diff options
Diffstat (limited to 'drivers/net/mdio/mdio-mscc-miim.c')
| -rw-r--r-- | drivers/net/mdio/mdio-mscc-miim.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c new file mode 100644 index 000000000..037649bef --- /dev/null +++ b/drivers/net/mdio/mdio-mscc-miim.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +/* + * Driver for the MDIO interface of Microsemi network switches. + * + * Author: Alexandre Belloni <alexandre.belloni@bootlin.com> + * Copyright (c) 2017 Microsemi Corporation + */ + +#include <linux/bitops.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_mdio.h> +#include <linux/phy.h> +#include <linux/platform_device.h> + +#define MSCC_MIIM_REG_STATUS 0x0 +#define MSCC_MIIM_STATUS_STAT_PENDING BIT(2) +#define MSCC_MIIM_STATUS_STAT_BUSY BIT(3) +#define MSCC_MIIM_REG_CMD 0x8 +#define MSCC_MIIM_CMD_OPR_WRITE BIT(1) +#define MSCC_MIIM_CMD_OPR_READ BIT(2) +#define MSCC_MIIM_CMD_WRDATA_SHIFT 4 +#define MSCC_MIIM_CMD_REGAD_SHIFT 20 +#define MSCC_MIIM_CMD_PHYAD_SHIFT 25 +#define MSCC_MIIM_CMD_VLD BIT(31) +#define MSCC_MIIM_REG_DATA 0xC +#define MSCC_MIIM_DATA_ERROR (BIT(16) | BIT(17)) + +#define MSCC_PHY_REG_PHY_CFG 0x0 +#define PHY_CFG_PHY_ENA (BIT(0) | BIT(1) | BIT(2) | BIT(3)) +#define PHY_CFG_PHY_COMMON_RESET BIT(4) +#define PHY_CFG_PHY_RESET (BIT(5) | BIT(6) | BIT(7) | BIT(8)) +#define MSCC_PHY_REG_PHY_STATUS 0x4 + +struct mscc_miim_dev { + void __iomem *regs; + void __iomem *phy_regs; +}; + +/* When high resolution timers aren't built-in: we can't use usleep_range() as + * we would sleep way too long. Use udelay() instead. + */ +#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \ +({ \ + if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \ + readl_poll_timeout_atomic(addr, val, cond, delay_us, \ + timeout_us); \ + readl_poll_timeout(addr, val, cond, delay_us, timeout_us); \ +}) + +static int mscc_miim_wait_ready(struct mii_bus *bus) +{ + struct mscc_miim_dev *miim = bus->priv; + u32 val; + + return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val, + !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50, + 10000); +} + +static int mscc_miim_wait_pending(struct mii_bus *bus) +{ + struct mscc_miim_dev *miim = bus->priv; + u32 val; + + return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val, + !(val & MSCC_MIIM_STATUS_STAT_PENDING), + 50, 10000); +} + +static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum) +{ + struct mscc_miim_dev *miim = bus->priv; + u32 val; + int ret; + + if (regnum & MII_ADDR_C45) + return -EOPNOTSUPP; + + ret = mscc_miim_wait_pending(bus); + if (ret) + goto out; + + writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) | + (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ, + miim->regs + MSCC_MIIM_REG_CMD); + + ret = mscc_miim_wait_ready(bus); + if (ret) + goto out; + + val = readl(miim->regs + MSCC_MIIM_REG_DATA); + if (val & MSCC_MIIM_DATA_ERROR) { + ret = -EIO; + goto out; + } + + ret = val & 0xFFFF; +out: + return ret; +} + +static int mscc_miim_write(struct mii_bus *bus, int mii_id, + int regnum, u16 value) +{ + struct mscc_miim_dev *miim = bus->priv; + int ret; + + if (regnum & MII_ADDR_C45) + return -EOPNOTSUPP; + + ret = mscc_miim_wait_pending(bus); + if (ret < 0) + goto out; + + writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) | + (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | + (value << MSCC_MIIM_CMD_WRDATA_SHIFT) | + MSCC_MIIM_CMD_OPR_WRITE, + miim->regs + MSCC_MIIM_REG_CMD); + +out: + return ret; +} + +static int mscc_miim_reset(struct mii_bus *bus) +{ + struct mscc_miim_dev *miim = bus->priv; + + if (miim->phy_regs) { + writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG); + writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG); + mdelay(500); + } + + return 0; +} + +static int mscc_miim_probe(struct platform_device *pdev) +{ + struct resource *res; + struct mii_bus *bus; + struct mscc_miim_dev *dev; + int ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev)); + if (!bus) + return -ENOMEM; + + bus->name = "mscc_miim"; + bus->read = mscc_miim_read; + bus->write = mscc_miim_write; + bus->reset = mscc_miim_reset; + snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev)); + bus->parent = &pdev->dev; + + dev = bus->priv; + dev->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dev->regs)) { + dev_err(&pdev->dev, "Unable to map MIIM registers\n"); + return PTR_ERR(dev->regs); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (res) { + dev->phy_regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dev->phy_regs)) { + dev_err(&pdev->dev, "Unable to map internal phy registers\n"); + return PTR_ERR(dev->phy_regs); + } + } + + ret = of_mdiobus_register(bus, pdev->dev.of_node); + if (ret < 0) { + dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret); + return ret; + } + + platform_set_drvdata(pdev, bus); + + return 0; +} + +static int mscc_miim_remove(struct platform_device *pdev) +{ + struct mii_bus *bus = platform_get_drvdata(pdev); + + mdiobus_unregister(bus); + + return 0; +} + +static const struct of_device_id mscc_miim_match[] = { + { .compatible = "mscc,ocelot-miim" }, + { } +}; +MODULE_DEVICE_TABLE(of, mscc_miim_match); + +static struct platform_driver mscc_miim_driver = { + .probe = mscc_miim_probe, + .remove = mscc_miim_remove, + .driver = { + .name = "mscc-miim", + .of_match_table = mscc_miim_match, + }, +}; + +module_platform_driver(mscc_miim_driver); + +MODULE_DESCRIPTION("Microsemi MIIM driver"); +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); +MODULE_LICENSE("Dual MIT/GPL"); |