mtd: nand: sunxi: fix OOB handling in ->write_xxx() functions

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 helper macros to convert an OOB buffer into a suitable
USER_DATA value and vice-versa.

This patch also fixes an error in the oob_required logic (some OOB data
are not written even if the user required it) by removing the
oob_required condition, which is perfectly valid since the core already
fill ->oob_poi with FFs when oob_required is false.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: <stable@vger.kernel.org> # 3.19+
Fixes: 1fef62c1423b ("mtd: nand: add sunxi NAND flash controller support")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index f97a58d..279cafd 100644 (file)
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -147,6 +147,10 @@
 #define NFC_ECC_MODE           GENMASK(15, 12)
 #define NFC_RANDOM_SEED                GENMASK(30, 16)
 
+/* NFC_USER_DATA helper macros */
+#define NFC_BUF_TO_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
@@ -646,15 +650,9 @@ 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_BUF_TO_USER_DATA(chip->oob_poi +
+                                           layout->oobfree[i].offset),
+                      nfc->regs + NFC_REG_USER_DATA_BASE);
 
                chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
 
@@ -784,14 +782,8 @@ 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_BUF_TO_USER_DATA(oob),
+                      nfc->regs + NFC_REG_USER_DATA_BASE);
 
                tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
                      (1 << 30);