mtd/parsers/ofpart_core.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Flash partitions described by the OF (or flattened) device tree
0004  *
0005  * Copyright © 2006 MontaVista Software Inc.
0006  * Author: Vitaly Wool <vwool@ru.mvista.com>
0007  *
0008  * Revised to handle newer style flash binding by:
0009  *   Copyright © 2007 David Gibson, IBM Corporation.
0010  */
0011
0012 #include <linux/module.h>
0013 #include <linux/init.h>
0014 #include <linux/of.h>
0015 #include <linux/mtd/mtd.h>
0016 #include <linux/slab.h>
0017 #include <linux/mtd/partitions.h>
0018
0019 #include "ofpart_bcm4908.h"
0020 #include "ofpart_linksys_ns.h"
0021
0022 struct fixed_partitions_quirks {
0023     int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
0024 };
0025
0026 static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
0027     .post_parse = bcm4908_partitions_post_parse,
0028 };
0029
0030 static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
0031     .post_parse = linksys_ns_partitions_post_parse,
0032 };
0033
0034 static const struct of_device_id parse_ofpart_match_table[];
0035
0036 static bool node_has_compatible(struct device_node *pp)
0037 {
0038     return of_get_property(pp, "compatible", NULL);
0039 }
0040
0041 static int parse_fixed_partitions(struct mtd_info *master,
0042                   const struct mtd_partition **pparts,
0043                   struct mtd_part_parser_data *data)
0044 {
0045     const struct fixed_partitions_quirks *quirks;
0046     const struct of_device_id *of_id;
0047     struct mtd_partition *parts;
0048     struct device_node *mtd_node;
0049     struct device_node *ofpart_node;
0050     const char *partname;
0051     struct device_node *pp;
0052     int nr_parts, i, ret = 0;
0053     bool dedicated = true;
0054
0055     /* Pull of_node from the master device node */
0056     mtd_node = mtd_get_of_node(master);
0057     if (!mtd_node)
0058         return 0;
0059
0060     if (!master->parent) { /* Master */
0061         ofpart_node = of_get_child_by_name(mtd_node, "partitions");
0062         if (!ofpart_node) {
0063             /*
0064              * We might get here even when ofpart isn't used at all (e.g.,
0065              * when using another parser), so don't be louder than
0066              * KERN_DEBUG
0067              */
0068             pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
0069                 master->name, mtd_node);
0070             ofpart_node = mtd_node;
0071             dedicated = false;
0072         }
0073     } else { /* Partition */
0074         ofpart_node = mtd_node;
0075     }
0076
0077     of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
0078     if (dedicated && !of_id) {
0079         /* The 'partitions' subnode might be used by another parser */
0080         return 0;
0081     }
0082
0083     quirks = of_id ? of_id->data : NULL;
0084
0085     /* First count the subnodes */
0086     nr_parts = 0;
0087     for_each_child_of_node(ofpart_node,  pp) {
0088         if (!dedicated && node_has_compatible(pp))
0089             continue;
0090
0091         nr_parts++;
0092     }
0093
0094     if (nr_parts == 0)
0095         return 0;
0096
0097     parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
0098     if (!parts)
0099         return -ENOMEM;
0100
0101     i = 0;
0102     for_each_child_of_node(ofpart_node,  pp) {
0103         const __be32 *reg;
0104         int len;
0105         int a_cells, s_cells;
0106
0107         if (!dedicated && node_has_compatible(pp))
0108             continue;
0109
0110         reg = of_get_property(pp, "reg", &len);
0111         if (!reg) {
0112             if (dedicated) {
0113                 pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
0114                      master->name, pp,
0115                      mtd_node);
0116                 goto ofpart_fail;
0117             } else {
0118                 nr_parts--;
0119                 continue;
0120             }
0121         }
0122
0123         a_cells = of_n_addr_cells(pp);
0124         s_cells = of_n_size_cells(pp);
0125         if (len / 4 != a_cells + s_cells) {
0126             pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
0127                  master->name, pp,
0128                  mtd_node);
0129             goto ofpart_fail;
0130         }
0131
0132         parts[i].offset = of_read_number(reg, a_cells);
0133         parts[i].size = of_read_number(reg + a_cells, s_cells);
