1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2015 Broadcom Corporation
6 #include <linux/delay.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
11 #include <linux/of_platform.h>
12 #include <linux/of_mdio.h>
13 #include <linux/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/sched.h>
17 #define IPROC_GPHY_MDCDIV 0x1a
19 #define MII_CTRL_OFFSET 0x000
21 #define MII_CTRL_DIV_SHIFT 0
22 #define MII_CTRL_PRE_SHIFT 7
23 #define MII_CTRL_BUSY_SHIFT 8
25 #define MII_DATA_OFFSET 0x004
26 #define MII_DATA_MASK 0xffff
27 #define MII_DATA_TA_SHIFT 16
28 #define MII_DATA_TA_VAL 2
29 #define MII_DATA_RA_SHIFT 18
30 #define MII_DATA_PA_SHIFT 23
31 #define MII_DATA_OP_SHIFT 28
32 #define MII_DATA_OP_WRITE 1
33 #define MII_DATA_OP_READ 2
34 #define MII_DATA_SB_SHIFT 30
36 struct iproc_mdio_priv {
37 struct mii_bus *mii_bus;
41 static inline int iproc_mdio_wait_for_idle(void __iomem *base)
44 unsigned int timeout = 1000; /* loop for 1s */
47 val = readl(base + MII_CTRL_OFFSET);
48 if ((val & BIT(MII_CTRL_BUSY_SHIFT)) == 0)
51 usleep_range(1000, 2000);
57 static inline void iproc_mdio_config_clk(void __iomem *base)
61 val = (IPROC_GPHY_MDCDIV << MII_CTRL_DIV_SHIFT) |
62 BIT(MII_CTRL_PRE_SHIFT);
63 writel(val, base + MII_CTRL_OFFSET);
66 static int iproc_mdio_read(struct mii_bus *bus, int phy_id, int reg)
68 struct iproc_mdio_priv *priv = bus->priv;
72 rc = iproc_mdio_wait_for_idle(priv->base);
76 /* Prepare the read operation */
77 cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) |
78 (reg << MII_DATA_RA_SHIFT) |
79 (phy_id << MII_DATA_PA_SHIFT) |
80 BIT(MII_DATA_SB_SHIFT) |
81 (MII_DATA_OP_READ << MII_DATA_OP_SHIFT);
83 writel(cmd, priv->base + MII_DATA_OFFSET);
85 rc = iproc_mdio_wait_for_idle(priv->base);
89 cmd = readl(priv->base + MII_DATA_OFFSET) & MII_DATA_MASK;
94 static int iproc_mdio_write(struct mii_bus *bus, int phy_id,
97 struct iproc_mdio_priv *priv = bus->priv;
101 rc = iproc_mdio_wait_for_idle(priv->base);
105 /* Prepare the write operation */
106 cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) |
107 (reg << MII_DATA_RA_SHIFT) |
108 (phy_id << MII_DATA_PA_SHIFT) |
109 BIT(MII_DATA_SB_SHIFT) |
110 (MII_DATA_OP_WRITE << MII_DATA_OP_SHIFT) |
111 ((u32)(val) & MII_DATA_MASK);
113 writel(cmd, priv->base + MII_DATA_OFFSET);
115 rc = iproc_mdio_wait_for_idle(priv->base);
122 static int iproc_mdio_probe(struct platform_device *pdev)
124 struct iproc_mdio_priv *priv;
128 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
132 priv->base = devm_platform_ioremap_resource(pdev, 0);
133 if (IS_ERR(priv->base)) {
134 dev_err(&pdev->dev, "failed to ioremap register\n");
135 return PTR_ERR(priv->base);
138 priv->mii_bus = mdiobus_alloc();
139 if (!priv->mii_bus) {
140 dev_err(&pdev->dev, "MDIO bus alloc failed\n");
146 bus->name = "iProc MDIO bus";
147 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
148 bus->parent = &pdev->dev;
149 bus->read = iproc_mdio_read;
150 bus->write = iproc_mdio_write;
152 iproc_mdio_config_clk(priv->base);
154 rc = of_mdiobus_register(bus, pdev->dev.of_node);
156 dev_err(&pdev->dev, "MDIO bus registration failed\n");
160 platform_set_drvdata(pdev, priv);
162 dev_info(&pdev->dev, "Broadcom iProc MDIO bus registered\n");
171 static int iproc_mdio_remove(struct platform_device *pdev)
173 struct iproc_mdio_priv *priv = platform_get_drvdata(pdev);
175 mdiobus_unregister(priv->mii_bus);
176 mdiobus_free(priv->mii_bus);
181 #ifdef CONFIG_PM_SLEEP
182 static int iproc_mdio_resume(struct device *dev)
184 struct platform_device *pdev = to_platform_device(dev);
185 struct iproc_mdio_priv *priv = platform_get_drvdata(pdev);
187 /* restore the mii clock configuration */
188 iproc_mdio_config_clk(priv->base);
193 static const struct dev_pm_ops iproc_mdio_pm_ops = {
194 .resume = iproc_mdio_resume
196 #endif /* CONFIG_PM_SLEEP */
198 static const struct of_device_id iproc_mdio_of_match[] = {
199 { .compatible = "brcm,iproc-mdio", },
202 MODULE_DEVICE_TABLE(of, iproc_mdio_of_match);
204 static struct platform_driver iproc_mdio_driver = {
206 .name = "iproc-mdio",
207 .of_match_table = iproc_mdio_of_match,
208 #ifdef CONFIG_PM_SLEEP
209 .pm = &iproc_mdio_pm_ops,
212 .probe = iproc_mdio_probe,
213 .remove = iproc_mdio_remove,
216 module_platform_driver(iproc_mdio_driver);
218 MODULE_AUTHOR("Broadcom Corporation");
219 MODULE_DESCRIPTION("Broadcom iProc MDIO bus controller");
220 MODULE_LICENSE("GPL v2");
221 MODULE_ALIAS("platform:iproc-mdio");