drivers/i2c/i2c-core-of.c

   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                 /*
 182                  * Clear the flag before adding the device so that fw_devlink
 183                  * 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
 217 struct notifier_block i2c_of_notifier = {
 218         .notifier_call = of_i2c_notify,
 219 };
 220 #endif /* CONFIG_OF_DYNAMIC */