target/linux/generic/backport-5.4/402-v5.12-0003-mtd-parsers-ofpart-support-BCM4908-fixed-partitions.patch

   1 From 09cf6ee6d21cd9ef2eb857ccb24305cf51166792 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Thu, 11 Feb 2021 23:04:27 +0100
   4 Subject: [PATCH] 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 Signed-off-by: Richard Weinberger <richard@nod.at>
  22 ---
  23  drivers/mtd/parsers/Makefile             |  1 +
  24  drivers/mtd/parsers/bcm4908-partitions.c | 64 ++++++++++++++++++++++++
  25  drivers/mtd/parsers/bcm4908-partitions.h |  7 +++
  26  drivers/mtd/parsers/ofpart.c             | 28 ++++++++++-
  27  4 files changed, 98 insertions(+), 2 deletions(-)
  28  create mode 100644 drivers/mtd/parsers/bcm4908-partitions.c
  29  create mode 100644 drivers/mtd/parsers/bcm4908-partitions.h
  30
  31 --- a/drivers/mtd/parsers/Makefile
  32 +++ b/drivers/mtd/parsers/Makefile
  33 @@ -4,6 +4,7 @@ obj-$(CONFIG_MTD_BCM47XX_PARTS)         += bcm4
  34  obj-$(CONFIG_MTD_BCM63XX_PARTS)                += bcm63xxpart.o
  35  obj-$(CONFIG_MTD_CMDLINE_PARTS)                += cmdlinepart.o
  36  obj-$(CONFIG_MTD_OF_PARTS)             += ofpart.o
  37 +obj-$(CONFIG_MTD_OF_PARTS)             += bcm4908-partitions.o
  38  obj-$(CONFIG_MTD_PARSER_IMAGETAG)      += parser_imagetag.o
  39  obj-$(CONFIG_MTD_AFS_PARTS)            += afs.o
  40  obj-$(CONFIG_MTD_PARSER_TRX)           += parser_trx.o
  41 --- /dev/null
  42 +++ b/drivers/mtd/parsers/bcm4908-partitions.c
  43 @@ -0,0 +1,64 @@
  44 +// SPDX-License-Identifier: GPL-2.0
  45 +/*
  46 + * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
  47 + */
  48 +
  49 +#include <linux/module.h>
  50 +#include <linux/init.h>
  51 +#include <linux/of.h>
  52 +#include <linux/mtd/mtd.h>
  53 +#include <linux/slab.h>
  54 +#include <linux/mtd/partitions.h>
  55 +
  56 +#include "bcm4908-partitions.h"
  57 +
  58 +#define BLPARAMS_FW_OFFSET             "NAND_RFS_OFS"
  59 +
  60 +static long long bcm4908_partitions_fw_offset(void)
  61 +{
  62 +       struct device_node *root;
  63 +       struct property *prop;
  64 +       const char *s;
  65 +
  66 +       root = of_find_node_by_path("/");
  67 +       if (!root)
  68 +               return -ENOENT;
  69 +
  70 +       of_property_for_each_string(root, "brcm_blparms", prop, s) {
  71 +               size_t len = strlen(BLPARAMS_FW_OFFSET);
  72 +               unsigned long offset;
  73 +               int err;
  74 +
  75 +               if (strncmp(s, BLPARAMS_FW_OFFSET, len) || s[len] != '=')
  76 +                       continue;
  77 +
  78 +               err = kstrtoul(s + len + 1, 0, &offset);
  79 +               if (err) {
  80 +                       pr_err("failed to parse %s\n", s + len + 1);
  81 +                       return err;
  82 +               }
  83 +
  84 +               return offset << 10;
  85 +       }
  86 +
  87 +       return -ENOENT;
  88 +}
  89 +
  90 +int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts)
  91 +{
  92 +       long long fw_offset;
  93 +       int i;
  94 +
  95 +       fw_offset = bcm4908_partitions_fw_offset();
  96 +
  97 +       for (i = 0; i < nr_parts; i++) {
  98 +               if (of_device_is_compatible(parts[i].of_node, "brcm,bcm4908-firmware")) {
  99 +                       if (fw_offset < 0 || parts[i].offset == fw_offset)
 100 +                               parts[i].name = "firmware";
