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@kernel.org> 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 info->fwnode = of_fwnode_handle(node); 54 55 if (of_property_read_bool(node, "host-notify")) 56 info->flags |= I2C_CLIENT_HOST_NOTIFY; 57 58 if (of_get_property(node, "wakeup-source", NULL)) 59 info->flags |= I2C_CLIENT_WAKE; 60 61 return 0; 62 } 63 EXPORT_SYMBOL_GPL(of_i2c_get_board_info); 64 65 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, 66 struct device_node *node) 67 { 68 struct i2c_client *client; 69 struct i2c_board_info info; 70 int ret; 71 72 dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node); 73 74 ret = of_i2c_get_board_info(&adap->dev, node, &info); 75 if (ret) 76 return ERR_PTR(ret); 77 78 client = i2c_new_client_device(adap, &info); 79 if (IS_ERR(client)) 80 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); 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 const struct of_device_id* 117 i2c_of_match_device_sysfs(const struct of_device_id *matches, 118 struct i2c_client *client) 119 { 120 const char *name; 121 122 for (; matches->compatible[0]; matches++) { 123 /* 124 * Adding devices through the i2c sysfs interface provides us 125 * a string to match which may be compatible with the device 126 * tree compatible strings, however with no actual of_node the 127 * of_match_device() will not match 128 */ 129 if (sysfs_streq(client->name, matches->compatible)) 130 return matches; 131 132 name = strchr(matches->compatible, ','); 133 if (!name) 134 name = matches->compatible; 135 else 136 name++; 137 138 if (sysfs_streq(client->name, name)) 139 return matches; 140 } 141 142 return NULL; 143 } 144 145 const struct of_device_id 146 *i2c_of_match_device(const struct of_device_id *matches, 147 struct i2c_client *client) 148 { 149 const struct of_device_id *match; 150 151 if (!(client && matches)) 152 return NULL; 153 154 match = of_match_device(matches, &client->dev); 155 if (match) 156 return match; 157 158 return i2c_of_match_device_sysfs(matches, client); 159 } 160 EXPORT_SYMBOL_GPL(i2c_of_match_device); 161 162 #if IS_ENABLED(CONFIG_OF_DYNAMIC) 163 static int of_i2c_notify(struct notifier_block *nb, unsigned long action, 164 void *arg) 165 { 166 struct of_reconfig_data *rd = arg; 167 struct i2c_adapter *adap; 168 struct i2c_client *client; 169 170 switch (of_reconfig_get_state_change(action, rd)) { 171 case OF_RECONFIG_CHANGE_ADD: 172 adap = of_find_i2c_adapter_by_node(rd->dn->parent); 173 if (adap == NULL) 174 return NOTIFY_OK; /* not for us */ 175 176 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { 177 put_device(&adap->dev); 178 return NOTIFY_OK; 179 } 180 181 client = of_i2c_register_device(adap, rd->dn); 182 if (IS_ERR(client)) { 183 dev_err(&adap->dev, "failed to create client for '%pOF'\n", 184 rd->dn); 185 put_device(&adap->dev); 186 of_node_clear_flag(rd->dn, OF_POPULATED); 187 return notifier_from_errno(PTR_ERR(client)); 188 } 189 put_device(&adap->dev); 190 break; 191 case OF_RECONFIG_CHANGE_REMOVE: 192 /* already depopulated? */ 193 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 194 return NOTIFY_OK; 195 196 /* find our device by node */ 197 client = of_find_i2c_device_by_node(rd->dn); 198 if (client == NULL) 199 return NOTIFY_OK; /* no? not meant for us */ 200 201 /* unregister takes one ref away */ 202 i2c_unregister_device(client); 203 204 /* and put the reference of the find */ 205 put_device(&client->dev); 206 break; 207 } 208 209 return NOTIFY_OK; 210 } 211 212 struct notifier_block i2c_of_notifier = { 213 .notifier_call = of_i2c_notify, 214 }; 215 #endif /* CONFIG_OF_DYNAMIC */ 216