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* [RFC] ns16550: support for UART with broken FIFO
@ 2012-01-17 10:39 Antony Pavlov
  2012-01-17 13:09 ` Sascha Hauer
  0 siblings, 1 reply; 6+ messages in thread
From: Antony Pavlov @ 2012-01-17 10:39 UTC (permalink / raw)
  To: barebox

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
 include/ns16550.h               |    2 ++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
index 1217a5f..01de964 100644
--- a/drivers/serial/serial_ns16550.c
+++ b/drivers/serial/serial_ns16550.c
@@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
 static void ns16550_serial_init_port(struct console_device *cdev)
 {
 	unsigned int baud_divisor;
+	struct NS16550_plat *plat = (struct NS16550_plat *)
+	    cdev->dev->platform_data;
 
 	/* Setup the serial port with the defaults first */
 	baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
@@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
 	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
 	ns16550_write(cdev, LCRVAL, lcr);
 	ns16550_write(cdev, MCRVAL, mcr);
-	ns16550_write(cdev, FCRVAL, fcr);
+
+	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
+		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
+	} else {
+		ns16550_write(cdev, FCRVAL, fcr);
+	}
+
 #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
 	ns16550_write(cdev, 0x00,  mdr1);
 #endif
@@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
 static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
 {
 	unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
+	struct NS16550_plat *plat = (struct NS16550_plat *)
+	    cdev->dev->platform_data;
 
 	ns16550_write(cdev, 0x00, ier);
 	ns16550_write(cdev, LCR_BKSE, lcr);
@@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
 	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
 	ns16550_write(cdev, LCRVAL, lcr);
 	ns16550_write(cdev, MCRVAL, mcr);
-	ns16550_write(cdev, FCRVAL, fcr);
+	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
+		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
+	} else {
+		ns16550_write(cdev, FCRVAL, fcr);
+	}
+
 	return 0;
 }
 
diff --git a/include/ns16550.h b/include/ns16550.h
index 5fd52fa..4a41b93 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -52,6 +52,8 @@ struct NS16550_plat {
 				    unsigned char reg_offset);
 
 	int shift;
+	unsigned int flags;
+#define NS16650_FLAG_DISABLE_FIFO	1
 };
 
 #endif				/* __NS16650_PLATFORM_H_ */
-- 
1.7.8.3


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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [RFC] ns16550: support for UART with broken FIFO
  2012-01-17 10:39 [RFC] ns16550: support for UART with broken FIFO Antony Pavlov
@ 2012-01-17 13:09 ` Sascha Hauer
  2012-01-17 13:27   ` Antony Pavlov
  0 siblings, 1 reply; 6+ messages in thread
From: Sascha Hauer @ 2012-01-17 13:09 UTC (permalink / raw)
  To: Antony Pavlov; +Cc: barebox

On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> ---
>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
>  include/ns16550.h               |    2 ++
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
> index 1217a5f..01de964 100644
> --- a/drivers/serial/serial_ns16550.c
> +++ b/drivers/serial/serial_ns16550.c
> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
>  static void ns16550_serial_init_port(struct console_device *cdev)
>  {
>  	unsigned int baud_divisor;
> +	struct NS16550_plat *plat = (struct NS16550_plat *)
> +	    cdev->dev->platform_data;
>  
>  	/* Setup the serial port with the defaults first */
>  	baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
>  	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>  	ns16550_write(cdev, LCRVAL, lcr);
>  	ns16550_write(cdev, MCRVAL, mcr);
> -	ns16550_write(cdev, FCRVAL, fcr);
> +
> +	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> +		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> +	} else {
> +		ns16550_write(cdev, FCRVAL, fcr);
> +	}

unnecessary braces here..

> +
>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>  	ns16550_write(cdev, 0x00,  mdr1);
>  #endif
> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>  {
>  	unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
> +	struct NS16550_plat *plat = (struct NS16550_plat *)
> +	    cdev->dev->platform_data;
>  
>  	ns16550_write(cdev, 0x00, ier);
>  	ns16550_write(cdev, LCR_BKSE, lcr);
> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>  	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>  	ns16550_write(cdev, LCRVAL, lcr);
>  	ns16550_write(cdev, MCRVAL, mcr);
> -	ns16550_write(cdev, FCRVAL, fcr);
> +	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> +		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> +	} else {
> +		ns16550_write(cdev, FCRVAL, fcr);
> +	}

and here. Otherwise this looks ok.

