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authorAaron Sierra <asierra@xes-inc.com>2014-09-25 12:20:24 -0500
committerBrian Norris <computersforpeace@gmail.com>2015-01-09 23:24:27 -0800
commit6958024ad5cdd78deae4da47a8722b06317dff45 (patch)
tree14e081920d299eab8c7fa7ece0f67aefd60c37df /drivers/mtd/chips
parent3fc1cf5f0af4b625adff03c610f188fa8bc89911 (diff)
mtd: map_rom: Support UBI on ROM
UBI needs to know the physical erase block size, even on read-only devices, since it defines the on-device layout. Use a device-tree provided value to support previously written UBI on read-only NOR. UBI also needs a non-zero writebufsize, so we set it to one. Note: This was implemented because hardware write-protected CFI NOR cannot be probed for the physical erase block size. Signed-off-by: Joe Schultz <jschultz@xes-inc.ccom> Signed-off-by: Aaron Sierra <asierra@xes-inc.ccom> [Brian: removed unneeded #ifdef, note 'optional' erase-size property] Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/chips')
-rw-r--r--drivers/mtd/chips/map_rom.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/mtd/chips/map_rom.c b/drivers/mtd/chips/map_rom.c
index 47a43cf7e5c6..e67f73ab44c9 100644
--- a/drivers/mtd/chips/map_rom.c
+++ b/drivers/mtd/chips/map_rom.c
@@ -11,6 +11,7 @@
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
+#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
@@ -28,6 +29,15 @@ static struct mtd_chip_driver maprom_chipdrv = {
.module = THIS_MODULE
};
+static unsigned int default_erasesize(struct map_info *map)
+{
+ const __be32 *erase_size = NULL;
+
+ erase_size = of_get_property(map->device_node, "erase-size", NULL);
+
+ return !erase_size ? map->size : be32_to_cpu(*erase_size);
+}
+
static struct mtd_info *map_rom_probe(struct map_info *map)
{
struct mtd_info *mtd;
@@ -47,8 +57,9 @@ static struct mtd_info *map_rom_probe(struct map_info *map)
mtd->_sync = maprom_nop;
mtd->_erase = maprom_erase;
mtd->flags = MTD_CAP_ROM;
- mtd->erasesize = map->size;
+ mtd->erasesize = default_erasesize(map);
mtd->writesize = 1;
+ mtd->writebufsize = 1;
__module_get(THIS_MODULE);
return mtd;