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

[Guochun Mao <guochun.mao@mediatek.com>]

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

Signed-off-by: Guochun Mao <guochun.mao@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