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