Commit f30ac0ce authored by Sonic Zhang's avatar Sonic Zhang Committed by Bryan Wu
Browse files

Blackfin Serial Driver: Use timer to poll CTS PIN instead of workqueue. 



This allows other threads to run when the serial driver polls the CTS
PIN in a loop.

Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
parent ec64b6c8

drivers/serial/bfin_5xx.c

+18 −22
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 
#define DMA_RX_YCOUNT		(PAGE_SIZE / DMA_RX_XCOUNT)



#define DMA_RX_FLUSH_JIFFIES	(HZ / 50)

#define CTS_CHECK_JIFFIES	(HZ / 50)



#ifdef CONFIG_SERIAL_BFIN_DMA

static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
@@ -290,11 +291,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart) 
{

	struct circ_buf *xmit = &uart->port.info->xmit;



	if (uart->port.x_char) {

		UART_PUT_CHAR(uart, uart->port.x_char);

		uart->port.icount.tx++;

		uart->port.x_char = 0;

	}

	/*

	 * Check the modem control lines before

	 * transmitting anything.
@@ -306,6 +302,12 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart) 
		return;

	}



	if (uart->port.x_char) {

		UART_PUT_CHAR(uart, uart->port.x_char);

		uart->port.icount.tx++;

		uart->port.x_char = 0;

	}



	while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {

		UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -345,15 +347,6 @@ static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id) 
}

#endif



#ifdef CONFIG_SERIAL_BFIN_CTSRTS

static void bfin_serial_do_work(struct work_struct *work)

{

	struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);



	bfin_serial_mctrl_check(uart);

}

#endif



#ifdef CONFIG_SERIAL_BFIN_DMA

static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)

{
@@ -361,6 +354,12 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 


	uart->tx_done = 0;



	/*

	 * Check the modem control lines before

	 * transmitting anything.

	 */

	bfin_serial_mctrl_check(uart);



	if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {

		uart->tx_count = 0;

		uart->tx_done = 1;
@@ -373,12 +372,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 
		uart->port.x_char = 0;

	}



	/*

	 * Check the modem control lines before

	 * transmitting anything.

	 */

	bfin_serial_mctrl_check(uart);



	uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);

	if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))

		uart->tx_count = UART_XMIT_SIZE - xmit->tail;
@@ -565,7 +558,10 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart) 
	uart_handle_cts_change(&uart->port, status & TIOCM_CTS);

	if (!(status & TIOCM_CTS)) {

		tty->hw_stopped = 1;

		schedule_work(&uart->cts_workqueue);

		uart->cts_timer.data = (unsigned long)(uart);

		uart->cts_timer.function = (void *)bfin_serial_mctrl_check;

		uart->cts_timer.expires = jiffies + CTS_CHECK_JIFFIES;

		add_timer(&(uart->cts_timer));

	} else {

		tty->hw_stopped = 0;

	}
@@ -885,7 +881,7 @@ static void __init bfin_serial_init_ports(void) 
		init_timer(&(bfin_serial_ports[i].rx_dma_timer));

#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

		INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);

		init_timer(&(bfin_serial_ports[i].cts_timer));

		bfin_serial_ports[i].cts_pin	    =

			bfin_serial_resource[i].uart_cts_pin;

		bfin_serial_ports[i].rts_pin	    =

include/asm-blackfin/mach-bf527/bfin_serial_5xx.h

+1 −1
Original line number Diff line number Diff line
@@ -96,7 +96,7 @@ struct bfin_serial_port { 
	struct work_struct tx_dma_workqueue;

#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

	struct work_struct cts_workqueue;

	struct timer_list cts_timer;

	int cts_pin;

	int rts_pin;

#endif

include/asm-blackfin/mach-bf533/bfin_serial_5xx.h

+1 −1
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ struct bfin_serial_port { 
# endif

#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

	struct work_struct 	cts_workqueue;

	struct timer_list       cts_timer;

	int			cts_pin;

	int			rts_pin;

#endif

include/asm-blackfin/mach-bf537/bfin_serial_5xx.h

+1 −1
Original line number Diff line number Diff line
@@ -96,7 +96,7 @@ struct bfin_serial_port { 
	struct work_struct	tx_dma_workqueue;

#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

	struct work_struct 	cts_workqueue;

	struct timer_list 	cts_timer;

	int		cts_pin;

	int 		rts_pin;

#endif

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

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ struct bfin_serial_port { 
	struct work_struct	tx_dma_workqueue;

#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS

	struct work_struct 	cts_workqueue;

	struct timer_list 	cts_timer;

	int		cts_pin;

	int 		rts_pin;

#endif