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1 | /* |
2 | * Linux I2C core OF support code | |
3 | * | |
4 | * Copyright (C) 2008 Jochen Friedrich <jochen@scram.de> | |
5 | * based on a previous patch from Jon Smirl <jonsmirl@gmail.com> | |
6 | * | |
7 | * Copyright (C) 2013 Wolfram Sang <wsa@the-dreams.de> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms of the GNU General Public License as published by the Free | |
11 | * Software Foundation; either version 2 of the License, or (at your option) | |
12 | * any later version. | |
13 | */ | |
14 | ||
15 | #include <dt-bindings/i2c/i2c.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/i2c.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/of_device.h> | |
22 | ||
23 | #include "i2c-core.h" | |
24 | ||
25 | static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, | |
26 | struct device_node *node) | |
27 | { | |
28 | struct i2c_client *result; | |
29 | struct i2c_board_info info = {}; | |
30 | struct dev_archdata dev_ad = {}; | |
31 | const __be32 *addr_be; | |
32 | u32 addr; | |
33 | int len; | |
34 | ||
35 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); | |
36 | ||
37 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { | |
38 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", | |
39 | node->full_name); | |
40 | return ERR_PTR(-EINVAL); | |
41 | } | |
42 | ||
43 | addr_be = of_get_property(node, "reg", &len); | |
44 | if (!addr_be || (len < sizeof(*addr_be))) { | |
45 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", | |
46 | node->full_name); | |
47 | return ERR_PTR(-EINVAL); | |
48 | } | |
49 | ||
50 | addr = be32_to_cpup(addr_be); | |
51 | if (addr & I2C_TEN_BIT_ADDRESS) { | |
52 | addr &= ~I2C_TEN_BIT_ADDRESS; | |
53 | info.flags |= I2C_CLIENT_TEN; | |
54 | } | |
55 | ||
56 | if (addr & I2C_OWN_SLAVE_ADDRESS) { | |
57 | addr &= ~I2C_OWN_SLAVE_ADDRESS; | |
58 | info.flags |= I2C_CLIENT_SLAVE; | |
59 | } | |
60 | ||
61 | if (i2c_check_addr_validity(addr, info.flags)) { | |
62 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", | |
63 | addr, node->full_name); | |
64 | return ERR_PTR(-EINVAL); | |
65 | } | |
66 | ||
67 | info.addr = addr; | |
68 | info.of_node = of_node_get(node); | |
69 | info.archdata = &dev_ad; | |
70 | ||
71 | if (of_property_read_bool(node, "host-notify")) | |
72 | info.flags |= I2C_CLIENT_HOST_NOTIFY; | |
73 | ||
74 | if (of_get_property(node, "wakeup-source", NULL)) | |
75 | info.flags |= I2C_CLIENT_WAKE; | |
76 | ||
77 | result = i2c_new_device(adap, &info); | |
78 | if (result == NULL) { | |
79 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", | |
80 | node->full_name); | |
81 | of_node_put(node); | |
82 | return ERR_PTR(-EINVAL); | |
83 | } | |
84 | return result; | |
85 | } | |
86 | ||
87 | void of_i2c_register_devices(struct i2c_adapter *adap) | |
88 | { | |
89 | struct device_node *bus, *node; | |
90 | struct i2c_client *client; | |
91 | ||
92 | /* Only register child devices if the adapter has a node pointer set */ | |
93 | if (!adap->dev.of_node) | |
94 | return; | |
95 | ||
96 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); | |
97 | ||
98 | bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); | |
99 | if (!bus) | |
100 | bus = of_node_get(adap->dev.of_node); | |
101 | ||
102 | for_each_available_child_of_node(bus, node) { | |
103 | if (of_node_test_and_set_flag(node, OF_POPULATED)) | |
104 | continue; | |
105 | ||
106 | client = of_i2c_register_device(adap, node); | |
107 | if (IS_ERR(client)) { | |
108 | dev_warn(&adap->dev, | |
109 | "Failed to create I2C device for %s\n", | |
110 | node->full_name); | |
111 | of_node_clear_flag(node, OF_POPULATED); | |
112 | } | |
113 | } | |
114 | ||
115 | of_node_put(bus); | |
116 | } | |
117 | ||
118 | static int of_dev_node_match(struct device *dev, void *data) | |
119 | { | |
120 | return dev->of_node == data; | |
121 | } | |
122 | ||
123 | /* must call put_device() when done with returned i2c_client device */ | |
124 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
125 | { | |
126 | struct device *dev; | |
127 | struct i2c_client *client; | |
128 | ||
129 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); | |
130 | if (!dev) | |
131 | return NULL; | |
132 | ||
133 | client = i2c_verify_client(dev); | |
134 | if (!client) | |
135 | put_device(dev); | |
136 | ||
137 | return client; | |
138 | } | |
139 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
