| /* |
| * Broadcom UniMAC MDIO bus controller driver |
| * |
| * Copyright (C) 2014-2016 Broadcom |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/phy.h> |
| #include <linux/platform_device.h> |
| #include <linux/sched.h> |
| #include <linux/module.h> |
| #include <linux/io.h> |
| #include <linux/delay.h> |
| |
| #include <linux/of.h> |
| #include <linux/of_platform.h> |
| #include <linux/of_mdio.h> |
| |
| #define MDIO_CMD 0x00 |
| #define MDIO_START_BUSY (1 << 29) |
| #define MDIO_READ_FAIL (1 << 28) |
| #define MDIO_RD (2 << 26) |
| #define MDIO_WR (1 << 26) |
| #define MDIO_PMD_SHIFT 21 |
| #define MDIO_PMD_MASK 0x1F |
| #define MDIO_REG_SHIFT 16 |
| #define MDIO_REG_MASK 0x1F |
| |
| #define MDIO_CFG 0x04 |
| #define MDIO_C22 (1 << 0) |
| #define MDIO_C45 0 |
| #define MDIO_CLK_DIV_SHIFT 4 |
| #define MDIO_CLK_DIV_MASK 0x3F |
| #define MDIO_SUPP_PREAMBLE (1 << 12) |
| |
| struct unimac_mdio_priv { |
| struct mii_bus *mii_bus; |
| void __iomem *base; |
| }; |
| |
| static inline void unimac_mdio_start(struct unimac_mdio_priv *priv) |
| { |
| u32 reg; |
| |
| reg = __raw_readl(priv->base + MDIO_CMD); |
| reg |= MDIO_START_BUSY; |
| __raw_writel(reg, priv->base + MDIO_CMD); |
| } |
| |
| static inline unsigned int unimac_mdio_busy(struct unimac_mdio_priv *priv) |
| { |
| return __raw_readl(priv->base + MDIO_CMD) & MDIO_START_BUSY; |
| } |
| |
| static int unimac_mdio_read(struct mii_bus *bus, int phy_id, int reg) |
| { |
| struct unimac_mdio_priv *priv = bus->priv; |
| unsigned int timeout = 1000; |
| u32 cmd; |
| |
| /* Prepare the read operation */ |
| cmd = MDIO_RD | (phy_id << MDIO_PMD_SHIFT) | (reg << MDIO_REG_SHIFT); |
| __raw_writel(cmd, priv->base + MDIO_CMD); |
| |
| /* Start MDIO transaction */ |
| unimac_mdio_start(priv); |
| |
| do { |
| if (!unimac_mdio_busy(priv)) |
| break; |
| |
| usleep_range(1000, 2000); |
| } while (timeout--); |
| |
| if (!timeout) |
| return -ETIMEDOUT; |
| |
| cmd = __raw_readl(priv->base + MDIO_CMD); |
| if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (cmd & MDIO_READ_FAIL)) |
| return -EIO; |
| |
| return cmd & 0xffff; |
| } |
| |
| static int unimac_mdio_write(struct mii_bus *bus, int phy_id, |
| int reg, u16 val) |
| { |
| struct unimac_mdio_priv *priv = bus->priv; |
| unsigned int timeout = 1000; |
| u32 cmd; |
| |
| /* Prepare the write operation */ |
| cmd = MDIO_WR | (phy_id << MDIO_PMD_SHIFT) | |
| (reg << MDIO_REG_SHIFT) | (0xffff & val); |
| __raw_writel(cmd, priv->base + MDIO_CMD); |
| |
| unimac_mdio_start(priv); |
| |
| do { |
| if (!unimac_mdio_busy(priv)) |
| break; |
| |
| usleep_range(1000, 2000); |
| } while (timeout--); |
| |
| if (!timeout) |
| return -ETIMEDOUT; |
| |
| return 0; |
| } |
| |
| /* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with |
| * their internal MDIO management controller making them fail to successfully |
| * be read from or written to for the first transaction. We insert a dummy |
| * BMSR read here to make sure that phy_get_device() and get_phy_id() can |
| * correctly read the PHY MII_PHYSID1/2 registers and successfully register a |
| * PHY device for this peripheral. |
| * |
| * Once the PHY driver is registered, we can workaround subsequent reads from |
| * there (e.g: during system-wide power management). |
| * |
| * bus->reset is invoked before mdiobus_scan during mdiobus_register and is |
