[U-Boot] [PATCH v4 3/5] mtd: nand: fix GET/SET_FEATURES address on 16-bit devices

[Pekon Gupta]

From: David Mosberger <davidm at egauge.net>

As per following Sections in ONFI Spec, GET_FEATURES and SET_FEATURES also need
byte-addressing on 16-bit devices.

*Section: Target Initialization"
"The Read ID and Read Parameter Page commands only use the lower 8-bits of the
 data bus. The host shall not issue commands that use a word data width on x16
 devices until the host determines the device supports a 16-bit data bus width
 in the parameter page."

*Section: Bus Width Requirements*
"When the host supports a 16-bit bus width, only data is transferred at the
 16-bit width. All address and command line transfers shall use only the lower
 8-bits of the data bus. During command transfers, the host may place any value
 on the upper 8-bits of the data bus. During address transfers, the host shall
 set the upper 8-bits of the data bus to 00h."

So porting following commit from linux kernel
    commit e34fcb07a6d57411de6e15a47724fbe92c5caa42
    Author: David Mosberger <davidm at egauge.net>  (preserving authorship)
    mtd: nand: fix GET/SET_FEATURES address on 16-bit devices

Signed-off-by: Pekon Gupta <pekon at ti.com>
---
 include/linux/mtd/nand.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 4be8858..991bd8e 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -725,7 +725,16 @@ static inline int onfi_get_sync_timing_mode(struct nand_chip *chip)
  */
 static inline int nand_opcode_8bits(unsigned int command)
 {
-	return command == NAND_CMD_READID;
+	switch (command) {
+	case NAND_CMD_READID:
+	case NAND_CMD_PARAM:
+	case NAND_CMD_GET_FEATURES:
+	case NAND_CMD_SET_FEATURES:
+		return 1;
+	default:
+		break;
+	}
+	return 0;
 }
 
 
-- 
1.8.5.1.163.gd7aced9