0;
+}
+
+static const struct of_device_id orion_mdio_match[] = {
+ { .compatible = "marvell,orion-mdio" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, orion_mdio_match);
+
+static struct platform_driver orion_mdio_driver = {
+ .probe = orion_mdio_probe,
+ .remove = __devexit_p(orion_mdio_remove),
+ .driver = {
+ .name = "orion-mdio",
+ .of_match_table = orion_mdio_match,
+ },
+};
+
+module_platform_driver(orion_mdio_driver);
+
+MODULE_DESCRIPTION("Marvell MDIO interface driver");
+MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
+MODULE_LICENSE("GPL");
projects / ~andy / linux / commitdiff