aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/marvell/mvmdio.c
blob: 6d6002bab060dadd2cdff65fc6525c1153979f2e (plain) (blame)
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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
 * Driver for the MDIO interface of Marvell network interfaces.
 *
 * Since the MDIO interface of Marvell network interfaces is shared
 * between all network interfaces, having a single driver allows to
 * handle concurrent accesses properly (you may have four Ethernet
 * ports, but they in fact share the same SMI interface to access the
 * MDIO bus). Moreover, this MDIO interface code is similar between
 * the mv643xx_eth driver and the mvneta driver. For now, it is only
 * used by the mvneta driver, but it could later be used by the
 * mv643xx_eth driver as well.
 *
 * Copyright (C) 2012 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/platform_device.h>
#include <linux/delay.h>

#define MVMDIO_SMI_DATA_SHIFT              0
#define MVMDIO_SMI_PHY_ADDR_SHIFT          16
#define MVMDIO_SMI_PHY_REG_SHIFT           21
#define MVMDIO_SMI_READ_OPERATION          BIT(26)
#define MVMDIO_SMI_WRITE_OPERATION         0
#define MVMDIO_SMI_READ_VALID              BIT(27)
#define MVMDIO_SMI_BUSY                    BIT(28)

struct orion_mdio_dev {
	struct mutex lock;
	void __iomem *smireg;
};

/* Wait for the SMI unit to be ready for another operation
 */
static int orion_mdio_wait_ready(struct mii_bus *bus)
{
	struct orion_mdio_dev *dev = bus->priv;
	int count;
	u32 val;

	count = 0;
	while (1) {
		val = readl(dev->smireg);
		if (!(val & MVMDIO_SMI_BUSY))
			break;

		if (count > 100) {
			dev_err(bus->parent, "Timeout: SMI busy for too long\n");
			return -ETIMEDOUT;
		}

		udelay(10);
		count++;
	}

	return 0;
}

static int orion_mdio_read(struct mii_bus *bus, int mii_id,
			   int regnum)
{
	struct orion_mdio_dev *dev = bus->priv;
	int count;
	u32 val;
	int ret;

	mutex_lock(&dev->lock);

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0) {
		mutex_unlock(&dev->lock);
		return ret;
	}

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
		MVMDIO_SMI_READ_OPERATION),
	       dev->smireg);

	/* Wait for the value to become available */
	count = 0;
	while (1) {
		val = readl(dev->smireg);
		if (val & MVMDIO_SMI_READ_VALID)
			break;

		if (count > 100) {
			dev_err(bus->parent, "Timeout when reading PHY\n");
			mutex_unlock(&dev->lock);
			return -ETIMEDOUT;
		}

		udelay(10);
		count++;
	}

	mutex_unlock(&dev->lock);

	return val & 0xFFFF;
}

static int orion_mdio_write(struct mii_bus *bus, int mii_id,
			    int regnum, u16 value)
{
	struct orion_mdio_dev *dev = bus->priv;
	int ret;

	mutex_lock(&dev->lock);

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0) {
		mutex_unlock(&dev->lock);
		return ret;
	}

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
		MVMDIO_SMI_WRITE_OPERATION            |
		(value << MVMDIO_SMI_DATA_SHIFT)),
	       dev->smireg);

	mutex_unlock(&dev->lock);

	return 0;
}

static int orion_mdio_reset(struct mii_bus *bus)
{
	return 0;
}

static int __devinit orion_mdio_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct mii_bus *bus;
	struct orion_mdio_dev *dev;
	int i, ret;

	bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
	if (!bus) {
		dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
		return -ENOMEM;
	}

	bus->name = "orion_mdio_bus";
	bus->read = orion_mdio_read;
	bus->write = orion_mdio_write;
	bus->reset = orion_mdio_reset;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
		 dev_name(&pdev->dev));
	bus->parent = &pdev->dev;

	bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
	if (!bus->irq) {
		dev_err(&pdev->dev, "Cannot allocate PHY IRQ array\n");
		mdiobus_free(bus);
		return -ENOMEM;
	}

	for (i = 0; i < PHY_MAX_ADDR; i++)
		bus->irq[i] = PHY_POLL;

	dev = bus->priv;
	dev->smireg = of_iomap(pdev->dev.of_node, 0);
	if (!dev->smireg) {
		dev_err(&pdev->dev, "No SMI register address given in DT\n");
		kfree(bus->irq);
		mdiobus_free(bus);
		return -ENODEV;
	}

	mutex_init(&dev->lock);

	ret = of_mdiobus_register(bus, np);
	if (ret < 0) {
		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
		iounmap(dev->smireg);
		kfree(bus->irq);
		mdiobus_free(bus);
		return ret;
	}

	platform_set_drvdata(pdev, bus);

	return 0;
}

static int __devexit orion_mdio_remove(struct platform_device *pdev)
{
	struct mii_bus *bus = platform_get_drvdata(pdev);
	mdiobus_unregister(bus);
	kfree(bus->irq);
	mdiobus_free(bus);
	return 0;
}

static const struct of_device_id orion_mdio_match[] = {
	{ .compatible = "marvell,orion-mdio" },
	{ }
};
MODULE_DEVICE_TABLE(of, orion_mdio_match);

static struct platform_driver orion_mdio_driver = {
	.probe = orion_mdio_probe,
	.remove = __devexit_p(orion_mdio_remove),
	.driver = {
		.name = "orion-mdio",
		.of_match_table = orion_mdio_match,
	},
};

module_platform_driver(orion_mdio_driver);

MODULE_DESCRIPTION("Marvell MDIO interface driver");
MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
MODULE_LICENSE("GPL");