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                 int a_cells, s_cells;
  59
  60                 reg = of_get_property(pp, "reg", &len);
  61                 if (!reg) {
  62                         nr_parts--;
  63                         continue;
  64                 }
  65
  66                 a_cells = of_n_addr_cells(pp);
  67                 s_cells = of_n_size_cells(pp);
  68                 (*pparts)[i].offset = of_read_number(reg, a_cells);
  69                 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
  70
  71                 partname = of_get_property(pp, "label", &len);
  72                 if (!partname)
  73                         partname = of_get_property(pp, "name", &len);
  74                 (*pparts)[i].name = (char *)partname;
  75
  76                 if (of_get_property(pp, "read-only", &len))
  77                         (*pparts)[i].mask_flags |= MTD_WRITEABLE;
  78
  79                 if (of_get_property(pp, "lock", &len))
  80                         (*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
  81
  82                 i++;
  83         }
  84
  85         if (!i) {
  86                 of_node_put(pp);
  87                 pr_err("No valid partition found on %s\n", node->full_name);
  88                 kfree(*pparts);
  89                 *pparts = NULL;
  90                 return -EINVAL;
  91         }
  92
  93         return nr_parts;
  94 }
  95
  96 static struct mtd_part_parser ofpart_parser = {
  97         .owner = THIS_MODULE,
  98         .parse_fn = parse_ofpart_partitions,
  99         .name = "ofpart",
 100 };
 101
 102 static int parse_ofoldpart_partitions(struct mtd_info *master,
 103                                       struct mtd_partition **pparts,
 104                                       struct mtd_part_parser_data *data)
 105 {
 106         struct device_node *dp;
 107         int i, plen, nr_parts;
 108         const struct {
 109                 __be32 offset, len;
 110         } *part;
 111         const char *names;
 112
 113         if (!data)
 114                 return 0;
 115
 116         dp = data->of_node;
 117         if (!dp)
 118                 return 0;
 119
 120         part = of_get_property(dp, "partitions", &plen);
 121         if (!part)
 122                 return 0; /* No partitions found */
 123
 124         pr_warning("Device tree uses obsolete partition map binding: %s\n",
 125                         dp->full_name);
 126
 127         nr_parts = plen / sizeof(part[0]);
 128
 129         *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
 130         if (!*pparts)
 131                 return -ENOMEM;
 132
 133         names = of_get_property(dp, "partition-names", &plen);
 134
 135         for (i = 0; i < nr_parts; i++) {
 136                 (*pparts)[i].offset = be32_to_cpu(part->offset);
 137                 (*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
 138                 /* bit 0 set signifies read only partition */
 139                 if (be32_to_cpu(part->len) & 1)
 140                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
 141
 142                 if (names && (plen > 0)) {
 143                         int len = strlen(names) + 1;
 144
 145                         (*pparts)[i].name = (char *)names;
 146                         plen -= len;
 147                         names += len;
 148                 } else {
 149                         (*pparts)[i].name = "unnamed";
 150                 }
 151
 152                 part++;
 153         }
 154
 155         return nr_parts;
 156 }
 157
 158 static struct mtd_part_parser ofoldpart_parser = {
 159         .owner = THIS_MODULE,
 160         .parse_fn = parse_ofoldpart_partitions,
 161         .name = "ofoldpart",
 162 };
 163
 164 static int __init ofpart_parser_init(void)
 165 {
 166         int rc;
 167         rc = register_mtd_parser(&ofpart_parser);
 168         if (rc)
 169                 goto out;
 170
 171         rc = register_mtd_parser(&ofoldpart_parser);
 172         if (!rc)
 173                 return 0;
 174
 175         deregister_mtd_parser(&ofoldpart_parser);
 176 out:
 177         return rc;
 178 }
 179
 180 static void __exit ofpart_parser_exit(void)
 181 {
 182         deregister_mtd_parser(&ofpart_parser);
 183         deregister_mtd_parser(&ofoldpart_parser);
 184 }
 185
 186 module_init(ofpart_parser_init);
 187 module_exit(ofpart_parser_exit);
 188
 189 MODULE_LICENSE("GPL");
 190 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 191 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 192 /*
 193  * When MTD core cannot find the requested parser, it tries to load the module
 194  * with the same name. Since we provide the ofoldpart parser, we should have
 195  * the corresponding alias.
 196  */
 197 MODULE_ALIAS("ofoldpart");