summaryrefslogtreecommitdiff
path: root/sys/dev/mii/mii_bitbang.c
blob: ee3870b79da8fdfcbc67b3ee99f6e60d1dd94601 (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
/*	$OpenBSD: mii_bitbang.c,v 1.3 2004/09/27 18:25:48 brad Exp $	*/

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Common module for bit-bang'ing the MII.
 */

#include <sys/param.h>
#include <sys/device.h>

#include <dev/mii/mii.h>
#include <dev/mii/mii_bitbang.h>

void	mii_bitbang_sync(struct device *, mii_bitbang_ops_t);
void	mii_bitbang_sendbits(struct device *, mii_bitbang_ops_t,
	    u_int32_t, int);

#define	WRITE(x)							\
do {									\
	ops->mbo_write(sc, (x));					\
	delay(1);							\
} while (0)

#define	READ		ops->mbo_read(sc)

#define	MDO		ops->mbo_bits[MII_BIT_MDO]
#define	MDI		ops->mbo_bits[MII_BIT_MDI]
#define	MDC		ops->mbo_bits[MII_BIT_MDC]
#define	MDIRPHY		ops->mbo_bits[MII_BIT_DIR_HOST_PHY]
#define	MDIRHOST	ops->mbo_bits[MII_BIT_DIR_PHY_HOST]

/*
 * mii_bitbang_sync:
 *
 *	Synchronize the MII.
 */
void
mii_bitbang_sync(struct device *sc, mii_bitbang_ops_t ops)
{
	int i, v;

	v = MDIRPHY | MDO;

	WRITE(v);
	for (i = 0; i < 32; i++) {
		WRITE(v | MDC);
		WRITE(v);
	}
}

/*
 * mii_bitbang_sendbits:
 *
 *	Send a series of bits to the MII.
 */
void
mii_bitbang_sendbits(struct device *sc, mii_bitbang_ops_t ops,
    u_int32_t data, int nbits)
{
	int i, v;

	v = MDIRPHY;
	WRITE(v);

	for (i = 1 << (nbits - 1); i != 0; i >>= 1) {
		if (data & i)
			v |= MDO;
		else
			v &= ~MDO;
		WRITE(v);
		WRITE(v | MDC);
		WRITE(v);
	}
}

/*
 * mii_bitbang_readreg:
 *
 *	Read a PHY register by bit-bang'ing the MII.
 */
int
mii_bitbang_readreg(struct device *sc, mii_bitbang_ops_t ops, int phy,
    int reg)
{
	int val = 0, err = 0, i;

	mii_bitbang_sync(sc, ops);

	mii_bitbang_sendbits(sc, ops, MII_COMMAND_START, 2);
	mii_bitbang_sendbits(sc, ops, MII_COMMAND_READ, 2);
	mii_bitbang_sendbits(sc, ops, phy, 5);
	mii_bitbang_sendbits(sc, ops, reg, 5);

	/* Switch direction to PHY->host, without a clock transition. */
	WRITE(MDIRHOST);

	/* Turnaround clock. */
	WRITE(MDIRHOST | MDC);
	WRITE(MDIRHOST);

	/* Check for error. */
	err = READ & MDI;

	/* Idle clock. */
	WRITE(MDIRHOST | MDC);
	WRITE(MDIRHOST);

	for (i = 0; i < 16; i++) {
		val <<= 1;
		/* Read data prior to clock low-high transition. */
		if (err == 0 && (READ & MDI) != 0)
			val |= 1;

		WRITE(MDIRHOST | MDC);
		WRITE(MDIRHOST);
	}

	/* Set direction to host->PHY, without a clock transition. */
	WRITE(MDIRPHY);

	return (err ? 0 : val);
}

/*
 * mii_bitbang_writereg:
 *
 *	Write a PHY register by bit-bang'ing the MII.
 */
void
mii_bitbang_writereg(struct device *sc, mii_bitbang_ops_t ops,
    int phy, int reg, int val)
{

	mii_bitbang_sync(sc, ops);

	mii_bitbang_sendbits(sc, ops, MII_COMMAND_START, 2);
	mii_bitbang_sendbits(sc, ops, MII_COMMAND_WRITE, 2);
	mii_bitbang_sendbits(sc, ops, phy, 5);
	mii_bitbang_sendbits(sc, ops, reg, 5);
	mii_bitbang_sendbits(sc, ops, MII_COMMAND_ACK, 2);
	mii_bitbang_sendbits(sc, ops, val, 16);

	WRITE(MDIRPHY);
}