 101 +                       else
 102 +                               parts[i].name = "backup";
 103 +               }
 104 +       }
 105 +
 106 +       return 0;
 107 +}
 108 --- /dev/null
 109 +++ b/drivers/mtd/parsers/bcm4908-partitions.h
 110 @@ -0,0 +1,7 @@
 111 +/* SPDX-License-Identifier: GPL-2.0 */
 112 +#ifndef __BCM4908_PARTITIONS_H
 113 +#define __BCM4908_PARTITIONS_H
 114 +
 115 +int bcm4908_partitions_post_parse(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
 116 +
 117 +#endif
 118 --- a/drivers/mtd/parsers/ofpart.c
 119 +++ b/drivers/mtd/parsers/ofpart.c
 120 @@ -16,6 +16,18 @@
 121  #include <linux/slab.h>
 122  #include <linux/mtd/partitions.h>
 123
 124 +#include "bcm4908-partitions.h"
 125 +
 126 +struct fixed_partitions_quirks {
 127 +       int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
 128 +};
 129 +
 130 +struct fixed_partitions_quirks bcm4908_partitions_quirks = {
 131 +       .post_parse = bcm4908_partitions_post_parse,
 132 +};
 133 +
 134 +static const struct of_device_id parse_ofpart_match_table[];
 135 +
 136  static bool node_has_compatible(struct device_node *pp)
 137  {
 138         return of_get_property(pp, "compatible", NULL);
 139 @@ -25,6 +37,8 @@ static int parse_fixed_partitions(struct
 140                                   const struct mtd_partition **pparts,
 141                                   struct mtd_part_parser_data *data)
 142  {
 143 +       const struct fixed_partitions_quirks *quirks;
 144 +       const struct of_device_id *of_id;
 145         struct mtd_partition *parts;
 146         struct device_node *mtd_node;
 147         struct device_node *ofpart_node;
 148 @@ -33,7 +47,6 @@ static int parse_fixed_partitions(struct
 149         int nr_parts, i, ret = 0;
 150         bool dedicated = true;
 151
 152 -
 153         /* Pull of_node from the master device node */
 154         mtd_node = mtd_get_of_node(master);
 155         if (!mtd_node)
 156 @@ -50,11 +63,16 @@ static int parse_fixed_partitions(struct
 157                          master->name, mtd_node);
 158                 ofpart_node = mtd_node;
 159                 dedicated = false;
 160 -       } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) {
 161 +       }
 162 +
 163 +       of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
 164 +       if (dedicated && !of_id) {
 165                 /* The 'partitions' subnode might be used by another parser */
 166                 return 0;
 167         }
 168
 169 +       quirks = of_id ? of_id->data : NULL;
 170 +
 171         /* First count the subnodes */
 172         nr_parts = 0;
 173         for_each_child_of_node(ofpart_node,  pp) {
 174 @@ -123,6 +141,9 @@ static int parse_fixed_partitions(struct
 175         if (!nr_parts)
 176                 goto ofpart_none;
 177
 178 +       if (quirks && quirks->post_parse)
 179 +               quirks->post_parse(master, parts, nr_parts);
 180 +
 181         *pparts = parts;
 182         return nr_parts;
 183
 184 @@ -137,7 +158,10 @@ ofpart_none:
 185  }
 186
 187  static const struct of_device_id parse_ofpart_match_table[] = {
 188 +       /* Generic */
 189         { .compatible = "fixed-partitions" },
 190 +       /* Customized */
 191 +       { .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
 192         {},
 193  };
 194  MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);