1 // SPDX-License-Identifier: GPL-2.0+
3 * Broadcom BCM6368 mdiomux bus controller driver
5 * Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com>
8 #include <linux/delay.h>
10 #include <linux/kernel.h>
11 #include <linux/mdio-mux.h>
12 #include <linux/module.h>
14 #include <linux/of_platform.h>
15 #include <linux/of_mdio.h>
16 #include <linux/phy.h>
17 #include <linux/platform_device.h>
18 #include <linux/sched.h>
21 #define MDIOC_EXT_MASK BIT(16)
22 #define MDIOC_REG_SHIFT 20
23 #define MDIOC_PHYID_SHIFT 25
24 #define MDIOC_RD_MASK BIT(30)
25 #define MDIOC_WR_MASK BIT(31)
29 struct bcm6368_mdiomux_desc {
33 struct mii_bus *mii_bus;
37 static int bcm6368_mdiomux_read(struct mii_bus *bus, int phy_id, int loc)
39 struct bcm6368_mdiomux_desc *md = bus->priv;
43 __raw_writel(0, md->base + MDIOC_REG);
46 (phy_id << MDIOC_PHYID_SHIFT) |
47 (loc << MDIOC_REG_SHIFT);
49 reg |= MDIOC_EXT_MASK;
51 __raw_writel(reg, md->base + MDIOC_REG);
53 ret = __raw_readw(md->base + MDIOD_REG);
58 static int bcm6368_mdiomux_write(struct mii_bus *bus, int phy_id, int loc,
61 struct bcm6368_mdiomux_desc *md = bus->priv;
64 __raw_writel(0, md->base + MDIOC_REG);
67 (phy_id << MDIOC_PHYID_SHIFT) |
68 (loc << MDIOC_REG_SHIFT);
70 reg |= MDIOC_EXT_MASK;
73 __raw_writel(reg, md->base + MDIOC_REG);
79 static int bcm6368_mdiomux_switch_fn(int current_child, int desired_child,
82 struct bcm6368_mdiomux_desc *md = data;
84 md->ext_phy = desired_child;
89 static int bcm6368_mdiomux_probe(struct platform_device *pdev)
91 struct bcm6368_mdiomux_desc *md;
96 md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
101 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
106 * Just ioremap, as this MDIO block is usually integrated into an
107 * Ethernet MAC controller register range
109 md->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
111 dev_err(&pdev->dev, "failed to ioremap register\n");
115 md->mii_bus = devm_mdiobus_alloc(&pdev->dev);
117 dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
123 bus->name = "BCM6368 MDIO mux bus";
124 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
125 bus->parent = &pdev->dev;
126 bus->read = bcm6368_mdiomux_read;
127 bus->write = bcm6368_mdiomux_write;
128 bus->phy_mask = 0x3f;
129 bus->dev.of_node = pdev->dev.of_node;
131 rc = mdiobus_register(bus);
133 dev_err(&pdev->dev, "mdiomux registration failed\n");
137 platform_set_drvdata(pdev, md);
139 rc = mdio_mux_init(md->dev, md->dev->of_node,
140 bcm6368_mdiomux_switch_fn, &md->mux_handle, md,
143 dev_info(md->dev, "mdiomux initialization failed\n");
147 dev_info(&pdev->dev, "Broadcom BCM6368 MDIO mux bus\n");
152 mdiobus_unregister(bus);
156 static int bcm6368_mdiomux_remove(struct platform_device *pdev)
158 struct bcm6368_mdiomux_desc *md = platform_get_drvdata(pdev);
160 mdio_mux_uninit(md->mux_handle);
161 mdiobus_unregister(md->mii_bus);
166 static const struct of_device_id bcm6368_mdiomux_ids[] = {
167 { .compatible = "brcm,bcm6368-mdio-mux", },
170 MODULE_DEVICE_TABLE(of, bcm6368_mdiomux_ids);
172 static struct platform_driver bcm6368_mdiomux_driver = {
174 .name = "bcm6368-mdio-mux",
175 .of_match_table = bcm6368_mdiomux_ids,
177 .probe = bcm6368_mdiomux_probe,
178 .remove = bcm6368_mdiomux_remove,
180 module_platform_driver(bcm6368_mdiomux_driver);
182 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
183 MODULE_DESCRIPTION("BCM6368 mdiomux bus controller driver");
184 MODULE_LICENSE("GPL v2");