recipes/linux/linux-2.6.18/mtd-unlock-nor-flash-automatically-where-necessary.patch

   1 From 187ef15268e638603dea55a91fdfa29feaed6d13 Mon Sep 17 00:00:00 2001
   2 From: =?utf-8?q?H=C3=A5vard_Skinnemoen?= <hskinnemoen@atmel.com>
   3 Date: Fri, 22 Sep 2006 10:07:08 +0100
   4 Subject: [PATCH] [MTD] Unlock NOR flash automatically where necessary
   5 Content-Type: text/plain; charset=UTF-8
   6 Content-Transfer-Encoding: 8bit
   7
   8 Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is
   9 always locked after power-up, so all sectors need to be unlocked before it
  10 is usable.
  11
  12 If this flag is set, and the chip provides an unlock() operation,
  13 mtd_add_device will unlock the whole MTD device if it's writeable.  This
  14 means that non-writeable partitions will stay locked.
  15
  16 Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work
  17 as expected.
  18
  19 Signed-off-by: Håvard Skinnemoen <hskinnemoen@atmel.com>
  20 Signed-off-by: Andrew Morton <akpm@osdl.org>
  21 Signed-off-by: David Woodhouse <dwmw2@infradead.org>
  22 ---
  23  drivers/mtd/chips/cfi_cmdset_0002.c |    1 +
  24  drivers/mtd/mtdcore.c               |   10 ++++++++++
  25  include/mtd/mtd-abi.h               |    1 +
  26  3 files changed, 12 insertions(+), 0 deletions(-)
  27
  28 diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
  29 index a482e89..702ae4c 100644
  30 --- a/drivers/mtd/chips/cfi_cmdset_0002.c
  31 +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
  32 @@ -212,6 +212,7 @@ static void fixup_use_atmel_lock(struct mtd_info *mtd, void *param)
  33  {
  34         mtd->lock = cfi_atmel_lock;
  35         mtd->unlock = cfi_atmel_unlock;
  36 +       mtd->flags |= MTD_STUPID_LOCK;
  37  }
  38
  39  static struct cfi_fixup cfi_fixup_table[] = {
  40 diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
  41 index 168d3ba..c4d26de 100644
  42 --- a/drivers/mtd/mtdcore.c
  43 +++ b/drivers/mtd/mtdcore.c
  44 @@ -57,6 +57,16 @@ int add_mtd_device(struct mtd_info *mtd)
  45                         mtd->index = i;
  46                         mtd->usecount = 0;
  47
  48 +                       /* Some chips always power up locked. Unlock them now */
  49 +                       if ((mtd->flags & MTD_WRITEABLE)
  50 +                           && (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
  51 +                               if (mtd->unlock(mtd, 0, mtd->size))
  52 +                                       printk(KERN_WARNING
  53 +                                              "%s: unlock failed, "
  54 +                                              "writes may not work\n",
  55 +                                              mtd->name);
  56 +                       }
  57 +
  58                         DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
  59                         /* No need to get a refcount on the module containing
  60                            the notifier, since we hold the mtd_table_mutex */
  61 diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h
  62 index 1da3f7f..b0a67b7 100644
  63 --- a/include/mtd/mtd-abi.h
  64 +++ b/include/mtd/mtd-abi.h
  65 @@ -34,6 +34,7 @@ struct mtd_oob_buf {
  66  #define MTD_WRITEABLE          0x400   /* Device is writeable */
  67  #define MTD_BIT_WRITEABLE      0x800   /* Single bits can be flipped */
  68  #define MTD_NO_ERASE           0x1000  /* No erase necessary */
  69 +#define MTD_STUPID_LOCK                0x2000  /* Always locked after reset */
  70
  71  // Some common devices / combinations of capabilities
  72  #define MTD_CAP_ROM            0
  73 --
  74 1.4.4.1
  75