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 static int parse_ofpart_partitions(struct mtd_info *master,
  24                                    struct mtd_partition **pparts,
  25                                    struct mtd_part_parser_data *data)
  26 {
  27         struct device_node *node;
  28         const char *partname;
  29         struct device_node *pp;
  30         int nr_parts, i;
  31
  32
  33         if (!data)
  34                 return 0;
  35
  36         node = data->of_node;
  37         if (!node)
  38                 return 0;
  39
  40         /* First count the subnodes */
  41         pp = NULL;
  42         nr_parts = 0;
  43         while ((pp = of_get_next_child(node, pp)))
  44                 nr_parts++;
  45
  46         if (nr_parts == 0)
  47                 return 0;
  48
  49         *pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
  50         if (!*pparts)
  51                 return -ENOMEM;
  52
  53         pp = NULL;
  54         i = 0;
  55         while ((pp = of_get_next_child(node, pp))) {
  56                 const __be32 *reg;
  57                 int len;
  58
  59                 reg = of_get_property(pp, "reg", &len);
  60                 if (!reg) {
  61                         nr_parts--;
  62                         continue;
  63                 }
  64
  65                 (*pparts)[i].offset = be32_to_cpu(reg[0]);
  66                 (*pparts)[i].size = be32_to_cpu(reg[1]);
  67
  68                 partname = of_get_property(pp, "label", &len);
  69                 if (!partname)
  70                         partname = of_get_property(pp, "name", &len);
  71                 (*pparts)[i].name = (char *)partname;
  72
  73                 if (of_get_property(pp, "read-only", &len))
  74                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
  75
  76                 i++;
  77         }
  78
  79         if (!i) {
  80                 of_node_put(pp);
  81                 pr_err("No valid partition found on %s\n", node->full_name);
  82                 kfree(*pparts);
  83                 *pparts = NULL;
  84                 return -EINVAL;
  85         }
  86
  87         return nr_parts;
  88 }
  89
  90 static struct mtd_part_parser ofpart_parser = {
  91         .owner = THIS_MODULE,
  92         .parse_fn = parse_ofpart_partitions,
  93         .name = "ofpart",
  94 };
  95
  96 static int parse_ofoldpart_partitions(struct mtd_info *master,
  97                                       struct mtd_partition **pparts,
  98                                       struct mtd_part_parser_data *data)
  99 {
 100         struct device_node *dp;
 101         int i, plen, nr_parts;
 102         const struct {
 103                 __be32 offset, len;
 104         } *part;
 105         const char *names;
 106
 107         if (!data)
 108                 return 0;
 109
 110         dp = data->of_node;
 111         if (!dp)
 112                 return 0;
 113
 114         part = of_get_property(dp, "partitions", &plen);
 115         if (!part)
 116                 return 0; /* No partitions found */
 117
 118         pr_warning("Device tree uses obsolete partition map binding: %s\n",
 119                         dp->full_name);
 120
 121         nr_parts = plen / sizeof(part[0]);
 122
 123         *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
 124         if (!pparts)
 125                 return -ENOMEM;
 126
 127         names = of_get_property(dp, "partition-names", &plen);
 128
 129         for (i = 0; i < nr_parts; i++) {
 130                 (*pparts)[i].offset = be32_to_cpu(part->offset);
 131                 (*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
 132                 /* bit 0 set signifies read only partition */
 133                 if (be32_to_cpu(part->len) & 1)
 134                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
 135
 136                 if (names && (plen > 0)) {
 137                         int len = strlen(names) + 1;
 138
 139                         (*pparts)[i].name = (char *)names;
 140                         plen -= len;
 141                         names += len;
 142                 } else {
 143                         (*pparts)[i].name = "unnamed";
 144                 }
 145
 146                 part++;
 147         }
 148
 149         return nr_parts;
 150 }
 151
 152 static struct mtd_part_parser ofoldpart_parser = {
 153         .owner = THIS_MODULE,
 154         .parse_fn = parse_ofoldpart_partitions,
 155         .name = "ofoldpart",
 156 };
 157
 158 static int __init ofpart_parser_init(void)
 159 {
 160         int rc;
 161         rc = register_mtd_parser(&ofpart_parser);
 162         if (rc)
 163                 goto out;
 164
 165         rc = register_mtd_parser(&ofoldpart_parser);
 166         if (!rc)
 167                 return 0;
 168
 169         deregister_mtd_parser(&ofoldpart_parser);
 170 out:
 171         return rc;
 172 }
 173
 174 module_init(ofpart_parser_init);
 175
 176 MODULE_LICENSE("GPL");
 177 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 178 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 179 /*
 180  * When MTD core cannot find the requested parser, it tries to load the module
 181  * with the same name. Since we provide the ofoldpart parser, we should have
 182  * the corresponding alias.
 183  */
 184 MODULE_ALIAS("ofoldpart");