text: /*
   * OF helpers for the I2C API
   *
   * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
   *
   * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  #include <linux/i2c.h>
  #include <linux/irq.h>
  #include <linux/of.h>
  #include <linux/of_i2c.h>
  #include <linux/of_irq.h>
  #include <linux/module.h>
  
  void of_i2c_register_devices(struct i2c_adapter *adap)
  {
  	void *result;
  	struct device_node *node;
  
  	/* Only register child devices if the adapter has a node pointer set */
  	if (!adap->dev.of_node)
  		return;
  
  	dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
  
  	for_each_child_of_node(adap->dev.of_node, node) {
  		struct i2c_board_info info = {};
  		struct dev_archdata dev_ad = {};
  		const __be32 *addr;
  		int len;
  
  		dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
  
  		if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
  			dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
  				node->full_name);
  			continue;
  		}
  
  		addr = of_get_property(node, "reg", &len);
  		if (!addr || (len < sizeof(int))) {
  			dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
  				node->full_name);
  			continue;
  		}
  
  		info.addr = be32_to_cpup(addr);
  		if (info.addr > (1 << 10) - 1) {
  			dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
  				info.addr, node->full_name);
  			continue;
  		}
  
  		info.irq = irq_of_parse_and_map(node, 0);
  		info.of_node = of_node_get(node);
  		info.archdata = &dev_ad;
  
  		if (of_get_property(node, "wakeup-source", NULL))
  			info.flags |= I2C_CLIENT_WAKE;
  
  		request_module("%s%s", I2C_MODULE_PREFIX, info.type);
  
  		result = i2c_new_device(adap, &info);
  		if (result == NULL) {
  			dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
  			        node->full_name);
  			of_node_put(node);
  			irq_dispose_mapping(info.irq);
  			continue;
  		}
  	}
  }
  EXPORT_SYMBOL(of_i2c_register_devices);
  
  static int of_dev_node_match(struct device *dev, void *data)
  {
          return dev->of_node == data;
  }
  
  /* must call put_device() when done with returned i2c_client device */
  struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
  {
  	struct device *dev;
  
  	dev = bus_find_device(&i2c_bus_type, NULL, node,
  					 of_dev_node_match);
  	if (!dev)
  		return NULL;
  
  	return i2c_verify_client(dev);
  }
  EXPORT_SYMBOL(of_find_i2c_device_by_node);
  
  /* must call put_device() when done with returned i2c_adapter device */
  struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
  {
  	struct device *dev;
  
  	dev = bus_find_device(&i2c_bus_type, NULL, node,
  					 of_dev_node_match);
  	if (!dev)
  		return NULL;
  
  	return i2c_verify_adapter(dev);
  }
  EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
  
  MODULE_LICENSE("GPL");
  