Move RS485 implementation from drivers to serial core (v3)

Move RS485 implementation from drivers to serial core (v3)

[Lino Sanfilippo]

This patch series is an attempt to simplify rs485 implementation in drivers
by moving the following tasks out of the drivers into the serial core:

- ensure sane RTS settings: in case of an invalid configuration (both RTS
  after send and RTS on send set or both unset) enable RTS on send and
  disable RTS after send

- nullify the padding field of the serial_rs485 struct before it is
  returned to userspace

- copy the configuration stored in the serial_rs485 struct to the port
  configuration if setting the configuration in the driver was successfull

- limit the RTS delay to 100ms


Redundant code has been removed from the following drivers for now:

- atmel
- fsl_lpuart
- amba
- imx
- max310x
- omap-serial
- sc16is7xx
- stm32-usart

The code has been tested with the amba pl011 driver. This series applies
against Gregs tty-testing branch.

Changes in v2:
- use a makro for max RTS delays and comment it (as requested by Jiri)
- add a comment concerning the memset of a structures padding field
- correct typos in the commit message (found by Uwe) 
- rephrase all commit messages to make more clear that function 
  uart_set_rs485_config() has been extended by checks and other
  functionalities (as requested by Uwe)

Changes in v3:
- add warning messages if the serial core corrects RS485 values (as requested by Lukas Wunner)
- dont expose the macro for max RTS delays to userspace (as requested by Greg) 


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[PATCH v3 1/9] serial: core: move RS485 configuration tasks from drivers into core

[Lino Sanfilippo]

Several drivers that support setting the RS485 configuration via userspace
implement one or more of the following tasks:

- in case of an invalid RTS configuration (both RTS after send and RTS on
  send set or both unset) fall back to enable RTS on send and disable RTS
  after send

- nullify the padding field of the returned serial_rs485 struct

- copy the configuration into the uart port struct

- limit RTS delays to 100 ms

Move these tasks into the serial core to make them generic and to provide
a consistent behaviour among all drivers.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/serial_core.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 846192a7b4bf..2b3afe038c1c 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -42,6 +42,11 @@ static struct lock_class_key port_lock_key;
 
 #define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
 
+/*
+ * Max time with active RTS before/after data is sent.
+ */
+#define RS485_MAX_RTS_DELAY	100 /* msecs */
+
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios);
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
@@ -1282,8 +1287,32 @@ static int uart_set_rs485_config(struct uart_port *port,
 	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
 		return -EFAULT;
 
+	/* pick sane settings if the user hasn't */
+	if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
+	    !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
+		pr_warn("invalid RTS setting, using RTS_ON_SEND instead\n");
+		rs485.flags |= SER_RS485_RTS_ON_SEND;
+		rs485.flags &= ~SER_RS485_RTS_AFTER_SEND;
+	}
+
+	if (rs485.delay_rts_before_send > RS485_MAX_RTS_DELAY) {
+		rs485.delay_rts_before_send = RS485_MAX_RTS_DELAY;
+		pr_warn("RTS delay before sending clamped to %u ms\n",
+			rs485.delay_rts_before_send);
+	}
+
+	if (rs485.delay_rts_after_send > RS485_MAX_RTS_DELAY) {
+		rs485.delay_rts_after_send = RS485_MAX_RTS_DELAY;
+		pr_warn("RTS delay after sending clamped to %u ms\n",
+			rs485.delay_rts_after_send);
+	}
+	/* Return clean padding area to userspace */
+	memset(rs485.padding, 0, sizeof(rs485.padding));
+
 	spin_lock_irqsave(&port->lock, flags);
 	ret = port->rs485_config(port, &rs485);
+	if (!ret)
+		port->rs485 = rs485;
 	spin_unlock_irqrestore(&port->lock, flags);
 	if (ret)
 		return ret;

base-commit: a603ca60cebff8589882427a67f870ed946b3fc8
-- 
2.35.1

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Re: [PATCH v3 1/9] serial: core: move RS485 configuration tasks from drivers into core

[Jiri Slaby]

