1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2015 Broadcom Corporation |
4 | */ |
5 | |
6 | #include <linux/delay.h> |
7 | #include <linux/io.h> |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> |
10 | #include <linux/of.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> |
16 | |
17 | #define IPROC_GPHY_MDCDIV 0x1a |
18 | |
19 | #define MII_CTRL_OFFSET 0x000 |
20 | |
21 | #define MII_CTRL_DIV_SHIFT 0 |
22 | #define MII_CTRL_PRE_SHIFT 7 |
23 | #define MII_CTRL_BUSY_SHIFT 8 |
24 | |
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 |
35 | |
36 | struct iproc_mdio_priv { |
37 | struct mii_bus *mii_bus; |
38 | void __iomem *base; |
39 | }; |
40 | |
41 | static inline int iproc_mdio_wait_for_idle(void __iomem *base) |
42 | { |
43 | u32 val; |
44 | unsigned int timeout = 1000; /* loop for 1s */ |
45 | |
46 | do { |
47 | val = readl(addr: base + MII_CTRL_OFFSET); |
48 | if ((val & BIT(MII_CTRL_BUSY_SHIFT)) == 0) |
49 | return 0; |
50 | |
51 | usleep_range(min: 1000, max: 2000); |
52 | } while (timeout--); |
53 | |
54 | return -ETIMEDOUT; |
55 | } |
56 | |
57 | static inline void iproc_mdio_config_clk(void __iomem *base) |
58 | { |
59 | u32 val; |
60 | |
61 | val = (IPROC_GPHY_MDCDIV << MII_CTRL_DIV_SHIFT) | |
62 | BIT(MII_CTRL_PRE_SHIFT); |
63 | writel(val, addr: base + MII_CTRL_OFFSET); |
64 | } |
65 | |
66 | static int iproc_mdio_read(struct mii_bus *bus, int phy_id, int reg) |
67 | { |
68 | struct iproc_mdio_priv *priv = bus->priv; |
69 | u32 cmd; |
70 | int rc; |
71 | |
72 | rc = iproc_mdio_wait_for_idle(base: priv->base); |
73 | if (rc) |
74 | return rc; |
75 | |
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); |
82 | |
83 | writel(val: cmd, addr: priv->base + MII_DATA_OFFSET); |
84 | |
85 | rc = iproc_mdio_wait_for_idle(base: priv->base); |
86 | if (rc) |
87 | return rc; |
88 | |
89 | cmd = readl(addr: priv->base + MII_DATA_OFFSET) & MII_DATA_MASK; |
90 | |
91 | return cmd; |
92 | } |
93 | |
94 | static int iproc_mdio_write(struct mii_bus *bus, int phy_id, |
95 | int reg, u16 val) |
96 | { |
97 | struct iproc_mdio_priv *priv = bus->priv; |
98 | u32 cmd; |
99 | int rc; |
100 | |
101 | rc = iproc_mdio_wait_for_idle(base: priv->base); |
102 | if (rc) |
103 | return rc; |
104 | |
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); |
112 | |
113 | writel(val: cmd, addr: priv->base + MII_DATA_OFFSET); |
114 | |
115 | rc = iproc_mdio_wait_for_idle(base: priv->base); |
116 | if (rc) |
117 | return rc; |
118 | |
119 | return 0; |
120 | } |
121 | |
122 | static int iproc_mdio_probe(struct platform_device *pdev) |
123 | { |
124 | struct iproc_mdio_priv *priv; |
125 | struct mii_bus *bus; |
126 | int rc; |
127 | |
128 | priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL); |
129 | if (!priv) |
130 | return -ENOMEM; |
131 | |
132 | priv->base = devm_platform_ioremap_resource(pdev, index: 0); |
133 | if (IS_ERR(ptr: priv->base)) { |
134 | dev_err(&pdev->dev, "failed to ioremap register\n" ); |
135 | return PTR_ERR(ptr: priv->base); |
136 | } |
137 | |
138 | priv->mii_bus = mdiobus_alloc(); |
139 | if (!priv->mii_bus) { |
140 | dev_err(&pdev->dev, "MDIO bus alloc failed\n" ); |
141 | return -ENOMEM; |
142 | } |
143 | |
144 | bus = priv->mii_bus; |
145 | bus->priv = priv; |
146 | bus->name = "iProc MDIO bus" ; |
147 | snprintf(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s-%d" , pdev->name, pdev->id); |
148 | bus->parent = &pdev->dev; |
149 | bus->read = iproc_mdio_read; |
150 | bus->write = iproc_mdio_write; |
151 | |
152 | iproc_mdio_config_clk(base: priv->base); |
153 | |
154 | rc = of_mdiobus_register(mdio: bus, np: pdev->dev.of_node); |
155 | if (rc) { |
156 | dev_err(&pdev->dev, "MDIO bus registration failed\n" ); |
157 | goto err_iproc_mdio; |
158 | } |
159 | |
160 | platform_set_drvdata(pdev, data: priv); |
161 | |
162 | dev_info(&pdev->dev, "Broadcom iProc MDIO bus registered\n" ); |
163 | |
164 | return 0; |
165 | |
166 | err_iproc_mdio: |
167 | mdiobus_free(bus); |
168 | return rc; |
169 | } |
170 | |
171 | static void iproc_mdio_remove(struct platform_device *pdev) |
172 | { |
173 | struct iproc_mdio_priv *priv = platform_get_drvdata(pdev); |
174 | |
175 | mdiobus_unregister(bus: priv->mii_bus); |
176 | mdiobus_free(bus: priv->mii_bus); |
177 | } |
178 | |
179 | #ifdef CONFIG_PM_SLEEP |
180 | static int iproc_mdio_resume(struct device *dev) |
181 | { |
182 | struct platform_device *pdev = to_platform_device(dev); |
183 | struct iproc_mdio_priv *priv = platform_get_drvdata(pdev); |
184 | |
185 | /* restore the mii clock configuration */ |
186 | iproc_mdio_config_clk(base: priv->base); |
187 | |
188 | return 0; |
189 | } |
190 | |
191 | static const struct dev_pm_ops iproc_mdio_pm_ops = { |
192 | .resume = iproc_mdio_resume |
193 | }; |
194 | #endif /* CONFIG_PM_SLEEP */ |
195 | |
196 | static const struct of_device_id iproc_mdio_of_match[] = { |
197 | { .compatible = "brcm,iproc-mdio" , }, |
198 | { /* sentinel */ }, |
199 | }; |
200 | MODULE_DEVICE_TABLE(of, iproc_mdio_of_match); |
201 | |
202 | static struct platform_driver iproc_mdio_driver = { |
203 | .driver = { |
204 | .name = "iproc-mdio" , |
205 | .of_match_table = iproc_mdio_of_match, |
206 | #ifdef CONFIG_PM_SLEEP |
207 | .pm = &iproc_mdio_pm_ops, |
208 | #endif |
209 | }, |
210 | .probe = iproc_mdio_probe, |
211 | .remove_new = iproc_mdio_remove, |
212 | }; |
213 | |
214 | module_platform_driver(iproc_mdio_driver); |
215 | |
216 | MODULE_AUTHOR("Broadcom Corporation" ); |
217 | MODULE_DESCRIPTION("Broadcom iProc MDIO bus controller" ); |
218 | MODULE_LICENSE("GPL v2" ); |
219 | MODULE_ALIAS("platform:iproc-mdio" ); |
220 | |