Sascha


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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [RFC] ns16550: support for UART with broken FIFO
  2012-01-17 13:09 ` Sascha Hauer
@ 2012-01-17 13:27   ` Antony Pavlov
  2012-01-17 14:53     ` Jean-Christophe PLAGNIOL-VILLARD
  0 siblings, 1 reply; 6+ messages in thread
From: Antony Pavlov @ 2012-01-17 13:27 UTC (permalink / raw)
  To: Sascha Hauer; +Cc: barebox

On 17 January 2012 17:09, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
>> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
>> ---
>>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
>>  include/ns16550.h               |    2 ++
>>  2 files changed, 19 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
>> index 1217a5f..01de964 100644
>> --- a/drivers/serial/serial_ns16550.c
>> +++ b/drivers/serial/serial_ns16550.c
>> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
>>  static void ns16550_serial_init_port(struct console_device *cdev)
>>  {
>>       unsigned int baud_divisor;
>> +     struct NS16550_plat *plat = (struct NS16550_plat *)
>> +         cdev->dev->platform_data;
>>
>>       /* Setup the serial port with the defaults first */
>>       baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
>> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
>>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>>       ns16550_write(cdev, LCRVAL, lcr);
>>       ns16550_write(cdev, MCRVAL, mcr);
>> -     ns16550_write(cdev, FCRVAL, fcr);
>> +
>> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
>> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
>> +     } else {
>> +             ns16550_write(cdev, FCRVAL, fcr);
>> +     }
>
> unnecessary braces here..
>
>> +
>>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>>       ns16550_write(cdev, 0x00,  mdr1);
>>  #endif
>> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
>>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>>  {
>>       unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
>> +     struct NS16550_plat *plat = (struct NS16550_plat *)
>> +         cdev->dev->platform_data;
>>
>>       ns16550_write(cdev, 0x00, ier);
>>       ns16550_write(cdev, LCR_BKSE, lcr);
>> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>>       ns16550_write(cdev, LCRVAL, lcr);
>>       ns16550_write(cdev, MCRVAL, mcr);
>> -     ns16550_write(cdev, FCRVAL, fcr);
>> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
>> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
>> +     } else {
>> +             ns16550_write(cdev, FCRVAL, fcr);
>> +     }
>
> and here. Otherwise this looks ok.

Ok, I shall remove the braces.

Sascha!

We have special OMAP code, e.g.:

#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
        ns16550_write(cdev, 0x07, mdr1);        /* Disable */
#endif

I think, that we can change it to something like this:

    if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
        ns16550_write(cdev, 0x07, mdr1);        /* Disable */

-- 
Best regards,
  Antony Pavlov

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [RFC] ns16550: support for UART with broken FIFO
  2012-01-17 13:27   ` Antony Pavlov
@ 2012-01-17 14:53     ` Jean-Christophe PLAGNIOL-VILLARD
  2012-01-17 19:40       ` Antony Pavlov
  0 siblings, 1 reply; 6+ messages in thread
From: Jean-Christophe PLAGNIOL-VILLARD @ 2012-01-17 14:53 UTC (permalink / raw)
  To: Antony Pavlov; +Cc: barebox

On 17:27 Tue 17 Jan     , Antony Pavlov wrote:
> On 17 January 2012 17:09, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
> >> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> >> ---
> >>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
> >>  include/ns16550.h               |    2 ++
> >>  2 files changed, 19 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
> >> index 1217a5f..01de964 100644
> >> --- a/drivers/serial/serial_ns16550.c
> >> +++ b/drivers/serial/serial_ns16550.c
> >> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
> >>  static void ns16550_serial_init_port(struct console_device *cdev)
> >>  {
> >>       unsigned int baud_divisor;
> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
> >> +         cdev->dev->platform_data;
> >>
> >>       /* Setup the serial port with the defaults first */
> >>       baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
> >> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
> >>       ns16550_write(cdev, LCRVAL, lcr);
> >>       ns16550_write(cdev, MCRVAL, mcr);
> >> -     ns16550_write(cdev, FCRVAL, fcr);
> >> +
> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> >> +     } else {
> >> +             ns16550_write(cdev, FCRVAL, fcr);
> >> +     }
> >
> > unnecessary braces here..
> >
> >> +
> >>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
> >>       ns16550_write(cdev, 0x00,  mdr1);
> >>  #endif
> >> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
> >>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
> >>  {
> >>       unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
> >> +         cdev->dev->platform_data;
> >>
> >>       ns16550_write(cdev, 0x00, ier);
> >>       ns16550_write(cdev, LCR_BKSE, lcr);
> >> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
> >>       ns16550_write(cdev, LCRVAL, lcr);
> >>       ns16550_write(cdev, MCRVAL, mcr);
> >> -     ns16550_write(cdev, FCRVAL, fcr);
> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> >> +     } else {
> >> +             ns16550_write(cdev, FCRVAL, fcr);
> >> +     }
> >
> > and here. Otherwise this looks ok.
> 
> Ok, I shall remove the braces.
> 
> Sascha!
> 
> We have special OMAP code, e.g.:
> 
> #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
> #endif
> 
> I think, that we can change it to something like this:
> 
>     if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
I don't like to add dead code in the binary
just use
	if (IS_ENABLED(CONFIG_...)

