summaryrefslogtreecommitdiffstats
path: root/drivers/net/phy/mdio-bcm-unimac.c
blob: fc7abc50b4f17544741d1166960fb549b8554fbd (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
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
/*
 * Broadcom UniMAC MDIO bus controller driver
 *
 * Copyright (C) 2014, Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/delay.h>

#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_mdio.h>

#define MDIO_CMD		0x00
#define  MDIO_START_BUSY	(1 << 29)
#define  MDIO_READ_FAIL		(1 << 28)
#define  MDIO_RD		(2 << 26)
#define  MDIO_WR		(1 << 26)
#define  MDIO_PMD_SHIFT		21
#define  MDIO_PMD_MASK		0x1F
#define  MDIO_REG_SHIFT		16
#define  MDIO_REG_MASK		0x1F

#define MDIO_CFG		0x04
#define  MDIO_C22		(1 << 0)
#define  MDIO_C45		0
#define  MDIO_CLK_DIV_SHIFT	4
#define  MDIO_CLK_DIV_MASK	0x3F
#define  MDIO_SUPP_PREAMBLE	(1 << 12)

struct unimac_mdio_priv {
	struct mii_bus		*mii_bus;
	void __iomem		*base;
};

static inline void unimac_mdio_start(struct unimac_mdio_priv *priv)
{
	u32 reg;

	reg = __raw_readl(priv->base + MDIO_CMD);
	reg |= MDIO_START_BUSY;
	__raw_writel(reg, priv->base + MDIO_CMD);
}

static inline unsigned int unimac_mdio_busy(struct unimac_mdio_priv *priv)
{
	return __raw_readl(priv->base + MDIO_CMD) & MDIO_START_BUSY;
}

static int unimac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
	struct unimac_mdio_priv *priv = bus->priv;
	unsigned int timeout = 1000;
	u32 cmd;

	/* Prepare the read operation */
	cmd = MDIO_RD | (phy_id << MDIO_PMD_SHIFT) | (reg << MDIO_REG_SHIFT);
	__raw_writel(cmd, priv->base + MDIO_CMD);

	/* Start MDIO transaction */
	unimac_mdio_start(priv);

	do {
		if (!unimac_mdio_busy(priv))
			break;

		usleep_range(1000, 2000);
	} while (timeout--);

	if (!timeout)
		return -ETIMEDOUT;

	cmd = __raw_readl(priv->base + MDIO_CMD);

	/* Some broken devices are known not to release the line during
	 * turn-around, e.g: Broadcom BCM53125 external switches, so check for
	 * that condition here and ignore the MDIO controller read failure
	 * indication.
	 */
	if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (cmd & MDIO_READ_FAIL))
		return -EIO;

	return cmd & 0xffff;
}

static int unimac_mdio_write(struct mii_bus *bus, int phy_id,
			     int reg, u16 val)
{
	struct unimac_mdio_priv *priv = bus->priv;
	unsigned int timeout = 1000;
	u32 cmd;

	/* Prepare the write operation */
	cmd = MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
		(reg << MDIO_REG_SHIFT) | (0xffff & val);
	__raw_writel(cmd, priv->base + MDIO_CMD);

	unimac_mdio_start(priv);

	do {
		if (!unimac_mdio_busy(priv))
			break;

		usleep_range(1000, 2000);
	} while (timeout--);

	if (!timeout)
		return -ETIMEDOUT;

	return 0;
}

static int unimac_mdio_probe(struct platform_device *pdev)
{
	struct unimac_mdio_priv *priv;
	struct device_node *np;
	struct mii_bus *bus;
	struct resource *r;
	int ret;

	np = pdev->dev.of_node;

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

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	/* Just ioremap, as this MDIO block is usually integrated into an
	 * Ethernet MAC controller register range
	 */
	priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (!priv->base) {
		dev_err(&pdev->dev, "failed to remap register\n");
		return -ENOMEM;
	}

	priv->mii_bus = mdiobus_alloc();
	if (!priv->mii_bus)
		return -ENOMEM;

	bus = priv->mii_bus;
	bus->priv = priv;
	bus->name = "unimac MII bus";
	bus->parent = &pdev->dev;
	bus->read = unimac_mdio_read;
	bus->write = unimac_mdio_write;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);

	bus->irq = kcalloc(PHY_MAX_ADDR, sizeof(int), GFP_KERNEL);
	if (!bus->irq) {
		ret = -ENOMEM;
		goto out_mdio_free;
	}

	ret = of_mdiobus_register(bus, np);
	if (ret) {
		dev_err(&pdev->dev, "MDIO bus registration failed\n");
		goto out_mdio_irq;
	}

	platform_set_drvdata(pdev, priv);

	dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus at 0x%p\n", priv->base);

	return 0;

out_mdio_irq:
	kfree(bus->irq);
out_mdio_free:
	mdiobus_free(bus);
	return ret;
}

static int unimac_mdio_remove(struct platform_device *pdev)
{
	struct unimac_mdio_priv *priv = platform_get_drvdata(pdev);

	mdiobus_unregister(priv->mii_bus);
	kfree(priv->mii_bus->irq);
	mdiobus_free(priv->mii_bus);

	return 0;
}

static const struct of_device_id unimac_mdio_ids[] = {
	{ .compatible = "brcm,genet-mdio-v4", },
	{ .compatible = "brcm,genet-mdio-v3", },
	{ .compatible = "brcm,genet-mdio-v2", },
	{ .compatible = "brcm,genet-mdio-v1", },
	{ .compatible = "brcm,unimac-mdio", },
	{ /* sentinel */ },
};

static struct platform_driver unimac_mdio_driver = {
	.driver = {
		.name = "unimac-mdio",
		.of_match_table = unimac_mdio_ids,
	},
	.probe	= unimac_mdio_probe,
	.remove	= unimac_mdio_remove,
};
module_platform_driver(unimac_mdio_driver);

MODULE_AUTHOR("Broadcom Corporation");
MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:unimac-mdio");
OpenPOWER on IntegriCloud