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/*
29 * Machine-independent ISA PnP enumerator implementing a subset of the
30 * ISA PnP specification.
31 */
32#include <stand.h>
33#include <string.h>
34#include <bootstrap.h>
35#include <isapnp.h>
36
37#define	inb(x)		(archsw.arch_isainb((x)))
38#define	outb(x,y)	(archsw.arch_isaoutb((x),(y)))
39
40static void	isapnp_write(int d, int r);
41static void	isapnp_send_Initiation_LFSR(void);
42static int	isapnp_get_serial(uint8_t *p);
43static int	isapnp_isolation_protocol(void);
44static void	isapnp_enumerate(void);
45
46/* PnP read data port */
47int		isapnp_readport = 0;
48
49#define	_PNP_ID_LEN	9
50
51struct pnphandler isapnphandler =
52{
53    "ISA bus",
54    isapnp_enumerate
55};
56
57static void
58isapnp_write(int d, int r)
59{
60    outb (_PNP_ADDRESS, d);
61    outb (_PNP_WRITE_DATA, r);
62}
63
64/*
65 * Send Initiation LFSR as described in "Plug and Play ISA Specification",
66 * Intel May 94.
67 */
68static void
69isapnp_send_Initiation_LFSR(void)
70{
71    int cur, i;
72
73    /* Reset the LSFR */
74    outb(_PNP_ADDRESS, 0);
75    outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
76
77    cur = 0x6a;
78    outb(_PNP_ADDRESS, cur);
79
80    for (i = 1; i < 32; i++) {
81	cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
82	outb(_PNP_ADDRESS, cur);
83    }
84}
85
86/*
87 * Get the device's serial number.  Returns 1 if the serial is valid.
88 */
89static int
90isapnp_get_serial(uint8_t *data)
91{
92    int		i, bit, valid = 0, sum = 0x6a;
93
94    bzero(data, _PNP_ID_LEN);
95    outb(_PNP_ADDRESS, SERIAL_ISOLATION);
96    for (i = 0; i < 72; i++) {
97	bit = inb(isapnp_readport) == 0x55;
98	delay(250);	/* Delay 250 usec */
99
100	/* Can't Short Circuit the next evaluation, so 'and' is last */
101	bit = (inb(isapnp_readport) == 0xaa) && bit;
102	delay(250);	/* Delay 250 usec */
103
104	valid = valid || bit;
105
106	if (i < 64)
107	    sum = (sum >> 1) |
108		(((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
109
110	data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
111    }
112
113    valid = valid && (data[8] == sum);
114
115    return valid;
116}
117
118/*
119 * Fills the buffer with resource info from the device.
120 * Returns nonzero if the device fails to report
121 */
122static int
123isapnp_get_resource_info(uint8_t *buffer, int len)
124{
125    int		i, j;
126    u_char	temp;
127
128    for (i = 0; i < len; i++) {
129	outb(_PNP_ADDRESS, STATUS);
130	for (j = 0; j < 100; j++) {
131	    if ((inb(isapnp_readport)) & 0x1)
132		break;
133	    delay(1);
134	}
135	if (j == 100) {
136	    printf("PnP device failed to report resource data\n");
137	    return(1);
138	}
139	outb(_PNP_ADDRESS, RESOURCE_DATA);
140	temp = inb(isapnp_readport);
141	if (buffer != NULL)
142	    buffer[i] = temp;
143    }
144    return(0);
145}
146
147/*
148 * Scan Resource Data for useful information.
149 *
150 * We scan the resource data for compatible device IDs and
151 * identifier strings; we only take the first identifier string
152 * and assume it's for the card as a whole.
153 *
154 * Returns 0 if the scan completed OK, nonzero on error.
