1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Linux I2C core OF support code
4 *
5 * Copyright (C) 2008 Jochen Friedrich <jochen@scram.de>
6 * based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
7 *
8 * Copyright (C) 2013, 2018 Wolfram Sang <wsa@kernel.org>
9 */
10
11 #include <dt-bindings/i2c/i2c.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/sysfs.h>
19
20 #include "i2c-core.h"
21
of_i2c_get_board_info(struct device * dev,struct device_node * node,struct i2c_board_info * info)22 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
23 struct i2c_board_info *info)
24 {
25 u32 addr;
26 int ret;
27
28 memset(info, 0, sizeof(*info));
29
30 if (of_alias_from_compatible(node, info->type, sizeof(info->type)) < 0) {
31 dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
32 return -EINVAL;
33 }
34
35 ret = of_property_read_u32(node, "reg", &addr);
36 if (ret) {
37 dev_err(dev, "of_i2c: invalid reg on %pOF\n", node);
38 return ret;
39 }
40
41 if (addr & I2C_TEN_BIT_ADDRESS) {
42 addr &= ~I2C_TEN_BIT_ADDRESS;
43 info->flags |= I2C_CLIENT_TEN;
44 }
45
46 if (addr & I2C_OWN_SLAVE_ADDRESS) {
47 addr &= ~I2C_OWN_SLAVE_ADDRESS;
48 info->flags |= I2C_CLIENT_SLAVE;
49 }
50
51 info->addr = addr;
52 info->fwnode = of_fwnode_handle(node);
53
54 if (of_property_read_bool(node, "host-notify"))
55 info->flags |= I2C_CLIENT_HOST_NOTIFY;
56
57 if (of_property_read_bool(node, "wakeup-source"))
58 info->flags |= I2C_CLIENT_WAKE;
59
60 return 0;
61 }
62 EXPORT_SYMBOL_GPL(of_i2c_get_board_info);
63
of_i2c_register_device(struct i2c_adapter * adap,struct device_node * node)64 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
65 struct device_node *node)
66 {
67 struct i2c_client *client;
68 struct i2c_board_info info;
69 int ret;
70
71 dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node);
72
73 ret = of_i2c_get_board_info(&adap->dev, node, &info);
74 if (ret)
75 return ERR_PTR(ret);
76
77 client = i2c_new_client_device(adap, &info);
78 if (IS_ERR(client))
79 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node);
80
81 return client;
82 }
83
of_i2c_register_devices(struct i2c_adapter * adap)84 void of_i2c_register_devices(struct i2c_adapter *adap)
85 {
86 struct device_node *bus, *node;
87 struct i2c_client *client;
88
89 /* Only register child devices if the adapter has a node pointer set */
90 if (!adap->dev.of_node)
91 return;
92
93 dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
94
95 bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
96 if (!bus)
97 bus = of_node_get(adap->dev.of_node);
98
99 for_each_available_child_of_node(bus, node) {
100 if (of_node_test_and_set_flag(node, OF_POPULATED))
101 continue;
102
103 client = of_i2c_register_device(adap, node);
104 if (IS_ERR(client)) {
105 dev_err(&adap->dev,
106 "Failed to create I2C device for %pOF\n",
107 node);
108 of_node_clear_flag(node, OF_POPULATED);
109 }
110 }
111
112 of_node_put(bus);
113 }
114
115 static const struct of_device_id*
i2c_of_match_device_sysfs(const struct of_device_id * matches,struct i2c_client * client)116 i2c_of_match_device_sysfs(const struct of_device_id *matches,
117 struct i2c_client *client)
118 {
119 const char *name;
120
121 for (; matches->compatible[0]; matches++) {
122 /*
123 * Adding devices through the i2c sysfs interface provides us
124 * a string to match which may be compatible with the device
125 * tree compatible strings, however with no actual of_node the
126 * of_match_device() will not match
127 */
128 if (sysfs_streq(client->name, matches->compatible))
129 return matches;
130
131 name = strchr(matches->compatible, ',');
132 if (!name)
133 name = matches->compatible;
134 else
135 name++;
136
137 if (sysfs_streq(client->name, name))
138 return matches;
139 }
140
141 return NULL;
142 }
143
144 const struct of_device_id
i2c_of_match_device(const struct of_device_id * matches,struct i2c_client * client)145 *i2c_of_match_device(const struct of_device_id *matches,
146 struct i2c_client *client)
147 {
148 const struct of_device_id *match;
149
150 if (!(client && matches))
151 return NULL;
152
153 match = of_match_device(matches, &client->dev);
154 if (match)
155 return match;
156
157 return i2c_of_match_device_sysfs(matches, client);
158 }
159
160 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_i2c_notify(struct notifier_block * nb,unsigned long action,void * arg)161 static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
162 void *arg)
163 {
164 struct of_reconfig_data *rd = arg;
165 struct i2c_adapter *adap;
166 struct i2c_client *client;
167
168 switch (of_reconfig_get_state_change(action, rd)) {
169 case OF_RECONFIG_CHANGE_ADD:
170 adap = of_find_i2c_adapter_by_node(rd->dn->parent);
171 if (adap == NULL)
172 return NOTIFY_OK; /* not for us */
173
174 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
175 put_device(&adap->dev);
176 return NOTIFY_OK;
177 }
178
179 /*
180 * Clear the flag before adding the device so that fw_devlink
181 * doesn't skip adding consumers to this device.
182 */
183 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
184 client = of_i2c_register_device(adap, rd->dn);
185 if (IS_ERR(client)) {
186 dev_err(&adap->dev, "failed to create client for '%pOF'\n",
187 rd->dn);
188 put_device(&adap->dev);
189 of_node_clear_flag(rd->dn, OF_POPULATED);
190 return notifier_from_errno(PTR_ERR(client));
191 }
192 put_device(&adap->dev);
193 break;
194 case OF_RECONFIG_CHANGE_REMOVE:
195 /* already depopulated? */
196 if (!of_node_check_flag(rd->dn, OF_POPULATED))
197 return NOTIFY_OK;
198
199 /* find our device by node */
200 client = of_find_i2c_device_by_node(rd->dn);
201 if (client == NULL)
202 return NOTIFY_OK; /* no? not meant for us */
203
204 /* unregister takes one ref away */
205 i2c_unregister_device(client);
206
207 /* and put the reference of the find */
208 put_device(&client->dev);
209 break;
210 }
211
212 return NOTIFY_OK;
213 }
214
215 struct notifier_block i2c_of_notifier = {
216 .notifier_call = of_i2c_notify,
217 };
218 #endif /* CONFIG_OF_DYNAMIC */
219