1/*
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28
29/*
30 * PnP BIOS enumerator.
31 */
32
33#include <stand.h>
34#include <machine/stdarg.h>
35#include <bootstrap.h>
36#include <isapnp.h>
37#include <btxv86.h>
38
39
40static int	biospnp_init(void);
41static void	biospnp_enumerate(void);
42
43struct pnphandler biospnphandler =
44{
45    "PnP BIOS",
46    biospnp_enumerate
47};
48
49struct pnp_ICstructure
50{
51    u_int8_t	pnp_signature[4];
52    u_int8_t	pnp_version;
53    u_int8_t	pnp_length;
54    u_int16_t	pnp_BIOScontrol;
55    u_int8_t	pnp_checksum;
56    u_int32_t	pnp_eventflag;
57    u_int16_t	pnp_rmip;
58    u_int16_t	pnp_rmcs;
59    u_int16_t	pnp_pmip;
60    u_int32_t	pnp_pmcs;
61    u_int8_t	pnp_OEMdev[4];
62    u_int16_t	pnp_rmds;
63    u_int32_t	pnp_pmds;
64} __packed;
65
66struct pnp_devNode
67{
68    u_int16_t	dn_size;
69    u_int8_t	dn_handle;
70    u_int8_t	dn_id[4];
71    u_int8_t	dn_type[3];
72    u_int16_t	dn_attrib;
73    u_int8_t	dn_data[1];
74} __packed;
75
76struct pnp_isaConfiguration
77{
78    u_int8_t	ic_revision;
79    u_int8_t	ic_nCSN;
80    u_int16_t	ic_rdport;
81    u_int16_t	ic_reserved;
82} __packed;
83
84static struct pnp_ICstructure	*pnp_Icheck = NULL;
85static u_int16_t		pnp_NumNodes;
86static u_int16_t		pnp_NodeSize;
87
88static void	biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn);
89static int	biospnp_call(int func, const char *fmt, ...);
90
91#define vsegofs(vptr)	(((u_int32_t)VTOPSEG(vptr) << 16) + VTOPOFF(vptr))
92
93typedef void    v86bios_t(u_int32_t, u_int32_t, u_int32_t, u_int32_t);
94v86bios_t	*v86bios = (v86bios_t *)v86int;
95
96#define	biospnp_f00(NumNodes, NodeSize)			biospnp_call(0x00, "ll", NumNodes, NodeSize)
97#define biospnp_f01(Node, devNodeBuffer, Control)	biospnp_call(0x01, "llw", Node, devNodeBuffer, Control)
98#define biospnp_f40(Configuration)			biospnp_call(0x40, "l", Configuration)
99
100/* PnP BIOS return codes */
101#define PNP_SUCCESS			0x00
102#define PNP_FUNCTION_NOT_SUPPORTED	0x80
103
104/*
105 * Initialisation: locate the PnP BIOS, test that we can call it.
106 * Returns nonzero if the PnP BIOS is not usable on this system.
107 */
108static int
109biospnp_init(void)
110{
111    struct pnp_isaConfiguration	icfg;
112    char			*sigptr;
113    int				result;
114
115    /* Search for the $PnP signature */
116    pnp_Icheck = NULL;
117    for (sigptr = PTOV(0xf0000); sigptr < PTOV(0xfffff); sigptr += 16)
118	if (!bcmp(sigptr, "$PnP", 4)) {
119	    pnp_Icheck = (struct pnp_ICstructure *)sigptr;
120	    break;
121	}
122
123    /* No signature, no BIOS */
124    if (pnp_Icheck == NULL)
125	return(1);
126
127    /*
128     * Fetch the system table parameters as a test of the BIOS
129     */
130    result = biospnp_f00(vsegofs(&pnp_NumNodes), vsegofs(&pnp_NodeSize));
131    if (result != PNP_SUCCESS) {
132	return(1);
133    }
134
135    /*
136     * Look for the PnP ISA configuration table
137     */
138    result = biospnp_f40(vsegofs(&icfg));
139    switch (result) {
140    case PNP_SUCCESS:
141	/* If the BIOS found some PnP devices, take its hint for the read port */
142	if ((icfg.ic_revision == 1) && (icfg.ic_nCSN > 0))
143	    isapnp_readport = icfg.ic_rdport;
144	break;
145    case PNP_FUNCTION_NOT_SUPPORTED:
146	/* The BIOS says there is no ISA bus (should we trust that this works?) */
147	printf("PnP BIOS claims no ISA bus\n");
148	isapnp_readport = -1;
149	break;
150    }
151    return(0);
152}
153
154static void
155biospnp_enumerate(void)
156{
157    u_int8_t		Node;
158    struct pnp_devNode	*devNodeBuffer;
159    int			result;
160    struct pnpinfo	*pi;
161    int			count;
162
163    /* Init/check state */
164    if (biospnp_init())
165	return;
166
167    devNodeBuffer = (struct pnp_devNode *)alloca(pnp_NodeSize);
168    Node = 0;
169    count = 1000;
170    while((Node != 0xff) && (count-- > 0)) {
171	result = biospnp_f01(vsegofs(&Node), vsegofs(devNodeBuffer), 0x1);
172	if (result != PNP_SUCCESS) {
173	    printf("PnP BIOS node %d: error 0x%x\n", Node, result);
174	} else {
175	    pi = pnp_allocinfo();
176	    pnp_addident(pi, pnp_eisaformat(devNodeBuffer->dn_id));
177	    biospnp_scanresdata(pi, devNodeBuffer);
178	    pnp_addinfo(pi);
179	}
180    }
181}
182
183/*
184 * Scan the resource data in the node's data area for compatible device IDs
185 * and descriptions.
