xref: /netbsd-src/sys/dev/fdt/fdt_i2c.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /* $NetBSD: fdt_i2c.c,v 1.8 2020/06/12 03:32:30 thorpej 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 1.8 2020/06/12 03:32:30 thorpej Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kmem.h>
35 #include <sys/queue.h>
36 
37 #include <libfdt.h>
38 #include <dev/fdt/fdtvar.h>
39 
40 struct fdtbus_i2c_controller {
41 	device_t i2c_dev;
42 	int i2c_phandle;
43 	const struct fdtbus_i2c_controller_func *i2c_funcs;
44 
45 	LIST_ENTRY(fdtbus_i2c_controller) i2c_next;
46 };
47 
48 static LIST_HEAD(, fdtbus_i2c_controller) fdtbus_i2c_controllers =
49     LIST_HEAD_INITIALIZER(fdtbus_i2c_controllers);
50 
51 int
52 fdtbus_register_i2c_controller(device_t dev, int phandle,
53     const struct fdtbus_i2c_controller_func *funcs)
54 {
55 	struct fdtbus_i2c_controller *i2c;
56 
57 	i2c = kmem_alloc(sizeof(*i2c), KM_SLEEP);
58 	i2c->i2c_dev = dev;
59 	i2c->i2c_phandle = phandle;
60 	i2c->i2c_funcs = funcs;
61 
62 	LIST_INSERT_HEAD(&fdtbus_i2c_controllers, i2c, i2c_next);
63 
64 	return 0;
65 }
66 
67 static struct fdtbus_i2c_controller *
68 fdtbus_get_i2c_controller(int phandle)
69 {
70 	struct fdtbus_i2c_controller *i2c;
71 
72 	LIST_FOREACH(i2c, &fdtbus_i2c_controllers, i2c_next) {
73 		if (i2c->i2c_phandle == phandle)
74 			return i2c;
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 
92 i2c_tag_t
93 fdtbus_i2c_acquire(int phandle, const char *prop)
94 {
95 	int i2c_phandle;
96 
97 	i2c_phandle = fdtbus_get_phandle(phandle, prop);
98 	if (i2c_phandle == -1)
99 		return NULL;
100 
101 	return fdtbus_get_i2c_tag(i2c_phandle);
102 }
103 
104 device_t
105 fdtbus_attach_i2cbus(device_t dev, int phandle, i2c_tag_t tag, cfprint_t print)
106 {
107 	struct i2cbus_attach_args iba;
108 	prop_dictionary_t devs, props;
109 	device_t ret;
110 	u_int address_cells;
111 
112 	devs = prop_dictionary_create();
113 	if (of_getprop_uint32(phandle, "#address-cells", &address_cells))
114 		address_cells = 1;
115 
116 	of_enter_i2c_devs(devs, phandle, address_cells * 4, 0);
117 
118 	memset(&iba, 0, sizeof(iba));
119 	iba.iba_tag = tag;
120 	iba.iba_child_devices = prop_dictionary_get(devs, "i2c-child-devices");
121 	if (iba.iba_child_devices)
122 		prop_object_retain(iba.iba_child_devices);
123 	prop_object_release(devs);
124 
125 	props = device_properties(dev);
126 	prop_dictionary_set_bool(props, "i2c-no-indirect-config", true);
127 
128 	ret = config_found_ia(dev, "i2cbus", &iba, print);
129 	if (iba.iba_child_devices)
130 		prop_object_release(iba.iba_child_devices);
131 
132 	return ret;
133 }
134