0134         parts[i].of_node = pp;
0135
0136         partname = of_get_property(pp, "label", &len);
0137         if (!partname)
0138             partname = of_get_property(pp, "name", &len);
0139         parts[i].name = partname;
0140
0141         if (of_get_property(pp, "read-only", &len))
0142             parts[i].mask_flags |= MTD_WRITEABLE;
0143
0144         if (of_get_property(pp, "lock", &len))
0145             parts[i].mask_flags |= MTD_POWERUP_LOCK;
0146
0147         if (of_property_read_bool(pp, "slc-mode"))
0148             parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;
0149
0150         i++;
0151     }
0152
0153     if (!nr_parts)
0154         goto ofpart_none;
0155
0156     if (quirks && quirks->post_parse)
0157         quirks->post_parse(master, parts, nr_parts);
0158
0159     *pparts = parts;
0160     return nr_parts;
0161
0162 ofpart_fail:
0163     pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
0164            master->name, pp, mtd_node);
0165     ret = -EINVAL;
0166 ofpart_none:
0167     of_node_put(pp);
0168     kfree(parts);
0169     return ret;
0170 }
0171
0172 static const struct of_device_id parse_ofpart_match_table[] = {
0173     /* Generic */
0174     { .compatible = "fixed-partitions" },
0175     /* Customized */
0176     { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
0177     { .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
0178     {},
0179 };
0180 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);
0181
0182 static struct mtd_part_parser ofpart_parser = {
0183     .parse_fn = parse_fixed_partitions,
0184     .name = "fixed-partitions",
0185     .of_match_table = parse_ofpart_match_table,
0186 };
0187
0188 static int parse_ofoldpart_partitions(struct mtd_info *master,
0189                       const struct mtd_partition **pparts,
0190                       struct mtd_part_parser_data *data)
0191 {
0192     struct mtd_partition *parts;
0193     struct device_node *dp;
0194     int i, plen, nr_parts;
0195     const struct {
0196         __be32 offset, len;
0197     } *part;
0198     const char *names;
0199
0200     /* Pull of_node from the master device node */
0201     dp = mtd_get_of_node(master);
0202     if (!dp)
0203         return 0;
0204
0205     part = of_get_property(dp, "partitions", &plen);
0206     if (!part)
0207         return 0; /* No partitions found */
0208
0209     pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);
0210
0211     nr_parts = plen / sizeof(part[0]);
0212
0213     parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
0214     if (!parts)
0215         return -ENOMEM;
0216
0217     names = of_get_property(dp, "partition-names", &plen);
0218
0219     for (i = 0; i < nr_parts; i++) {
0220         parts[i].offset = be32_to_cpu(part->offset);
0221         parts[i].size   = be32_to_cpu(part->len) & ~1;
0222         /* bit 0 set signifies read only partition */
0223         if (be32_to_cpu(part->len) & 1)
0224             parts[i].mask_flags = MTD_WRITEABLE;
0225
0226         if (names && (plen > 0)) {
0227             int len = strlen(names) + 1;
0228
0229             parts[i].name = names;
0230             plen -= len;
0231             names += len;
0232         } else {
0233             parts[i].name = "unnamed";
0234         }
0235
0236         part++;
0237     }
0238
0239     *pparts = parts;
0240     return nr_parts;
0241 }
0242
0243 static struct mtd_part_parser ofoldpart_parser = {
0244     .parse_fn = parse_ofoldpart_partitions,
0245     .name = "ofoldpart",
0246 };
0247
0248 static int __init ofpart_parser_init(void)
0249 {
0250     register_mtd_parser(&ofpart_parser);
0251     register_mtd_parser(&ofoldpart_parser);
0252     return 0;
0253 }
0254
0255 static void __exit ofpart_parser_exit(void)
0256 {
0257     deregister_mtd_parser(&ofpart_parser);
0258     deregister_mtd_parser(&ofoldpart_parser);
0259 }
0260
0261 module_init(ofpart_parser_init);
0262 module_exit(ofpart_parser_exit);
0263
0264 MODULE_LICENSE("GPL");
0265 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
0266 MODULE_AUTHOR("Vitaly Wool, David Gibson");
0267 /*
0268  * When MTD core cannot find the requested parser, it tries to load the module
0269  * with the same name. Since we provide the ofoldpart parser, we should have
0270  * the corresponding alias.
0271  */
0272 MODULE_ALIAS("fixed-partitions");
0273 MODULE_ALIAS("ofoldpart");