[PATCH] mtd: maps: lantiq-flash: Check if the EBU endianness swap is enabled

[Sebastien Decourriere <sebtx452@gmail.com>]

The purpose of this patch is to enable the software address endianness
swapping only when the in SoC EBU endianness swapping is disabled.
To perform this check, I look at Bit 30 of the EBU_CON_0 register.
Actually, the driver expects that the in SoC swapping is disabled.
This is the case with current bootloaders shuch as U-boot. But,

I have a router which uses a proprietary bootloader which keeps
the in SoC swapping enabled. The SoC in this router is a vrx200 v1.2.
In this SoC version, I can keep the in SoC swapping without any problem.

Signed-off-by: Sebastien Decourriere <sebtx452@gmail.com>
---
 drivers/mtd/maps/lantiq-flash.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/maps/lantiq-flash.c b/drivers/mtd/maps/lantiq-flash.c
index c8febb3..a091efa 100644
--- a/drivers/mtd/maps/lantiq-flash.c
+++ b/drivers/mtd/maps/lantiq-flash.c
@@ -151,6 +151,11 @@ ltq_mtd_probe(struct platform_device *pdev)
 	ltq_mtd->map->copy_to = ltq_copy_to;
 
 	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
+	/* We swap the addresses only if the EBU endianness swap is disabled */
+	if (ltq_ebu_r32(LTQ_EBU_BUSCON0) & BIT(30))
+		ltq_mtd->map[i].map_priv_1 = LTQ_NOR_NORMAL;
+	else
+		ltq_mtd->map[i].map_priv_1 = LTQ_NOR_PROBING;
 	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
 	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
 
@@ -163,8 +168,11 @@ ltq_mtd_probe(struct platform_device *pdev)
 	mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
 
 	cfi = ltq_mtd->map->fldrv_priv;
-	cfi->addr_unlock1 ^= 1;
-	cfi->addr_unlock2 ^= 1;
+	/* We swap the addresses only if the EBU endianness swap is disabled */
+	if (!(ltq_ebu_r32(LTQ_EBU_BUSCON0) & BIT(30))) {
+		cfi->addr_unlock1 ^= 1;
+		cfi->addr_unlock2 ^= 1;
+	}
 
 	err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
 	if (err) {
-- 
2.1.4