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