[PATCH V2 6/8] serial: at91: make DBGU support dma and pdc transfers

[Jean-Christophe PLAGNIOL-VILLARD]

On 10:43 Tue 16 Jul     , Elen Song wrote:
> Because the DBGU lack of receive timeout register, so we use a timer to trigger
> data receive.

please re-order the patch put patch 7 before 6
so we can distinguish the uart type not by line = 0 which is wrong as if you
can have no dbgu registered and line == 0 can be a normal usart

Best Regards,
J.
> 
> 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 |   48 ++++++++++++++++++++++++++++++++-----
>  1 file changed, 42 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index ad787fd1..afecdfa 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 */
>  	int (*prepare_rx)(struct uart_port *port);
>  	int (*prepare_tx)(struct uart_port *port);
>  	void (*schedule_rx)(struct uart_port *port);
> @@ -821,6 +823,9 @@ static void atmel_release_rx_dma(struct uart_port *port)
>  	atmel_port->desc_rx = NULL;
>  	atmel_port->chan_rx = NULL;
>  	atmel_port->cookie_rx = -EINVAL;
> +
> +	if (port->line == 0)
> +		del_timer_sync(&atmel_port->uart_timer);
>  }
>  
>  static void atmel_rx_from_dma(struct uart_port *port)
> @@ -950,6 +955,15 @@ chan_err:
>  	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.
>   */
> @@ -1213,6 +1227,9 @@ static void atmel_release_rx_pdc(struct uart_port *port)
>  				 DMA_FROM_DEVICE);
>  		kfree(pdc->buf);
>  	}
> +
> +	if (port->line == 0)
> +		del_timer_sync(&atmel_port->uart_timer);
>  }
>  
>  static void atmel_rx_from_pdc(struct uart_port *port)
> @@ -1546,17 +1563,36 @@ 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);
> +		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));
> +		/* set USART timeout */
> +		} 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);
> +			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)) {
> -		UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> -		UART_PUT_CR(port, ATMEL_US_STTTO);
> +		/* set UART 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));
> +		/* set USART timeout */
> +		} else {
> +			UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
> +			UART_PUT_CR(port, ATMEL_US_STTTO);
>  
> -		UART_PUT_IER(port, ATMEL_US_TIMEOUT);
> +			UART_PUT_IER(port, ATMEL_US_TIMEOUT);
> +		}
>  	} else {
>  		/* enable receive only */
>  		UART_PUT_IER(port, ATMEL_US_RXRDY);
> -- 
> 1.7.9.5
>