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/of_mdio.h>
12#include <linux/of_address.h>
13#include <linux/platform_device.h>
14#include <linux/regmap.h>
15
16/* MII address register definitions */
17#define MII_ADDR_REG_ADDR 0x10
18#define MII_BUSY BIT(0)
19#define MII_WRITE BIT(1)
20#define MII_CLKRANGE(x) ((x) << 2)
21#define MII_CLKRANGE_60_100M MII_CLKRANGE(0)
22#define MII_CLKRANGE_100_150M MII_CLKRANGE(1)
23#define MII_CLKRANGE_20_35M MII_CLKRANGE(2)
24#define MII_CLKRANGE_35_60M MII_CLKRANGE(3)
25#define MII_CLKRANGE_150_250M MII_CLKRANGE(4)
26#define MII_CLKRANGE_250_300M MII_CLKRANGE(5)
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 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
61 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
62
63 regmap_write(map: priv->base, MII_ADDR_REG_ADDR, val: miiaddr);
64 usleep_range(min: 10, max: 13);
65
66 err = ipq8064_mdio_wait_busy(priv);
67 if (err)
68 return err;
69
70 regmap_read(map: priv->base, MII_DATA_REG_ADDR, val: &ret_val);
71 return (int)ret_val;
72}
73
74static int
75ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
76{
77 u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M;
78 struct ipq8064_mdio *priv = bus->priv;
79
80 regmap_write(map: priv->base, MII_DATA_REG_ADDR, val: data);
81
82 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
83 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
84
85 regmap_write(map: priv->base, MII_ADDR_REG_ADDR, val: miiaddr);
86
87 /* For the specific reg 31 extra time is needed or the next
88 * read will produce garbage data.
89 */
90 if (reg_offset == 31)
91 usleep_range(min: 30, max: 43);
92 else
93 usleep_range(min: 10, max: 13);
94
95 return ipq8064_mdio_wait_busy(priv);
96}
97
98static const struct regmap_config ipq8064_mdio_regmap_config = {
99 .reg_bits = 32,
100 .reg_stride = 4,
101 .val_bits = 32,
102 .can_multi_write = false,
103 /* the mdio lock is used by any user of this mdio driver */
104 .disable_locking = true,
105
106 .cache_type = REGCACHE_NONE,
107};
108
109static int
110ipq8064_mdio_probe(struct platform_device *pdev)
111{
112 struct device_node *np = pdev->dev.of_node;
113 struct ipq8064_mdio *priv;
114 struct resource res;
115 struct mii_bus *bus;
116 void __iomem *base;
117 int ret;
118
119 if (of_address_to_resource(dev: np, index: 0, r: &res))
120 return -ENOMEM;
121
122 base = devm_ioremap(dev: &pdev->dev, offset: res.start, size: resource_size(res: &res));
123 if (!base)
124 return -ENOMEM;
125
126 bus = devm_mdiobus_alloc_size(dev: &pdev->dev, sizeof_priv: sizeof(*priv));
127 if (!bus)
128 return -ENOMEM;
129
130 bus->name = "ipq8064_mdio_bus";
131 bus->read = ipq8064_mdio_read;
132 bus->write = ipq8064_mdio_write;
133 snprintf(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s-mii", dev_name(dev: &pdev->dev));
134 bus->parent = &pdev->dev;
135
136 priv = bus->priv;
137 priv->base = devm_regmap_init_mmio(&pdev->dev, base,
138 &ipq8064_mdio_regmap_config);
139 if (IS_ERR(ptr: priv->base))
140 return PTR_ERR(ptr: priv->base);
141
142 ret = of_mdiobus_register(mdio: bus, np);
143 if (ret)
144 return ret;
145
146 platform_set_drvdata(pdev, data: bus);
147 return 0;
148}
149
150static void ipq8064_mdio_remove(struct platform_device *pdev)
151{
152 struct mii_bus *bus = platform_get_drvdata(pdev);
153
154 mdiobus_unregister(bus);
155}
156
157static const struct of_device_id ipq8064_mdio_dt_ids[] = {
158 { .compatible = "qcom,ipq8064-mdio" },
159 { }
160};
161MODULE_DEVICE_TABLE(of, ipq8064_mdio_dt_ids);
162
163static struct platform_driver ipq8064_mdio_driver = {
164 .probe = ipq8064_mdio_probe,
165 .remove = ipq8064_mdio_remove,
166 .driver = {
167 .name = "ipq8064-mdio",
168 .of_match_table = ipq8064_mdio_dt_ids,
169 },
170};
171
172module_platform_driver(ipq8064_mdio_driver);
173
174MODULE_DESCRIPTION("Qualcomm IPQ8064 MDIO interface driver");
175MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
176MODULE_AUTHOR("Ansuel Smith <ansuelsmth@gmail.com>");
177MODULE_LICENSE("GPL");
178

source code of linux/drivers/net/mdio/mdio-ipq8064.c