xref: /netbsd-src/sys/dev/fdt/fdt_i2c.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* $NetBSD: fdt_i2c.c,v 1.2 2015/12/16 12:17:45 jmcneill Exp $ */
2 
3 /*-
4  * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: fdt_i2c.c,v 1.2 2015/12/16 12:17:45 jmcneill Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kmem.h>
35 
36 #include <libfdt.h>
37 #include <dev/fdt/fdtvar.h>
38 
39 struct fdtbus_i2c_controller {
40 	device_t i2c_dev;
41 	int i2c_phandle;
42 	const struct fdtbus_i2c_controller_func *i2c_funcs;
43 
44 	struct fdtbus_i2c_controller *i2c_next;
45 };
46 
47 static struct fdtbus_i2c_controller *fdtbus_i2c = NULL;
48 
49 int
50 fdtbus_register_i2c_controller(device_t dev, int phandle,
51     const struct fdtbus_i2c_controller_func *funcs)
52 {
53 	struct fdtbus_i2c_controller *i2c;
54 
55 	i2c = kmem_alloc(sizeof(*i2c), KM_SLEEP);
56 	i2c->i2c_dev = dev;
57 	i2c->i2c_phandle = phandle;
58 	i2c->i2c_funcs = funcs;
59 
60 	i2c->i2c_next = fdtbus_i2c;
61 	fdtbus_i2c = i2c;
62 
63 	return 0;
64 }
65 
66 static struct fdtbus_i2c_controller *
67 fdtbus_get_i2c_controller(int phandle)
68 {
69 	struct fdtbus_i2c_controller *i2c;
70 
71 	for (i2c = fdtbus_i2c; i2c; i2c = i2c->i2c_next) {
72 		if (i2c->i2c_phandle == phandle) {
73 			return i2c;
74 		}
75 	}
76 
77 	return NULL;
78 }
79 
80 i2c_tag_t
81 fdtbus_get_i2c_tag(int phandle)
82 {
83 	struct fdtbus_i2c_controller *i2c;
84 
85 	i2c = fdtbus_get_i2c_controller(phandle);
86 	if (i2c == NULL)
87 		return NULL;
88 
89 	return i2c->i2c_funcs->get_tag(i2c->i2c_dev);
90 }
91