diff options
Diffstat (limited to 'drivers/net/mdio/mdio-mux-bcm6368.c')
| -rw-r--r-- | drivers/net/mdio/mdio-mux-bcm6368.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-mux-bcm6368.c b/drivers/net/mdio/mdio-mux-bcm6368.c new file mode 100644 index 000000000..8b444a8eb --- /dev/null +++ b/drivers/net/mdio/mdio-mux-bcm6368.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Broadcom BCM6368 mdiomux bus controller driver + * + * Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com> + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mdio-mux.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_mdio.h> +#include <linux/phy.h> +#include <linux/platform_device.h> +#include <linux/sched.h> + +#define MDIOC_REG 0x0 +#define MDIOC_EXT_MASK BIT(16) +#define MDIOC_REG_SHIFT 20 +#define MDIOC_PHYID_SHIFT 25 +#define MDIOC_RD_MASK BIT(30) +#define MDIOC_WR_MASK BIT(31) + +#define MDIOD_REG 0x4 + +struct bcm6368_mdiomux_desc { + void *mux_handle; + void __iomem *base; + struct device *dev; + struct mii_bus *mii_bus; + int ext_phy; +}; + +static int bcm6368_mdiomux_read(struct mii_bus *bus, int phy_id, int loc) +{ + struct bcm6368_mdiomux_desc *md = bus->priv; + uint32_t reg; + int ret; + + __raw_writel(0, md->base + MDIOC_REG); + + reg = MDIOC_RD_MASK | + (phy_id << MDIOC_PHYID_SHIFT) | + (loc << MDIOC_REG_SHIFT); + if (md->ext_phy) + reg |= MDIOC_EXT_MASK; + + __raw_writel(reg, md->base + MDIOC_REG); + udelay(50); + ret = __raw_readw(md->base + MDIOD_REG); + + return ret; +} + +static int bcm6368_mdiomux_write(struct mii_bus *bus, int phy_id, int loc, + uint16_t val) +{ + struct bcm6368_mdiomux_desc *md = bus->priv; + uint32_t reg; + + __raw_writel(0, md->base + MDIOC_REG); + + reg = MDIOC_WR_MASK | + (phy_id << MDIOC_PHYID_SHIFT) | + (loc << MDIOC_REG_SHIFT); + if (md->ext_phy) + reg |= MDIOC_EXT_MASK; + reg |= val; + + __raw_writel(reg, md->base + MDIOC_REG); + udelay(50); + + return 0; +} + +static int bcm6368_mdiomux_switch_fn(int current_child, int desired_child, + void *data) +{ + struct bcm6368_mdiomux_desc *md = data; + + md->ext_phy = desired_child; + + return 0; +} + +static int bcm6368_mdiomux_probe(struct platform_device *pdev) +{ + struct bcm6368_mdiomux_desc *md; + struct mii_bus *bus; + struct resource *res; + int rc; + + md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL); + if (!md) + return -ENOMEM; + md->dev = &pdev->dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; + + /* + * Just ioremap, as this MDIO block is usually integrated into an + * Ethernet MAC controller register range + */ + md->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!md->base) { + dev_err(&pdev->dev, "failed to ioremap register\n"); + return -ENOMEM; + } + + md->mii_bus = devm_mdiobus_alloc(&pdev->dev); + if (!md->mii_bus) { + dev_err(&pdev->dev, "mdiomux bus alloc failed\n"); + return -ENOMEM; + } + + bus = md->mii_bus; + bus->priv = md; + bus->name = "BCM6368 MDIO mux bus"; + snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id); + bus->parent = &pdev->dev; + bus->read = bcm6368_mdiomux_read; + bus->write = bcm6368_mdiomux_write; + bus->phy_mask = 0x3f; + bus->dev.of_node = pdev->dev.of_node; + + rc = mdiobus_register(bus); + if (rc) { + dev_err(&pdev->dev, "mdiomux registration failed\n"); + return rc; + } + + platform_set_drvdata(pdev, md); + + rc = mdio_mux_init(md->dev, md->dev->of_node, + bcm6368_mdiomux_switch_fn, &md->mux_handle, md, + md->mii_bus); + if (rc) { + dev_info(md->dev, "mdiomux initialization failed\n"); + goto out_register; + } + + dev_info(&pdev->dev, "Broadcom BCM6368 MDIO mux bus\n"); + + return 0; + +out_register: + mdiobus_unregister(bus); + return rc; +} + +static int bcm6368_mdiomux_remove(struct platform_device *pdev) +{ + struct bcm6368_mdiomux_desc *md = platform_get_drvdata(pdev); + + mdio_mux_uninit(md->mux_handle); + mdiobus_unregister(md->mii_bus); + + return 0; +} + +static const struct of_device_id bcm6368_mdiomux_ids[] = { + { .compatible = "brcm,bcm6368-mdio-mux", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, bcm6368_mdiomux_ids); + +static struct platform_driver bcm6368_mdiomux_driver = { + .driver = { + .name = "bcm6368-mdio-mux", + .of_match_table = bcm6368_mdiomux_ids, + }, + .probe = bcm6368_mdiomux_probe, + .remove = bcm6368_mdiomux_remove, +}; +module_platform_driver(bcm6368_mdiomux_driver); + +MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>"); +MODULE_DESCRIPTION("BCM6368 mdiomux bus controller driver"); +MODULE_LICENSE("GPL v2"); |