On 22. 02. 22, 2:14, Lino Sanfilippo wrote:
> Several drivers that support setting the RS485 configuration via userspace
> implement one or more of the following tasks:
> 
> - in case of an invalid RTS configuration (both RTS after send and RTS on
>    send set or both unset) fall back to enable RTS on send and disable RTS
>    after send
> 
> - nullify the padding field of the returned serial_rs485 struct
> 
> - copy the configuration into the uart port struct
> 
> - limit RTS delays to 100 ms
> 
> Move these tasks into the serial core to make them generic and to provide
> a consistent behaviour among all drivers.
> 
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> ---
>   drivers/tty/serial/serial_core.c | 29 +++++++++++++++++++++++++++++
>   1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 846192a7b4bf..2b3afe038c1c 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -42,6 +42,11 @@ static struct lock_class_key port_lock_key;
>   
>   #define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
>   
> +/*
> + * Max time with active RTS before/after data is sent.
> + */
> +#define RS485_MAX_RTS_DELAY	100 /* msecs */
> +
>   static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
>   					struct ktermios *old_termios);
>   static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
> @@ -1282,8 +1287,32 @@ static int uart_set_rs485_config(struct uart_port *port,
>   	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
>   		return -EFAULT;
>   
> +	/* pick sane settings if the user hasn't */
> +	if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
> +	    !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
> +		pr_warn("invalid RTS setting, using RTS_ON_SEND instead\n");

Can't we have a device prefix here, so that everyone knows what device 
is affected? Without that, it's not that useful. At least port->name & 
port->line could be printed. The uart core uses dev_* prints, but prints 
also line as uport->dev can be NULL sometimes.

Hm, we could introduce uart_print family (to print something like what 
is in uart_report_port).

thanks,
-- 
js
suse labs

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Re: [PATCH v3 1/9] serial: core: move RS485 configuration tasks from drivers into core

[Jiri Slaby]

On 22. 02. 22, 7:51, Jiri Slaby wrote:
> On 22. 02. 22, 2:14, Lino Sanfilippo wrote:
>> Several drivers that support setting the RS485 configuration via 
>> userspace
>> implement one or more of the following tasks:
>>
>> - in case of an invalid RTS configuration (both RTS after send and RTS on
>>    send set or both unset) fall back to enable RTS on send and disable 
>> RTS
>>    after send
>>
>> - nullify the padding field of the returned serial_rs485 struct
>>
>> - copy the configuration into the uart port struct
>>
>> - limit RTS delays to 100 ms
>>
>> Move these tasks into the serial core to make them generic and to provide
>> a consistent behaviour among all drivers.
>>
>> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
>> ---
>>   drivers/tty/serial/serial_core.c | 29 +++++++++++++++++++++++++++++
>>   1 file changed, 29 insertions(+)
>>
>> diff --git a/drivers/tty/serial/serial_core.c 
>> b/drivers/tty/serial/serial_core.c
>> index 846192a7b4bf..2b3afe038c1c 100644
>> --- a/drivers/tty/serial/serial_core.c
>> +++ b/drivers/tty/serial/serial_core.c
>> @@ -42,6 +42,11 @@ static struct lock_class_key port_lock_key;
>>   #define HIGH_BITS_OFFSET    ((sizeof(long)-sizeof(int))*8)
>> +/*
>> + * Max time with active RTS before/after data is sent.
>> + */
>> +#define RS485_MAX_RTS_DELAY    100 /* msecs */
>> +
>>   static void uart_change_speed(struct tty_struct *tty, struct 
>> uart_state *state,
>>                       struct ktermios *old_termios);
>>   static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
>> @@ -1282,8 +1287,32 @@ static int uart_set_rs485_config(struct 
>> uart_port *port,
>>       if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
>>           return -EFAULT;
>> +    /* pick sane settings if the user hasn't */
>> +    if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
>> +        !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
>> +        pr_warn("invalid RTS setting, using RTS_ON_SEND instead\n");
> 
> Can't we have a device prefix here, so that everyone knows what device 
> is affected? Without that, it's not that useful. At least port->name & 
> port->line could be printed. The uart core uses dev_* prints, but prints 
> also line as uport->dev can be NULL sometimes.

And this comes from userspace, so should be ratelimited.

