[PATCH V1 1/1] mtd: mtk-nor: set controller to 4B mode with large capacity flash

[Guochun Mao]

when nor's size larger than 16MByte, nor and controller should
enter 4Byte mode simultaneously.

Signed-off-by: Guochun Mao <guochun....@mediatek.com>
---
 drivers/mtd/spi-nor/mtk-quadspi.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mtd/spi-nor/mtk-quadspi.c 
b/drivers/mtd/spi-nor/mtk-quadspi.c
index e661877..05cd8a8 100644
--- a/drivers/mtd/spi-nor/mtk-quadspi.c
+++ b/drivers/mtd/spi-nor/mtk-quadspi.c
@@ -369,6 +369,13 @@ static int mt8173_nor_write_reg(struct spi_nor *nor, u8 
opcode, u8 *buf,
                /* We only handle 1 byte */
                ret = mt8173_nor_wr_sr(mt8173_nor, *buf);
                break;
+       case SPINOR_OP_EN4B:
+               /* Set nor controller to 4-byte address mode,
+                * and simultaneously set nor flash.
+                * This case should cooperate with default operation.
+                */
+               writeb(readb(mt8173_nor->base + MTK_NOR_DUAL_REG) | 0x10,
+                               mt8173_nor->base + MTK_NOR_DUAL_REG);
        default:
                ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, buf, len, NULL, 
0);
                if (ret)
-- 
1.7.9.5