[PATCH 4/7] serial: at91: make DBGU support dma and pdc transfers

[Jean-Christophe PLAGNIOL-VILLARD]

On 14:33 Tue 09 Jul     , Elen Song wrote:
> Because the DBGU lack of receive timeout register, so we use a timer to trigger
> data receive.
> 
> Signed-off-by: Elen Song <elen.song at atmel.com>
> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> ---
>  drivers/tty/serial/atmel_serial.c |   51 ++++++++++++++++++++++++++++++-------
>  1 file changed, 42 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index a425ff2..52beb7e 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -41,6 +41,7 @@
>  #include <linux/uaccess.h>
>  #include <linux/pinctrl/consumer.h>
>  #include <linux/platform_data/atmel.h>
> +#include <linux/timer.h>
>  
>  #include <asm/io.h>
>  #include <asm/ioctls.h>
> @@ -167,6 +168,7 @@ struct atmel_uart_port {
>  
>  	struct serial_rs485	rs485;		/* rs485 settings */
>  	unsigned int		tx_done_mask;
> +	struct timer_list 	uart_timer;	/* dbgu timer */
>  };
>  
>  static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
> @@ -968,6 +970,15 @@ err_dma:
>  	return -EINVAL;
>  }
>  
> +static void atmel_uart_timer_callback(unsigned long data)
> +{
> +	struct uart_port *port = (void *)data;
> +	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +
> +	tasklet_schedule(&atmel_port->tasklet);
> +	mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port));
> +}
> +
>  /*
>   * receive interrupt handler.
>   */
> @@ -1424,18 +1435,34 @@ static int atmel_startup(struct uart_port *port)
>  
>  	if (atmel_use_pdc_rx(port)) {
>  		/* set UART timeout */
> -		UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> -		UART_PUT_CR(port, ATMEL_US_STTTO);
> -
> -		UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
> +		if (port->line == 0) {
> +			setup_timer(&atmel_port->uart_timer,
> +				    atmel_uart_timer_callback,
> +				    (unsigned long)port);
> +			mod_timer(&atmel_port->uart_timer,
> +				  jiffies + uart_poll_timeout(port));
> +		} else {
> +			UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> +			UART_PUT_CR(port, ATMEL_US_STTTO);
> +
> +			UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
> +		}
>  		/* enable PDC controller */
>  		UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
>  	} else if (atmel_use_dma_rx(port)) {
>  		/* set UART timeout */
> -		UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> -		UART_PUT_CR(port, ATMEL_US_STTTO);
> -
> -		UART_PUT_IER(port, ATMEL_US_TIMEOUT);
> +		if (port->line == 0) {
> +			setup_timer(&atmel_port->uart_timer,
> +				    atmel_uart_timer_callback,
> +				    (unsigned long)port);
> +			mod_timer(&atmel_port->uart_timer,
> +				  jiffies + uart_poll_timeout(port));
> +		} else {
> +			UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> +			UART_PUT_CR(port, ATMEL_US_STTTO);
> +
> +			UART_PUT_IER(port, ATMEL_US_TIMEOUT);
> +		}
>  	} else {
>  		/* enable receive only */
>  		UART_PUT_IER(port, ATMEL_US_RXRDY);
> @@ -1471,6 +1498,9 @@ static void atmel_shutdown(struct uart_port *port)
>  					 DMA_FROM_DEVICE);
>  			kfree(pdc->buf);
>  		}
> +
> +		if (port->line == 0)
> +			del_timer_sync(&atmel_port->uart_timer);
>  	}
>  	if (atmel_use_pdc_tx(port)) {
>  		struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
> @@ -1484,8 +1514,11 @@ static void atmel_shutdown(struct uart_port *port)
>  	if (atmel_use_dma_tx(port))
>  		atmel_tx_dma_release(atmel_port);
>  
> -	if (atmel_use_dma_rx(port))
> +	if (atmel_use_dma_rx(port)) {
>  		atmel_rx_dma_release(atmel_port);
> +		if (port->line == 0)
> +			del_timer_sync(&atmel_port->uart_timer);
> +	}

use function pointer to seperate the code this will simplify the code and
easier the maintainance by droping all of those if(xx) else

Best Regards,
J.
>  
>  	/*
>  	 * Disable all interrupts, port and break condition.
> -- 
> 1.7.9.5
>