[PATCH v2] nand: sunxi: fix write to USER_DATA reg

[Boris Brezillon]

The USER_DATA register cannot be accessed using byte accessors on A13
SoCs, thus triggering a bug when using memcpy_toio on this register.
Declare an NFC_USER_DATA() macro to convert the OOB buffer content into
a suitable u32 value which can then be programmed with writel().

Also drop the oob_required contidion, since ->oob_pio already contains
FFs when oob_required is false.

Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>

---
Changes since v1:
- drop the !oob_required conditional path
- replace endianness conversions by a macro relying on byte shifting
  operations
---
 drivers/mtd/nand/sunxi_nand.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index 6f93b29..0c29f6c 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -138,6 +138,10 @@
 #define NFC_ECC_MODE		GENMASK(15, 12)
 #define NFC_RANDOM_SEED		GENMASK(30, 16)
 
+/* NFC_USER_DATA helper macro */
+#define NFC_USER_DATA(buf)	((buf)[0] | ((buf)[1] << 8) | \
+				 ((buf)[2] << 16) | ((buf)[3] << 24))
+
 #define NFC_DEFAULT_TIMEOUT_MS	1000
 
 #define NFC_SRAM_SIZE		1024
@@ -632,15 +636,9 @@ static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
 		offset = layout->eccpos[i * ecc->bytes] - 4 + mtd->writesize;
 
 		/* Fill OOB data in */
-		if (oob_required) {
-			tmp = 0xffffffff;
-			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
-				    4);
-		} else {
-			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE,
-				    chip->oob_poi + offset - mtd->writesize,
-				    4);
-		}
+		writel(NFC_USER_DATA(chip->oob_poi +
+				     layout->oobfree[i].offset),
+		       nfc->regs + NFC_REG_USER_DATA_BASE);
 
 		chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
 
@@ -770,14 +768,7 @@ static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd,
 		offset += ecc->size;
 
 		/* Fill OOB data in */
-		if (oob_required) {
-			tmp = 0xffffffff;
-			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
-				    4);
-		} else {
-			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, oob,
-				    4);
-		}
+		writel(NFC_USER_DATA(oob), nfc->regs + NFC_REG_USER_DATA_BASE);
 
 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
 		      (1 << 30);
-- 
1.9.1