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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Linux I2C core OF support code4 *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 22int 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->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_property_read_bool(node, "wakeup-source"))59 info->flags |= I2C_CLIENT_WAKE;60 61 return 0;62}63EXPORT_SYMBOL_GPL(of_i2c_get_board_info);64 65static 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 85void 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 116static const struct of_device_id*117i2c_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 us125 * a string to match which may be compatible with the device126 * tree compatible strings, however with no actual of_node the127 * of_match_device() will not match128 */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 else136 name++;137 138 if (sysfs_streq(client->name, name))139 return matches;140 }141 142 return NULL;143}144 145const struct of_device_id146*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}160EXPORT_SYMBOL_GPL(i2c_of_match_device);161 162#if IS_ENABLED(CONFIG_OF_DYNAMIC)163static 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 /*182 * Clear the flag before adding the device so that fw_devlink183 * doesn't skip adding consumers to this device.184 */185 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;186 client = of_i2c_register_device(adap, rd->dn);187 if (IS_ERR(client)) {188 dev_err(&adap->dev, "failed to create client for '%pOF'\n",189 rd->dn);190 put_device(&adap->dev);191 of_node_clear_flag(rd->dn, OF_POPULATED);192 return notifier_from_errno(PTR_ERR(client));193 }194 put_device(&adap->dev);195 break;196 case OF_RECONFIG_CHANGE_REMOVE:197 /* already depopulated? */198 if (!of_node_check_flag(rd->dn, OF_POPULATED))199 return NOTIFY_OK;200 201 /* find our device by node */202 client = of_find_i2c_device_by_node(rd->dn);203 if (client == NULL)204 return NOTIFY_OK; /* no? not meant for us */205 206 /* unregister takes one ref away */207 i2c_unregister_device(client);208 209 /* and put the reference of the find */210 put_device(&client->dev);211 break;212 }213 214 return NOTIFY_OK;215}216 217struct notifier_block i2c_of_notifier = {218 .notifier_call = of_i2c_notify,219};220#endif /* CONFIG_OF_DYNAMIC */221