drivers/mtd/ofpart.c

   1 /*
   2  * Flash partitions described by the OF (or flattened) device tree
   3  *
   4  * Copyright © 2006 MontaVista Software Inc.
   5  * Author: Vitaly Wool <vwool@ru.mvista.com>
   6  *
   7  * Revised to handle newer style flash binding by:
   8  *   Copyright © 2007 David Gibson, IBM Corporation.
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/of.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/slab.h>
  21 #include <linux/mtd/partitions.h>
  22
  23 int __devinit of_mtd_parse_partitions(struct device *dev,
  24                                       struct device_node *node,
  25                                       struct mtd_partition **pparts)
  26 {
  27         const char *partname;
  28         struct device_node *pp;
  29         int nr_parts, i;
  30
  31         /* First count the subnodes */
  32         pp = NULL;
  33         nr_parts = 0;
  34         while ((pp = of_get_next_child(node, pp)))
  35                 nr_parts++;
  36
  37         if (nr_parts == 0)
  38                 return 0;
  39
  40         *pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
  41         if (!*pparts)
  42                 return -ENOMEM;
  43
  44         pp = NULL;
  45         i = 0;
  46         while ((pp = of_get_next_child(node, pp))) {
  47                 const __be32 *reg;
  48                 int len;
  49
  50                 reg = of_get_property(pp, "reg", &len);
  51                 if (!reg) {
  52                         nr_parts--;
  53                         continue;
  54                 }
  55
  56                 (*pparts)[i].offset = be32_to_cpu(reg[0]);
  57                 (*pparts)[i].size = be32_to_cpu(reg[1]);
  58
  59                 partname = of_get_property(pp, "label", &len);
  60                 if (!partname)
  61                         partname = of_get_property(pp, "name", &len);
  62                 (*pparts)[i].name = (char *)partname;
  63
  64                 if (of_get_property(pp, "read-only", &len))
  65                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
  66
  67                 i++;
  68         }
  69
  70         if (!i) {
  71                 of_node_put(pp);
  72                 dev_err(dev, "No valid partition found on %s\n", node->full_name);
  73                 kfree(*pparts);
  74                 *pparts = NULL;
  75                 return -EINVAL;
  76         }
  77
  78         return nr_parts;
  79 }
  80 EXPORT_SYMBOL(of_mtd_parse_partitions);
  81
  82 MODULE_LICENSE("GPL");