xref: /freebsd/stand/common/isapnp.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
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("$FreeBSD$");
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 
43 static void	isapnp_write(int d, int r);
44 static void	isapnp_send_Initiation_LFSR(void);
45 static int	isapnp_get_serial(uint8_t *p);
46 static int	isapnp_isolation_protocol(void);
47 static void	isapnp_enumerate(void);
48 
49 /* PnP read data port */
50 int		isapnp_readport = 0;
51 
52 #define	_PNP_ID_LEN	9
53 
54 struct pnphandler isapnphandler =
55 {
56     "ISA bus",
57     isapnp_enumerate
58 };
59 
60 static void
61 isapnp_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  */
71 static void
72 isapnp_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  */
92 static int
93 isapnp_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  */
125 static int
126 isapnp_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  */
159 static int
160 isapnp_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  */
227 static int
228 isapnp_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  */
276 static void
277 isapnp_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