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authorStefan Roese <sr@denx.de>2012-08-17 15:22:32 +0200
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-09-29 15:05:55 +0100
commitd0788ce4924758249c9552c91cc33024d3434419 (patch)
tree5d490b8024a663de0fa4fc8cf3c876f94fd4c7c9 /drivers/mtd
parente1ed147fd4a322741e63f66d76e68ad83876d2ea (diff)
mtd: physmap_of: Add "no-unaligned-direct-access" DT property
On some platforms (e.g. MPC5200) a direct 1:1 mapping may cause problems with JFFS2 usage, as the local bus (LPB) doesn't support unaligned accesses as implemented in the JFFS2 code via memcpy(). By defining "no-unaligned-direct-access", the flash will not be exposed directly to the MTD users (e.g. JFFS2) any more. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/maps/physmap_of.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index 2e6fb6831d55..6f19acadb06c 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -169,6 +169,7 @@ static int __devinit of_flash_probe(struct platform_device *dev)
struct mtd_info **mtd_list = NULL;
resource_size_t res_size;
struct mtd_part_parser_data ppdata;
+ bool map_indirect;
match = of_match_device(of_flash_match, &dev->dev);
if (!match)
@@ -192,6 +193,8 @@ static int __devinit of_flash_probe(struct platform_device *dev)
}
count /= reg_tuple_size;
+ map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
+
err = -ENOMEM;
info = kzalloc(sizeof(struct of_flash) +
sizeof(struct of_flash_list) * count, GFP_KERNEL);
@@ -247,6 +250,17 @@ static int __devinit of_flash_probe(struct platform_device *dev)
simple_map_init(&info->list[i].map);
+ /*
+ * On some platforms (e.g. MPC5200) a direct 1:1 mapping
+ * may cause problems with JFFS2 usage, as the local bus (LPB)
+ * doesn't support unaligned accesses as implemented in the
+ * JFFS2 code via memcpy(). By setting NO_XIP, the
+ * flash will not be exposed directly to the MTD users
+ * (e.g. JFFS2) any more.
+ */
+ if (map_indirect)
+ info->list[i].map.phys = NO_XIP;
+
if (probe_type) {
info->list[i].mtd = do_map_probe(probe_type,
&info->list[i].map);