Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-13 Thread Grant Likely 
On Sat, 9 Feb 2013 12:15:10 +0530, Vineet Gupta  
wrote:
> On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
> > On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta 
> >  wrote:
> >> +- clock-frequency : the input clock frequency for the UART
> >> +- baud: baud rate for UART
> > change 'baud' to 'current-speed'. There is already precedence for this
> > with other serial devices.
> 
> While I'm OK with this - I can only see of_serial.c following the rule :-)
> More importantly I'm not clear about the logistics of this fix. Obviously 
> this has
> a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
> driver)
> routed thru the subsystem tree or the arch tree or bits from both with
> bisectability not considered - which feels wrong. We have to also consider the
> fact that Greg has closed the tty/serial for 3.9. So while I have no 
> objection to
> your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
> alternate way.

I would consider it a bug fix. The binding isn't what it should be and
it needs to be addressed before appearing in a released kernel. If this
patch has already been merged, then write and post a fixup patch.

> >
> >> @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
> >> platform_device *pdev)
> >>  static int arc_serial_probe(struct platform_device *pdev)
> >>  {
> >>int rc, dev_id;
> >> +  struct device_node *np = pdev->dev.of_node;
> >> +
> >> +  /* no device tree device */
> >> +  if (!np)
> >> +  return -ENODEV;
> > This breaks non-DT users. Is this what you intend? It creates a flag day
> > where users have to switch from non-DT to DT cold-turkey.
> 
> Not supporting non-DT user was not the idea - it just simplifies the code a 
> bit
> given that it would only even be runtime used in a ARC Linux port based 
> platform -
> which unconditionally enables OF.  Further - the ARC port itself is not yet
> upstream so there are no "official" user of this in tree driver.
> FWIW, ARC Linux port was recently reviewed on lkml/arch mailing lists and is 
> now
> in linux-next for a possible 3.9 merge.

If there are no users, then nobody is broken. If this driver only
supports DT platforms then my comment can be ignored.

> >> +  dev_id = of_alias_get_id(np, "serial");
> >> +  if (dev_id < 0) {
> >> +  dev_err(>dev, "failed to get alias id: %d\n", dev_id);
> >> +  return dev_id;
> >> +  }
> > Don't fail on this. If you can't get an id then choose one dynamically.
> 
> You mean just assume 0.

No, I mean dynamically assign an ID from ids that are available. Say you
had two of these devices in a system, and neither had an alias; they
couldn't both be '0'.  :-)

g.

> 
> Thanks for reviewing.
> -Vineet

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-13 Thread Grant Likely 
On Sat, 9 Feb 2013 12:15:10 +0530, Vineet Gupta vineet.gup...@synopsys.com 
wrote:
 On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
  On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta 
  vineet.gup...@synopsys.com wrote:
  +- clock-frequency : the input clock frequency for the UART
  +- baud: baud rate for UART
  change 'baud' to 'current-speed'. There is already precedence for this
  with other serial devices.
 
 While I'm OK with this - I can only see of_serial.c following the rule :-)
 More importantly I'm not clear about the logistics of this fix. Obviously 
 this has
 a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
 driver)
 routed thru the subsystem tree or the arch tree or bits from both with
 bisectability not considered - which feels wrong. We have to also consider the
 fact that Greg has closed the tty/serial for 3.9. So while I have no 
 objection to
 your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
 alternate way.

I would consider it a bug fix. The binding isn't what it should be and
it needs to be addressed before appearing in a released kernel. If this
patch has already been merged, then write and post a fixup patch.

 
  @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
  platform_device *pdev)
   static int arc_serial_probe(struct platform_device *pdev)
   {
 int rc, dev_id;
  +  struct device_node *np = pdev-dev.of_node;
  +
  +  /* no device tree device */
  +  if (!np)
  +  return -ENODEV;
  This breaks non-DT users. Is this what you intend? It creates a flag day
  where users have to switch from non-DT to DT cold-turkey.
 
 Not supporting non-DT user was not the idea - it just simplifies the code a 
 bit
 given that it would only even be runtime used in a ARC Linux port based 
 platform -
 which unconditionally enables OF.  Further - the ARC port itself is not yet
 upstream so there are no official user of this in tree driver.
 FWIW, ARC Linux port was recently reviewed on lkml/arch mailing lists and is 
 now
 in linux-next for a possible 3.9 merge.

If there are no users, then nobody is broken. If this driver only
supports DT platforms then my comment can be ignored.

  +  dev_id = of_alias_get_id(np, serial);
  +  if (dev_id  0) {
  +  dev_err(pdev-dev, failed to get alias id: %d\n, dev_id);
  +  return dev_id;
  +  }
  Don't fail on this. If you can't get an id then choose one dynamically.
 
