summaryrefslogtreecommitdiffstats
path: root/drivers/net/mdio/mdio-ipq8064.c
blob: f71b6e1c66e42826907c07f4c2a86c44cf740a57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
// SPDX-License-Identifier: GPL-2.0
/* Qualcomm IPQ8064 MDIO interface driver
 *
 * Copyright (C) 2019 Christian Lamparter <chunkeey@gmail.com>
 * Copyright (C) 2020 Ansuel Smith <ansuelsmth@gmail.com>
 */

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* MII address register definitions */
#define MII_ADDR_REG_ADDR			0x10
#define MII_BUSY				BIT(0)
#define MII_WRITE				BIT(1)
#define MII_CLKRANGE(x)				((x) << 2)
#define MII_CLKRANGE_60_100M			MII_CLKRANGE(0)
#define MII_CLKRANGE_100_150M			MII_CLKRANGE(1)
#define MII_CLKRANGE_20_35M			MII_CLKRANGE(2)
#define MII_CLKRANGE_35_60M			MII_CLKRANGE(3)
#define MII_CLKRANGE_150_250M			MII_CLKRANGE(4)
#define MII_CLKRANGE_250_300M			MII_CLKRANGE(5)
#define MII_CLKRANGE_MASK			GENMASK(4, 2)
#define MII_REG_SHIFT				6
#define MII_REG_MASK				GENMASK(10, 6)
#define MII_ADDR_SHIFT				11
#define MII_ADDR_MASK				GENMASK(15, 11)

#define MII_DATA_REG_ADDR			0x14

#define MII_MDIO_DELAY_USEC			(1000)
#define MII_MDIO_RETRY_MSEC			(10)

struct ipq8064_mdio {
	struct regmap *base; /* NSS_GMAC0_BASE */
};

static int
ipq8064_mdio_wait_busy(struct ipq8064_mdio *priv)
{
	u32 busy;

	return regmap_read_poll_timeout(priv->base, MII_ADDR_REG_ADDR, busy,
					!(busy & MII_BUSY), MII_MDIO_DELAY_USEC,
					MII_MDIO_RETRY_MSEC * USEC_PER_MSEC);
}

static int
ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
{
	u32 miiaddr = MII_BUSY | MII_CLKRANGE_250_300M;
	struct ipq8064_mdio *priv = bus->priv;
	u32 ret_val;
	int err;

	miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
		   ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);

	regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
	usleep_range(10, 13);

	err = ipq8064_mdio_wait_busy(priv);
	if (err)
		return err;

	regmap_read(priv->base, MII_DATA_REG_ADDR, &ret_val);
	return (int)ret_val;
}

static int
ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
{
	u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M;
	struct ipq8064_mdio *priv = bus->priv;

	regmap_write(priv->base, MII_DATA_REG_ADDR, data);

	miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
		   ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);

	regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);

	/* For the specific reg 31 extra time is needed or the next
	 * read will produce garbage data.
	 */
	if (reg_offset == 31)
		usleep_range(30, 43);
	else
		usleep_range(10, 13);

	return ipq8064_mdio_wait_busy(priv);
}

static const struct regmap_config ipq8064_mdio_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.can_multi_write = false,
	/* the mdio lock is used by any user of this mdio driver */
	.disable_locking = true,

	.cache_type = REGCACHE_NONE,
};

static int
ipq8064_mdio_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct ipq8064_mdio *priv;
	struct resource res;
	struct mii_bus *bus;
	void __iomem *base;
	int ret;

	if (of_address_to_resource(np, 0, &res))
		return -ENOMEM;

	base = devm_ioremap(&pdev->dev, res.start, resource_size(&res));
	if (!base)
		return -ENOMEM;

	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
	if (!bus)
		return -ENOMEM;

	bus->name = "ipq8064_mdio_bus";
	bus->read = ipq8064_mdio_read;
	bus->write = ipq8064_mdio_write;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
	bus->parent = &pdev->dev;

	priv = bus->priv;
	priv->base = devm_regmap_init_mmio(&pdev->dev, base,
					   &ipq8064_mdio_regmap_config);
	if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

	ret = of_mdiobus_register(bus, np);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, bus);
	return 0;
}

static void ipq8064_mdio_remove(struct platform_device *pdev)
{
	struct mii_bus *bus = platform_get_drvdata(pdev);

	mdiobus_unregister(bus);
}

static const struct of_device_id ipq8064_mdio_dt_ids[] = {
	{ .compatible = "qcom,ipq8064-mdio" },
	{ }
};
MODULE_DEVICE_TABLE(of, ipq8064_mdio_dt_ids);

static struct platform_driver ipq8064_mdio_driver = {
	.probe = ipq8064_mdio_probe,
	.remove_new = ipq8064_mdio_remove,
	.driver = {
		.name = "ipq8064-mdio",
		.of_match_table = ipq8064_mdio_dt_ids,
	},
};

module_platform_driver(ipq8064_mdio_driver);

MODULE_DESCRIPTION("Qualcomm IPQ8064 MDIO interface driver");
MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
MODULE_AUTHOR("Ansuel Smith <ansuelsmth@gmail.com>");
MODULE_LICENSE("GPL");