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 bool node_has_compatible(struct device_node *pp)
  24 {
  25         return of_get_property(pp, "compatible", NULL);
  26 }
  27
  28 static int parse_ofpart_partitions(struct mtd_info *master,
  29                                    struct mtd_partition **pparts,
  30                                    struct mtd_part_parser_data *data)
  31 {
  32         struct device_node *mtd_node;
  33         struct device_node *ofpart_node;
  34         const char *partname;
  35         struct device_node *pp;
  36         int nr_parts, i, ret = 0;
  37         bool dedicated = true;
  38
  39
  40         if (!data)
  41                 return 0;
  42
  43         mtd_node = data->of_node;
  44         if (!mtd_node)
  45                 return 0;
  46
  47         ofpart_node = of_get_child_by_name(mtd_node, "partitions");
  48         if (!ofpart_node) {
  49                 pr_warn("%s: 'partitions' subnode not found on %s. Trying to parse direct subnodes as partitions.\n",
  50                         master->name, mtd_node->full_name);
  51                 ofpart_node = mtd_node;
  52                 dedicated = false;
  53         }
  54
  55         /* First count the subnodes */
  56         nr_parts = 0;
  57         for_each_child_of_node(ofpart_node,  pp) {
  58                 if (!dedicated && node_has_compatible(pp))
  59                         continue;
  60
  61                 nr_parts++;
  62         }
  63
  64         if (nr_parts == 0)
  65                 return 0;
  66
  67         *pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
  68         if (!*pparts)
  69                 return -ENOMEM;
  70
  71         i = 0;
  72         for_each_child_of_node(ofpart_node,  pp) {
  73                 const __be32 *reg;
  74                 int len;
  75                 int a_cells, s_cells;
  76
  77                 if (!dedicated && node_has_compatible(pp))
  78                         continue;
  79
  80                 reg = of_get_property(pp, "reg", &len);
  81                 if (!reg) {
  82                         if (dedicated) {
  83                                 pr_debug("%s: ofpart partition %s (%s) missing reg property.\n",
  84                                          master->name, pp->full_name,
  85                                          mtd_node->full_name);
  86                                 goto ofpart_fail;
  87                         } else {
  88                                 nr_parts--;
  89                                 continue;
  90                         }
  91                 }
  92
  93                 a_cells = of_n_addr_cells(pp);
  94                 s_cells = of_n_size_cells(pp);
  95                 if (len / 4 != a_cells + s_cells) {
  96                         pr_debug("%s: ofpart partition %s (%s) error parsing reg property.\n",
  97                                  master->name, pp->full_name,
  98                                  mtd_node->full_name);
  99                         goto ofpart_fail;
 100                 }
 101
 102                 (*pparts)[i].offset = of_read_number(reg, a_cells);
 103                 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
 104
 105                 partname = of_get_property(pp, "label", &len);
 106                 if (!partname)
 107                         partname = of_get_property(pp, "name", &len);
 108                 (*pparts)[i].name = partname;
 109
 110                 if (of_get_property(pp, "read-only", &len))
 111                         (*pparts)[i].mask_flags |= MTD_WRITEABLE;
 112
 113                 if (of_get_property(pp, "lock", &len))
 114                         (*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
 115
 116                 i++;
 117         }
 118
 119         if (!nr_parts)
 120                 goto ofpart_none;
 121
 122         return nr_parts;
 123
 124 ofpart_fail:
 125         pr_err("%s: error parsing ofpart partition %s (%s)\n",
 126                master->name, pp->full_name, mtd_node->full_name);
 127         ret = -EINVAL;
 128 ofpart_none:
 129         of_node_put(pp);
 130         kfree(*pparts);
 131         *pparts = NULL;
 132         return ret;
 133 }
 134
 135 static struct mtd_part_parser ofpart_parser = {
 136         .owner = THIS_MODULE,
 137         .parse_fn = parse_ofpart_partitions,
 138         .name = "ofpart",
 139 };
 140
 141 static int parse_ofoldpart_partitions(struct mtd_info *master,
 142                                       struct mtd_partition **pparts,
 143                                       struct mtd_part_parser_data *data)
 144 {
 145         struct device_node *dp;
 146         int i, plen, nr_parts;
 147         const struct {
 148                 __be32 offset, len;
 149         } *part;
 150         const char *names;
 151
 152         if (!data)
 153                 return 0;
 154
 155         dp = data->of_node;
 156         if (!dp)
 157                 return 0;
 158
 159         part = of_get_property(dp, "partitions", &plen);
 160         if (!part)
 161                 return 0; /* No partitions found */
 162
 163         pr_warning("Device tree uses obsolete partition map binding: %s\n",
 164                         dp->full_name);
 165
 166         nr_parts = plen / sizeof(part[0]);
 167
 168         *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
 169         if (!*pparts)
 170                 return -ENOMEM;
 171
 172         names = of_get_property(dp, "partition-names", &plen);
 173
 174         for (i = 0; i < nr_parts; i++) {
 175                 (*pparts)[i].offset = be32_to_cpu(part->offset);
 176                 (*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
 177                 /* bit 0 set signifies read only partition */
 178                 if (be32_to_cpu(part->len) & 1)
 179                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
 180
 181                 if (names && (plen > 0)) {
 182                         int len = strlen(names) + 1;
 183
 184                         (*pparts)[i].name = names;
 185                         plen -= len;
 186                         names += len;
 187                 } else {
 188                         (*pparts)[i].name = "unnamed";
 189                 }
 190
 191                 part++;
 192         }
 193
 194         return nr_parts;
 195 }
 196
 197 static struct mtd_part_parser ofoldpart_parser = {
 198         .owner = THIS_MODULE,
 199         .parse_fn = parse_ofoldpart_partitions,
 200         .name = "ofoldpart",
 201 };
 202
 203 static int __init ofpart_parser_init(void)
 204 {
 205         register_mtd_parser(&ofpart_parser);
 206         register_mtd_parser(&ofoldpart_parser);
 207         return 0;
 208 }
 209
 210 static void __exit ofpart_parser_exit(void)
 211 {
 212         deregister_mtd_parser(&ofpart_parser);
 213         deregister_mtd_parser(&ofoldpart_parser);
 214 }
 215
 216 module_init(ofpart_parser_init);
 217 module_exit(ofpart_parser_exit);
 218
 219 MODULE_LICENSE("GPL");
 220 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 221 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 222 /*
 223  * When MTD core cannot find the requested parser, it tries to load the module
 224  * with the same name. Since we provide the ofoldpart parser, we should have
 225  * the corresponding alias.
 226  */
 227 MODULE_ALIAS("ofoldpart");