186 */
187static void
188biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn)
189{
190    u_int	tag, i, rlen, dlen;
191    u_int8_t	*p;
192    char	*str;
193
194    p = dn->dn_data;			/* point to resource data */
195    dlen = dn->dn_size - (p - (u_int8_t *)dn);	/* length of resource data */
196
197    for (i = 0; i < dlen; i+= rlen) {
198	tag = p[i];
199	i++;
200	if (PNP_RES_TYPE(tag) == 0) {
201	    rlen = PNP_SRES_LEN(tag);
202	    /* small resource */
203	    switch (PNP_SRES_NUM(tag)) {
204
205	    case COMP_DEVICE_ID:
206		/* got a compatible device ID */
207		pnp_addident(pi, pnp_eisaformat(p + i));
208		break;
209
210	    case END_TAG:
211		return;
212	    }
213	} else {
214	    /* large resource */
215	    rlen = *(u_int16_t *)(p + i);
216	    i += sizeof(u_int16_t);
217
218	    switch(PNP_LRES_NUM(tag)) {
219
220	    case ID_STRING_ANSI:
221		str = malloc(rlen + 1);
222		bcopy(p + i, str, rlen);
223		str[rlen] = 0;
224		if (pi->pi_desc == NULL) {
225		    pi->pi_desc = str;
226		} else {
227		    free(str);
228		}
229		break;
230	    }
231	}
232    }
233}
234
235
236/*
237 * Make a 16-bit realmode PnP BIOS call.
238 *
239 * The first argument passed is the function number, the last is the
240 * BIOS data segment selector.  Intermediate arguments may be 16 or
241 * 32 bytes in length, and are described by the format string.
242 *
243 * Arguments to the BIOS functions must be packed on the stack, hence
244 * this evil.
245 */
246static int
247biospnp_call(int func, const char *fmt, ...)
248{
249    va_list	ap;
250    const char	*p;
251    uint8_t	*argp;
252    uint16_t	int16;
253    uint32_t	args[4];
254    uint32_t	i;
255
256    /* function number first */
257    argp = (uint8_t *)args;
258    int16 = func;
259    bcopy(&int16, argp, sizeof (int16));
260    argp += sizeof(uint16_t);
261
262    /* take args according to format */
263    va_start(ap, fmt);
264    for (p = fmt; *p != 0; p++) {
265	switch(*p) {
266	case 'w':
267	    i = va_arg(ap, uint32_t);
268	    int16 = i;
269	    bcopy(&int16, argp, sizeof (int16));
270	    argp += sizeof (uint16_t);
271	    break;
272
273	case 'l':
274	    i = va_arg(ap, uint32_t);
275	    bcopy(&i, argp, sizeof (i));
276	    argp += sizeof (uint32_t);
277	    break;
278	}
279    }
280    va_end(ap);
281
282    /* BIOS segment last */
283    int16 = pnp_Icheck->pnp_rmds;
284    bcopy(&int16, argp, sizeof (int16));
285    argp += sizeof(uint16_t);
286
287    /* prepare for call */
288    v86.ctl = V86_ADDR | V86_CALLF;
289    v86.addr = ((uint32_t)pnp_Icheck->pnp_rmcs << 16) + pnp_Icheck->pnp_rmip;
290
291    /* call with packed stack and return */
292    v86bios(args[0], args[1], args[2], args[3]);
293    return (v86.eax & 0xffff);
294}
295