From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mo6-p05-ob.rzone.de ([2a01:238:20a:202:5305::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SlyT3-0005Q1-8w for linux-mtd@lists.infradead.org; Tue, 03 Jul 2012 08:28:23 +0000 From: Stefan Roese To: linux-mtd@lists.infradead.org Subject: [PATCH] mtd: physmap_of: Add "map-indirect" DT property Date: Tue, 3 Jul 2012 10:26:31 +0200 Message-Id: <1341303991-6219-1-git-send-email-sr@denx.de> Cc: Albrecht Dress , Anatolij Gustschin , Stephan Gatzka List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 "map-indirect", the flash will not be exposed directly to the MTD users (e.g. JFFS2) any more. Signed-off-by: Stefan Roese Cc: Stephan Gatzka Cc: Anatolij Gustschin Cc: Albrecht Dress --- Documentation/devicetree/bindings/mtd/mtd-physmap.txt | 7 +++++++ drivers/mtd/maps/physmap_of.c | 14 ++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt index a63c2bd7..97a7245 100644 --- a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt +++ b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt @@ -16,6 +16,13 @@ file systems on embedded devices. - #address-cells, #size-cells : Must be present if the device has sub-nodes representing partitions (see below). In this case both #address-cells and #size-cells must be equal to 1. + - map-indirect: boolean to disable the default direct mapping of the + flash. + 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 "map-indirect", the flash will not be exposed directly + to the MTD users (e.g. JFFS2) any more. For JEDEC compatible devices, the following additional properties are defined: diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c index 2e6fb68..a96011d 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, "map-indirect"); + 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); -- 1.7.11.1