1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Hisilicon Fast Ethernet MDIO Bus Driver
4 *
5 * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
6 */
7
8#include <linux/clk.h>
9#include <linux/iopoll.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/of_address.h>
13#include <linux/of_mdio.h>
14#include <linux/platform_device.h>
15
16#define MDIO_RWCTRL 0x00
17#define MDIO_RO_DATA 0x04
18#define MDIO_WRITE BIT(13)
19#define MDIO_RW_FINISH BIT(15)
20#define BIT_PHY_ADDR_OFFSET 8
21#define BIT_WR_DATA_OFFSET 16
22
23struct hisi_femac_mdio_data {
24 struct clk *clk;
25 void __iomem *membase;
26};
27
28static int hisi_femac_mdio_wait_ready(struct hisi_femac_mdio_data *data)
29{
30 u32 val;
31
32 return readl_poll_timeout(data->membase + MDIO_RWCTRL,
33 val, val & MDIO_RW_FINISH, 20, 10000);
34}
35
36static int hisi_femac_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
37{
38 struct hisi_femac_mdio_data *data = bus->priv;
39 int ret;
40
41 ret = hisi_femac_mdio_wait_ready(data);
42 if (ret)
43 return ret;
44
45 writel(val: (mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
46 addr: data->membase + MDIO_RWCTRL);
47
48 ret = hisi_femac_mdio_wait_ready(data);
49 if (ret)
50 return ret;
51
52 return readl(addr: data->membase + MDIO_RO_DATA) & 0xFFFF;
53}
54
55static int hisi_femac_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
56 u16 value)
57{
58 struct hisi_femac_mdio_data *data = bus->priv;
59 int ret;
60
61 ret = hisi_femac_mdio_wait_ready(data);
62 if (ret)
63 return ret;
64
65 writel(MDIO_WRITE | (value << BIT_WR_DATA_OFFSET) |
66 (mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
67 addr: data->membase + MDIO_RWCTRL);
68
69 return hisi_femac_mdio_wait_ready(data);
70}
71
72static int hisi_femac_mdio_probe(struct platform_device *pdev)
73{
74 struct device_node *np = pdev->dev.of_node;
75 struct mii_bus *bus;
76 struct hisi_femac_mdio_data *data;
77 int ret;
78
79 bus = mdiobus_alloc_size(size: sizeof(*data));
80 if (!bus)
81 return -ENOMEM;
82
83 bus->name = "hisi_femac_mii_bus";
84 bus->read = &hisi_femac_mdio_read;
85 bus->write = &hisi_femac_mdio_write;
86 snprintf(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s", pdev->name);
87 bus->parent = &pdev->dev;
88
89 data = bus->priv;
90 data->membase = devm_platform_ioremap_resource(pdev, index: 0);
91 if (IS_ERR(ptr: data->membase)) {
92 ret = PTR_ERR(ptr: data->membase);
93 goto err_out_free_mdiobus;
94 }
95
96 data->clk = devm_clk_get(dev: &pdev->dev, NULL);
97 if (IS_ERR(ptr: data->clk)) {
98 ret = PTR_ERR(ptr: data->clk);
99 goto err_out_free_mdiobus;
100 }
101
102 ret = clk_prepare_enable(clk: data->clk);
103 if (ret)
104 goto err_out_free_mdiobus;
105
106 ret = of_mdiobus_register(mdio: bus, np);
107 if (ret)
108 goto err_out_disable_clk;
109
110 platform_set_drvdata(pdev, data: bus);
111
112 return 0;
113
114err_out_disable_clk:
115 clk_disable_unprepare(clk: data->clk);
116err_out_free_mdiobus:
117 mdiobus_free(bus);
118 return ret;
119}
120
121static void hisi_femac_mdio_remove(struct platform_device *pdev)
122{
123 struct mii_bus *bus = platform_get_drvdata(pdev);
124 struct hisi_femac_mdio_data *data = bus->priv;
125
126 mdiobus_unregister(bus);
127 clk_disable_unprepare(clk: data->clk);
128 mdiobus_free(bus);
129}
130
131static const struct of_device_id hisi_femac_mdio_dt_ids[] = {
132 { .compatible = "hisilicon,hisi-femac-mdio" },
133 { }
134};
135MODULE_DEVICE_TABLE(of, hisi_femac_mdio_dt_ids);
136
137static struct platform_driver hisi_femac_mdio_driver = {
138 .probe = hisi_femac_mdio_probe,
139 .remove = hisi_femac_mdio_remove,
140 .driver = {
141 .name = "hisi-femac-mdio",
142 .of_match_table = hisi_femac_mdio_dt_ids,
143 },
144};
145
146module_platform_driver(hisi_femac_mdio_driver);
147
148MODULE_DESCRIPTION("Hisilicon Fast Ethernet MAC MDIO interface driver");
149MODULE_AUTHOR("Dongpo Li <lidongpo@hisilicon.com>");
150MODULE_LICENSE("GPL");
151

source code of linux/drivers/net/mdio/mdio-hisi-femac.c