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Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0
2/* Qualcomm IPQ8064 MDIO interface driver
3 *
4 * Copyright (C) 2019 Christian Lamparter <chunkeey@gmail.com>
5 * Copyright (C) 2020 Ansuel Smith <ansuelsmth@gmail.com>
6 */
7
8#include <linux/delay.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/regmap.h>
12#include <linux/of_mdio.h>
13#include <linux/phy.h>
14#include <linux/platform_device.h>
15#include <linux/mfd/syscon.h>
16
17/* MII address register definitions */
18#define MII_ADDR_REG_ADDR 0x10
19#define MII_BUSY BIT(0)
20#define MII_WRITE BIT(1)
21#define MII_CLKRANGE_60_100M (0 << 2)
22#define MII_CLKRANGE_100_150M (1 << 2)
23#define MII_CLKRANGE_20_35M (2 << 2)
24#define MII_CLKRANGE_35_60M (3 << 2)
25#define MII_CLKRANGE_150_250M (4 << 2)
26#define MII_CLKRANGE_250_300M (5 << 2)
27#define MII_CLKRANGE_MASK GENMASK(4, 2)
28#define MII_REG_SHIFT 6
29#define MII_REG_MASK GENMASK(10, 6)
30#define MII_ADDR_SHIFT 11
31#define MII_ADDR_MASK GENMASK(15, 11)
32
33#define MII_DATA_REG_ADDR 0x14
34
35#define MII_MDIO_DELAY_USEC (1000)
36#define MII_MDIO_RETRY_MSEC (10)
37
38struct ipq8064_mdio {
39 struct regmap *base; /* NSS_GMAC0_BASE */
40};
41
42static int
43ipq8064_mdio_wait_busy(struct ipq8064_mdio *priv)
44{
45 u32 busy;
46
47 return regmap_read_poll_timeout(priv->base, MII_ADDR_REG_ADDR, busy,
48 !(busy & MII_BUSY), MII_MDIO_DELAY_USEC,
49 MII_MDIO_RETRY_MSEC * USEC_PER_MSEC);
50}
51
52static int
53ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
54{
55 u32 miiaddr = MII_BUSY | MII_CLKRANGE_250_300M;
56 struct ipq8064_mdio *priv = bus->priv;
57 u32 ret_val;
58 int err;
59
60 /* Reject clause 45 */
61 if (reg_offset & MII_ADDR_C45)
62 return -EOPNOTSUPP;
63
64 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
65 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
66
67 regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
68 usleep_range(8, 10);
69
70 err = ipq8064_mdio_wait_busy(priv);
71 if (err)
72 return err;
73
74 regmap_read(priv->base, MII_DATA_REG_ADDR, &ret_val);
75 return (int)ret_val;
76}
77
78static int
79ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
80{
81 u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M;
82 struct ipq8064_mdio *priv = bus->priv;
83
84 /* Reject clause 45 */
85 if (reg_offset & MII_ADDR_C45)
86 return -EOPNOTSUPP;
87
88 regmap_write(priv->base, MII_DATA_REG_ADDR, data);
89
90 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
91 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
92
93 regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
94 usleep_range(8, 10);
95
96 return ipq8064_mdio_wait_busy(priv);
97}
98
99static int
100ipq8064_mdio_probe(struct platform_device *pdev)
101{
102 struct device_node *np = pdev->dev.of_node;
103 struct ipq8064_mdio *priv;
104 struct mii_bus *bus;
105 int ret;
106
107 bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
108 if (!bus)
109 return -ENOMEM;
110
111 bus->name = "ipq8064_mdio_bus";
112 bus->read = ipq8064_mdio_read;
113 bus->write = ipq8064_mdio_write;
114 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
115 bus->parent = &pdev->dev;
116
117 priv = bus->priv;
118 priv->base = device_node_to_regmap(np);
119 if (IS_ERR(priv->base)) {
120 if (priv->base == ERR_PTR(-EPROBE_DEFER))
121 return -EPROBE_DEFER;
122
123 dev_err(&pdev->dev, "error getting device regmap, error=%pe\n",
124 priv->base);
125 return PTR_ERR(priv->base);
126 }
127
128 ret = of_mdiobus_register(bus, np);
129 if (ret)
130 return ret;
131
132 platform_set_drvdata(pdev, bus);
133 return 0;
134}
135
136static int
137ipq8064_mdio_remove(struct platform_device *pdev)
138{
139 struct mii_bus *bus = platform_get_drvdata(pdev);
140
141 mdiobus_unregister(bus);
142
143 return 0;
144}
145
146static const struct of_device_id ipq8064_mdio_dt_ids[] = {
147 { .compatible = "qcom,ipq8064-mdio" },
148 { }
149};
150MODULE_DEVICE_TABLE(of, ipq8064_mdio_dt_ids);
151
152static struct platform_driver ipq8064_mdio_driver = {
153 .probe = ipq8064_mdio_probe,
154 .remove = ipq8064_mdio_remove,
155 .driver = {
156 .name = "ipq8064-mdio",
157 .of_match_table = ipq8064_mdio_dt_ids,
158 },
159};
160
161module_platform_driver(ipq8064_mdio_driver);
162
163MODULE_DESCRIPTION("Qualcomm IPQ8064 MDIO interface driver");
164MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
165MODULE_AUTHOR("Ansuel Smith <ansuelsmth@gmail.com>");
166MODULE_LICENSE("GPL");