155 */
156static int
157isapnp_scan_resdata(struct pnpinfo *pi)
158{
159    u_char	tag, resinfo[8];
160    u_int	limit;
161    size_t	large_len;
162    u_char	*str;
163
164    limit = 1000;
165    while ((limit-- > 0) && !isapnp_get_resource_info(&tag, 1)) {
166	if (PNP_RES_TYPE(tag) == 0) {
167	    /* Small resource */
168	    switch (PNP_SRES_NUM(tag)) {
169
170		case COMP_DEVICE_ID:
171		    /* Got a compatible device id resource */
172		    if (isapnp_get_resource_info(resinfo, PNP_SRES_LEN(tag)))
173			return(1);
174		    pnp_addident(pi, pnp_eisaformat(resinfo));
175
176		case END_TAG:
177		    return(0);
178		    break;
179
180		default:
181		    /* Skip this resource */
182		    if (isapnp_get_resource_info(NULL, PNP_SRES_LEN(tag)))
183			return(1);
184		    break;
185	    }
186	} else {
187	    /* Large resource */
188	    if (isapnp_get_resource_info(resinfo, 2))
189		return(1);
190
191	    large_len = resinfo[1];
192	    large_len = (large_len << 8) + resinfo[0];
193
194	    switch(PNP_LRES_NUM(tag)) {
195
196	    case ID_STRING_ANSI:
197		str = malloc(large_len + 1);
198		if (isapnp_get_resource_info(str, (ssize_t)large_len)) {
199		    free(str);
200		    return(1);
201		}
202		str[large_len] = 0;
203		if (pi->pi_desc == NULL) {
204		    pi->pi_desc = (char *)str;
205		} else {
206		    free(str);
207		}
208		break;
209
210	    default:
211		/* Large resource, skip it */
212		if (isapnp_get_resource_info(NULL, (ssize_t)large_len))
213		    return(1);
214	    }
215	}
216    }
217    return(1);
218}
219
220/*
221 * Run the isolation protocol. Upon exiting, all cards are aware that
222 * they should use isapnp_readport as the READ_DATA port.
223 */
224static int
225isapnp_isolation_protocol(void)
226{
227    int			csn;
228    struct pnpinfo	*pi;
229    uint8_t		cardid[_PNP_ID_LEN];
230    int			ndevs;
231
232    isapnp_send_Initiation_LFSR();
233    ndevs = 0;
234
235    isapnp_write(CONFIG_CONTROL, 0x04);	/* Reset CSN for All Cards */
236
237    for (csn = 1; ; csn++) {
238	/* Wake up cards without a CSN (ie. all of them) */
239	isapnp_write(WAKE, 0);
240	isapnp_write(SET_RD_DATA, (isapnp_readport >> 2));
241	outb(_PNP_ADDRESS, SERIAL_ISOLATION);
242	delay(1000);	/* Delay 1 msec */
243
244	if (isapnp_get_serial(cardid)) {
245	    isapnp_write(SET_CSN, csn);
246	    pi = pnp_allocinfo();
247	    ndevs++;
248	    pnp_addident(pi, pnp_eisaformat(cardid));
249	    /* scan the card obtaining all the identifiers it holds */
250	    if (isapnp_scan_resdata(pi)) {
251		pnp_freeinfo(pi);	/* error getting data, ignore */
252	    } else {
253		pnp_addinfo(pi);
254	    }
255	} else {
256	    break;
257	}
258    }
259    /* Move all cards to wait-for-key state */
260    while (--csn > 0) {
261	isapnp_send_Initiation_LFSR();
262	isapnp_write(WAKE, csn);
263	isapnp_write(CONFIG_CONTROL, 0x02);
264	delay(1000); /* XXX is it really necessary ? */
265	csn--;
266    }
267    return(ndevs);
268}
269
270/*
271 * Locate ISA-PnP devices and populate the supplied list.
272 */
273static void
274isapnp_enumerate(void)
275{
276    int		pnp_rd_port;
277
278    /* Check for I/O port access */
279    if ((archsw.arch_isainb == NULL) || (archsw.arch_isaoutb == NULL))
280	return;
281
282    /*
283     * Validate a possibly-suggested read port value.  If the autoscan failed
284     * last time, this will return us to autoscan mode again.
285     */
286    if ((isapnp_readport > 0) &&
287	(((isapnp_readport < 0x203) ||
288	  (isapnp_readport > 0x3ff) ||
289	  (isapnp_readport & 0x3) != 0x3)))
290	 /* invalid, go look for ourselves */
291	isapnp_readport = 0;
292
293    if (isapnp_readport < 0) {
294	/* someone is telling us there is no ISA in the system */
295	return;
296
297    } else if (isapnp_readport > 0) {
298	/* Someone has told us where the port is/should be, or we found one last time */
299	isapnp_isolation_protocol();
300
301    } else {
302	/* No clues, look for it ourselves */
303	for (pnp_rd_port = 0x80; pnp_rd_port < 0xff; pnp_rd_port += 0x10) {
304	    /* Look for something, quit when we find it */
305	    isapnp_readport = (pnp_rd_port << 2) | 0x3;
306	    if (isapnp_isolation_protocol() > 0)
307		break;
308	}
309    }
310}
311