1/* $NetBSD: fdt_i2c.c,v 1.12 2022/02/23 07:55:55 skrll 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 1.12 2022/02/23 07:55:55 skrll 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
40struct fdtbus_i2c_controller {
41	i2c_tag_t i2c_tag;
42	int i2c_phandle;
43
44	LIST_ENTRY(fdtbus_i2c_controller) i2c_next;
45};
46
47static LIST_HEAD(, fdtbus_i2c_controller) fdtbus_i2c_controllers =
48    LIST_HEAD_INITIALIZER(fdtbus_i2c_controllers);
49
50int
51fdtbus_register_i2c_controller(i2c_tag_t tag, int phandle)
52{
53	struct fdtbus_i2c_controller *i2c;
54
55	i2c = kmem_alloc(sizeof(*i2c), KM_SLEEP);
56	i2c->i2c_tag = tag;
57	i2c->i2c_phandle = phandle;
58
59	LIST_INSERT_HEAD(&fdtbus_i2c_controllers, i2c, i2c_next);
60
61	return 0;
62}
63
64static struct fdtbus_i2c_controller *
65fdtbus_get_i2c_controller(int phandle)
66{
67	struct fdtbus_i2c_controller *i2c;
68
69	LIST_FOREACH(i2c, &fdtbus_i2c_controllers, i2c_next) {
70		if (i2c->i2c_phandle == phandle)
71			return i2c;
72	}
73
74	return NULL;
75}
76
77i2c_tag_t
78fdtbus_i2c_get_tag(int phandle)
79{
80	struct fdtbus_i2c_controller *i2c;
81
82	i2c = fdtbus_get_i2c_controller(phandle);
83	if (i2c == NULL)
84		return NULL;
85
86	return i2c->i2c_tag;
87}
88
89i2c_tag_t
90fdtbus_i2c_acquire(int phandle, const char *prop)
91{
92	int i2c_phandle;
93
94	i2c_phandle = fdtbus_get_phandle(phandle, prop);
95	if (i2c_phandle == -1)
96		return NULL;
97
98	return fdtbus_i2c_get_tag(i2c_phandle);
99}
100
101device_t
102fdtbus_attach_i2cbus(device_t dev, int phandle, i2c_tag_t tag, cfprint_t print)
103{
104	struct i2cbus_attach_args iba;
105	prop_dictionary_t devs, props;
106	device_t ret;
107	u_int address_cells;
108
109	devs = prop_dictionary_create();
110	if (of_getprop_uint32(phandle, "#address-cells", &address_cells))
111		address_cells = 1;
112
113	of_enter_i2c_devs(devs, phandle, address_cells * 4, 0);
114
115	memset(&iba, 0, sizeof(iba));
116	iba.iba_tag = tag;
117	iba.iba_child_devices = prop_dictionary_get(devs, "i2c-child-devices");
118	if (iba.iba_child_devices)
119		prop_object_retain(iba.iba_child_devices);
120	prop_object_release(devs);
121
122	props = device_properties(dev);
123	prop_dictionary_set_bool(props, "i2c-no-indirect-config", true);
124
125	ret = config_found(dev, &iba, print,
126	    CFARGS(.iattr = "i2cbus"));
127	if (iba.iba_child_devices)
128		prop_object_release(iba.iba_child_devices);
129
130	return ret;
131}
132