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Commit b6b4bcb4 authored by Razvan Stefanescu's avatar Razvan Stefanescu Committed by Greg Kroah-Hartman
Browse files

tty/serial: atmel: Add is_half_duplex helper 



commit f3040983132bf3477acd45d2452a906e67c2fec9 upstream.

Use a helper function to check that a port needs to use half duplex
communication, replacing several occurrences of multi-line bit checking.

Fixes: b389f173 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarRazvan Stefanescu <razvan.stefanescu@microchip.com>
Acked-by: default avatarRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2dbc7c66

drivers/tty/serial/atmel_serial.c

+11 −8
Original line number Diff line number Diff line
@@ -225,6 +225,12 @@ static inline void atmel_uart_write_char(struct uart_port *port, u8 value) 
	__raw_writeb(value, port->membase + ATMEL_US_THR);

}



static inline int atmel_uart_is_half_duplex(struct uart_port *port)

{

	return (port->rs485.flags & SER_RS485_ENABLED) &&

		!(port->rs485.flags & SER_RS485_RX_DURING_TX);

}



#ifdef CONFIG_SERIAL_ATMEL_PDC

static bool atmel_use_pdc_rx(struct uart_port *port)

{
@@ -481,9 +487,9 @@ static void atmel_stop_tx(struct uart_port *port) 
	/* Disable interrupts */

	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);



	if ((port->rs485.flags & SER_RS485_ENABLED) &&

	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))

	if (atmel_uart_is_half_duplex(port))

		atmel_start_rx(port);



}



/*
@@ -500,8 +506,7 @@ static void atmel_start_tx(struct uart_port *port) 
		return;



	if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))

		if ((port->rs485.flags & SER_RS485_ENABLED) &&

		    !(port->rs485.flags & SER_RS485_RX_DURING_TX))

		if (atmel_uart_is_half_duplex(port))

			atmel_stop_rx(port);



	if (atmel_use_pdc_tx(port))
@@ -799,8 +804,7 @@ static void atmel_complete_tx_dma(void *arg) 
	 */

	if (!uart_circ_empty(xmit))

		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);

	else if ((port->rs485.flags & SER_RS485_ENABLED) &&

		 !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {

	else if (atmel_uart_is_half_duplex(port)) {

		/* DMA done, stop TX, start RX for RS485 */

		atmel_start_rx(port);

	}
@@ -1377,8 +1381,7 @@ static void atmel_tx_pdc(struct uart_port *port) 
		atmel_uart_writel(port, ATMEL_US_IER,

				  atmel_port->tx_done_mask);

	} else {

		if ((port->rs485.flags & SER_RS485_ENABLED) &&

		    !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {

		if (atmel_uart_is_half_duplex(port)) {

			/* DMA done, stop TX, start RX for RS485 */

			atmel_start_rx(port);

		}