spl: nand: sunxi: introduce the nand_wait_cmd_fifo_empty() helper
One bit in the control registers indicates if the NAND controller is
ready to receive a new command. Otherwise, the command FIFO is full and
we should wait for this bit to flip. It then states that the last
command has been processed and the FIFO is now free to welcome another
command.
Add this sanity check before starting any new command.
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>
diff --git a/drivers/mtd/nand/sunxi_nand_spl.c b/drivers/mtd/nand/sunxi_nand_spl.c
index c2f4f2c..cd823cd 100644
--- a/drivers/mtd/nand/sunxi_nand_spl.c
+++ b/drivers/mtd/nand/sunxi_nand_spl.c
@@ -155,6 +155,17 @@
return check_value_inner(offset, unexpected_bits, timeout_us, 1);
}
+static int nand_wait_cmd_fifo_empty(void)
+{
+ if (!check_value_negated(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_FIFO_STAT,
+ DEFAULT_TIMEOUT_US)) {
+ printf("nand: timeout waiting for empty cmd FIFO\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
static int nand_wait_int(void)
{
if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
@@ -183,6 +194,8 @@
}
/* reset NAND */
+ nand_wait_cmd_fifo_empty();
+
writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
writel(NFC_SEND_CMD1 | NFC_WAIT_FLAG | NAND_CMD_RESET,
SUNXI_NFC_BASE + NFC_CMD);
@@ -194,6 +207,8 @@
{
u32 val;
+ nand_wait_cmd_fifo_empty();
+
val = readl(SUNXI_NFC_BASE + NFC_CTL);
val &= ~NFC_CTL_PAGE_SIZE_MASK;
writel(val | NFC_CTL_RAM_METHOD | NFC_CTL_PAGE_SIZE(conf->page_size),
@@ -206,6 +221,8 @@
{
int page = offs / conf->page_size;
+ nand_wait_cmd_fifo_empty();
+
writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
(NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
(NFC_CMD_READSTART << NFC_READ_CMD_OFFSET),
@@ -222,6 +239,8 @@
static int nand_reset_column(void)
{
+ nand_wait_cmd_fifo_empty();
+
writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
(NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
(NFC_CMD_RNDOUTSTART << NFC_READ_CMD_OFFSET),