| * therefore the right location to stick that workaround. Since we do not want |
| * to read from non-existing PHYs, we either use bus->phy_mask or do a manual |
| * Device Tree scan to limit the search area. |
| */ |
| static int unimac_mdio_reset(struct mii_bus *bus) |
| { |
| struct device_node *np = bus->dev.of_node; |
| struct device_node *child; |
| u32 read_mask = 0; |
| int addr; |
| |
| if (!np) { |
| read_mask = ~bus->phy_mask; |
| } else { |
| for_each_available_child_of_node(np, child) { |
| addr = of_mdio_parse_addr(&bus->dev, child); |
| if (addr < 0) |
| continue; |
| |
| read_mask |= 1 << addr; |
| } |
| } |
| |
| for (addr = 0; addr < PHY_MAX_ADDR; addr++) { |
| if (read_mask & 1 << addr) |
| mdiobus_read(bus, addr, MII_BMSR); |
| } |
| |
| return 0; |
| } |
| |
| static int unimac_mdio_probe(struct platform_device *pdev) |
| { |
| struct unimac_mdio_priv *priv; |
| struct device_node *np; |
| struct mii_bus *bus; |
| struct resource *r; |
| int ret; |
| |
| np = pdev->dev.of_node; |
| |
| priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
| if (!priv) |
| return -ENOMEM; |
| |
| r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| |
| /* Just ioremap, as this MDIO block is usually integrated into an |
| * Ethernet MAC controller register range |
| */ |
| priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r)); |
| if (!priv->base) { |
| dev_err(&pdev->dev, "failed to remap register\n"); |
| return -ENOMEM; |
| } |
| |
| priv->mii_bus = mdiobus_alloc(); |
| if (!priv->mii_bus) |
| return -ENOMEM; |
| |
| bus = priv->mii_bus; |
| bus->priv = priv; |
| bus->name = "unimac MII bus"; |
| bus->parent = &pdev->dev; |
| bus->read = unimac_mdio_read; |
| bus->write = unimac_mdio_write; |
| bus->reset = unimac_mdio_reset; |
| snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); |
| |
| bus->irq = kcalloc(PHY_MAX_ADDR, sizeof(int), GFP_KERNEL); |
| if (!bus->irq) { |
| ret = -ENOMEM; |
| goto out_mdio_free; |
| } |
| |
| ret = of_mdiobus_register(bus, np); |
| if (ret) { |
| dev_err(&pdev->dev, "MDIO bus registration failed\n"); |
| goto out_mdio_irq; |
| } |
| |
| platform_set_drvdata(pdev, priv); |
| |
| dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus at 0x%p\n", priv->base); |
| |
| return 0; |
| |
| out_mdio_irq: |
| kfree(bus->irq); |
| out_mdio_free: |
| mdiobus_free(bus); |
| return ret; |
| } |
| |
| static int unimac_mdio_remove(struct platform_device *pdev) |
| { |
| struct unimac_mdio_priv *priv = platform_get_drvdata(pdev); |
| |
| mdiobus_unregister(priv->mii_bus); |
| kfree(priv->mii_bus->irq); |
| mdiobus_free(priv->mii_bus); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id unimac_mdio_ids[] = { |
| { .compatible = "brcm,genet-mdio-v5", }, |
| { .compatible = "brcm,genet-mdio-v4", }, |
| { .compatible = "brcm,genet-mdio-v3", }, |
| { .compatible = "brcm,genet-mdio-v2", }, |
| { .compatible = "brcm,genet-mdio-v1", }, |
| { .compatible = "brcm,unimac-mdio", }, |
| { /* sentinel */ }, |
| }; |
| |
| static struct platform_driver unimac_mdio_driver = { |
| .driver = { |
| .name = "unimac-mdio", |
| .of_match_table = unimac_mdio_ids, |
| }, |
| .probe = unimac_mdio_probe, |
| .remove = unimac_mdio_remove, |
| }; |
| module_platform_driver(unimac_mdio_driver); |
| |
| MODULE_AUTHOR("Broadcom Corporation"); |
| MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:unimac-mdio"); |