target/linux/sunxi/patches-4.1/112-mtd-add-dt-nand-partition-parser.patch

   1 From 0460e9868fd82a3675db02f6ceb6edfd8501c194 Mon Sep 17 00:00:00 2001
   2 From: Boris BREZILLON <boris.brezillon@free-electrons.com>
   3 Date: Mon, 28 Jul 2014 14:31:42 +0200
   4 Subject: [PATCH] mtd: nand: Add DT NAND partition parser
   5
   6 Add a of_nandpart_parse function to help parsing NAND partitions from DT.
   7 This function should be called from NAND controller drivers just after the
   8 nand_scan_tail in place of mtd_device_parse_register.
   9 The caller can specify a parser function to retrieve HW specific
  10 informations from the DT.
  11
  12 Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
  13 Signed-off-by: Hans de Goede <hdegoede@redhat.com>
  14 ---
  15  drivers/mtd/nand/ofnandpart.c | 104 ++++++++++++++++++++++++++++++++++++++++++
  16  include/linux/mtd/nand.h      |  17 +++++++
  17  2 files changed, 121 insertions(+)
  18  create mode 100644 drivers/mtd/nand/ofnandpart.c
  19
  20 --- /dev/null
  21 +++ b/drivers/mtd/nand/ofnandpart.c
  22 @@ -0,0 +1,104 @@
  23 +/*
  24 + * NAND Flash partitions described by the OF (or flattened) device tree
  25 + *
  26 + * Copyright © 2014 Boris BREZILLON <b.brezillon.dev@gmail.com>
  27 + *
  28 + * This program is free software; you can redistribute  it and/or modify it
  29 + * under  the terms of  the GNU General  Public License as published by the
  30 + * Free Software Foundation;  either version 2 of the  License, or (at your
  31 + * option) any later version.
  32 + */
  33 +
  34 +#include <linux/module.h>
  35 +#include <linux/init.h>
  36 +#include <linux/of.h>
  37 +#include <linux/mtd/mtd.h>
  38 +#include <linux/slab.h>
  39 +#include <linux/mtd/nand.h>
  40 +
  41 +static inline bool node_has_compatible(struct device_node *pp)
  42 +{
  43 +       return of_get_property(pp, "compatible", NULL);
  44 +}
  45 +
  46 +int ofnandpart_parse(struct mtd_info *master,
  47 +                    const struct ofnandpart_data *data)
  48 +{
  49 +       struct device_node *node;
  50 +       const char *partname;
  51 +       struct device_node *pp;
  52 +       int i;
  53 +
  54 +       if (!data)
  55 +               return 0;
  56 +
  57 +       node = data->node;
  58 +       if (!node)
  59 +               return 0;
  60 +
  61 +       i = 0;
  62 +       for_each_child_of_node(node,  pp) {
  63 +               const __be32 *reg;
  64 +               int len;
  65 +               int a_cells, s_cells;
  66 +               uint64_t offset, size;
  67 +               uint32_t mask_flags = 0;
  68 +               struct nand_part *part;
  69 +
  70 +               if (node_has_compatible(pp))
  71 +                       continue;
  72 +
  73 +               reg = of_get_property(pp, "reg", &len);
  74 +               if (!reg)
  75 +                       continue;
  76 +
  77 +               a_cells = of_n_addr_cells(pp);
  78 +               s_cells = of_n_size_cells(pp);
  79 +               offset = of_read_number(reg, a_cells);
  80 +               size = of_read_number(reg + a_cells, s_cells);
  81 +
  82 +               partname = of_get_property(pp, "label", &len);
  83 +               if (!partname)
  84 +                       partname = of_get_property(pp, "name", &len);
  85 +
  86 +               if (of_get_property(pp, "read-only", &len))
  87 +                       mask_flags |= MTD_WRITEABLE;
  88 +
  89 +               if (of_get_property(pp, "lock", &len))
  90 +                       mask_flags |= MTD_POWERUP_LOCK;
  91 +
  92 +               if (data->parse)
  93 +                       part = data->parse(data->priv, master, pp);
  94 +               else
  95 +                       part = nandpart_alloc();
  96 +
  97 +               if (IS_ERR(part))
  98 +                       continue;
  99 +
 100 +               part->offset = offset;
 101 +               part->master = master;
 102 +               part->mtd.name = partname;
 103 +               part->mtd.size = size;
 104 +               part->mtd.flags = mask_flags;
 105 +
 106 +               if (nand_add_partition(master, part)) {
 107 +                       if (part->release)
 108 +                               part->release(part);
 109 +                       continue;
 110 +               }
 111 +
 112 +               i++;
 113 +       }
 114 +
 115 +       if (!i) {
 116 +               of_node_put(pp);
 117 +               pr_err("No valid partition found on %s\n", node->full_name);
 118 +       }
 119 +
 120 +       return i;
 121 +}
 122 +EXPORT_SYMBOL(ofnandpart_parse);
 123 +
 124 +MODULE_LICENSE("GPL");
 125 +MODULE_DESCRIPTION("Parser for NAND flash partitioning information in device tree");
 126 +MODULE_AUTHOR("Boris BREZILLON");
 127 --- a/include/linux/mtd/nand.h
 128 +++ b/include/linux/mtd/nand.h
 129 @@ -1014,6 +1014,23 @@ static inline int jedec_feature(struct n
 130                 : 0;
 131  }
 132
 133 +/**
 134 + * struct ofnandpart_data - struct used to retrieve NAND partitions from a DT
 135 + *                         node
 136 + * @parse:             driver specific parser function
 137 + * @priv:              driver private data
 138 + * @node:              OF node containing NAND partitions
 139 + */
 140 +struct ofnandpart_data {
 141 +       struct nand_part *(*parse)(void *priv, struct mtd_info *master,
 142 +                                  struct device_node *pp);
 143 +       void *priv;
 144 +       struct device_node *node;
 145 +};
 146 +
 147 +int ofnandpart_parse(struct mtd_info *master,
 148 +                    const struct ofnandpart_data *data);
 149 +
 150  /*
 151   * struct nand_sdr_timings - SDR NAND chip timings
 152   *