1/*-
2 * Copyright (c) 1998, Michael Smith
3 * Copyright (c) 1996, Sujal M. Patel
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/11/stand/common/isapnp.c 332154 2018-04-06 21:37:25Z kevans $");
30
31/*
32 * Machine-independant ISA PnP enumerator implementing a subset of the
33 * ISA PnP specification.
34 */
35#include <stand.h>
36#include <string.h>
37#include <bootstrap.h>
38#include <isapnp.h>
39
40#define	inb(x)		(archsw.arch_isainb((x)))
41#define	outb(x,y)	(archsw.arch_isaoutb((x),(y)))
42
43static void	isapnp_write(int d, int r);
44static void	isapnp_send_Initiation_LFSR(void);
45static int	isapnp_get_serial(uint8_t *p);
46static int	isapnp_isolation_protocol(void);
47static void	isapnp_enumerate(void);
48
49/* PnP read data port */
50int		isapnp_readport = 0;
51
52#define	_PNP_ID_LEN	9
53
54struct pnphandler isapnphandler =
55{
56    "ISA bus",
57    isapnp_enumerate
58};
59
60static void
61isapnp_write(int d, int r)
62{
63    outb (_PNP_ADDRESS, d);
64    outb (_PNP_WRITE_DATA, r);
65}
66
67/*
68 * Send Initiation LFSR as described in "Plug and Play ISA Specification",
69 * Intel May 94.
70 */
71static void
72isapnp_send_Initiation_LFSR(void)
73{
74    int cur, i;
75
76    /* Reset the LSFR */
77    outb(_PNP_ADDRESS, 0);
78    outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
79
80    cur = 0x6a;
81    outb(_PNP_ADDRESS, cur);
82
83    for (i = 1; i < 32; i++) {
84	cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
85	outb(_PNP_ADDRESS, cur);
86    }
87}
88
89/*
90 * Get the device's serial number.  Returns 1 if the serial is valid.
91 */
92static int
93isapnp_get_serial(uint8_t *data)
94{
95    int		i, bit, valid = 0, sum = 0x6a;
96
97    bzero(data, _PNP_ID_LEN);
98    outb(_PNP_ADDRESS, SERIAL_ISOLATION);
99    for (i = 0; i < 72; i++) {
100	bit = inb(isapnp_readport) == 0x55;
101	delay(250);	/* Delay 250 usec */
102
103	/* Can't Short Circuit the next evaluation, so 'and' is last */
104	bit = (inb(isapnp_readport) == 0xaa) && bit;
105	delay(250);	/* Delay 250 usec */
106
107	valid = valid || bit;
108
109	if (i < 64)
110	    sum = (sum >> 1) |
111		(((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
112
113	data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
114    }
115
116    valid = valid && (data[8] == sum);
117
118    return valid;
119}
120
121/*
122 * Fills the buffer with resource info from the device.
123 * Returns nonzero if the device fails to report
124 */
125static int
126isapnp_get_resource_info(uint8_t *buffer, int len)
127{
128    int		i, j;
129    u_char	temp;
130
131    for (i = 0; i < len; i++) {
132	outb(_PNP_ADDRESS, STATUS);
133	for (j = 0; j < 100; j++) {
134	    if ((inb(isapnp_readport)) & 0x1)
135		break;
136	    delay(1);
137	}
138	if (j == 100) {
139	    printf("PnP device failed to report resource data\n");
140	    return(1);
141	}
142	outb(_PNP_ADDRESS, RESOURCE_DATA);
143	temp = inb(isapnp_readport);
144	if (buffer != NULL)
145	    buffer[i] = temp;
146    }
147    return(0);
148}
149
150/*
151 * Scan Resource Data for useful information.
152 *
153 * We scan the resource data for compatible device IDs and
154 * identifier strings; we only take the first identifier string
155 * and assume it's for the card as a whole.
156 *
157 * Returns 0 if the scan completed OK, nonzero on error.
