aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/xilinx/ll_temac_mdio.c
blob: a4667326f745350fc90a121cf7672a9467c9ca8d (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
// SPDX-License-Identifier: GPL-2.0
/*
 * MDIO bus driver for the Xilinx TEMAC device
 *
 * Copyright (c) 2009 Secret Lab Technologies, Ltd.
 */

#include <linux/io.h>
#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/of_mdio.h>
#include <linux/platform_data/xilinx-ll-temac.h>

#include "ll_temac.h"

/* ---------------------------------------------------------------------
 * MDIO Bus functions
 */
static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
	struct temac_local *lp = bus->priv;
	u32 rc;

	/* Write the PHY address to the MIIM Access Initiator register.
	 * When the transfer completes, the PHY register value will appear
	 * in the LSW0 register */
	mutex_lock(lp->indirect_mutex);
	temac_iow(lp, XTE_LSW0_OFFSET, (phy_id << 5) | reg);
	rc = temac_indirect_in32(lp, XTE_MIIMAI_OFFSET);
	mutex_unlock(lp->indirect_mutex);

	dev_dbg(lp->dev, "temac_mdio_read(phy_id=%i, reg=%x) == %x\n",
		phy_id, reg, rc);

	return rc;
}

static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
{
	struct temac_local *lp = bus->priv;

	dev_dbg(lp->dev, "temac_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
		phy_id, reg, val);

	/* First write the desired value into the write data register
	 * and then write the address into the access initiator register
	 */
	mutex_lock(lp->indirect_mutex);
	temac_indirect_out32(lp, XTE_MGTDR_OFFSET, val);
	temac_indirect_out32(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
	mutex_unlock(lp->indirect_mutex);

	return 0;
}

int temac_mdio_setup(struct temac_local *lp, struct platform_device *pdev)
{
	struct ll_temac_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct device_node *np = dev_of_node(&pdev->dev);
	struct mii_bus *bus;
	u32 bus_hz;
	int clk_div;
	int rc;
	struct resource res;

	/* Get MDIO bus frequency (if specified) */
	bus_hz = 0;
	if (np)
		of_property_read_u32(np, "clock-frequency", &bus_hz);
	else if (pdata)
		bus_hz = pdata->mdio_clk_freq;

	/* Calculate a reasonable divisor for the clock rate */
	clk_div = 0x3f; /* worst-case default setting */
	if (bus_hz != 0) {
		clk_div = bus_hz / (2500 * 1000 * 2) - 1;
		if (clk_div < 1)
			clk_div = 1;
		if (clk_div > 0x3f)
			clk_div = 0x3f;
	}

	/* Enable the MDIO bus by asserting the enable bit and writing
	 * in the clock config */
	mutex_lock(lp->indirect_mutex);
	temac_indirect_out32(lp, XTE_MC_OFFSET, 1 << 6 | clk_div);
	mutex_unlock(lp->indirect_mutex);

	bus = devm_mdiobus_alloc(&pdev->dev);
	if (!bus)
		return -ENOMEM;

	if (np) {
		of_address_to_resource(np, 0, &res);
		snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
			 (unsigned long long)res.start);
	} else if (pdata) {
		snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
			 pdata->mdio_bus_id);
	}

	bus->priv = lp;
	bus->name = "Xilinx TEMAC MDIO";
	bus->read = temac_mdio_read;
	bus->write = temac_mdio_write;
	bus->parent = lp->dev;

	lp->mii_bus = bus;

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

	mutex_lock(lp->indirect_mutex);
	dev_dbg(lp->dev, "MDIO bus registered;  MC:%x\n",
		temac_indirect_in32(lp, XTE_MC_OFFSET));
	mutex_unlock(lp->indirect_mutex);
	return 0;
}

void temac_mdio_teardown(struct temac_local *lp)
{
	mdiobus_unregister(lp->mii_bus);
}