1// SPDX-License-Identifier: GPL-2.0
2/*
3 * compat.c - A series of functions to make it easier to convert drivers that use
4 *            the old isapnp APIs. If possible use the new APIs instead.
5 *
6 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
7 */
8
9#include <linux/module.h>
10#include <linux/isapnp.h>
11#include <linux/string.h>
12
13static void pnp_convert_id(char *buf, unsigned short vendor,
14			   unsigned short device)
15{
16	sprintf(buf, "%c%c%c%x%x%x%x",
17		'A' + ((vendor >> 2) & 0x3f) - 1,
18		'A' + (((vendor & 3) << 3) | ((vendor >> 13) & 7)) - 1,
19		'A' + ((vendor >> 8) & 0x1f) - 1,
20		(device >> 4) & 0x0f, device & 0x0f,
21		(device >> 12) & 0x0f, (device >> 8) & 0x0f);
22}
23
24struct pnp_dev *pnp_find_dev(struct pnp_card *card, unsigned short vendor,
25			     unsigned short function, struct pnp_dev *from)
26{
27	char id[8];
28	char any[8];
29
30	pnp_convert_id(id, vendor, function);
31	pnp_convert_id(any, ISAPNP_ANY_ID, ISAPNP_ANY_ID);
32	if (card == NULL) {	/* look for a logical device from all cards */
33		struct list_head *list;
34
35		list = pnp_global.next;
36		if (from)
37			list = from->global_list.next;
38
39		while (list != &pnp_global) {
40			struct pnp_dev *dev = global_to_pnp_dev(list);
41
42			if (compare_pnp_id(dev->id, id) ||
43			    (memcmp(id, any, 7) == 0))
44				return dev;
45			list = list->next;
46		}
47	} else {
48		struct list_head *list;
49
50		list = card->devices.next;
51		if (from) {
52			list = from->card_list.next;
53			if (from->card != card)	/* something is wrong */
54				return NULL;
55		}
56		while (list != &card->devices) {
57			struct pnp_dev *dev = card_to_pnp_dev(list);
58
59			if (compare_pnp_id(dev->id, id))
60				return dev;
61			list = list->next;
62		}
63	}
64	return NULL;
65}
66EXPORT_SYMBOL(pnp_find_dev);
67