158 */
159static int
160isapnp_scan_resdata(struct pnpinfo *pi)
161{
162    u_char	tag, resinfo[8];
163    u_int	limit;
164    size_t	large_len;
165    u_char	*str;
166
167    limit = 1000;
168    while ((limit-- > 0) && !isapnp_get_resource_info(&tag, 1)) {
169	if (PNP_RES_TYPE(tag) == 0) {
170	    /* Small resource */
171	    switch (PNP_SRES_NUM(tag)) {
172
173		case COMP_DEVICE_ID:
174		    /* Got a compatible device id resource */
175		    if (isapnp_get_resource_info(resinfo, PNP_SRES_LEN(tag)))
176			return(1);
177		    pnp_addident(pi, pnp_eisaformat(resinfo));
178
179		case END_TAG:
180		    return(0);
181		    break;
182
183		default:
184		    /* Skip this resource */
185		    if (isapnp_get_resource_info(NULL, PNP_SRES_LEN(tag)))
186			return(1);
187		    break;
188	    }
189	} else {
190	    /* Large resource */
191	    if (isapnp_get_resource_info(resinfo, 2))
192		return(1);
193
194	    large_len = resinfo[1];
195	    large_len = (large_len << 8) + resinfo[0];
196
197	    switch(PNP_LRES_NUM(tag)) {
198
199	    case ID_STRING_ANSI:
200		str = malloc(large_len + 1);
201		if (isapnp_get_resource_info(str, (ssize_t)large_len)) {
202		    free(str);
203		    return(1);
204		}
205		str[large_len] = 0;
206		if (pi->pi_desc == NULL) {
207		    pi->pi_desc = (char *)str;
208		} else {
209		    free(str);
210		}
211		break;
212
213	    default:
214		/* Large resource, skip it */
215		if (isapnp_get_resource_info(NULL, (ssize_t)large_len))
216		    return(1);
217	    }
218	}
219    }
220    return(1);
221}
222
223/*
224 * Run the isolation protocol. Upon exiting, all cards are aware that
225 * they should use isapnp_readport as the READ_DATA port.
226 */
227static int
228isapnp_isolation_protocol(void)
229{
230    int			csn;
231    struct pnpinfo	*pi;
232    uint8_t		cardid[_PNP_ID_LEN];
233    int			ndevs;
234
235    isapnp_send_Initiation_LFSR();
236    ndevs = 0;
237
238    isapnp_write(CONFIG_CONTROL, 0x04);	/* Reset CSN for All Cards */
239
240    for (csn = 1; ; csn++) {
241	/* Wake up cards without a CSN (ie. all of them) */
242	isapnp_write(WAKE, 0);
243	isapnp_write(SET_RD_DATA, (isapnp_readport >> 2));
244	outb(_PNP_ADDRESS, SERIAL_ISOLATION);
245	delay(1000);	/* Delay 1 msec */
246
247	if (isapnp_get_serial(cardid)) {
248	    isapnp_write(SET_CSN, csn);
249	    pi = pnp_allocinfo();
250	    ndevs++;
251	    pnp_addident(pi, pnp_eisaformat(cardid));
252	    /* scan the card obtaining all the identifiers it holds */
253	    if (isapnp_scan_resdata(pi)) {
254		pnp_freeinfo(pi);	/* error getting data, ignore */
255	    } else {
256		pnp_addinfo(pi);
257	    }
258	} else {
259	    break;
260	}
261    }
262    /* Move all cards to wait-for-key state */
263    while (--csn > 0) {
264	isapnp_send_Initiation_LFSR();
265	isapnp_write(WAKE, csn);
266	isapnp_write(CONFIG_CONTROL, 0x02);
267	delay(1000); /* XXX is it really necessary ? */
268	csn--;
269    }
270    return(ndevs);
271}
272
273/*
274 * Locate ISA-PnP devices and populate the supplied list.
275 */
276static void
277isapnp_enumerate(void)
278{
279    int		pnp_rd_port;
280
281    /* Check for I/O port access */
282    if ((archsw.arch_isainb == NULL) || (archsw.arch_isaoutb == NULL))
283	return;
284
285    /*
286     * Validate a possibly-suggested read port value.  If the autoscan failed
287     * last time, this will return us to autoscan mode again.
288     */
289    if ((isapnp_readport > 0) &&
290	(((isapnp_readport < 0x203) ||
291	  (isapnp_readport > 0x3ff) ||
292	  (isapnp_readport & 0x3) != 0x3)))
293	 /* invalid, go look for ourselves */
294	isapnp_readport = 0;
295
296    if (isapnp_readport < 0) {
297	/* someone is telling us there is no ISA in the system */
298	return;
299
300    } else if (isapnp_readport > 0) {
301	/* Someone has told us where the port is/should be, or we found one last time */
302	isapnp_isolation_protocol();
303
304    } else {
305	/* No clues, look for it ourselves */
306	for (pnp_rd_port = 0x80; pnp_rd_port < 0xff; pnp_rd_port += 0x10) {
307	    /* Look for something, quit when we find it */
308	    isapnp_readport = (pnp_rd_port << 2) | 0x3;
309	    if (isapnp_isolation_protocol() > 0)
310		break;
311	}
312    }
313}
314