[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>
---
 .../mips/include/asm/mach-lantiq/xway/lantiq_soc.h |  1 +
 drivers/mtd/maps/lantiq-flash.c                    | 29 +++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
index 17b41bb..0ed0896 100644
--- a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
@@ -87,6 +87,7 @@ extern __iomem void *ltq_cgu_membase;
 #define LTQ_EBU_PCC_ISTAT	0x00A0
 #define LTQ_EBU_BUSCON1		0x0064
 #define LTQ_EBU_ADDRSEL1	0x0024
+#define EBU_FLASH_ENDIAN_SWAP	0x40000000
 #define EBU_WRDIS		0x80000000
 
 /* WDT */
diff --git a/drivers/mtd/maps/lantiq-flash.c b/drivers/mtd/maps/lantiq-flash.c
index c8febb3..8d628d2 100644
--- a/drivers/mtd/maps/lantiq-flash.c
+++ b/drivers/mtd/maps/lantiq-flash.c
@@ -113,6 +113,24 @@ ltq_mtd_probe(struct platform_device *pdev)
 	struct ltq_mtd *ltq_mtd;
 	struct cfi_private *cfi;
 	int err;
+	bool mtd_addr_swap = true;
+
+#ifdef CONFIG_SOC_TYPE_XWAY
+	/* If SoC is vr9 rev 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_FLASH_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;
+			break;
+		}
+	}
+#endif
 
 	if (of_machine_is_compatible("lantiq,falcon") &&
 			(ltq_boot_select() != BS_FLASH)) {
@@ -150,7 +168,10 @@ 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 +184,10 @@ 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