drivers/of/of_i2c.c

   1 /*
   2  * OF helpers for the I2C API
   3  *
   4  * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
   5  *
   6  * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/i2c.h>
  15 #include <linux/of.h>
  16 #include <linux/of_i2c.h>
  17 #include <linux/module.h>
  18
  19 void of_register_i2c_devices(struct i2c_adapter *adap,
  20                              struct device_node *adap_node)
  21 {
  22         void *result;
  23         struct device_node *node;
  24
  25         for_each_child_of_node(adap_node, node) {
  26                 struct i2c_board_info info = {};
  27                 const u32 *addr;
  28                 int len;
  29
  30                 if (of_modalias_node(node, info.type, sizeof(info.type)) < 0)
  31                         continue;
  32
  33                 addr = of_get_property(node, "reg", &len);
  34                 if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) {
  35                         printk(KERN_ERR
  36                                "of-i2c: invalid i2c device entry\n");
  37                         continue;
  38                 }
  39
  40                 info.irq = irq_of_parse_and_map(node, 0);
  41
  42                 info.addr = *addr;
  43
  44                 request_module(info.type);
  45
  46                 result = i2c_new_device(adap, &info);
  47                 if (result == NULL) {
  48                         printk(KERN_ERR
  49                                "of-i2c: Failed to load driver for %s\n",
  50                                info.type);
  51                         irq_dispose_mapping(info.irq);
  52                         continue;
  53                 }
  54         }
  55 }
  56 EXPORT_SYMBOL(of_register_i2c_devices);
  57
  58 MODULE_LICENSE("GPL");