 You mean just assume 0.

No, I mean dynamically assign an ID from ids that are available. Say you
had two of these devices in a system, and neither had an alias; they
couldn't both be '0'.  :-)

g.

 
 Thanks for reviewing.
 -Vineet

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-09 Thread Arnd Bergmann 
On Saturday 09 February 2013, Vineet Gupta wrote:
> On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
> > On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta 
> >  wrote:
> >> +- clock-frequency   : the input clock frequency for the UART
> >> +- baud  : baud rate for UART
> > change 'baud' to 'current-speed'. There is already precedence for this
> > with other serial devices.
> 
> While I'm OK with this - I can only see of_serial.c following the rule :-)
> More importantly I'm not clear about the logistics of this fix. Obviously 
> this has
> a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
> driver)
> routed thru the subsystem tree or the arch tree or bits from both with
> bisectability not considered - which feels wrong. We have to also consider the
> fact that Greg has closed the tty/serial for 3.9. So while I have no 
> objection to
> your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
> alternate way.

I'd consider this one a bug fix, so while Greg is not accepting any new
features for the serial tree, I think it should still get in that way
and should not be controversial as an add-on change.


Arnd
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-09 Thread Arnd Bergmann 
On Saturday 09 February 2013, Vineet Gupta wrote:
 On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
  On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta 
  vineet.gup...@synopsys.com wrote:
  +- clock-frequency   : the input clock frequency for the UART
  +- baud  : baud rate for UART
  change 'baud' to 'current-speed'. There is already precedence for this
  with other serial devices.
 
 While I'm OK with this - I can only see of_serial.c following the rule :-)
 More importantly I'm not clear about the logistics of this fix. Obviously 
 this has
 a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
 driver)
 routed thru the subsystem tree or the arch tree or bits from both with
 bisectability not considered - which feels wrong. We have to also consider the
 fact that Greg has closed the tty/serial for 3.9. So while I have no 
 objection to
 your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
 alternate way.

I'd consider this one a bug fix, so while Greg is not accepting any new
features for the serial tree, I think it should still get in that way
and should not be controversial as an add-on change.


Arnd
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-08 Thread Vineet Gupta 
On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
> On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta  
> wrote:
>> +- clock-frequency   : the input clock frequency for the UART
>> +- baud  : baud rate for UART
> change 'baud' to 'current-speed'. There is already precedence for this
> with other serial devices.

While I'm OK with this - I can only see of_serial.c following the rule :-)
More importantly I'm not clear about the logistics of this fix. Obviously this 
has
a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
driver)
routed thru the subsystem tree or the arch tree or bits from both with
bisectability not considered - which feels wrong. We have to also consider the
fact that Greg has closed the tty/serial for 3.9. So while I have no objection 
to
your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
alternate way.

>
>> @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
>> platform_device *pdev)
>>  static int arc_serial_probe(struct platform_device *pdev)
>>  {
>>  int rc, dev_id;
>> +struct device_node *np = pdev->dev.of_node;
>> +
>> +/* no device tree device */
>> +if (!np)
>> +return -ENODEV;
> This breaks non-DT users. Is this what you intend? It creates a flag day
> where users have to switch from non-DT to DT cold-turkey.

Not supporting non-DT user was not the idea - it just simplifies the code a bit
given that it would only even be runtime used in a ARC Linux port based 
platform -
which unconditionally enables OF.  Further - the ARC port itself is not yet
upstream so there are no "official" user of this in tree driver.
FWIW, ARC Linux port was recently reviewed on lkml/arch mailing lists and is now
in linux-next for a possible 3.9 merge.

>> +dev_id = of_alias_get_id(np, "serial");
>> +if (dev_id < 0) {
>> +dev_err(>dev, "failed to get alias id: %d\n", dev_id);
>> +return dev_id;
>> +}
> Don't fail on this. If you can't get an id then choose one dynamically.

You mean just assume 0.

Thanks for reviewing.
-Vineet
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-08 Thread Grant Likely 
On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta  
wrote:
> * DT binding for arc-uart
> * With alll the bits in place we can now use DT probing.
> 
> Note that there's a bit of kludge right now because earlyprintk portion
> of driver can't use the DT infrastrcuture to get resoures/plat_data.
> This requires some infrastructre changes to of_flat_ framework
> 
> Signed-off-by: Vineet Gupta 
> Cc: Grant Likely 
> Cc: Arnd Bergmann 
> Cc: linux-ser...@vger.kernel.org
> Cc: Alan Cox 
> Cc: Greg Kroah-Hartman 
> Cc: devicetree-disc...@lists.ozlabs.org
> Cc: Rob Herring 
> Cc: Rob Landley 
> Cc: linux-ser...@vger.kernel.org
> ---
>  .../devicetree/bindings/tty/serial/arc-uart.txt|   26 
>  drivers/tty/serial/arc_uart.c  |   43 ++-
>  2 files changed, 66 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/tty/serial/arc-uart.txt
> 
> diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt 
> b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
> new file mode 100644
> index 000..c3bd8f9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
> @@ -0,0 +1,26 @@
> +* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
> +
> +Required properties:
> +- compatible : "snps,arc-uart"
> +- reg: offset and length of the register set for the 
> device.
> +- interrupts : device interrupt
> +- clock-frequency: the input clock frequency for the UART
> +- baud   : baud rate for UART

change 'baud' to 'current-speed'. There is already precedence for this
with other serial devices.

g.

