summaryrefslogtreecommitdiff
path: root/tools/csr_h4.c
blob: 27ea3e3cce8e99eb76c4a84c88e14b286c426846 (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
/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2004-2008  Marcel Holtmann <marcel@holtmann.org>
 *
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdint.h>
#include <termios.h>

#include "csr.h"

static uint16_t seqnum = 0x0000;

static int fd = -1;

int csr_open_h4(char *device)
{
	struct termios ti;

	if (!device)
		device = "/dev/ttyS0";

	fd = open(device, O_RDWR | O_NOCTTY);
	if (fd < 0) {
		fprintf(stderr, "Can't open serial port: %s (%d)\n",
						strerror(errno), errno);
		return -1;
	}

	tcflush(fd, TCIOFLUSH);

	if (tcgetattr(fd, &ti) < 0) {
		fprintf(stderr, "Can't get port settings: %s (%d)\n",
						strerror(errno), errno);
		close(fd);
		return -1;
	}

	cfmakeraw(&ti);

	ti.c_cflag |= CLOCAL;
	ti.c_cflag |= CRTSCTS;

	cfsetospeed(&ti, B38400);

	if (tcsetattr(fd, TCSANOW, &ti) < 0) {
		fprintf(stderr, "Can't change port settings: %s (%d)\n",
						strerror(errno), errno);
		close(fd);
		return -1;
	}

	tcflush(fd, TCIOFLUSH);

	return 0;
}

static int do_command(uint16_t command, uint16_t seqnum, uint16_t varid, uint8_t *value, uint16_t length)
{
	unsigned char cp[254], rp[254];
	uint8_t cmd[10];
	uint16_t size;
	int len, offset = 3;

	size = (length < 8) ? 9 : ((length + 1) / 2) + 5;

	cmd[0] = command & 0xff;
	cmd[1] = command >> 8;
	cmd[2] = size & 0xff;
	cmd[3] = size >> 8;
	cmd[4] = seqnum & 0xff;
	cmd[5] = seqnum >> 8;
	cmd[6] = varid & 0xff;
	cmd[7] = varid >> 8;
	cmd[8] = 0x00;
	cmd[9] = 0x00;

	memset(cp, 0, sizeof(cp));
	cp[0] = 0x01;
	cp[1] = 0x00;
	cp[2] = 0xfc;
	cp[3] = (size * 2) + 1;
	cp[4] = 0xc2;
	memcpy(cp + 5, cmd, sizeof(cmd));
	memcpy(cp + 15, value, length);

	if (write(fd, cp, (size * 2) + 5) < 0)
		return -1;

	switch (varid) {
	case CSR_VARID_COLD_RESET:
	case CSR_VARID_WARM_RESET:
	case CSR_VARID_COLD_HALT:
	case CSR_VARID_WARM_HALT:
		return 0;
	}

	do {
		if (read(fd, rp, 1) < 1)
			return -1;
	} while (rp[0] != 0x04);

	if (read(fd, rp + 1, 2) < 2)
		return -1;

	do {
		len = read(fd, rp + offset, sizeof(rp) - offset);
		offset += len;
	} while (offset < rp[2] + 3);

	if (rp[0] != 0x04 || rp[1] != 0xff || rp[3] != 0xc2) {
		errno = EIO;
		return -1;
	}

	if ((rp[12] + (rp[13] << 8)) != 0) {
		errno = ENXIO;
		return -1;
	}

	memcpy(value, rp + 14, length);

	return 0;
}

int csr_read_h4(uint16_t varid, uint8_t *value, uint16_t length)
{
	return do_command(0x0000, seqnum++, varid, value, length);
}

int csr_write_h4(uint16_t varid, uint8_t *value, uint16_t length)
{
	return do_command(0x0002, seqnum++, varid, value, length);
}

void csr_close_h4(void)
{
	close(fd);
}