-- 
js
suse labs

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Aw: Re: [PATCH v3 1/9] serial: core: move RS485 configuration tasks from drivers into core

[Lino Sanfilippo]

Hi,


> On 22. 02. 22, 7:51, Jiri Slaby wrote:
> > On 22. 02. 22, 2:14, Lino Sanfilippo wrote:
> >> Several drivers that support setting the RS485 configuration via 
> >> userspace
> >> implement one or more of the following tasks:
> >>
> >> - in case of an invalid RTS configuration (both RTS after send and RTS on
> >>    send set or both unset) fall back to enable RTS on send and disable 
> >> RTS
> >>    after send
> >>
> >> - nullify the padding field of the returned serial_rs485 struct
> >>
> >> - copy the configuration into the uart port struct
> >>
> >> - limit RTS delays to 100 ms
> >>
> >> Move these tasks into the serial core to make them generic and to provide
> >> a consistent behaviour among all drivers.
> >>
> >> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> >> ---
> >>   drivers/tty/serial/serial_core.c | 29 +++++++++++++++++++++++++++++
> >>   1 file changed, 29 insertions(+)
> >>
> >> diff --git a/drivers/tty/serial/serial_core.c 
> >> b/drivers/tty/serial/serial_core.c
> >> index 846192a7b4bf..2b3afe038c1c 100644
> >> --- a/drivers/tty/serial/serial_core.c
> >> +++ b/drivers/tty/serial/serial_core.c
> >> @@ -42,6 +42,11 @@ static struct lock_class_key port_lock_key;
> >>   #define HIGH_BITS_OFFSET    ((sizeof(long)-sizeof(int))*8)
> >> +/*
> >> + * Max time with active RTS before/after data is sent.
> >> + */
> >> +#define RS485_MAX_RTS_DELAY    100 /* msecs */
> >> +
> >>   static void uart_change_speed(struct tty_struct *tty, struct 
> >> uart_state *state,
> >>                       struct ktermios *old_termios);
> >>   static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
> >> @@ -1282,8 +1287,32 @@ static int uart_set_rs485_config(struct 
> >> uart_port *port,
> >>       if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
> >>           return -EFAULT;
> >> +    /* pick sane settings if the user hasn't */
> >> +    if (!(rs485.flags & SER_RS485_RTS_ON_SEND) ==
> >> +        !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) {
> >> +        pr_warn("invalid RTS setting, using RTS_ON_SEND instead\n");
> > 
> > Can't we have a device prefix here, so that everyone knows what device 
> > is affected? Without that, it's not that useful. At least port->name & 
> > port->line could be printed. The uart core uses dev_* prints, but prints 
> > also line as uport->dev can be NULL sometimes.
> 
> And this comes from userspace, so should be ratelimited.
> 

Right, ratelimiting makes sense here. I will change it as suggested in the next patch version.
Thanks a lot for the review.

Regards,
Lino


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[PATCH v3 2/9] serial: amba-pl011: remove redundant code in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already

- ensures that only one of both options RTS on send or RTS after send is
  set

- nullifies the padding field of the passed serial_rs485 struct

- clamps the RTS delays

- assigns the passed serial_rs485 struct to the uart port

So remove these tasks from the code of the drivers rs485_config() function
to avoid redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/amba-pl011.c | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index ba053a68529f..35c633739975 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2170,25 +2170,11 @@ static int pl011_rs485_config(struct uart_port *port,
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 
-	/* pick sane settings if the user hasn't */
-	if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
-	    !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
-		rs485->flags |= SER_RS485_RTS_ON_SEND;
-		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
-	}
-	/* clamp the delays to [0, 100ms] */
-	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
-	rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
-	memset(rs485->padding, 0, sizeof(rs485->padding));
-
 	if (port->rs485.flags & SER_RS485_ENABLED)
 		pl011_rs485_tx_stop(uap);
 
-	/* Set new configuration */
-	port->rs485 = *rs485;
-
 	/* Make sure auto RTS is disabled */
-	if (port->rs485.flags & SER_RS485_ENABLED) {
+	if (rs485->flags & SER_RS485_ENABLED) {
 		u32 cr = pl011_read(uap, REG_CR);
 
 		cr &= ~UART011_CR_RTSEN;
-- 
2.35.1

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[PATCH v3 3/9] serial: stm32: remove redundant code in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set. It also assigns the
passed serial_rs485 struct to the uart port.

