marvell: uart: a3720: Implement console_a3700_core_getc
Implementation is simple, just check if there is a pending character in
RX FIFO via RXRDY bit of Status Register and if yes, read it from
UART_RX_REG register.
Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I226b6e336f44f5d0ca8dcb68e49a68e8f2f49708
diff --git a/drivers/marvell/uart/a3700_console.S b/drivers/marvell/uart/a3700_console.S
index dc374ee..9a557aa 100644
--- a/drivers/marvell/uart/a3700_console.S
+++ b/drivers/marvell/uart/a3700_console.S
@@ -196,14 +196,23 @@
* int console_a3700_core_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
- * or -1 on error.
+ * or -1 if no character is available.
* In : w0 - console base address
- * Out : return -1 on error else return character.
+ * Out : w0 - character if available, else -1
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_a3700_core_getc
- mov w0, #-1
+ /* Check if there is a pending character */
+ ldr w1, [x0, #UART_STATUS_REG]
+ and w1, w1, #UARTLSR_RXRDY
+ cmp w1, #UARTLSR_RXRDY
+ b.ne getc_no_char
+ ldr w0, [x0, #UART_RX_REG]
+ and w0, w0, #0xff
+ ret
+getc_no_char:
+ mov w0, #ERROR_NO_PENDING_CHAR
ret
endfunc console_a3700_core_getc
diff --git a/include/drivers/marvell/uart/a3700_console.h b/include/drivers/marvell/uart/a3700_console.h
index 5e3ab05..e77a165 100644
--- a/include/drivers/marvell/uart/a3700_console.h
+++ b/include/drivers/marvell/uart/a3700_console.h
@@ -48,6 +48,7 @@
/* Line Status Register bits */
#define UARTLSR_TXFIFOFULL (1 << 11) /* Tx Fifo Full */
+#define UARTLSR_RXRDY (1 << 4) /* Rx Ready */
/* UART Control Register bits */
#define UART_CTRL_RXFIFO_RESET (1 << 14)