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, 2018 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 *client; 29 struct i2c_board_info info = {}; 30 struct dev_archdata dev_ad = {}; 31 u32 addr; 32 int ret; 33 34 dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node); 35 36 if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { 37 dev_err(&adap->dev, "of_i2c: modalias failure on %pOF\n", 38 node); 39 return ERR_PTR(-EINVAL); 40 } 41 42 ret = of_property_read_u32(node, "reg", &addr); 43 if (ret) { 44 dev_err(&adap->dev, "of_i2c: invalid reg on %pOF\n", node); 45 return ERR_PTR(ret); 46 } 47 48 if (addr & I2C_TEN_BIT_ADDRESS) { 49 addr &= ~I2C_TEN_BIT_ADDRESS; 50 info.flags |= I2C_CLIENT_TEN; 51 } 52 53 if (addr & I2C_OWN_SLAVE_ADDRESS) { 54 addr &= ~I2C_OWN_SLAVE_ADDRESS; 55 info.flags |= I2C_CLIENT_SLAVE; 56 } 57 58 info.addr = addr; 59 info.archdata = &dev_ad; 60 info.of_node = of_node_get(node); 61 62 if (of_property_read_bool(node, "host-notify")) 63 info.flags |= I2C_CLIENT_HOST_NOTIFY; 64 65 if (of_get_property(node, "wakeup-source", NULL)) 66 info.flags |= I2C_CLIENT_WAKE; 67 68 client = i2c_new_device(adap, &info); 69 if (!client) { 70 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); 71 of_node_put(node); 72 return ERR_PTR(-EINVAL); 73 } 74 return client; 75 } 76 77 void of_i2c_register_devices(struct i2c_adapter *adap) 78 { 79 struct device_node *bus, *node; 80 struct i2c_client *client; 81 82 /* Only register child devices if the adapter has a node pointer set */ 83 if (!adap->dev.of_node) 84 return; 85 86 dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); 87 88 bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); 89 if (!bus) 90 bus = of_node_get(adap->dev.of_node); 91 92 for_each_available_child_of_node(bus, node) { 93 if (of_node_test_and_set_flag(node, OF_POPULATED)) 94 continue; 95 96 client = of_i2c_register_device(adap, node); 97 if (IS_ERR(client)) { 98 dev_err(&adap->dev, 99 "Failed to create I2C device for %pOF\n", 100 node); 101 of_node_clear_flag(node, OF_POPULATED); 102 } 103 } 104 105 of_node_put(bus); 106 } 107 108 static int of_dev_node_match(struct device *dev, void *data) 109 { 110 return dev->of_node == data; 111 } 112 113 /* must call put_device() when done with returned i2c_client device */ 114 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 115 { 116 struct device *dev; 117 struct i2c_client *client; 118 119 dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); 120 if (!dev) 121 return NULL; 122 123 client = i2c_verify_client(dev); 124 if (!client) 125 put_device(dev); 126 127 return client; 128 } 129 EXPORT_SYMBOL(of_find_i2c_device_by_node); 130 131 /* must call put_device() when done with returned i2c_adapter device */ 132 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 133 { 134 struct device *dev; 135 struct i2c_adapter *adapter; 136 137 dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); 138 if (!dev) 139 return NULL; 140 141 adapter = i2c_verify_adapter(dev); 142 if (!adapter) 143 put_device(dev); 144 145 return adapter; 146 } 147 EXPORT_SYMBOL(of_find_i2c_adapter_by_node); 148 149 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 150 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 151 { 152 struct i2c_adapter *adapter; 153 154 adapter = of_find_i2c_adapter_by_node(node); 155 if (!adapter) 156 return NULL; 157 158 if (!try_module_get(adapter->owner)) { 159 put_device(&adapter->dev); 160 adapter = NULL; 161 } 162 163 return adapter; 164 } 165 EXPORT_SYMBOL(of_get_i2c_adapter_by_node); 166 167 static const struct of_device_id* 168 i2c_of_match_device_sysfs(const struct of_device_id *matches, 169 struct i2c_client *client) 170 { 171 const char *name; 172 173 for (; matches->compatible[0]; matches++) { 174 /* 175 * Adding devices through the i2c sysfs interface provides us 176 * a string to match which may be compatible with the device 177 * tree compatible strings, however with no actual of_node the 178 * of_match_device() will not match 179 */ 180 if (sysfs_streq(client->name, matches->compatible)) 181 return matches; 182 183 name = strchr(matches->compatible, ','); 184 if (!name) 185 name = matches->compatible; 186 else 187 name++; 188 189 if (sysfs_streq(client->name, name)) 190 return matches; 191 } 192 193 return NULL; 194 } 195 196 const struct of_device_id 197 *i2c_of_match_device(const struct of_device_id *matches, 198 struct i2c_client *client) 199 { 200 const struct of_device_id *match; 201 202 if (!(client && matches)) 203 return NULL; 204 205 match = of_match_device(matches, &client->dev); 206 if (match) 207 return match; 208 209 return i2c_of_match_device_sysfs(matches, client); 210 } 211 EXPORT_SYMBOL_GPL(i2c_of_match_device); 212 213 #if IS_ENABLED(CONFIG_OF_DYNAMIC) 214 static int of_i2c_notify(struct notifier_block *nb, unsigned long action, 215 void *arg) 216 { 217 struct of_reconfig_data *rd = arg; 218 struct i2c_adapter *adap; 219 struct i2c_client *client; 220 221 switch (of_reconfig_get_state_change(action, rd)) { 222 case OF_RECONFIG_CHANGE_ADD: 223 adap = of_find_i2c_adapter_by_node(rd->dn->parent); 224 if (adap == NULL) 225 return NOTIFY_OK; /* not for us */ 226 227 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { 228 put_device(&adap->dev); 229 return NOTIFY_OK; 230 } 231 232 client = of_i2c_register_device(adap, rd->dn); 233 put_device(&adap->dev); 234 235 if (IS_ERR(client)) { 236 dev_err(&adap->dev, "failed to create client for '%pOF'\n", 237 rd->dn); 238 of_node_clear_flag(rd->dn, OF_POPULATED); 239 return notifier_from_errno(PTR_ERR(client)); 240 } 241 break; 242 case OF_RECONFIG_CHANGE_REMOVE: 243 /* already depopulated? */ 244 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 245 return NOTIFY_OK; 246 247 /* find our device by node */ 248 client = of_find_i2c_device_by_node(rd->dn); 249 if (client == NULL) 250 return NOTIFY_OK; /* no? not meant for us */ 251 252 /* unregister takes one ref away */ 253 i2c_unregister_device(client); 254 255 /* and put the reference of the find */ 256 put_device(&client->dev); 257 break; 258 } 259 260 return NOTIFY_OK; 261 } 262 263 struct notifier_block i2c_of_notifier = { 264 .notifier_call = of_i2c_notify, 265 }; 266 #endif /* CONFIG_OF_DYNAMIC */ 267