So remove the check and the assignment from the drivers rs485_config()
function to avoid redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/stm32-usart.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 1b3a611ac39e..6a014168102c 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -107,8 +107,6 @@ static int stm32_usart_config_rs485(struct uart_port *port,
 
 	stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
-	port->rs485 = *rs485conf;
-
 	rs485conf->flags |= SER_RS485_RX_DURING_TX;
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
@@ -128,13 +126,10 @@ static int stm32_usart_config_rs485(struct uart_port *port,
 					     rs485conf->delay_rts_after_send,
 					     baud);
 
-		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		if (rs485conf->flags & SER_RS485_RTS_ON_SEND)
 			cr3 &= ~USART_CR3_DEP;
-			rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
-		} else {
+		else
 			cr3 |= USART_CR3_DEP;
-			rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
-		}
 
 		writel_relaxed(cr3, port->membase + ofs->cr3);
 		writel_relaxed(cr1, port->membase + ofs->cr1);
-- 
2.35.1

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[PATCH v3 4/9] serial: sc16is7xx: remove redundant check in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set.

So remove this check from the drivers rs485_config() function to avoid
redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/sc16is7xx.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 64e7e6c8145f..730f697bb517 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -959,16 +959,6 @@ static int sc16is7xx_config_rs485(struct uart_port *port,
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 
 	if (rs485->flags & SER_RS485_ENABLED) {
-		bool rts_during_rx, rts_during_tx;
-
-		rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;
-		rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;
-
-		if (rts_during_rx == rts_during_tx)
-			dev_err(port->dev,
-				"unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",
-				rts_during_tx, rts_during_rx);
-
 		/*
 		 * RTS signal is handled by HW, it's timing can't be influenced.
 		 * However, it's sometimes useful to delay TX even without RTS
-- 
2.35.1

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[PATCH v3 5/9] serial: omap: remove redundant code in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already clamps the RTS delays.
It also assigns the passed serial_rs485 struct to the uart port.

So remove these tasks from the drivers rs485_config() function to avoid
redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/omap-serial.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 0862941862c8..a3afcccfbd96 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1350,18 +1350,11 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
 
-	/* Clamp the delays to [0, 100ms] */
-	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
-	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
-
-	/* store new config */
-	port->rs485 = *rs485;
-
 	if (up->rts_gpiod) {
 		/* enable / disable rts */
-		val = (port->rs485.flags & SER_RS485_ENABLED) ?
+		val = (rs485->flags & SER_RS485_ENABLED) ?
 			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
-		val = (port->rs485.flags & val) ? 1 : 0;
+		val = (rs485->flags & val) ? 1 : 0;
 		gpiod_set_value(up->rts_gpiod, val);
 	}
 
@@ -1372,7 +1365,7 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
 	/* If RS-485 is disabled, make sure the THR interrupt is fired when
 	 * TX FIFO is below the trigger level.
 	 */
-	if (!(port->rs485.flags & SER_RS485_ENABLED) &&
+	if (!(rs485->flags & SER_RS485_ENABLED) &&
 	    (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
 		up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
 		serial_out(up, UART_OMAP_SCR, up->scr);
-- 
2.35.1

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[PATCH v3 6/9] serial: max310: remove redundant memset in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already nullifies the padding
field of the passed serial_rs485 struct before returning it to userspace.

Doing the same in the drivers rs485_config() function is redundant, so
remove the concerning memset in this function.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/max310x.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index dde0824b2fa5..2ecc5f66deaf 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1037,7 +1037,6 @@ static int max310x_rs485_config(struct uart_port *port,
 
 	rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX |
 			SER_RS485_ENABLED;
-	memset(rs485->padding, 0, sizeof(rs485->padding));
 	port->rs485 = *rs485;
 
 	schedule_work(&one->rs_work);
-- 
2.35.1

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[PATCH v3 7/9] serial: imx: remove redundant assignment in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port.