> @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
> platform_device *pdev)
>  static int arc_serial_probe(struct platform_device *pdev)
>  {
>   int rc, dev_id;
> + struct device_node *np = pdev->dev.of_node;
> +
> + /* no device tree device */
> + if (!np)
> + return -ENODEV;

This breaks non-DT users. Is this what you intend? It creates a flag day
where users have to switch from non-DT to DT cold-turkey.

> + dev_id = of_alias_get_id(np, "serial");
> + if (dev_id < 0) {
> + dev_err(>dev, "failed to get alias id: %d\n", dev_id);
> + return dev_id;
> + }

Don't fail on this. If you can't get an id then choose one dynamically.

>  
> - dev_id = pdev->id < 0 ? 0 : pdev->id;
>   rc = arc_uart_init_one(pdev, dev_id);
>   if (rc)
>   return rc;
> @@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device 
> *pdev)
>   return 0;
>  }
>  
> +static const struct of_device_id arc_uart_dt_ids[] = {
> + { .compatible = "snps,arc-uart" },
> + { /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
> +
>  static struct platform_driver arc_platform_driver = {
>   .probe = arc_serial_probe,
>   .remove = arc_serial_remove,
>   .driver = {
>   .name = DRIVER_NAME,
>   .owner = THIS_MODULE,
> + .of_match_table  = arc_uart_dt_ids,
>},
>  };
>  
> -- 
> 1.7.4.1
> 

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-08 Thread Grant Likely 
On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta vineet.gup...@synopsys.com 
wrote:
 * DT binding for arc-uart
 * With alll the bits in place we can now use DT probing.
 
 Note that there's a bit of kludge right now because earlyprintk portion
 of driver can't use the DT infrastrcuture to get resoures/plat_data.
 This requires some infrastructre changes to of_flat_ framework
 
 Signed-off-by: Vineet Gupta vgu...@synopsys.com
 Cc: Grant Likely grant.lik...@secretlab.ca
 Cc: Arnd Bergmann a...@arndb.de
 Cc: linux-ser...@vger.kernel.org
 Cc: Alan Cox a...@linux.intel.com
 Cc: Greg Kroah-Hartman gre...@linuxfoundation.org
 Cc: devicetree-disc...@lists.ozlabs.org
 Cc: Rob Herring rob.herr...@calxeda.com
 Cc: Rob Landley r...@landley.net
 Cc: linux-ser...@vger.kernel.org
 ---
  .../devicetree/bindings/tty/serial/arc-uart.txt|   26 
  drivers/tty/serial/arc_uart.c  |   43 ++-
  2 files changed, 66 insertions(+), 3 deletions(-)
  create mode 100644 Documentation/devicetree/bindings/tty/serial/arc-uart.txt
 
 diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt 
 b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
 new file mode 100644
 index 000..c3bd8f9
 --- /dev/null
 +++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
 @@ -0,0 +1,26 @@
 +* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
 +
 +Required properties:
 +- compatible : snps,arc-uart
 +- reg: offset and length of the register set for the 
 device.
 +- interrupts : device interrupt
 +- clock-frequency: the input clock frequency for the UART
 +- baud   : baud rate for UART

change 'baud' to 'current-speed'. There is already precedence for this
with other serial devices.

g.

 @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
 platform_device *pdev)
  static int arc_serial_probe(struct platform_device *pdev)
  {
   int rc, dev_id;
 + struct device_node *np = pdev-dev.of_node;
 +
 + /* no device tree device */
 + if (!np)
 + return -ENODEV;

This breaks non-DT users. Is this what you intend? It creates a flag day
where users have to switch from non-DT to DT cold-turkey.

 + dev_id = of_alias_get_id(np, serial);
 + if (dev_id  0) {
 + dev_err(pdev-dev, failed to get alias id: %d\n, dev_id);
 + return dev_id;
 + }

Don't fail on this. If you can't get an id then choose one dynamically.