Best Regards,
J.

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [RFC] ns16550: support for UART with broken FIFO
  2012-01-17 14:53     ` Jean-Christophe PLAGNIOL-VILLARD
@ 2012-01-17 19:40       ` Antony Pavlov
  2012-01-17 23:58         ` Jean-Christophe PLAGNIOL-VILLARD
  0 siblings, 1 reply; 6+ messages in thread
From: Antony Pavlov @ 2012-01-17 19:40 UTC (permalink / raw)
  To: Jean-Christophe PLAGNIOL-VILLARD; +Cc: barebox

On 17 January 2012 18:53, Jean-Christophe PLAGNIOL-VILLARD
<plagnioj@jcrosoft.com> wrote:
> On 17:27 Tue 17 Jan     , Antony Pavlov wrote:
>> On 17 January 2012 17:09, Sascha Hauer <s.hauer@pengutronix.de> wrote:
>> > On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
>> >> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
>> >> ---
>> >>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
>> >>  include/ns16550.h               |    2 ++
>> >>  2 files changed, 19 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
>> >> index 1217a5f..01de964 100644
>> >> --- a/drivers/serial/serial_ns16550.c
>> >> +++ b/drivers/serial/serial_ns16550.c
>> >> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
>> >>  static void ns16550_serial_init_port(struct console_device *cdev)
>> >>  {
>> >>       unsigned int baud_divisor;
>> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
>> >> +         cdev->dev->platform_data;
>> >>
>> >>       /* Setup the serial port with the defaults first */
>> >>       baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
>> >> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
>> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>> >>       ns16550_write(cdev, LCRVAL, lcr);
>> >>       ns16550_write(cdev, MCRVAL, mcr);
>> >> -     ns16550_write(cdev, FCRVAL, fcr);
>> >> +
>> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
>> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
>> >> +     } else {
>> >> +             ns16550_write(cdev, FCRVAL, fcr);
>> >> +     }
>> >
>> > unnecessary braces here..
>> >
>> >> +
>> >>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>> >>       ns16550_write(cdev, 0x00,  mdr1);
>> >>  #endif
>> >> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
>> >>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>> >>  {
>> >>       unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
>> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
>> >> +         cdev->dev->platform_data;
>> >>
>> >>       ns16550_write(cdev, 0x00, ier);
>> >>       ns16550_write(cdev, LCR_BKSE, lcr);
>> >> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>> >>       ns16550_write(cdev, LCRVAL, lcr);
>> >>       ns16550_write(cdev, MCRVAL, mcr);
>> >> -     ns16550_write(cdev, FCRVAL, fcr);
>> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
>> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
>> >> +     } else {
>> >> +             ns16550_write(cdev, FCRVAL, fcr);
>> >> +     }
>> >
>> > and here. Otherwise this looks ok.
>>
>> Ok, I shall remove the braces.
>>
>> Sascha!
>>
>> We have special OMAP code, e.g.:
>>
>> #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
>> #endif
>>
>> I think, that we can change it to something like this:
>>
>>     if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
>>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
> I don't like to add dead code in the binary
> just use
>        if (IS_ENABLED(CONFIG_...)

You is right, but there is another point of view.

If you have defined CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
macro, then you will use OMAP extensions for __ALL__ ports, not only
for OMAP internal port. May be OMAP have no other ports, only internal
ports with extensions. But in any case it is bad design example: we
have very special code (OMAP EXTENSIONS) in universal driver
(ns16550), and this special code works without checking presents of
the extensions.

