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 #include <trace/hooks/i2c.h>
20
21 #include "i2c-core.h"
22
of_i2c_get_board_info(struct device * dev,struct device_node * node,struct i2c_board_info * info)23 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
24 struct i2c_board_info *info)
25 {
26 u32 addr;
27 int ret;
28
29 memset(info, 0, sizeof(*info));
30
31 if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) {
32 dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
33 return -EINVAL;
34 }
35
36 trace_android_vh_of_i2c_get_board_info(node, &(info->dev_name));
37
38 ret = of_property_read_u32(node, "reg", &addr);
39 if (ret) {
40 dev_err(dev, "of_i2c: invalid reg on %pOF\n", node);
41 return ret;
42 }
43
44 if (addr & I2C_TEN_BIT_ADDRESS) {
45 addr &= ~I2C_TEN_BIT_ADDRESS;
46 info->flags |= I2C_CLIENT_TEN;
47 }
48
49 if (addr & I2C_OWN_SLAVE_ADDRESS) {
50 addr &= ~I2C_OWN_SLAVE_ADDRESS;
51 info->flags |= I2C_CLIENT_SLAVE;
52 }
53
54 info->addr = addr;
55 info->of_node = node;
56 info->fwnode = of_fwnode_handle(node);
57
58 if (of_property_read_bool(node, "host-notify"))
59 info->flags |= I2C_CLIENT_HOST_NOTIFY;
60
61 if (of_get_property(node, "wakeup-source", NULL))
62 info->flags |= I2C_CLIENT_WAKE;
63
64 return 0;
65 }
66 EXPORT_SYMBOL_GPL(of_i2c_get_board_info);
67
of_i2c_register_device(struct i2c_adapter * adap,struct device_node * node)68 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
69 struct device_node *node)
70 {
71 struct i2c_client *client;
72 struct i2c_board_info info;
73 int ret;
74
75 dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node);
76
77 ret = of_i2c_get_board_info(&adap->dev, node, &info);
78 if (ret)
79 return ERR_PTR(ret);
80
81 client = i2c_new_client_device(adap, &info);
82 if (IS_ERR(client))
83 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node);
84
85 return client;
86 }
87
of_i2c_register_devices(struct i2c_adapter * adap)88 void of_i2c_register_devices(struct i2c_adapter *adap)
89 {
90 struct device_node *bus, *node;
91 struct i2c_client *client;
92
93 /* Only register child devices if the adapter has a node pointer set */
94 if (!adap->dev.of_node)
95 return;
96
97 dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
98
99 bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
100 if (!bus)
101 bus = of_node_get(adap->dev.of_node);
102
103 for_each_available_child_of_node(bus, node) {
104 if (of_node_test_and_set_flag(node, OF_POPULATED))
105 continue;
106
107 client = of_i2c_register_device(adap, node);
108 if (IS_ERR(client)) {
109 dev_err(&adap->dev,
110 "Failed to create I2C device for %pOF\n",
111 node);
112 of_node_clear_flag(node, OF_POPULATED);
113 }
114 }
115
116 of_node_put(bus);
117 }
118
of_dev_or_parent_node_match(struct device * dev,const void * data)119 static int of_dev_or_parent_node_match(struct device *dev, const void *data)
120 {
121 if (dev->of_node == data)
122 return 1;
123
124 if (dev->parent)
125 return dev->parent->of_node == data;
126
127 return 0;
128 }
129
130 /* must call put_device() when done with returned i2c_client device */
of_find_i2c_device_by_node(struct device_node * node)131 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
132 {
133 struct device *dev;
134 struct i2c_client *client;
135
136 dev = bus_find_device_by_of_node(&i2c_bus_type, node);
137 if (!dev)
138 return NULL;
139
140 client = i2c_verify_client(dev);
141 if (!client)
142 put_device(dev);
143
144 return client;
145 }
146 EXPORT_SYMBOL(of_find_i2c_device_by_node);
147
148 /* must call put_device() when done with returned i2c_adapter device */
of_find_i2c_adapter_by_node(struct device_node * node)149 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
150 {
151 struct device *dev;
152 struct i2c_adapter *adapter;
