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 */ 277