I don't like dead code too. So there are another solutions:

#ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
        if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
            ns16550_write(cdev, 0x07, mdr1);        /* Disable */
#endif

or even
        if (IS_ENABLED(CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS) &&
         plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
            ns16550_write(cdev, 0x07, mdr1);        /* Disable */
-- 
Best regards,
  Antony Pavlov

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [RFC] ns16550: support for UART with broken FIFO
  2012-01-17 19:40       ` Antony Pavlov
@ 2012-01-17 23:58         ` Jean-Christophe PLAGNIOL-VILLARD
  0 siblings, 0 replies; 6+ messages in thread
From: Jean-Christophe PLAGNIOL-VILLARD @ 2012-01-17 23:58 UTC (permalink / raw)
  To: Antony Pavlov; +Cc: barebox

On 23:40 Tue 17 Jan     , Antony Pavlov wrote:
> On 17 January 2012 18:53, Jean-Christophe PLAGNIOL-VILLARD
> <plagnioj@jcrosoft.com> wrote:
> > On 17:27 Tue 17 Jan     , Antony Pavlov wrote:
> >> On 17 January 2012 17:09, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> >> > On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
> >> >> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> >> >> ---
> >> >>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
> >> >>  include/ns16550.h               |    2 ++
> >> >>  2 files changed, 19 insertions(+), 2 deletions(-)
> >> >>
> >> >> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
> >> >> index 1217a5f..01de964 100644
> >> >> --- a/drivers/serial/serial_ns16550.c
> >> >> +++ b/drivers/serial/serial_ns16550.c
> >> >> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
> >> >>  static void ns16550_serial_init_port(struct console_device *cdev)
> >> >>  {
> >> >>       unsigned int baud_divisor;
> >> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
> >> >> +         cdev->dev->platform_data;
> >> >>
> >> >>       /* Setup the serial port with the defaults first */
> >> >>       baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
> >> >> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
> >> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
> >> >>       ns16550_write(cdev, LCRVAL, lcr);
> >> >>       ns16550_write(cdev, MCRVAL, mcr);
> >> >> -     ns16550_write(cdev, FCRVAL, fcr);
> >> >> +
> >> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> >> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> >> >> +     } else {
> >> >> +             ns16550_write(cdev, FCRVAL, fcr);
> >> >> +     }
> >> >
> >> > unnecessary braces here..
> >> >
> >> >> +
> >> >>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
> >> >>       ns16550_write(cdev, 0x00,  mdr1);
> >> >>  #endif
> >> >> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
> >> >>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
> >> >>  {
> >> >>       unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
> >> >> +     struct NS16550_plat *plat = (struct NS16550_plat *)
> >> >> +         cdev->dev->platform_data;
> >> >>
> >> >>       ns16550_write(cdev, 0x00, ier);
> >> >>       ns16550_write(cdev, LCR_BKSE, lcr);
> >> >> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
> >> >>       ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
> >> >>       ns16550_write(cdev, LCRVAL, lcr);
> >> >>       ns16550_write(cdev, MCRVAL, mcr);
> >> >> -     ns16550_write(cdev, FCRVAL, fcr);
> >> >> +     if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> >> >> +             ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> >> >> +     } else {
> >> >> +             ns16550_write(cdev, FCRVAL, fcr);
> >> >> +     }
> >> >
> >> > and here. Otherwise this looks ok.
> >>
> >> Ok, I shall remove the braces.
> >>
> >> Sascha!
> >>
> >> We have special OMAP code, e.g.:
> >>
> >> #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
> >>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
> >> #endif
> >>
> >> I think, that we can change it to something like this:
> >>
> >>     if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
> >>         ns16550_write(cdev, 0x07, mdr1);        /* Disable */
> > I don't like to add dead code in the binary
> > just use
> >        if (IS_ENABLED(CONFIG_...)
> 
> You is right, but there is another point of view.
> 
> If you have defined CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
> macro, then you will use OMAP extensions for __ALL__ ports, not only
> for OMAP internal port. May be OMAP have no other ports, only internal
> ports with extensions. But in any case it is bad design example: we
> have very special code (OMAP EXTENSIONS) in universal driver
> (ns16550), and this special code works without checking presents of
> the extensions.
> 
> I don't like dead code too. So there are another solutions:
> 
> #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>         if (plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
>             ns16550_write(cdev, 0x07, mdr1);        /* Disable */
> #endif
> 
> or even
>         if (IS_ENABLED(CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS) &&
>          plat->flags & NS16650_FLAG_OMAP_EXTENSIONS)
>             ns16550_write(cdev, 0x07, mdr1);        /* Disable */
this one

Best Regards,
J.
> -- 
> Best regards,
>   Antony Pavlov

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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-01-17 23:59 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-01-17 10:39 [RFC] ns16550: support for UART with broken FIFO Antony Pavlov
2012-01-17 13:09 ` Sascha Hauer
2012-01-17 13:27   ` Antony Pavlov
2012-01-17 14:53     ` Jean-Christophe PLAGNIOL-VILLARD
2012-01-17 19:40       ` Antony Pavlov
2012-01-17 23:58         ` Jean-Christophe PLAGNIOL-VILLARD

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