target/linux/bcm4908/patches-5.4/140-0003-mtd-parsers-ofpart-support-BCM4908-fixed-partitions.patch

   1 From db18357719613cc40234300b10e28e4dfa075375 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Fri, 15 Jan 2021 16:23:01 +0100
   4 Subject: [PATCH 3/3] mtd: parsers: ofpart: support BCM4908 fixed partitions
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 BCM4908 partitioning is based on fixed layout but allows specifying
  10 multiple firmware partitions. It requires detecting which firmware
  11 partition was used for booting current kernel.
  12
  13 To support such cases without duplicating a lot of code (without copying
  14 most of the ofpart.c code) support for post-parsing callback was added.
  15
  16 BCM4908 callback simply reads offset of currently used firmware
  17 partition from the DT. Bootloader specifies it using the "brcm_blparms"
  18 property.
  19
  20 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  21 ---
  22  drivers/mtd/parsers/Makefile             |  1 +
  23  drivers/mtd/parsers/bcm4908-partitions.c | 62 ++++++++++++++++++++++++
  24  drivers/mtd/parsers/bcm4908-partitions.h |  7 +++
  25  drivers/mtd/parsers/ofpart.c             | 28 ++++++++++-
  26  4 files changed, 96 insertions(+), 2 deletions(-)
  27  create mode 100644 drivers/mtd/parsers/bcm4908-partitions.c
  28  create mode 100644 drivers/mtd/parsers/bcm4908-partitions.h
  29
  30 --- a/drivers/mtd/parsers/Makefile
  31 +++ b/drivers/mtd/parsers/Makefile
  32 @@ -5,6 +5,7 @@ obj-$(CONFIG_MTD_BCM63XX_PARTS)         += bcm6
  33  obj-$(CONFIG_MTD_CMDLINE_PARTS)                += cmdlinepart.o
  34  obj-$(CONFIG_MTD_MYLOADER_PARTS)               += myloader.o
  35  obj-$(CONFIG_MTD_OF_PARTS)             += ofpart.o
  36 +obj-$(CONFIG_MTD_OF_PARTS)             += bcm4908-partitions.o
  37  obj-$(CONFIG_MTD_PARSER_IMAGETAG)      += parser_imagetag.o
  38  obj-$(CONFIG_MTD_AFS_PARTS)            += afs.o
  39  obj-$(CONFIG_MTD_PARSER_TRX)           += parser_trx.o
  40 --- /dev/null
  41 +++ b/drivers/mtd/parsers/bcm4908-partitions.c
  42 @@ -0,0 +1,62 @@
  43 +// SPDX-License-Identifier: GPL-2.0
  44 +/*
  45 + * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
  46 + */
  47 +
  48 +#include <linux/module.h>
  49 +#include <linux/init.h>
  50 +#include <linux/of.h>
  51 +#include <linux/mtd/mtd.h>
  52 +#include <linux/slab.h>
  53 +#include <linux/mtd/partitions.h>
  54 +
  55 +#define BLPARAMS_FW_OFFSET             "NAND_RFS_OFS"
  56 +
  57 +static long long bcm4908_partitions_fw_offset(void)
  58 +{
  59 +       struct device_node *root;
  60 +       struct property *prop;
  61 +       const char *s;
  62 +
  63 +       root = of_find_node_by_path("/");
  64 +       if (!root)
  65 +               return -ENOENT;
  66 +
  67 +       of_property_for_each_string(root, "brcm_blparms", prop, s) {
  68 +               size_t len = strlen(BLPARAMS_FW_OFFSET);
  69 +               unsigned long offset;
  70 +               int err;
  71 +
  72 +               if (strncmp(s, BLPARAMS_FW_OFFSET, len) || s[len] != '=')
  73 +                       continue;
  74 +
  75 +               err = kstrtoul(s + len + 1, 0, &offset);
  76 +               if (err) {
  77 +                       pr_err("failed to parse %s\n", s + len + 1);
  78 +                       return err;
  79 +               }
  80 +
  81 +               return offset << 10;
  82 +       }
  83 +
  84 +       return -ENOENT;
  85 +}
  86 +
  87 +int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts)
  88 +{
  89 +       long long fw_offset;
  90 +       int i;
  91 +
  92 +       fw_offset = bcm4908_partitions_fw_offset();
