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5bf4fa7d WS |
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 | ||
453a237c | 35 | dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node); |
5bf4fa7d WS |
36 | |
37 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { | |
453a237c RH |
38 | dev_err(&adap->dev, "of_i2c: modalias failure on %pOF\n", |
39 | node); | |
5bf4fa7d WS |
40 | return ERR_PTR(-EINVAL); |
41 | } | |
42 | ||
43 | addr_be = of_get_property(node, "reg", &len); | |
44 | if (!addr_be || (len < sizeof(*addr_be))) { | |
453a237c | 45 | dev_err(&adap->dev, "of_i2c: invalid reg on %pOF\n", node); |
5bf4fa7d WS |
46 | return ERR_PTR(-EINVAL); |
47 | } | |
48 | ||
49 | addr = be32_to_cpup(addr_be); | |
50 | if (addr & I2C_TEN_BIT_ADDRESS) { | |
51 | addr &= ~I2C_TEN_BIT_ADDRESS; | |
52 | info.flags |= I2C_CLIENT_TEN; | |
53 | } | |
54 | ||
55 | if (addr & I2C_OWN_SLAVE_ADDRESS) { | |
56 | addr &= ~I2C_OWN_SLAVE_ADDRESS; | |
57 | info.flags |= I2C_CLIENT_SLAVE; | |
58 | } | |
59 | ||
60 | if (i2c_check_addr_validity(addr, info.flags)) { | |
453a237c RH |
61 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %pOF\n", |
62 | addr, node); | |
5bf4fa7d WS |
63 | return ERR_PTR(-EINVAL); |
64 | } | |
65 | ||
66 | info.addr = addr; | |
67 | info.of_node = of_node_get(node); | |
68 | info.archdata = &dev_ad; | |
69 | ||
70 | if (of_property_read_bool(node, "host-notify")) | |
71 | info.flags |= I2C_CLIENT_HOST_NOTIFY; | |
72 | ||
73 | if (of_get_property(node, "wakeup-source", NULL)) | |
74 | info.flags |= I2C_CLIENT_WAKE; | |
75 | ||
76 | result = i2c_new_device(adap, &info); | |
77 | if (result == NULL) { | |
453a237c | 78 | dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); |
5bf4fa7d WS |
79 | of_node_put(node); |
80 | return ERR_PTR(-EINVAL); | |
81 | } | |
82 | return result; | |
83 | } | |
84 | ||
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_warn(&adap->dev, | |
453a237c RH |
107 | "Failed to create I2C device for %pOF\n", |
108 | node); | |
5bf4fa7d WS |
109 | of_node_clear_flag(node, OF_POPULATED); |
110 | } | |
111 | } | |
112 | ||
113 | of_node_put(bus); | |
114 | } | |
115 | ||
116 | static int of_dev_node_match(struct device *dev, void *data) | |
117 | { | |
118 | return dev->of_node == data; | |
119 | } | |
120 | ||
121 | /* must call put_device() when done with returned i2c_client device */ | |
122 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
123 | { | |
124 | struct device *dev; | |
125 | struct i2c_client *client; | |
126 | ||
127 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); | |
128 | if (!dev) | |
129 | return NULL; | |
130 | ||
131 | client = i2c_verify_client(dev); | |
132 | if (!client) | |
133 | put_device(dev); | |
134 | ||
135 | return client; | |
136 | } | |
137 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
138 | ||
139 | /* must call put_device() when done with returned i2c_adapter device */ | |
140 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
141 | { | |
142 | struct device *dev; | |
143 | struct i2c_adapter *adapter; | |
144 | ||
145 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); | |
146 | if (!dev) | |
147 | return NULL; | |
148 | ||
149 | adapter = i2c_verify_adapter(dev); | |
150 | if (!adapter) | |
151 | put_device(dev); | |
152 | ||
153 | return adapter; | |
154 | } | |
155 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
156 | ||
157 | /* must call i2c_put_adapter() when done with returned i2c_adapter device */ | |
158 | struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) | |
159 | { | |
160 | struct i2c_adapter *adapter; | |
161 | ||