153
154 dev = bus_find_device(&i2c_bus_type, NULL, node,
155 of_dev_or_parent_node_match);
156 if (!dev)
157 return NULL;
158
159 adapter = i2c_verify_adapter(dev);
160 if (!adapter)
161 put_device(dev);
162
163 return adapter;
164 }
165 EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
166
167 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
of_get_i2c_adapter_by_node(struct device_node * node)168 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
169 {
170 struct i2c_adapter *adapter;
171
172 adapter = of_find_i2c_adapter_by_node(node);
173 if (!adapter)
174 return NULL;
175
176 if (!try_module_get(adapter->owner)) {
177 put_device(&adapter->dev);
178 adapter = NULL;
179 }
180
181 return adapter;
182 }
183 EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
184
185 static const struct of_device_id*
i2c_of_match_device_sysfs(const struct of_device_id * matches,struct i2c_client * client)186 i2c_of_match_device_sysfs(const struct of_device_id *matches,
187 struct i2c_client *client)
188 {
189 const char *name;
190
191 for (; matches->compatible[0]; matches++) {
192 /*
193 * Adding devices through the i2c sysfs interface provides us
194 * a string to match which may be compatible with the device
195 * tree compatible strings, however with no actual of_node the
196 * of_match_device() will not match
197 */
198 if (sysfs_streq(client->name, matches->compatible))
199 return matches;
200
201 name = strchr(matches->compatible, ',');
202 if (!name)
203 name = matches->compatible;
204 else
205 name++;
206
207 if (sysfs_streq(client->name, name))
208 return matches;
209 }
210
211 return NULL;
212 }
213
214 const struct of_device_id
i2c_of_match_device(const struct of_device_id * matches,struct i2c_client * client)215 *i2c_of_match_device(const struct of_device_id *matches,
216 struct i2c_client *client)
217 {
218 const struct of_device_id *match;
219
220 if (!(client && matches))
221 return NULL;
222
223 match = of_match_device(matches, &client->dev);
224 if (match)
225 return match;
226
227 return i2c_of_match_device_sysfs(matches, client);
228 }
229 EXPORT_SYMBOL_GPL(i2c_of_match_device);
230
231 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_i2c_notify(struct notifier_block * nb,unsigned long action,void * arg)232 static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
233 void *arg)
234 {
235 struct of_reconfig_data *rd = arg;
236 struct i2c_adapter *adap;
237 struct i2c_client *client;
238
239 switch (of_reconfig_get_state_change(action, rd)) {
240 case OF_RECONFIG_CHANGE_ADD:
241 adap = of_find_i2c_adapter_by_node(rd->dn->parent);
242 if (adap == NULL)
243 return NOTIFY_OK; /* not for us */
244
245 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
246 put_device(&adap->dev);
247 return NOTIFY_OK;
248 }
249
250 client = of_i2c_register_device(adap, rd->dn);
251 if (IS_ERR(client)) {
252 dev_err(&adap->dev, "failed to create client for '%pOF'\n",
253 rd->dn);
254 put_device(&adap->dev);
255 of_node_clear_flag(rd->dn, OF_POPULATED);
256 return notifier_from_errno(PTR_ERR(client));
257 }
258 put_device(&adap->dev);
259 break;
260 case OF_RECONFIG_CHANGE_REMOVE:
261 /* already depopulated? */
262 if (!of_node_check_flag(rd->dn, OF_POPULATED))
263 return NOTIFY_OK;
264
265 /* find our device by node */
266 client = of_find_i2c_device_by_node(rd->dn);
267 if (client == NULL)
268 return NOTIFY_OK; /* no? not meant for us */
269
270 /* unregister takes one ref away */
271 i2c_unregister_device(client);
272
273 /* and put the reference of the find */
274 put_device(&client->dev);
275 break;
276 }
277
278 return NOTIFY_OK;
279 }
280
281 struct notifier_block i2c_of_notifier = {
282 .notifier_call = of_i2c_notify,
283 };
284 #endif /* CONFIG_OF_DYNAMIC */
285