[Blackfin] serial driver: Add flow control support to bf54x

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

drivers/serial/Kconfig

@@ -699,14 +699,14 @@ config BFIN_UART1_CTSRTS
 
 config UART1_CTS_PIN
 	int "UART1 CTS pin"
-	depends on BFIN_UART1_CTSRTS && (BF53x || BF561)
+	depends on BFIN_UART1_CTSRTS && !BF54x
 	default -1
 	help
 	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
 
 config UART1_RTS_PIN
 	int "UART1 RTS pin"
-	depends on BFIN_UART1_CTSRTS && (BF53x || BF561)
+	depends on BFIN_UART1_CTSRTS && !BF54x
 	default -1
 	help
 	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.

drivers/serial/bfin_5xx.c

@@ -579,7 +579,11 @@ static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
 	if (uart->cts_pin < 0)
 		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 
+# ifdef BF54x
+	if (UART_GET_MSR(uart) & CTS)
+# else
 	if (gpio_get_value(uart->cts_pin))
+# endif
 		return TIOCM_DSR | TIOCM_CAR;
 	else
 #endif
@@ -594,9 +598,17 @@ static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		return;
 
 	if (mctrl & TIOCM_RTS)
+# ifdef BF54x
+		UART_PUT_MCR(uart, UART_GET_MCR(uart) & ~MRTS);
+# else
 		gpio_set_value(uart->rts_pin, 0);
+# endif
 	else
+# ifdef BF54x
+		UART_PUT_MCR(uart, UART_GET_MCR(uart) | MRTS);
+# else
 		gpio_set_value(uart->rts_pin, 1);
+# endif
 #endif
 }
 

include/asm-blackfin/mach-bf548/bfin_serial_5xx.h

@@ -24,6 +24,8 @@
 #define UART_GET_LCR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LCR))
 #define UART_GET_LSR(uart)      bfin_read16(((uart)->port.membase + OFFSET_LSR))
 #define UART_GET_GCTL(uart)     bfin_read16(((uart)->port.membase + OFFSET_GCTL))
+#define UART_GET_MSR(uart)      bfin_read16(((uart)->port.membase + OFFSET_MSR))
+#define UART_GET_MCR(uart)      bfin_read16(((uart)->port.membase + OFFSET_MCR))
 
 #define UART_PUT_CHAR(uart,v)   bfin_write16(((uart)->port.membase + OFFSET_THR),v)
 #define UART_PUT_DLL(uart,v)    bfin_write16(((uart)->port.membase + OFFSET_DLL),v)
@@ -34,6 +36,7 @@
 #define UART_PUT_LCR(uart,v)    bfin_write16(((uart)->port.membase + OFFSET_LCR),v)
 #define UART_CLEAR_LSR(uart)    bfin_write16(((uart)->port.membase + OFFSET_LSR), -1)
 #define UART_PUT_GCTL(uart,v)   bfin_write16(((uart)->port.membase + OFFSET_GCTL),v)
+#define UART_PUT_MCR(uart,v)    bfin_write16(((uart)->port.membase + OFFSET_MCR),v)
 
 #if defined(CONFIG_BFIN_UART0_CTSRTS) || defined(CONFIG_BFIN_UART1_CTSRTS)
 # define CONFIG_SERIAL_BFIN_CTSRTS