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281 lines
6.5 KiB
281 lines
6.5 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Linux I2C core OF support code |
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* |
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* Copyright (C) 2008 Jochen Friedrich <[email protected]> |
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* based on a previous patch from Jon Smirl <[email protected]> |
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* |
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* Copyright (C) 2013, 2018 Wolfram Sang <[email protected]> |
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*/ |
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#include <dt-bindings/i2c/i2c.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/i2c.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/sysfs.h> |
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#include "i2c-core.h" |
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int of_i2c_get_board_info(struct device *dev, struct device_node *node, |
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struct i2c_board_info *info) |
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{ |
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u32 addr; |
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int ret; |
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memset(info, 0, sizeof(*info)); |
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if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) { |
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dev_err(dev, "of_i2c: modalias failure on %pOF\n", node); |
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return -EINVAL; |
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} |
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ret = of_property_read_u32(node, "reg", &addr); |
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if (ret) { |
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dev_err(dev, "of_i2c: invalid reg on %pOF\n", node); |
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return ret; |
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} |
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if (addr & I2C_TEN_BIT_ADDRESS) { |
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addr &= ~I2C_TEN_BIT_ADDRESS; |
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info->flags |= I2C_CLIENT_TEN; |
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} |
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if (addr & I2C_OWN_SLAVE_ADDRESS) { |
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addr &= ~I2C_OWN_SLAVE_ADDRESS; |
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info->flags |= I2C_CLIENT_SLAVE; |
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} |
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info->addr = addr; |
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info->of_node = node; |
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info->fwnode = of_fwnode_handle(node); |
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if (of_property_read_bool(node, "host-notify")) |
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info->flags |= I2C_CLIENT_HOST_NOTIFY; |
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if (of_get_property(node, "wakeup-source", NULL)) |
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info->flags |= I2C_CLIENT_WAKE; |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(of_i2c_get_board_info); |
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static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, |
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struct device_node *node) |
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{ |
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struct i2c_client *client; |
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struct i2c_board_info info; |
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int ret; |
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dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node); |
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ret = of_i2c_get_board_info(&adap->dev, node, &info); |
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if (ret) |
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return ERR_PTR(ret); |
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client = i2c_new_client_device(adap, &info); |
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if (IS_ERR(client)) |
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dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node); |
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return client; |
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} |
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void of_i2c_register_devices(struct i2c_adapter *adap) |
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{ |
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struct device_node *bus, *node; |
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struct i2c_client *client; |
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/* Only register child devices if the adapter has a node pointer set */ |
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if (!adap->dev.of_node) |
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return; |
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dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); |
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bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus"); |
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if (!bus) |
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bus = of_node_get(adap->dev.of_node); |
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for_each_available_child_of_node(bus, node) { |
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if (of_node_test_and_set_flag(node, OF_POPULATED)) |
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continue; |
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client = of_i2c_register_device(adap, node); |
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if (IS_ERR(client)) { |
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dev_err(&adap->dev, |
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"Failed to create I2C device for %pOF\n", |
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node); |
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of_node_clear_flag(node, OF_POPULATED); |
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} |
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} |
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of_node_put(bus); |
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} |
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static int of_dev_or_parent_node_match(struct device *dev, const void *data) |
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{ |
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if (dev->of_node == data) |
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return 1; |
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if (dev->parent) |
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return dev->parent->of_node == data; |
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return 0; |
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} |
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/* must call put_device() when done with returned i2c_client device */ |
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struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) |
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{ |
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struct device *dev; |
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struct i2c_client *client; |
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dev = bus_find_device_by_of_node(&i2c_bus_type, node); |
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if (!dev) |
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return NULL; |
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client = i2c_verify_client(dev); |
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if (!client) |
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put_device(dev); |
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return client; |
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} |
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EXPORT_SYMBOL(of_find_i2c_device_by_node); |
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/* must call put_device() when done with returned i2c_adapter device */ |
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struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) |
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{ |
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struct device *dev; |
