target/linux/brcm63xx/patches-4.1/203-MTD-DEVICES-m25p80-add-support-for-limiting-reads.patch

   1 From 5fb4e8d7287ac8fcb33aae8b1e9e22c5a3c392bd Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jonas.gorski@gmail.com>
   3 Date: Thu, 10 Nov 2011 17:33:40 +0100
   4 Subject: [PATCH 51/79] MTD: DEVICES: m25p80: add support for limiting reads
   5
   6 Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
   7 ---
   8  drivers/mtd/devices/m25p80.c |   29 +++++++++++++++++++++++++++--
   9  include/linux/spi/flash.h    |    4 ++++
  10  2 files changed, 31 insertions(+), 2 deletions(-)
  11
  12 --- a/drivers/mtd/devices/m25p80.c
  13 +++ b/drivers/mtd/devices/m25p80.c
  14 @@ -31,6 +31,7 @@
  15  struct m25p {
  16         struct spi_device       *spi;
  17         struct spi_nor          spi_nor;
  18 +       int                     max_transfer_len;
  19         u8                      command[MAX_CMD_SIZE];
  20  };
  21
  22 @@ -119,7 +120,7 @@ static inline unsigned int m25p80_rx_nbi
  23   * Read an address range from the nor chip.  The address range
  24   * may be any size provided it is within the physical boundaries.
  25   */
  26 -static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
  27 +static int __m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
  28                         size_t *retlen, u_char *buf)
  29  {
  30         struct m25p *flash = nor->priv;
  31 @@ -152,6 +153,29 @@ static int m25p80_read(struct spi_nor *n
  32         return 0;
  33  }
  34
  35 +static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
  36 +       size_t *retlen, u_char *buf)
  37 +{
  38 +       struct m25p *flash = nor->priv;
  39 +       size_t off;
  40 +       size_t read_len = flash->max_transfer_len;
  41 +       size_t part_len;
  42 +       int ret = 0;
  43 +
  44 +       if (!read_len)
  45 +               return __m25p80_read(nor, from, len, retlen, buf);
  46 +
  47 +       *retlen = 0;
  48 +
  49 +       for (off = 0; off < len && !ret; off += read_len) {
  50 +               ret = __m25p80_read(nor, from + off, min(len - off, read_len),
  51 +                                   &part_len, buf + off);
  52 +                       *retlen += part_len;
  53 +       }
  54 +
  55 +       return ret;
  56 +}
  57 +
  58  static int m25p80_erase(struct spi_nor *nor, loff_t offset)
  59  {
  60         struct m25p *flash = nor->priv;
  61 @@ -223,6 +247,9 @@ static int m25p_probe(struct spi_device
  62         else
  63                 flash_name = spi->modalias;
  64
  65 +       if (data)
  66 +               flash->max_transfer_len = data->max_transfer_len;
  67 +
  68         ret = spi_nor_scan(nor, flash_name, mode);
  69         if (ret)
  70                 return ret;
  71 --- a/include/linux/spi/flash.h
  72 +++ b/include/linux/spi/flash.h
  73 @@ -13,6 +13,8 @@ struct mtd_part_parser_data;
  74   * @part_probe_types: optional list of MTD parser names to use for
  75   *     partitioning
  76   *
  77 + * @max_transfer_len: option maximum read/write length limitation for
  78 + *     SPI controllers not able to transfer any length commands.
  79   * Board init code (in arch/.../mach-xxx/board-yyy.c files) can
  80   * provide information about SPI flash parts (such as DataFlash) to
  81   * help set up the device and its appropriate default partitioning.
  82 @@ -28,6 +30,8 @@ struct flash_platform_data {
  83         char            *type;
  84
  85         const char      **part_probe_types;
  86 +
  87 +       unsigned int    max_transfer_len;
  88         /* we'll likely add more ... use JEDEC IDs, etc */
  89  };
  90