target/linux/generic/hack-5.10/422-drivers-mtd-parsers-add-nvmem-support-to-cmdlinepart.patch

   1 From 6fa9e3678eb002246df1280322b6a024853950a5 Mon Sep 17 00:00:00 2001
   2 From: Ansuel Smith <ansuelsmth@gmail.com>
   3 Date: Mon, 11 Oct 2021 00:53:14 +0200
   4 Subject: [PATCH] drivers: mtd: parsers: add nvmem support to cmdlinepart
   5
   6 Assuming cmdlinepart is only one level deep partition scheme and that
   7 static partition are also defined in DTS, we can assign an of_node for
   8 partition declared from bootargs. cmdlinepart have priority than
   9 fiexed-partition parser so in this specific case the parser doesn't
  10 assign an of_node. Fix this by searching a defined of_node using a
  11 similar fixed_partition parser and if a partition is found with the same
  12 label, check that it has the same offset and size and return the DT
  13 of_node to correctly use NVMEM cells.
  14
  15 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
  16 ---
  17  drivers/mtd/parsers/cmdlinepart.c | 71 +++++++++++++++++++++++++++++++
  18  1 file changed, 71 insertions(+)
  19
  20 --- a/drivers/mtd/parsers/cmdlinepart.c
  21 +++ b/drivers/mtd/parsers/cmdlinepart.c
  22 @@ -43,6 +43,7 @@
  23  #include <linux/mtd/partitions.h>
  24  #include <linux/module.h>
  25  #include <linux/err.h>
  26 +#include <linux/of.h>
  27
  28  /* debug macro */
  29  #if 0
  30 @@ -323,6 +324,68 @@ static int mtdpart_setup_real(char *s)
  31         return 0;
  32  }
  33
  34 +static int search_fixed_partition(struct mtd_info *master,
  35 +                                 struct mtd_partition *target_part,
  36 +                                 struct mtd_partition *fixed_part)
  37 +{
  38 +       struct device_node *mtd_node;
  39 +       struct device_node *ofpart_node;
  40 +       struct device_node *pp;
  41 +       struct mtd_partition part;
  42 +       const char *partname;
  43 +
  44 +       mtd_node = mtd_get_of_node(master);
  45 +       if (!mtd_node)
  46 +               return -EINVAL;
  47 +
  48 +       ofpart_node = of_get_child_by_name(mtd_node, "partitions");
  49 +
  50 +       for_each_child_of_node(ofpart_node,  pp) {
  51 +               const __be32 *reg;
  52 +               int len;
  53 +               int a_cells, s_cells;
  54 +
  55 +               reg = of_get_property(pp, "reg", &len);
  56 +               if (!reg) {
  57 +                       pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
  58 +                                master->name, pp,
  59 +                                mtd_node);
  60 +                       continue;
  61 +               }
  62 +
  63 +               a_cells = of_n_addr_cells(pp);
  64 +               s_cells = of_n_size_cells(pp);
  65 +               if (len / 4 != a_cells + s_cells) {
  66 +                       pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
  67 +                                master->name, pp,
  68 +                                mtd_node);
  69 +                       continue;
  70 +               }
  71 +
  72 +               part.offset = of_read_number(reg, a_cells);
  73 +               part.size = of_read_number(reg + a_cells, s_cells);
  74 +               part.of_node = pp;
  75 +
  76 +               partname = of_get_property(pp, "label", &len);
  77 +               if (!partname)
  78 +                       partname = of_get_property(pp, "name", &len);
  79 +               part.name = partname;
  80 +
  81 +               if (!strncmp(target_part->name, part.name, len)) {
  82 +                       if (part.offset != target_part->offset)
  83 +                               return -EINVAL;
  84 +
  85 +                       if (part.size != target_part->size)
  86 +                               return -EINVAL;
  87 +
  88 +                       memcpy(fixed_part, &part, sizeof(struct mtd_partition));
  89 +                       return 0;
  90 +               }
  91 +       }
  92 +
  93 +       return -EINVAL;
  94 +}
  95 +
  96  /*
  97   * Main function to be called from the MTD mapping driver/device to
  98   * obtain the partitioning information. At this point the command line
  99 @@ -338,6 +401,7 @@ static int parse_cmdline_partitions(stru
 100         int i, err;
 101         struct cmdline_mtd_partition *part;
 102         const char *mtd_id = master->name;
 103 +       struct mtd_partition fixed_part;
 104
 105         /* parse command line */
 106         if (!cmdline_parsed) {
 107 @@ -382,6 +446,13 @@ static int parse_cmdline_partitions(stru
 108                                 sizeof(*part->parts) * (part->num_parts - i));
 109                         i--;
 110                 }
 111 +
 112 +               err = search_fixed_partition(master, &part->parts[i], &fixed_part);
 113 +               if (!err) {
 114 +                       part->parts[i].of_node = fixed_part.of_node;
 115 +                       pr_info("Found partition defined in DT for %s. Assigning OF node to support nvmem.",
 116 +                               part->parts[i].name);
 117 +               }
 118         }
 119
 120         *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,