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struct i2c_adapter *adapter; |
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dev = bus_find_device(&i2c_bus_type, NULL, node, |
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of_dev_or_parent_node_match); |
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if (!dev) |
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return NULL; |
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adapter = i2c_verify_adapter(dev); |
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if (!adapter) |
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put_device(dev); |
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return adapter; |
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} |
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EXPORT_SYMBOL(of_find_i2c_adapter_by_node); |
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/* must call i2c_put_adapter() when done with returned i2c_adapter device */ |
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struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) |
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{ |
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struct i2c_adapter *adapter; |
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adapter = of_find_i2c_adapter_by_node(node); |
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if (!adapter) |
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return NULL; |
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if (!try_module_get(adapter->owner)) { |
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put_device(&adapter->dev); |
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adapter = NULL; |
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} |
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return adapter; |
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} |
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EXPORT_SYMBOL(of_get_i2c_adapter_by_node); |
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static const struct of_device_id* |
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i2c_of_match_device_sysfs(const struct of_device_id *matches, |
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struct i2c_client *client) |
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{ |
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const char *name; |
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for (; matches->compatible[0]; matches++) { |
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/* |
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* Adding devices through the i2c sysfs interface provides us |
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* a string to match which may be compatible with the device |
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* tree compatible strings, however with no actual of_node the |
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* of_match_device() will not match |
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*/ |
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if (sysfs_streq(client->name, matches->compatible)) |
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return matches; |
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name = strchr(matches->compatible, ','); |
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if (!name) |
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name = matches->compatible; |
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else |
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name++; |
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if (sysfs_streq(client->name, name)) |
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return matches; |
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} |
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return NULL; |
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} |
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const struct of_device_id |
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*i2c_of_match_device(const struct of_device_id *matches, |
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struct i2c_client *client) |
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{ |
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const struct of_device_id *match; |
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if (!(client && matches)) |
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return NULL; |
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match = of_match_device(matches, &client->dev); |
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if (match) |
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return match; |
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return i2c_of_match_device_sysfs(matches, client); |
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} |
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EXPORT_SYMBOL_GPL(i2c_of_match_device); |
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#if IS_ENABLED(CONFIG_OF_DYNAMIC) |
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static int of_i2c_notify(struct notifier_block *nb, unsigned long action, |
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void *arg) |
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{ |
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struct of_reconfig_data *rd = arg; |
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struct i2c_adapter *adap; |
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struct i2c_client *client; |
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switch (of_reconfig_get_state_change(action, rd)) { |
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case OF_RECONFIG_CHANGE_ADD: |
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adap = of_find_i2c_adapter_by_node(rd->dn->parent); |
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if (adap == NULL) |
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return NOTIFY_OK; /* not for us */ |
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if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
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put_device(&adap->dev); |
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return NOTIFY_OK; |
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} |
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client = of_i2c_register_device(adap, rd->dn); |
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if (IS_ERR(client)) { |
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dev_err(&adap->dev, "failed to create client for '%pOF'\n", |
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rd->dn); |
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put_device(&adap->dev); |
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of_node_clear_flag(rd->dn, OF_POPULATED); |
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return notifier_from_errno(PTR_ERR(client)); |
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} |
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put_device(&adap->dev); |
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break; |
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case OF_RECONFIG_CHANGE_REMOVE: |
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/* already depopulated? */ |
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if (!of_node_check_flag(rd->dn, OF_POPULATED)) |
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return NOTIFY_OK; |
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/* find our device by node */ |
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client = of_find_i2c_device_by_node(rd->dn); |
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if (client == NULL) |
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return NOTIFY_OK; /* no? not meant for us */ |
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/* unregister takes one ref away */ |
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i2c_unregister_device(client); |
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/* and put the reference of the find */ |
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put_device(&client->dev); |
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break; |
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} |
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return NOTIFY_OK; |
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} |
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struct notifier_block i2c_of_notifier = { |
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.notifier_call = of_i2c_notify, |
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}; |
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#endif /* CONFIG_OF_DYNAMIC */
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