aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/mdio/mdio-aspeed.c
blob: cad820568f75119f70c234d9efe15cb54847bd7f (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
// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (C) 2019 IBM Corp. */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>

#define DRV_NAME "mdio-aspeed"

#define ASPEED_MDIO_CTRL		0x0
#define   ASPEED_MDIO_CTRL_FIRE		BIT(31)
#define   ASPEED_MDIO_CTRL_ST		BIT(28)
#define     ASPEED_MDIO_CTRL_ST_C45	0
#define     ASPEED_MDIO_CTRL_ST_C22	1
#define   ASPEED_MDIO_CTRL_OP		GENMASK(27, 26)
#define     MDIO_C22_OP_WRITE		0b01
#define     MDIO_C22_OP_READ		0b10
#define   ASPEED_MDIO_CTRL_PHYAD	GENMASK(25, 21)
#define   ASPEED_MDIO_CTRL_REGAD	GENMASK(20, 16)
#define   ASPEED_MDIO_CTRL_MIIWDATA	GENMASK(15, 0)

#define ASPEED_MDIO_DATA		0x4
#define   ASPEED_MDIO_DATA_MDC_THRES	GENMASK(31, 24)
#define   ASPEED_MDIO_DATA_MDIO_EDGE	BIT(23)
#define   ASPEED_MDIO_DATA_MDIO_LATCH	GENMASK(22, 20)
#define   ASPEED_MDIO_DATA_IDLE		BIT(16)
#define   ASPEED_MDIO_DATA_MIIRDATA	GENMASK(15, 0)

#define ASPEED_MDIO_INTERVAL_US		100
#define ASPEED_MDIO_TIMEOUT_US		(ASPEED_MDIO_INTERVAL_US * 10)

struct aspeed_mdio {
	void __iomem *base;
};

static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
{
	struct aspeed_mdio *ctx = bus->priv;
	u32 ctrl;
	u32 data;
	int rc;

	dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d\n", __func__, addr,
		regnum);

	/* Just clause 22 for the moment */
	if (regnum & MII_ADDR_C45)
		return -EOPNOTSUPP;

	ctrl = ASPEED_MDIO_CTRL_FIRE
		| FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22)
		| FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_READ)
		| FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr)
		| FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum);

	iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);

	rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
				data & ASPEED_MDIO_DATA_IDLE,
				ASPEED_MDIO_INTERVAL_US,
				ASPEED_MDIO_TIMEOUT_US);
	if (rc < 0)
		return rc;

	return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data);
}

static int aspeed_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
{
	struct aspeed_mdio *ctx = bus->priv;
	u32 ctrl;

	dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d, val: 0x%x\n",
		__func__, addr, regnum, val);

	/* Just clause 22 for the moment */
	if (regnum & MII_ADDR_C45)
		return -EOPNOTSUPP;

	ctrl = ASPEED_MDIO_CTRL_FIRE
		| FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22)
		| FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_WRITE)
		| FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr)
		| FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum)
		| FIELD_PREP(ASPEED_MDIO_CTRL_MIIWDATA, val);

	iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);

	return readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
				  !(ctrl & ASPEED_MDIO_CTRL_FIRE),
				  ASPEED_MDIO_INTERVAL_US,
				  ASPEED_MDIO_TIMEOUT_US);
}

static int aspeed_mdio_probe(struct platform_device *pdev)
{
	struct aspeed_mdio *ctx;
	struct mii_bus *bus;
	int rc;

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

	ctx = bus->priv;
	ctx->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ctx->base))
		return PTR_ERR(ctx->base);

	bus->name = DRV_NAME;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id);
	bus->parent = &pdev->dev;
	bus->read = aspeed_mdio_read;
	bus->write = aspeed_mdio_write;

	rc = of_mdiobus_register(bus, pdev->dev.of_node);
	if (rc) {
		dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
		return rc;
	}

	platform_set_drvdata(pdev, bus);

	return 0;
}

static int aspeed_mdio_remove(struct platform_device *pdev)
{
	mdiobus_unregister(platform_get_drvdata(pdev));

	return 0;
}

static const struct of_device_id aspeed_mdio_of_match[] = {
	{ .compatible = "aspeed,ast2600-mdio", },
	{ },
};

static struct platform_driver aspeed_mdio_driver = {
	.driver = {
		.name = DRV_NAME,
		.of_match_table = aspeed_mdio_of_match,
	},
	.probe = aspeed_mdio_probe,
	.remove = aspeed_mdio_remove,
};

module_platform_driver(aspeed_mdio_driver);

MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
MODULE_LICENSE("GPL");