  93 +
  94 +       for (i = 0; i < nr_parts; i++) {
  95 +               if (of_device_is_compatible(parts[i].of_node, "brcm,bcm4908-firmware")) {
  96 +                       if (fw_offset < 0 || parts[i].offset == fw_offset)
  97 +                               parts[i].name = "firmware";
  98 +                       else
  99 +                               parts[i].name = "backup";
 100 +               }
 101 +       }
 102 +
 103 +       return 0;
 104 +}
 105 --- /dev/null
 106 +++ b/drivers/mtd/parsers/bcm4908-partitions.h
 107 @@ -0,0 +1,7 @@
 108 +/* SPDX-License-Identifier: GPL-2.0 */
 109 +#ifndef __BCM4908_PARTITIONS_H
 110 +#define __BCM4908_PARTITIONS_H
 111 +
 112 +int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
 113 +
 114 +#endif
 115 --- a/drivers/mtd/parsers/ofpart.c
 116 +++ b/drivers/mtd/parsers/ofpart.c
 117 @@ -16,6 +16,18 @@
 118  #include <linux/slab.h>
 119  #include <linux/mtd/partitions.h>
 120
 121 +#include "bcm4908-partitions.h"
 122 +
 123 +struct fixed_partitions_quirks {
 124 +       int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
 125 +};
 126 +
 127 +struct fixed_partitions_quirks bcm4908_partitions_quirks = {
 128 +       .post_parse = bcm4908_partitions_post_parse,
 129 +};
 130 +
 131 +static const struct of_device_id parse_ofpart_match_table[];
 132 +
 133  static bool node_has_compatible(struct device_node *pp)
 134  {
 135         return of_get_property(pp, "compatible", NULL);
 136 @@ -25,6 +37,8 @@ static int parse_fixed_partitions(struct
 137                                   const struct mtd_partition **pparts,
 138                                   struct mtd_part_parser_data *data)
 139  {
 140 +       const struct fixed_partitions_quirks *quirks;
 141 +       const struct of_device_id *of_id;
 142         struct mtd_partition *parts;
 143         struct device_node *mtd_node;
 144         struct device_node *ofpart_node;
 145 @@ -33,7 +47,6 @@ static int parse_fixed_partitions(struct
 146         int nr_parts, i, ret = 0;
 147         bool dedicated = true;
 148
 149 -
 150         /* Pull of_node from the master device node */
 151         mtd_node = mtd_get_of_node(master);
 152         if (!mtd_node)
 153 @@ -50,11 +63,16 @@ static int parse_fixed_partitions(struct
 154                          master->name, mtd_node);
 155                 ofpart_node = mtd_node;
 156                 dedicated = false;
 157 -       } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
 158 +       }
 159 +
 160 +       of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
 161 +       if (dedicated && !of_id) {
 162                 /* The 'partitions' subnode might be used by another parser */
 163                 return 0;
 164         }
 165
 166 +       quirks = of_id ? of_id->data : NULL;
 167 +
 168         /* First count the subnodes */
 169         nr_parts = 0;
 170         for_each_child_of_node(ofpart_node,  pp) {
 171 @@ -123,6 +141,9 @@ static int parse_fixed_partitions(struct
 172         if (!nr_parts)
 173                 goto ofpart_none;
 174
 175 +       if (quirks && quirks->post_parse)
 176 +               quirks->post_parse(master, parts, nr_parts);
 177 +
 178         *pparts = parts;
 179         return nr_parts;
 180
 181 @@ -137,7 +158,10 @@ ofpart_none:
 182  }
 183
 184  static const struct of_device_id parse_ofpart_match_table[] = {
 185 +       /* Generic */
 186         { .compatible = "fixed-partitions" },
 187 +       /* Customized */
 188 +       { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
 189         {},
 190  };
 191  MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);