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@the-dreams.de> 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 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 54 if (of_property_read_bool(node, "host-notify")) 55 info->flags |= I2C_CLIENT_HOST_NOTIFY; 56 57 if (of_get_property(node, "wakeup-source", NULL)) 58 info->flags |= I2C_CLIENT_WAKE; 59 60 return 0; 61 } 62 EXPORT_SYMBOL_GPL(of_i2c_get_board_info); 63 64 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, 65 struct device_node *node) 66 { 67 struct i2c_client *client; 68 struct i2c_board_info info; 69 int ret; 70 71 dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node); 72 73 ret = of_i2c_get_board_info(&adap->dev, node, &info); 74 if (ret) 75 return ERR_PTR(ret); 76 77 client = i2c_new_device(adap, &info); 78 if (!client) { 79 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); 80 return ERR_PTR(-EINVAL); 81 } 82 return client; 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_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 } 115 116 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 */ 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 */ 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 */ 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* 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 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) 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 put_device(&adap->dev); 249 250 if (IS_ERR(client)) { 251 dev_err(&adap->dev, "failed to create client for '%pOF'\n", 252 rd->dn); 253 of_node_clear_flag(rd->dn, OF_POPULATED); 254 return notifier_from_errno(PTR_ERR(client)); 255 } 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