linux/drivers/mtd/parsers/ofpart_core.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Flash partitions described by the OF (or flattened) device tree
   4 *
   5 * Copyright \xC2\xA9 2006 MontaVista Software Inc.
   6 * Author: Vitaly Wool <vwool@ru.mvista.com>
   7 *
   8 * Revised to handle newer style flash binding by:
   9 *   Copyright \xC2\xA9 2007 David Gibson, IBM Corporation.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/init.h>
  14#include <linux/of.h>
  15#include <linux/mtd/mtd.h>
  16#include <linux/slab.h>
  17#include <linux/mtd/partitions.h>
  18
  19#include "ofpart_bcm4908.h"
  20#include "ofpart_linksys_ns.h"
  21
  22struct fixed_partitions_quirks {
  23        int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
  24};
  25
  26static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
  27        .post_parse = bcm4908_partitions_post_parse,
  28};
  29
  30static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
  31        .post_parse = linksys_ns_partitions_post_parse,
  32};
  33
  34static const struct of_device_id parse_ofpart_match_table[];
  35
  36static bool node_has_compatible(struct device_node *pp)
  37{
  38        return of_get_property(pp, "compatible", NULL);
  39}
  40
  41static int parse_fixed_partitions(struct mtd_info *master,
  42                                  const struct mtd_partition **pparts,
  43                                  struct mtd_part_parser_data *data)
  44{
  45        const struct fixed_partitions_quirks *quirks;
  46        const struct of_device_id *of_id;
  47        struct mtd_partition *parts;
  48        struct device_node *mtd_node;
  49        struct device_node *ofpart_node;
  50        const char *partname;
  51        struct device_node *pp;
  52        int nr_parts, i, ret = 0;
  53        bool dedicated = true;
  54
  55        /* Pull of_node from the master device node */
  56        mtd_node = mtd_get_of_node(master);
  57        if (!mtd_node)
  58                return 0;
  59
  60        if (!master->parent) { /* Master */
  61                ofpart_node = of_get_child_by_name(mtd_node, "partitions");
  62                if (!ofpart_node) {
  63                        /*
  64                         * We might get here even when ofpart isn't used at all (e.g.,
  65                         * when using another parser), so don't be louder than
  66                         * KERN_DEBUG
  67                         */
  68                        pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
  69                                master->name, mtd_node);
  70                        ofpart_node = mtd_node;
  71                        dedicated = false;
  72                }
  73        } else { /* Partition */
  74                ofpart_node = mtd_node;
  75        }
  76
  77        of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
  78        if (dedicated && !of_id) {
  79                /* The 'partitions' subnode might be used by another parser */
  80                return 0;
  81        }
  82
  83        quirks = of_id ? of_id->data : NULL;
  84
  85        /* First count the subnodes */
  86        nr_parts = 0;
  87        for_each_child_of_node(ofpart_node,  pp) {
  88                if (!dedicated && node_has_compatible(pp))
  89                        continue;
  90
  91                nr_parts++;
  92        }
  93
  94        if (nr_parts == 0)
  95                return 0;
  96
  97        parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
  98        if (!parts)
  99                return -ENOMEM;
 100
 101        i = 0;
 102        for_each_child_of_node(ofpart_node,  pp) {
 103                const __be32 *reg;
 104                int len;
 105                int a_cells, s_cells;
 106
 107                if (!dedicated && node_has_compatible(pp))
 108                        continue;
 109
 110                reg = of_get_property(pp, "reg", &len);
 111                if (!reg) {
 112                        if (dedicated) {
 113                                pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
 114                                         master->name, pp,
 115                                         mtd_node);
 116                                goto ofpart_fail;
 117                        } else {
 118                                nr_parts--;
 119                                continue;
 120                        }
 121                }
 122
 123                a_cells = of_n_addr_cells(pp);
 124                s_cells = of_n_size_cells(pp);
 125                if (len / 4 != a_cells + s_cells) {
 126                        pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
 127                                 master->name, pp,
 128                                 mtd_node);
 129                        goto ofpart_fail;
 130                }
 131
