From: Ye Li ye.li@nxp.com
Enable the RX and TX FIFO in LPUART driver to avoid the input lost during u-boot boot up.
Signed-off-by: Ye Li ye.li@nxp.com Acked-by: Peng Fan peng.fan@nxp.com --- drivers/serial/serial_lpuart.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-)
diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c index a5a2f65c77..e99a49d0d9 100644 --- a/drivers/serial/serial_lpuart.c +++ b/drivers/serial/serial_lpuart.c @@ -40,6 +40,12 @@ #define CTRL_TE (1 << 19) #define CTRL_RE (1 << 18)
+#define FIFO_RXFLUSH (1 << 14) +#define FIFO_TXFLUSH (1 << 15) +#define FIFO_TXSIZE_MASK 0x70 +#define FIFO_TXSIZE_OFF 4 +#define FIFO_RXSIZE_MASK 0x7 +#define FIFO_RXSIZE_OFF 0 #define FIFO_TXFE 0x80 #ifdef CONFIG_IMX8 #define FIFO_RXFE 0x08 @@ -47,7 +53,7 @@ #define FIFO_RXFE 0x40 #endif
-#define WATER_TXWATER_OFF 1 +#define WATER_TXWATER_OFF 0 #define WATER_RXWATER_OFF 16
DECLARE_GLOBAL_DATA_PTR; @@ -318,15 +324,28 @@ static int _lpuart32_serial_tstc(struct lpuart_serial_platdata *plat) static int _lpuart32_serial_init(struct lpuart_serial_platdata *plat) { struct lpuart_fsl_reg32 *base = (struct lpuart_fsl_reg32 *)plat->reg; - u32 ctrl; + u32 val, tx_fifo_size;
- lpuart_read32(plat->flags, &base->ctrl, &ctrl); - ctrl &= ~CTRL_RE; - ctrl &= ~CTRL_TE; - lpuart_write32(plat->flags, &base->ctrl, ctrl); + lpuart_read32(plat->flags, &base->ctrl, &val); + val &= ~CTRL_RE; + val &= ~CTRL_TE; + lpuart_write32(plat->flags, &base->ctrl, val);
lpuart_write32(plat->flags, &base->modir, 0); - lpuart_write32(plat->flags, &base->fifo, ~(FIFO_TXFE | FIFO_RXFE)); + + lpuart_read32(plat->flags, &base->fifo, &val); + tx_fifo_size = (val & FIFO_TXSIZE_MASK) >> FIFO_TXSIZE_OFF; + /* Set the TX water to half of FIFO size */ + if (tx_fifo_size > 1) + tx_fifo_size = tx_fifo_size >> 1; + + /* Set RX water to 0, to be triggered by any receive data */ + lpuart_write32(plat->flags, &base->water, + (tx_fifo_size << WATER_TXWATER_OFF)); + + /* Enable TX and RX FIFO */ + val |= (FIFO_TXFE | FIFO_RXFE | FIFO_TXFLUSH | FIFO_RXFLUSH); + lpuart_write32(plat->flags, &base->fifo, val);
lpuart_write32(plat->flags, &base->match, 0);