From 4dac80a5e991dd3b5b99910d7927edfdf4c99bb3 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Wed, 28 Feb 2018 20:51:51 +0100
Subject: [PATCH] spl: nand: sunxi: ensure enough time has passed after
changing the column
When changing the column, the ONFI specification states that a minimum
time of tCCS (Change Column Setup time) must elapse between the last
address cycle is asserted on the bus and the first data cycle is
clocked. An usual value for average NANDs is 500 nanoseconds. Round it
up to 1 microsecond to be safe.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
---
drivers/mtd/nand/sunxi_nand_spl.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/sunxi_nand_spl.c b/drivers/mtd/nand/sunxi_nand_spl.c
index 25a0941fd2..d63aa978d4 100644
--- a/drivers/mtd/nand/sunxi_nand_spl.c
+++ b/drivers/mtd/nand/sunxi_nand_spl.c
@@ -243,15 +243,24 @@ static int nand_load_page(const struct nfc_config *conf, u32 offs)
static int nand_reset_column(void)
{
+ int ret;
+
writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
(NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
(NFC_CMD_RNDOUTSTART << NFC_READ_CMD_OFFSET),
SUNXI_NFC_BASE + NFC_RCMD_SET);
writel(0, SUNXI_NFC_BASE + NFC_ADDR_LOW);
- return nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
- (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR |
- NFC_CMD_RNDOUT);
+ ret = nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
+ (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR |
+ NFC_CMD_RNDOUT);
+ if (ret)
+ return ret;
+
+ /* Ensure tCCS has passed before reading data */
+ udelay(1);
+
+ return 0;
}
static int nand_read_page(const struct nfc_config *conf, u32 offs,
--
2.39.5