diff options
Diffstat (limited to 'drivers/net/ethernet/marvell/mvmdio.c')
| -rw-r--r-- | drivers/net/ethernet/marvell/mvmdio.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c new file mode 100644 index 00000000000..74f1c157a48 --- /dev/null +++ b/drivers/net/ethernet/marvell/mvmdio.c @@ -0,0 +1,228 @@ +/* + * 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 <linux/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 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 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 = 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"); |