[PATCH 07/10] MIPS: lantiq: add NOR flash CFI address swizzle

[John Crispin]

This patch adds the hack mentioned in the previous patch.

It is only a hack to make the map driver work until a better solution
is discussed.

Signed-off-by: John Crispin <blogic at openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel at lantiq.com>
Cc: David Woodhouse <dwmw2 at infradead.org>
Cc: linux-mips at linux-mips.org
Cc: linux-mtd at lists.infradead.org
---
 drivers/mtd/chips/Kconfig           |    9 +++++++++
 drivers/mtd/chips/cfi_cmdset_0002.c |    8 ++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/chips/Kconfig b/drivers/mtd/chips/Kconfig
index 35c6a23..9ecb5eb 100644
--- a/drivers/mtd/chips/Kconfig
+++ b/drivers/mtd/chips/Kconfig
@@ -39,6 +39,15 @@ config MTD_CFI_ADV_OPTIONS
 
 	  If unsure, say 'N'.
 
+config MTD_CFI_CMD_SWIZZLE
+	bool "Swizzle last bit of command address"
+	default y
+	depends on LANTIQ
+	help
+	  lantiq SoCs share the external bus unit with the pci interface
+	  for MTD to work at the the same time with PCI, we need to add
+	  this quirk
+
 choice
 	prompt "Flash cmd/query data swapping"
 	depends on MTD_CFI_ADV_OPTIONS
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 3b8e32d..e047af1 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -39,7 +39,12 @@
 #include <linux/mtd/xip.h>
 
 #define AMD_BOOTLOC_BUG
+
+#ifdef CONFIG_MTD_CFI_CMD_SWIZZLE
+#define FORCE_WORD_WRITE 1
+#else
 #define FORCE_WORD_WRITE 0
+#endif
 
 #define MAX_WORD_RETRIES 3
 
@@ -1140,6 +1145,9 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
 	int retry_cnt = 0;
 
 	adr += chip->start;
+#ifdef CONFIG_MTD_CFI_CMD_SWIZZLE
+	adr ^= 2;
+#endif
 
 	mutex_lock(&chip->mutex);
 	ret = get_chip(map, chip, adr, FL_WRITING);
-- 
1.7.2.3