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

[Sebastien Decourriere <sebtx452@xxxxxxxxx>]

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.

This applies only to vr9 (xrx200) rev 1.2 and ar10 (xrx300).

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.

This patch replaces my previous broken patch.

Signed-off-by: Sebastien Decourriere <sebtx452@xxxxxxxxx>
---
 drivers/mtd/maps/lantiq-flash.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/maps/lantiq-flash.c b/drivers/mtd/maps/lantiq-flash.c
index c8febb3..1cbbdcb 100644
--- a/drivers/mtd/maps/lantiq-flash.c
+++ b/drivers/mtd/maps/lantiq-flash.c
@@ -38,6 +38,8 @@ enum {
 	LTQ_NOR_NORMAL
 };
 
+#define EBU_ENDIAN_SWAP		BIT(30)
+
 struct ltq_mtd {
 	struct resource *res;
 	struct mtd_info *mtd;
@@ -113,6 +115,20 @@ ltq_mtd_probe(struct platform_device *pdev)
 	struct ltq_mtd *ltq_mtd;
 	struct cfi_private *cfi;
 	int err;
+	bool mtd_addr_swap;
+
+	/* If SoC is vr9 >= 1.2 or ar10 and EBU endian swap
+	   is enabled, we don't need to do software address swap */
+	if ( ltq_ebu_r32(LTQ_EBU_BUSCON0) & EBU_ENDIAN_SWAP ) {
+		switch (ltq_soc_type()) {
+			case SOC_TYPE_VR9_2 :
+			case SOC_TYPE_AR10 :
+				mtd_addr_swap = false;
+				break;
+			default :
+				mtd_addr_swap = true;
+		}
+	} else mtd_addr_swap = true;
 
 	if (of_machine_is_compatible("lantiq,falcon") &&
 			(ltq_boot_select() != BS_FLASH)) {
@@ -150,7 +166,10 @@ ltq_mtd_probe(struct platform_device *pdev)
 	ltq_mtd->map->copy_from = ltq_copy_from;
 	ltq_mtd->map->copy_to = ltq_copy_to;
 
-	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
+	if (mtd_addr_swap)
+		ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
+	else
+		ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
 	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
 	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
 
@@ -163,8 +182,10 @@ 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;
+	if (mtd_addr_swap) {
+		cfi->addr_unlock1 ^= 1;
+		cfi->addr_unlock2 ^= 1;
+	}
 
 	err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
 	if (err) {
-- 
2.1.4