linux/drivers/mtd/ofpart.c
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   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
  23static bool node_has_compatible(struct device_node *pp)
  24{
  25        return of_get_property(pp, "compatible", NULL);
  26}
  27
  28static 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 = (char *)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
 106static struct mtd_part_parser ofpart_parser = {
 107        .owner = THIS_MODULE,
 108        .parse_fn = parse_ofpart_partitions,
 109        .name = "ofpart",
 110};
 111
 112static 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 = (char *)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
 168static struct mtd_part_parser ofoldpart_parser = {
 169        .owner = THIS_MODULE,
 170        .parse_fn = parse_ofoldpart_partitions,
 171        .name = "ofoldpart",
 172};
 173
 174static int __init ofpart_parser_init(void)
 175{
 176        int rc;
 177        rc = register_mtd_parser(&ofpart_parser);
 178        if (rc)
 179                goto out;
 180
 181        rc = register_mtd_parser(&ofoldpart_parser);
 182        if (!rc)
 183                return 0;
 184
 185        deregister_mtd_parser(&ofoldpart_parser);
 186out:
 187        return rc;
 188}
 189
 190static void __exit ofpart_parser_exit(void)
 191{
 192        deregister_mtd_parser(&ofpart_parser);
 193        deregister_mtd_parser(&ofoldpart_parser);
 194}
 195
 196module_init(ofpart_parser_init);
 197module_exit(ofpart_parser_exit);
 198
 199MODULE_LICENSE("GPL");
 200MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 201MODULE_AUTHOR("Vitaly Wool, David Gibson");
 202/*
 203 * When MTD core cannot find the requested parser, it tries to load the module
 204 * with the same name. Since we provide the ofoldpart parser, we should have
 205 * the corresponding alias.
 206 */
 207MODULE_ALIAS("ofoldpart");
 208
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