serial: a3720: Implement pending method for output direction
To check if some output characters are waiting either in Transmitter
Holding Register or Transmitter Shift Register we need to look at
TX_EMPTY bit of UART Status Register.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/serial/serial_mvebu_a3700.c b/drivers/serial/serial_mvebu_a3700.c
index 5a1d40e..8f40487 100644
--- a/drivers/serial/serial_mvebu_a3700.c
+++ b/drivers/serial/serial_mvebu_a3700.c
@@ -23,6 +23,7 @@
#define UART_POSSR_REG 0x14
#define UART_STATUS_RX_RDY 0x10
+#define UART_STATUS_TX_EMPTY 0x40
#define UART_STATUS_TXFIFO_FULL 0x800
#define UART_CTRL_RXFIFO_RESET 0x4000
@@ -59,8 +60,13 @@
struct mvebu_plat *plat = dev_get_plat(dev);
void __iomem *base = plat->base;
- if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
- return 1;
+ if (input) {
+ if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
+ return 1;
+ } else {
+ if (!(readl(base + UART_STATUS_REG) & UART_STATUS_TX_EMPTY))
+ return 1;
+ }
return 0;
}