140 | ||
141 | /* must call put_device() when done with returned i2c_adapter device */ | |
142 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
143 | { | |
144 | struct device *dev; | |
145 | struct i2c_adapter *adapter; | |
146 | ||
147 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); | |
148 | if (!dev) | |
149 | return NULL; | |
150 | ||
151 | adapter = i2c_verify_adapter(dev); | |
152 | if (!adapter) | |
153 | put_device(dev); | |
154 | ||
155 | return adapter; | |
156 | } | |
157 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
158 | ||
159 | /* must call i2c_put_adapter() when done with returned i2c_adapter device */ | |
160 | struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) | |
161 | { | |
162 | struct i2c_adapter *adapter; | |
163 | ||
164 | adapter = of_find_i2c_adapter_by_node(node); | |
165 | if (!adapter) | |
166 | return NULL; | |
167 | ||
168 | if (!try_module_get(adapter->owner)) { | |
169 | put_device(&adapter->dev); | |
170 | adapter = NULL; | |
171 | } | |
172 | ||
173 | return adapter; | |
174 | } | |
175 | EXPORT_SYMBOL(of_get_i2c_adapter_by_node); | |
176 | ||
177 | static const struct of_device_id* | |
178 | i2c_of_match_device_sysfs(const struct of_device_id *matches, | |
179 | struct i2c_client *client) | |
180 | { | |
181 | const char *name; | |
182 | ||
183 | for (; matches->compatible[0]; matches++) { | |
184 | /* | |
185 | * Adding devices through the i2c sysfs interface provides us | |
186 | * a string to match which may be compatible with the device | |
187 | * tree compatible strings, however with no actual of_node the | |
188 | * of_match_device() will not match | |
189 | */ | |
190 | if (sysfs_streq(client->name, matches->compatible)) | |
191 | return matches; | |
192 | ||
193 | name = strchr(matches->compatible, ','); | |
194 | if (!name) | |
195 | name = matches->compatible; | |
196 | else | |
197 | name++; | |
198 | ||
199 | if (sysfs_streq(client->name, name)) | |
200 | return matches; | |
201 | } | |
202 | ||
203 | return NULL; | |
204 | } | |
205 | ||
206 | const struct of_device_id | |
207 | *i2c_of_match_device(const struct of_device_id *matches, | |
208 | struct i2c_client *client) | |
209 | { | |
210 | const struct of_device_id *match; | |
211 | ||
212 | if (!(client && matches)) | |
213 | return NULL; | |
214 | ||
215 | match = of_match_device(matches, &client->dev); | |
216 | if (match) | |
217 | return match; | |
218 | ||
219 | return i2c_of_match_device_sysfs(matches, client); | |
220 | } | |
221 | EXPORT_SYMBOL_GPL(i2c_of_match_device); | |
222 | ||
223 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) | |
224 | static int of_i2c_notify(struct notifier_block *nb, unsigned long action, | |
225 | void *arg) | |
226 | { | |
227 | struct of_reconfig_data *rd = arg; | |
228 | struct i2c_adapter *adap; | |
229 | struct i2c_client *client; | |
230 | ||
231 | switch (of_reconfig_get_state_change(action, rd)) { | |
232 | case OF_RECONFIG_CHANGE_ADD: | |
233 | adap = of_find_i2c_adapter_by_node(rd->dn->parent); | |
234 | if (adap == NULL) | |
235 | return NOTIFY_OK; /* not for us */ | |
236 | ||
237 | if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { | |
238 | put_device(&adap->dev); | |
239 | return NOTIFY_OK; | |
240 | } | |
241 | ||
242 | client = of_i2c_register_device(adap, rd->dn); | |
243 | put_device(&adap->dev); | |
244 | ||
245 | if (IS_ERR(client)) { | |
246 | dev_err(&adap->dev, "failed to create client for '%s'\n", | |
247 | rd->dn->full_name); | |
248 | of_node_clear_flag(rd->dn, OF_POPULATED); | |
249 | return notifier_from_errno(PTR_ERR(client)); | |
250 | } | |
251 | break; | |
252 | case OF_RECONFIG_CHANGE_REMOVE: | |
253 | /* already depopulated? */ | |
254 | if (!of_node_check_flag(rd->dn, OF_POPULATED)) | |
255 | return NOTIFY_OK; | |
256 | ||
257 | /* find our device by node */ | |
258 | client = of_find_i2c_device_by_node(rd->dn); | |
259 | if (client == NULL) | |
260 | return NOTIFY_OK; /* no? not meant for us */ | |
261 | ||
262 | /* unregister takes one ref away */ | |
263 | i2c_unregister_device(client); | |
264 | ||
265 | /* and put the reference of the find */ | |
266 | put_device(&client->dev); | |
267 | break; | |
268 | } | |
269 | ||
270 | return NOTIFY_OK; | |
271 | } | |
272 | ||
273 | struct notifier_block i2c_of_notifier = { | |
274 | .notifier_call = of_i2c_notify, | |
275 | }; | |
276 | #endif /* CONFIG_OF_DYNAMIC */ |