162 | adapter = of_find_i2c_adapter_by_node(node); | |
163 | if (!adapter) | |
164 | return NULL; | |
165 | ||
166 | if (!try_module_get(adapter->owner)) { | |
167 | put_device(&adapter->dev); | |
168 | adapter = NULL; | |
169 | } | |
170 | ||
171 | return adapter; | |
172 | } | |
173 | EXPORT_SYMBOL(of_get_i2c_adapter_by_node); | |
174 | ||
175 | static const struct of_device_id* | |
176 | i2c_of_match_device_sysfs(const struct of_device_id *matches, | |
177 | struct i2c_client *client) | |
178 | { | |
179 | const char *name; | |
180 | ||
181 | for (; matches->compatible[0]; matches++) { | |
182 | /* | |
183 | * Adding devices through the i2c sysfs interface provides us | |
184 | * a string to match which may be compatible with the device | |
185 | * tree compatible strings, however with no actual of_node the | |
186 | * of_match_device() will not match | |
187 | */ | |
188 | if (sysfs_streq(client->name, matches->compatible)) | |
189 | return matches; | |
190 | ||
191 | name = strchr(matches->compatible, ','); | |
192 | if (!name) | |
193 | name = matches->compatible; | |
194 | else | |
195 | name++; | |
196 | ||
197 | if (sysfs_streq(client->name, name)) | |
198 | return matches; | |
199 | } | |
200 | ||
201 | return NULL; | |
202 | } | |
203 | ||
204 | const struct of_device_id | |
205 | *i2c_of_match_device(const struct of_device_id *matches, | |
206 | struct i2c_client *client) | |
207 | { | |
208 | const struct of_device_id *match; | |
209 | ||
210 | if (!(client && matches)) | |
211 | return NULL; | |
212 | ||
213 | match = of_match_device(matches, &client->dev); | |
214 | if (match) | |
215 | return match; | |
216 | ||
217 | return i2c_of_match_device_sysfs(matches, client); | |
218 | } | |
219 | EXPORT_SYMBOL_GPL(i2c_of_match_device); | |
220 | ||
221 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) | |
222 | static int of_i2c_notify(struct notifier_block *nb, unsigned long action, | |
223 | void *arg) | |
224 | { | |
225 | struct of_reconfig_data *rd = arg; | |
226 | struct i2c_adapter *adap; | |
227 | struct i2c_client *client; | |
228 | ||
229 | switch (of_reconfig_get_state_change(action, rd)) { | |
230 | case OF_RECONFIG_CHANGE_ADD: | |
231 | adap = of_find_i2c_adapter_by_node(rd->dn->parent); | |
232 | if (adap == NULL) | |
233 | return NOTIFY_OK; /* not for us */ | |
234 | ||
235 | if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { | |
236 | put_device(&adap->dev); | |
237 | return NOTIFY_OK; | |
238 | } | |
239 | ||
240 | client = of_i2c_register_device(adap, rd->dn); | |
241 | put_device(&adap->dev); | |
242 | ||
243 | if (IS_ERR(client)) { | |
453a237c RH |
244 | dev_err(&adap->dev, "failed to create client for '%pOF'\n", |
245 | rd->dn); | |
5bf4fa7d WS |
246 | of_node_clear_flag(rd->dn, OF_POPULATED); |
247 | return notifier_from_errno(PTR_ERR(client)); | |
248 | } | |
249 | break; | |
250 | case OF_RECONFIG_CHANGE_REMOVE: | |
251 | /* already depopulated? */ | |
252 | if (!of_node_check_flag(rd->dn, OF_POPULATED)) | |
253 | return NOTIFY_OK; | |
254 | ||
255 | /* find our device by node */ | |
256 | client = of_find_i2c_device_by_node(rd->dn); | |
257 | if (client == NULL) | |
258 | return NOTIFY_OK; /* no? not meant for us */ | |
259 | ||
260 | /* unregister takes one ref away */ | |
261 | i2c_unregister_device(client); | |
262 | ||
263 | /* and put the reference of the find */ | |
264 | put_device(&client->dev); | |
265 | break; | |
266 | } | |
267 | ||
268 | return NOTIFY_OK; | |
269 | } | |
270 | ||
271 | struct notifier_block i2c_of_notifier = { | |
272 | .notifier_call = of_i2c_notify, | |
273 | }; | |
274 | #endif /* CONFIG_OF_DYNAMIC */ |