Patchwork [1/2] tty/serial: atmel: Add is_half_duplex helper

login
register
mail settings
Submitter Razvan Stefanescu
Date March 15, 2019, 9:23 a.m.
Message ID <20190315092334.13246-2-razvan.stefanescu@microchip.com>
Download mbox | patch
Permalink /patch/749415/
State New
Headers show

Comments

Razvan Stefanescu - March 15, 2019, 9:23 a.m.
Use a helper function to check that a port needs to use half duplex
communication, replacing several occurrences of multi-line bit checking.

Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
---
 drivers/tty/serial/atmel_serial.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)
Richard Genoud - March 18, 2019, 1:41 p.m.
[ adding Gil Weber in Cc: ]

Le 15/03/2019 à 10:23, Razvan Stefanescu a écrit :
> Use a helper function to check that a port needs to use half duplex
> communication, replacing several occurrences of multi-line bit checking.
> 
> Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
> ---
>  drivers/tty/serial/atmel_serial.c | 27 ++++++++++++++-------------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 05147fe24343..a6577b1c4461 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -231,6 +231,13 @@ 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)) ||
> +		(port->iso7816.flags & SER_ISO7816_ENABLED);
> +}
> +
>  #ifdef CONFIG_SERIAL_ATMEL_PDC
>  static bool atmel_use_pdc_rx(struct uart_port *port)
>  {
> @@ -608,10 +615,10 @@ 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)) ||
> -	    port->iso7816.flags & SER_ISO7816_ENABLED)
> -		atmel_start_rx(port);
> +	if (atmel_uart_is_half_duplex(port))
> +		if (!atomic_read(&atmel_port->tasklet_shutdown))
This check wasn't there before.
If it's really needed, please insert it in another patch and explain why
it's needed.

> +			atmel_start_rx(port);
> +
>  }
>  
>  /*
> @@ -628,9 +635,7 @@ 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)) ||
> -		    port->iso7816.flags & SER_ISO7816_ENABLED)
> +		if (atmel_uart_is_half_duplex(port))
>  			atmel_stop_rx(port);
>  
>  	if (atmel_use_pdc_tx(port))
> @@ -928,9 +933,7 @@ 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)) ||
> -		 port->iso7816.flags & SER_ISO7816_ENABLED) {
> +	else if (atmel_uart_is_half_duplex(port)) {
>  		/* DMA done, stop TX, start RX for RS485 */
>  		atmel_start_rx(port);
>  	}
> @@ -1508,9 +1511,7 @@ 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)) ||
> -		    port->iso7816.flags & SER_ISO7816_ENABLED) {
> +		if (atmel_uart_is_half_duplex(port)) {
>  			/* DMA done, stop TX, start RX for RS485 */
>  			atmel_start_rx(port);
>  		}
>
Razvan Stefanescu - March 18, 2019, 2:17 p.m.
On 18/03/2019 15:41, Richard Genoud wrote:
> [ adding Gil Weber in Cc: ]

> 

> Le 15/03/2019 à 10:23, Razvan Stefanescu a écrit :

>> Use a helper function to check that a port needs to use half duplex

>> communication, replacing several occurrences of multi-line bit checking.

>>

>> Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>

>> ---

>>   drivers/tty/serial/atmel_serial.c | 27 ++++++++++++++-------------

>>   1 file changed, 14 insertions(+), 13 deletions(-)

>>

>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c

>> index 05147fe24343..a6577b1c4461 100644

>> --- a/drivers/tty/serial/atmel_serial.c

>> +++ b/drivers/tty/serial/atmel_serial.c

>> @@ -231,6 +231,13 @@ 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)) ||

>> +		(port->iso7816.flags & SER_ISO7816_ENABLED);

>> +}

>> +

>>   #ifdef CONFIG_SERIAL_ATMEL_PDC

>>   static bool atmel_use_pdc_rx(struct uart_port *port)

>>   {

>> @@ -608,10 +615,10 @@ 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)) ||

>> -	    port->iso7816.flags & SER_ISO7816_ENABLED)

>> -		atmel_start_rx(port);

>> +	if (atmel_uart_is_half_duplex(port))

>> +		if (!atomic_read(&atmel_port->tasklet_shutdown))

> This check wasn't there before.

> If it's really needed, please insert it in another patch and explain why

> it's needed.

> 

Thank you for the feedback. It is not needed, will be removed in v2.

Best regards,
Razvan

>> +			atmel_start_rx(port);

>> +

>>   }

>>   

>>   /*

>> @@ -628,9 +635,7 @@ 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)) ||

>> -		    port->iso7816.flags & SER_ISO7816_ENABLED)

>> +		if (atmel_uart_is_half_duplex(port))

>>   			atmel_stop_rx(port);

>>   

>>   	if (atmel_use_pdc_tx(port))

>> @@ -928,9 +933,7 @@ 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)) ||

>> -		 port->iso7816.flags & SER_ISO7816_ENABLED) {

>> +	else if (atmel_uart_is_half_duplex(port)) {

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

>>   		atmel_start_rx(port);

>>   	}

>> @@ -1508,9 +1511,7 @@ 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)) ||

>> -		    port->iso7816.flags & SER_ISO7816_ENABLED) {

>> +		if (atmel_uart_is_half_duplex(port)) {

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

>>   			atmel_start_rx(port);

>>   		}

>>

>

Patch

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..a6577b1c4461 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -231,6 +231,13 @@  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)) ||
+		(port->iso7816.flags & SER_ISO7816_ENABLED);
+}
+
 #ifdef CONFIG_SERIAL_ATMEL_PDC
 static bool atmel_use_pdc_rx(struct uart_port *port)
 {
@@ -608,10 +615,10 @@  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)) ||
-	    port->iso7816.flags & SER_ISO7816_ENABLED)
-		atmel_start_rx(port);
+	if (atmel_uart_is_half_duplex(port))
+		if (!atomic_read(&atmel_port->tasklet_shutdown))
+			atmel_start_rx(port);
+
 }
 
 /*
@@ -628,9 +635,7 @@  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)) ||
-		    port->iso7816.flags & SER_ISO7816_ENABLED)
+		if (atmel_uart_is_half_duplex(port))
 			atmel_stop_rx(port);
 
 	if (atmel_use_pdc_tx(port))
@@ -928,9 +933,7 @@  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)) ||
-		 port->iso7816.flags & SER_ISO7816_ENABLED) {
+	else if (atmel_uart_is_half_duplex(port)) {
 		/* DMA done, stop TX, start RX for RS485 */
 		atmel_start_rx(port);
 	}
@@ -1508,9 +1511,7 @@  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)) ||
-		    port->iso7816.flags & SER_ISO7816_ENABLED) {
+		if (atmel_uart_is_half_duplex(port)) {
 			/* DMA done, stop TX, start RX for RS485 */
 			atmel_start_rx(port);
 		}