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                 if (of_get_property(pp, "lock", &len))
  77                         (*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
  78
  79                 i++;
  80         }
  81
  82         if (!i) {
  83                 of_node_put(pp);
  84                 pr_err("No valid partition found on %s\n", node->full_name);
  85                 kfree(*pparts);
  86                 *pparts = NULL;
  87                 return -EINVAL;
  88         }
  89
  90         return nr_parts;
  91 }
  92
  93 static struct mtd_part_parser ofpart_parser = {
  94         .owner = THIS_MODULE,
  95         .parse_fn = parse_ofpart_partitions,
  96         .name = "ofpart",
  97 };
  98
  99 static int parse_ofoldpart_partitions(struct mtd_info *master,
 100                                       struct mtd_partition **pparts,
 101                                       struct mtd_part_parser_data *data)
 102 {
 103         struct device_node *dp;
 104         int i, plen, nr_parts;
 105         const struct {
 106                 __be32 offset, len;
 107         } *part;
 108         const char *names;
 109
 110         if (!data)
 111                 return 0;
 112
 113         dp = data->of_node;
 114         if (!dp)
 115                 return 0;
 116
 117         part = of_get_property(dp, "partitions", &plen);
 118         if (!part)
 119                 return 0; /* No partitions found */
 120
 121         pr_warning("Device tree uses obsolete partition map binding: %s\n",
 122                         dp->full_name);
 123
 124         nr_parts = plen / sizeof(part[0]);
 125
 126         *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
 127         if (!*pparts)
 128                 return -ENOMEM;
 129
 130         names = of_get_property(dp, "partition-names", &plen);
 131
 132         for (i = 0; i < nr_parts; i++) {
 133                 (*pparts)[i].offset = be32_to_cpu(part->offset);
 134                 (*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
 135                 /* bit 0 set signifies read only partition */
 136                 if (be32_to_cpu(part->len) & 1)
 137                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
 138
 139                 if (names && (plen > 0)) {
 140                         int len = strlen(names) + 1;
 141
 142                         (*pparts)[i].name = (char *)names;
 143                         plen -= len;
 144                         names += len;
 145                 } else {
 146                         (*pparts)[i].name = "unnamed";
 147                 }
 148
 149                 part++;
 150         }
 151
 152         return nr_parts;
 153 }
 154
 155 static struct mtd_part_parser ofoldpart_parser = {
 156         .owner = THIS_MODULE,
 157         .parse_fn = parse_ofoldpart_partitions,
 158         .name = "ofoldpart",
 159 };
 160
 161 static int __init ofpart_parser_init(void)
 162 {
 163         int rc;
 164         rc = register_mtd_parser(&ofpart_parser);
 165         if (rc)
 166                 goto out;
 167
 168         rc = register_mtd_parser(&ofoldpart_parser);
 169         if (!rc)
 170                 return 0;
 171
 172         deregister_mtd_parser(&ofoldpart_parser);
 173 out:
 174         return rc;
 175 }
 176
 177 module_init(ofpart_parser_init);
 178
 179 MODULE_LICENSE("GPL");
 180 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 181 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 182 /*
 183  * When MTD core cannot find the requested parser, it tries to load the module
 184  * with the same name. Since we provide the ofoldpart parser, we should have
 185  * the corresponding alias.
 186  */
 187 MODULE_ALIAS("ofoldpart");