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 diff --git a/drivers/mtd/nand/ofnandpart.c b/drivers/mtd/nand/ofnandpart.c
  21 new file mode 100644
  22 index 0000000..293daee
  23 --- /dev/null
  24 +++ b/drivers/mtd/nand/ofnandpart.c
  25 @@ -0,0 +1,104 @@
  26 +/*
  27 + * NAND Flash partitions described by the OF (or flattened) device tree
  28 + *
  29 + * Copyright © 2014 Boris BREZILLON <b.brezillon.dev@gmail.com>
  30 + *
  31 + * This program is free software; you can redistribute  it and/or modify it
  32 + * under  the terms of  the GNU General  Public License as published by the
  33 + * Free Software Foundation;  either version 2 of the  License, or (at your
  34 + * option) any later version.
  35 + */
  36 +
  37 +#include <linux/module.h>
  38 +#include <linux/init.h>
  39 +#include <linux/of.h>
  40 +#include <linux/mtd/mtd.h>
  41 +#include <linux/slab.h>
  42 +#include <linux/mtd/nand.h>
  43 +
  44 +static inline bool node_has_compatible(struct device_node *pp)
  45 +{
  46 +       return of_get_property(pp, "compatible", NULL);
  47 +}
  48 +
  49 +int ofnandpart_parse(struct mtd_info *master,
  50 +                    const struct ofnandpart_data *data)
  51 +{
  52 +       struct device_node *node;
  53 +       const char *partname;
  54 +       struct device_node *pp;
  55 +       int i;
  56 +
  57 +       if (!data)
  58 +               return 0;
  59 +
  60 +       node = data->node;
  61 +       if (!node)
  62 +               return 0;
  63 +
  64 +       i = 0;
  65 +       for_each_child_of_node(node,  pp) {
  66 +               const __be32 *reg;
  67 +               int len;
  68 +               int a_cells, s_cells;
  69 +               uint64_t offset, size;
  70 +               uint32_t mask_flags = 0;
  71 +               struct nand_part *part;
  72 +
  73 +               if (node_has_compatible(pp))
  74 +                       continue;
  75 +
  76 +               reg = of_get_property(pp, "reg", &len);
  77 +               if (!reg)
  78 +                       continue;
  79 +
  80 +               a_cells = of_n_addr_cells(pp);
  81 +               s_cells = of_n_size_cells(pp);
  82 +               offset = of_read_number(reg, a_cells);
  83 +               size = of_read_number(reg + a_cells, s_cells);
  84 +
  85 +               partname = of_get_property(pp, "label", &len);
  86 +               if (!partname)
  87 +                       partname = of_get_property(pp, "name", &len);
  88 +
  89 +               if (of_get_property(pp, "read-only", &len))
  90 +                       mask_flags |= MTD_WRITEABLE;
  91 +
  92 +               if (of_get_property(pp, "lock", &len))
  93 +                       mask_flags |= MTD_POWERUP_LOCK;
  94 +
  95 +               if (data->parse)
  96 +                       part = data->parse(data->priv, master, pp);
  97 +               else
  98 +                       part = nandpart_alloc();
  99 +
 100 +               if (IS_ERR(part))
 101 +                       continue;
 102 +
 103 +               part->offset = offset;
 104 +               part->master = master;
 105 +               part->mtd.name = partname;
 106 +               part->mtd.size = size;
 107 +               part->mtd.flags = mask_flags;
 108 +
 109 +               if (nand_add_partition(master, part)) {
 110 +                       if (part->release)
 111 +                               part->release(part);
 112 +                       continue;
 113 +               }
 114 +
 115 +               i++;
 116 +       }
 117 +
 118 +       if (!i) {
 119 +               of_node_put(pp);
 120 +               pr_err("No valid partition found on %s\n", node->full_name);
 121 +       }
 122 +
 123 +       return i;
 124 +}
 125 +EXPORT_SYMBOL(ofnandpart_parse);
 126 +
 127 +MODULE_LICENSE("GPL");
 128 +MODULE_DESCRIPTION("Parser for NAND flash partitioning information in device tree");
 129 +MODULE_AUTHOR("Boris BREZILLON");
 130 diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
 131 index 510e09b..5616f51 100644
 132 --- a/include/linux/mtd/nand.h
 133 +++ b/include/linux/mtd/nand.h
 134 @@ -1013,6 +1013,23 @@ static inline int jedec_feature(struct nand_chip *chip)
 135                 : 0;
 136  }
 137
 138 +/**
 139 + * struct ofnandpart_data - struct used to retrieve NAND partitions from a DT
 140 + *                         node
 141 + * @parse:             driver specific parser function
 142 + * @priv:              driver private data
 143 + * @node:              OF node containing NAND partitions
 144 + */
 145 +struct ofnandpart_data {
 146 +       struct nand_part *(*parse)(void *priv, struct mtd_info *master,
 147 +                                  struct device_node *pp);
 148 +       void *priv;
 149 +       struct device_node *node;
 150 +};
 151 +
 152 +int ofnandpart_parse(struct mtd_info *master,
 153 +                    const struct ofnandpart_data *data);
 154 +
 155  /*
 156   * struct nand_sdr_timings - SDR NAND chip timings
 157   *