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                 /*
  50                  * We might get here even when ofpart isn't used at all (e.g.,
  51                  * when using another parser), so don't be louder than
  52                  * KERN_DEBUG
  53                  */
  54                 pr_debug("%s: 'partitions' subnode not found on %s. Trying to parse direct subnodes as partitions.\n",
  55                          master->name, mtd_node->full_name);
  56                 ofpart_node = mtd_node;
  57                 dedicated = false;
  58         } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
  59                 /* The 'partitions' subnode might be used by another parser */
  60                 return 0;
  61         }
  62
  63         /* First count the subnodes */
  64         nr_parts = 0;
  65         for_each_child_of_node(ofpart_node,  pp) {
  66                 if (!dedicated && node_has_compatible(pp))
  67                         continue;
  68
  69                 nr_parts++;
  70         }
  71
  72         if (nr_parts == 0)
  73                 return 0;
  74
  75         *pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
  76         if (!*pparts)
  77                 return -ENOMEM;
  78
  79         i = 0;
  80         for_each_child_of_node(ofpart_node,  pp) {
  81                 const __be32 *reg;
  82                 int len;
  83                 int a_cells, s_cells;
  84
  85                 if (!dedicated && node_has_compatible(pp))
  86                         continue;
  87
  88                 reg = of_get_property(pp, "reg", &len);
  89                 if (!reg) {
  90                         if (dedicated) {
  91                                 pr_debug("%s: ofpart partition %s (%s) missing reg property.\n",
  92                                          master->name, pp->full_name,
  93                                          mtd_node->full_name);
  94                                 goto ofpart_fail;
  95                         } else {
  96                                 nr_parts--;
  97                                 continue;
  98                         }
  99                 }
 100
 101                 a_cells = of_n_addr_cells(pp);
 102                 s_cells = of_n_size_cells(pp);
 103                 if (len / 4 != a_cells + s_cells) {
 104                         pr_debug("%s: ofpart partition %s (%s) error parsing reg property.\n",
 105                                  master->name, pp->full_name,
 106                                  mtd_node->full_name);
 107                         goto ofpart_fail;
 108                 }
 109
 110                 (*pparts)[i].offset = of_read_number(reg, a_cells);
 111                 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
 112
 113                 partname = of_get_property(pp, "label", &len);
 114                 if (!partname)
 115                         partname = of_get_property(pp, "name", &len);
 116                 (*pparts)[i].name = partname;
 117
 118                 if (of_get_property(pp, "read-only", &len))
 119                         (*pparts)[i].mask_flags |= MTD_WRITEABLE;
 120
 121                 if (of_get_property(pp, "lock", &len))
 122                         (*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;
 123
 124                 i++;
 125         }
 126
 127         if (!nr_parts)
 128                 goto ofpart_none;
 129
 130         return nr_parts;
 131
 132 ofpart_fail:
 133         pr_err("%s: error parsing ofpart partition %s (%s)\n",
 134                master->name, pp->full_name, mtd_node->full_name);
 135         ret = -EINVAL;
 136 ofpart_none:
 137         of_node_put(pp);
 138         kfree(*pparts);
 139         *pparts = NULL;
 140         return ret;
 141 }
 142
 143 static struct mtd_part_parser ofpart_parser = {
 144         .owner = THIS_MODULE,
 145         .parse_fn = parse_ofpart_partitions,
 146         .name = "ofpart",
 147 };
 148
 149 static int parse_ofoldpart_partitions(struct mtd_info *master,
 150                                       struct mtd_partition **pparts,
 151                                       struct mtd_part_parser_data *data)
 152 {
 153         struct device_node *dp;
 154         int i, plen, nr_parts;
 155         const struct {
 156                 __be32 offset, len;
 157         } *part;
 158         const char *names;
 159
 160         if (!data)
 161                 return 0;
 162
 163         dp = data->of_node;
 164         if (!dp)
 165                 return 0;
 166
 167         part = of_get_property(dp, "partitions", &plen);
 168         if (!part)
 169                 return 0; /* No partitions found */
 170
 171         pr_warning("Device tree uses obsolete partition map binding: %s\n",
 172                         dp->full_name);
 173
 174         nr_parts = plen / sizeof(part[0]);
 175
 176         *pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);
 177         if (!*pparts)
 178                 return -ENOMEM;
 179
 180         names = of_get_property(dp, "partition-names", &plen);
 181
 182         for (i = 0; i < nr_parts; i++) {
 183                 (*pparts)[i].offset = be32_to_cpu(part->offset);
 184                 (*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
 185                 /* bit 0 set signifies read only partition */
 186                 if (be32_to_cpu(part->len) & 1)
 187                         (*pparts)[i].mask_flags = MTD_WRITEABLE;
 188
 189                 if (names && (plen > 0)) {
 190                         int len = strlen(names) + 1;
 191
 192                         (*pparts)[i].name = names;
 193                         plen -= len;
 194                         names += len;
 195                 } else {
 196                         (*pparts)[i].name = "unnamed";
 197                 }
 198
 199                 part++;
 200         }
 201
 202         return nr_parts;
 203 }
 204
 205 static struct mtd_part_parser ofoldpart_parser = {
 206         .owner = THIS_MODULE,
 207         .parse_fn = parse_ofoldpart_partitions,
 208         .name = "ofoldpart",
 209 };
 210
 211 static int __init ofpart_parser_init(void)
 212 {
 213         register_mtd_parser(&ofpart_parser);
 214         register_mtd_parser(&ofoldpart_parser);
 215         return 0;
 216 }
 217
 218 static void __exit ofpart_parser_exit(void)
 219 {
 220         deregister_mtd_parser(&ofpart_parser);
 221         deregister_mtd_parser(&ofoldpart_parser);
 222 }
 223
 224 module_init(ofpart_parser_init);
 225 module_exit(ofpart_parser_exit);
 226
 227 MODULE_LICENSE("GPL");
 228 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 229 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 230 /*
 231  * When MTD core cannot find the requested parser, it tries to load the module
 232  * with the same name. Since we provide the ofoldpart parser, we should have
 233  * the corresponding alias.
 234  */
 235 MODULE_ALIAS("ofoldpart");