So remove the assignment in the drivers rs485_config() function to avoid
reduncancy.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/imx.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 0b467ce8d737..ab56ff23e8a9 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1937,8 +1937,6 @@ static int imx_uart_rs485_config(struct uart_port *port,
 	    rs485conf->flags & SER_RS485_RX_DURING_TX)
 		imx_uart_start_rx(port);
 
-	port->rs485 = *rs485conf;
-
 	return 0;
 }
 
-- 
2.35.1

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[PATCH v3 8/9] serial: fsl_lpuart: remove redundant code in rs485_config functions

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set. It also assigns the
passed serial_rs485 struct to the uart port.

So remove the check and the assignment from the drivers rs485_config()
function to avoid redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/fsl_lpuart.c | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 7d90c5a530ee..a201be44d68a 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1377,19 +1377,6 @@ static int lpuart_config_rs485(struct uart_port *port,
 		/* Enable auto RS-485 RTS mode */
 		modem |= UARTMODEM_TXRTSE;
 
-		/*
-		 * RTS needs to be logic HIGH either during transfer _or_ after
-		 * transfer, other variants are not supported by the hardware.
-		 */
-
-		if (!(rs485->flags & (SER_RS485_RTS_ON_SEND |
-				SER_RS485_RTS_AFTER_SEND)))
-			rs485->flags |= SER_RS485_RTS_ON_SEND;
-
-		if (rs485->flags & SER_RS485_RTS_ON_SEND &&
-				rs485->flags & SER_RS485_RTS_AFTER_SEND)
-			rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
-
 		/*
 		 * The hardware defaults to RTS logic HIGH while transfer.
 		 * Switch polarity in case RTS shall be logic HIGH
@@ -1402,9 +1389,6 @@ static int lpuart_config_rs485(struct uart_port *port,
 			modem |= UARTMODEM_TXRTSPOL;
 	}
 
-	/* Store the new configuration */
-	sport->port.rs485 = *rs485;
-
 	writeb(modem, sport->port.membase + UARTMODEM);
 	return 0;
 }
@@ -1428,19 +1412,6 @@ static int lpuart32_config_rs485(struct uart_port *port,
 		/* Enable auto RS-485 RTS mode */
 		modem |= UARTMODEM_TXRTSE;
 
-		/*
-		 * RTS needs to be logic HIGH either during transfer _or_ after
-		 * transfer, other variants are not supported by the hardware.
-		 */
-
-		if (!(rs485->flags & (SER_RS485_RTS_ON_SEND |
-				SER_RS485_RTS_AFTER_SEND)))
-			rs485->flags |= SER_RS485_RTS_ON_SEND;
-
-		if (rs485->flags & SER_RS485_RTS_ON_SEND &&
-				rs485->flags & SER_RS485_RTS_AFTER_SEND)
-			rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
-
 		/*
 		 * The hardware defaults to RTS logic HIGH while transfer.
 		 * Switch polarity in case RTS shall be logic HIGH
@@ -1453,9 +1424,6 @@ static int lpuart32_config_rs485(struct uart_port *port,
 			modem |= UARTMODEM_TXRTSPOL;
 	}
 
-	/* Store the new configuration */
-	sport->port.rs485 = *rs485;
-
 	lpuart32_write(&sport->port, modem, UARTMODIR);
 	return 0;
 }
-- 
2.35.1

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[PATCH v3 9/9] serial: atmel: remove redundant assignment in rs485_config

[Lino Sanfilippo]

In uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port.

So remove the assignment from the drivers rs485_config() function to avoid
redundancy.

Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
---
 drivers/tty/serial/atmel_serial.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 73d43919898d..18d3bbdcb7a2 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -299,11 +299,9 @@ static int atmel_config_rs485(struct uart_port *port,
 	/* Resetting serial mode to RS232 (0x0) */
 	mode &= ~ATMEL_US_USMODE;
 
-	port->rs485 = *rs485conf;
-
 	if (rs485conf->flags & SER_RS485_ENABLED) {
 		dev_dbg(port->dev, "Setting UART to RS485\n");
-		if (port->rs485.flags & SER_RS485_RX_DURING_TX)
+		if (rs485conf->flags & SER_RS485_RX_DURING_TX)
 			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
 		else
 			atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
-- 
2.35.1

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