 132                parts[i].offset = of_read_number(reg, a_cells);
 133                parts[i].size = of_read_number(reg + a_cells, s_cells);
 134                parts[i].of_node = pp;
 135
 136                partname = of_get_property(pp, "label", &len);
 137                if (!partname)
 138                        partname = of_get_property(pp, "name", &len);
 139                parts[i].name = partname;
 140
 141                if (of_get_property(pp, "read-only", &len))
 142                        parts[i].mask_flags |= MTD_WRITEABLE;
 143
 144                if (of_get_property(pp, "lock", &len))
 145                        parts[i].mask_flags |= MTD_POWERUP_LOCK;
 146
 147                if (of_property_read_bool(pp, "slc-mode"))
 148                        parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
 149
 150                i++;
 151        }
 152
 153        if (!nr_parts)
 154                goto ofpart_none;
 155
 156        if (quirks && quirks->post_parse)
 157                quirks->post_parse(master, parts, nr_parts);
 158
 159        *pparts = parts;
 160        return nr_parts;
 161
 162ofpart_fail:
 163        pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
 164               master->name, pp, mtd_node);
 165        ret = -EINVAL;
 166ofpart_none:
 167        of_node_put(pp);
 168        kfree(parts);
 169        return ret;
 170}
 171
 172static const struct of_device_id parse_ofpart_match_table[] = {
 173        /* Generic */
 174        { .compatible = "fixed-partitions" },
 175        /* Customized */
 176        { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
 177        { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
 178        {},
 179};
 180MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
 181
 182static struct mtd_part_parser ofpart_parser = {
 183        .parse_fn = parse_fixed_partitions,
 184        .name = "fixed-partitions",
 185        .of_match_table = parse_ofpart_match_table,
 186};
 187
 188static int parse_ofoldpart_partitions(struct mtd_info *master,
 189                                      const struct mtd_partition **pparts,
 190                                      struct mtd_part_parser_data *data)
 191{
 192        struct mtd_partition *parts;
 193        struct device_node *dp;
 194        int i, plen, nr_parts;
 195        const struct {
 196                __be32 offset, len;
 197        } *part;
 198        const char *names;
 199
 200        /* Pull of_node from the master device node */
 201        dp = mtd_get_of_node(master);
 202        if (!dp)
 203                return 0;
 204
 205        part = of_get_property(dp, "partitions", &plen);
 206        if (!part)
 207                return 0; /* No partitions found */
 208
 209        pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
 210
 211        nr_parts = plen / sizeof(part[0]);
 212
 213        parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
 214        if (!parts)
 215                return -ENOMEM;
 216
 217        names = of_get_property(dp, "partition-names", &plen);
 218
 219        for (i = 0; i < nr_parts; i++) {
 220                parts[i].offset = be32_to_cpu(part->offset);
 221                parts[i].size   = be32_to_cpu(part->len) & ~1;
 222                /* bit 0 set signifies read only partition */
 223                if (be32_to_cpu(part->len) & 1)
 224                        parts[i].mask_flags = MTD_WRITEABLE;
 225
 226                if (names && (plen > 0)) {
 227                        int len = strlen(names) + 1;
 228
 229                        parts[i].name = names;
 230                        plen -= len;
 231                        names += len;
 232                } else {
 233                        parts[i].name = "unnamed";
 234                }
 235
 236                part++;
 237        }
 238
 239        *pparts = parts;
 240        return nr_parts;
 241}
 242
 243static struct mtd_part_parser ofoldpart_parser = {
 244        .parse_fn = parse_ofoldpart_partitions,
 245        .name = "ofoldpart",
 246};
 247
 248static int __init ofpart_parser_init(void)
 249{
 250        register_mtd_parser(&ofpart_parser);
 251        register_mtd_parser(&ofoldpart_parser);
 252        return 0;
 253}
 254
 255static void __exit ofpart_parser_exit(void)
 256{
 257        deregister_mtd_parser(&ofpart_parser);
 258        deregister_mtd_parser(&ofoldpart_parser);
 259}
 260
 261module_init(ofpart_parser_init);
 262module_exit(ofpart_parser_exit);
 263
 264MODULE_LICENSE("GPL");
 265MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 266MODULE_AUTHOR("Vitaly Wool, David Gibson");
 267/*
 268 * When MTD core cannot find the requested parser, it tries to load the module
 269 * with the same name. Since we provide the ofoldpart parser, we should have
 270 * the corresponding alias.
 271 */
 272MODULE_ALIAS("fixed-partitions");
 273MODULE_ALIAS("ofoldpart");
 274