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_alias_from_compatible(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->fwnode = of_fwnode_handle(node); 53 54 if (of_property_read_bool(node, "host-notify")) 55 info->flags |= I2C_CLIENT_HOST_NOTIFY; 56 57 if (of_property_read_bool(node, "wakeup-source")) 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_client_device(adap, &info); 78 if (IS_ERR(client)) 79 dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); 80 81 return client; 82 } 83 84 void of_i2c_register_devices(struct i2c_adapter *adap) 85 { 86 struct device_node *bus, *node; 87 struct i2c_client *client; 88 89 /* Only register child devices if the adapter has a node pointer set */ 90 if (!adap->dev.of_node) 91 return; 92 93 dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); 94 95 bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); 96 if (!bus) 97 bus = of_node_get(adap->dev.of_node); 98 99 for_each_available_child_of_node(bus, node) { 100 if (of_node_test_and_set_flag(node, OF_POPULATED)) 101 continue; 102 103 client = of_i2c_register_device(adap, node); 104 if (IS_ERR(client)) { 105 dev_err(&adap->dev, 106 "Failed to create I2C device for %pOF\n", 107 node); 108 of_node_clear_flag(node, OF_POPULATED); 109 } 110 } 111 112 of_node_put(bus); 113 } 114 115 static const struct of_device_id* 116 i2c_of_match_device_sysfs(const struct of_device_id *matches, 117 struct i2c_client *client) 118 { 119 const char *name; 120 121 for (; matches->compatible[0]; matches++) { 122 /* 123 * Adding devices through the i2c sysfs interface provides us 124 * a string to match which may be compatible with the device 125 * tree compatible strings, however with no actual of_node the 126 * of_match_device() will not match 127 */ 128 if (sysfs_streq(client->name, matches->compatible)) 129 return matches; 130 131 name = strchr(matches->compatible, ','); 132 if (!name) 133 name = matches->compatible; 134 else 135 name++; 136 137 if (sysfs_streq(client->name, name)) 138 return matches; 139 } 140 141 return NULL; 142 } 143 144 const struct of_device_id 145 *i2c_of_match_device(const struct of_device_id *matches, 146 struct i2c_client *client) 147 { 148 const struct of_device_id *match; 149 150 if (!(client && matches)) 151 return NULL; 152 153 match = of_match_device(matches, &client->dev); 154 if (match) 155 return match; 156 157 return i2c_of_match_device_sysfs(matches, client); 158 } 159 160 #if IS_ENABLED(CONFIG_OF_DYNAMIC) 161 static int of_i2c_notify(struct notifier_block *nb, unsigned long action, 162 void *arg) 163 { 164 struct of_reconfig_data *rd = arg; 165 struct i2c_adapter *adap; 166 struct i2c_client *client; 167 168 switch (of_reconfig_get_state_change(action, rd)) { 169 case OF_RECONFIG_CHANGE_ADD: 170 adap = of_find_i2c_adapter_by_node(rd->dn->parent); 171 if (adap == NULL) 172 return NOTIFY_OK; /* not for us */ 173 174 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { 175 put_device(&adap->dev); 176 return NOTIFY_OK; 177 } 178 179 /* 180 * Clear the flag before adding the device so that fw_devlink 181 * doesn't skip adding consumers to this device. 182 */ 183 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE; 184 client = of_i2c_register_device(adap, rd->dn); 185 if (IS_ERR(client)) { 186 dev_err(&adap->dev, "failed to create client for '%pOF'\n", 187 rd->dn); 188 put_device(&adap->dev); 189 of_node_clear_flag(rd->dn, OF_POPULATED); 190 return notifier_from_errno(PTR_ERR(client)); 191 } 192 put_device(&adap->dev); 193 break; 194 case OF_RECONFIG_CHANGE_REMOVE: 195 /* already depopulated? */ 196 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 197 return NOTIFY_OK; 198 199 /* find our device by node */ 200 client = of_find_i2c_device_by_node(rd->dn); 201 if (client == NULL) 202 return NOTIFY_OK; /* no? not meant for us */ 203 204 /* unregister takes one ref away */ 205 i2c_unregister_device(client); 206 207 /* and put the reference of the find */ 208 put_device(&client->dev); 209 break; 210 } 211 212 return NOTIFY_OK; 213 } 214 215 struct notifier_block i2c_of_notifier = { 216 .notifier_call = of_i2c_notify, 217 }; 218 #endif /* CONFIG_OF_DYNAMIC */ 219