  
 - dev_id = pdev-id  0 ? 0 : pdev-id;
   rc = arc_uart_init_one(pdev, dev_id);
   if (rc)
   return rc;
 @@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device 
 *pdev)
   return 0;
  }
  
 +static const struct of_device_id arc_uart_dt_ids[] = {
 + { .compatible = snps,arc-uart },
 + { /* Sentinel */ }
 +};
 +MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
 +
  static struct platform_driver arc_platform_driver = {
   .probe = arc_serial_probe,
   .remove = arc_serial_remove,
   .driver = {
   .name = DRIVER_NAME,
   .owner = THIS_MODULE,
 + .of_match_table  = arc_uart_dt_ids,
},
  };
  
 -- 
 1.7.4.1
 

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.
--
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-02-08 Thread Vineet Gupta 
On Saturday 09 February 2013 04:31 AM, Grant Likely wrote:
 On Fri, 11 Jan 2013 11:50:23 +0530, Vineet Gupta vineet.gup...@synopsys.com 
 wrote:
 +- clock-frequency   : the input clock frequency for the UART
 +- baud  : baud rate for UART
 change 'baud' to 'current-speed'. There is already precedence for this
 with other serial devices.

While I'm OK with this - I can only see of_serial.c following the rule :-)
More importantly I'm not clear about the logistics of this fix. Obviously this 
has
a bearing on DT files in arch/arc/boot/*. So are such changes (platform + 
driver)
routed thru the subsystem tree or the arch tree or bits from both with
bisectability not considered - which feels wrong. We have to also consider the
fact that Greg has closed the tty/serial for 3.9. So while I have no objection 
to
your comment, it seems that the it needs to wait till 3.9-rc1 - or is there an
alternate way.


 @@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
 platform_device *pdev)
  static int arc_serial_probe(struct platform_device *pdev)
  {
  int rc, dev_id;
 +struct device_node *np = pdev-dev.of_node;
 +
 +/* no device tree device */
 +if (!np)
 +return -ENODEV;
 This breaks non-DT users. Is this what you intend? It creates a flag day
 where users have to switch from non-DT to DT cold-turkey.

Not supporting non-DT user was not the idea - it just simplifies the code a bit
given that it would only even be runtime used in a ARC Linux port based 
platform -
which unconditionally enables OF.  Further - the ARC port itself is not yet
upstream so there are no official user of this in tree driver.
FWIW, ARC Linux port was recently reviewed on lkml/arch mailing lists and is now
in linux-next for a possible 3.9 merge.

 +dev_id = of_alias_get_id(np, serial);
 +if (dev_id  0) {
 +dev_err(pdev-dev, failed to get alias id: %d\n, dev_id);
 +return dev_id;
 +}
 Don't fail on this. If you can't get an id then choose one dynamically.

You mean just assume 0.

Thanks for reviewing.
-Vineet
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Arnd Bergmann 
On Friday 11 January 2013, Vineet Gupta wrote:
> On Friday 11 January 2013 05:03 PM, Arnd Bergmann wrote:

> > Quick question about the name though: is this UART only used
> > on ARC, or is it something that synopsys licenses to other
> > parties as well? If the latter is true, we might want to 
> > add a more generic "compatible" value for those that use
> > it on another architecture.
> 
> It's not licensed as standalone IP - since its not a standard 8250. It is only
> (but actively) used on the internal FPGA flows from ARC days.
> 
Ok, thanks for the confirmation.

Arnd
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Vineet Gupta 
On Friday 11 January 2013 05:03 PM, Arnd Bergmann wrote:
> On Friday 11 January 2013, Vineet Gupta wrote:
>> * DT binding for arc-uart
>> * With alll the bits in place we can now use DT probing.
>>
>> Note that there's a bit of kludge right now because earlyprintk portion
>> of driver can't use the DT infrastrcuture to get resoures/plat_data.
>> This requires some infrastructre changes to of_flat_ framework
>>
>> Signed-off-by: Vineet Gupta 
>> Cc: Grant Likely 
>> Cc: Arnd Bergmann 
>> Cc: linux-ser...@vger.kernel.org
>> Cc: Alan Cox 
>> Cc: Greg Kroah-Hartman 
>> Cc: devicetree-disc...@lists.ozlabs.org
>> Cc: Rob Herring 
>> Cc: Rob Landley 
>> Cc: linux-ser...@vger.kernel.org
> Acked-by: Arnd Bergmann 
>
> Quick question about the name though: is this UART only used
> on ARC, or is it something that synopsys licenses to other
> parties as well? If the latter is true, we might want to 
> add a more generic "compatible" value for those that use
> it on another architecture.

It's not licensed as standalone IP - since its not a standard 8250. It is only
(but actively) used on the internal FPGA flows from ARC days.

Thx,
Vineet

>   Arnd

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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Arnd Bergmann 
On Friday 11 January 2013, Vineet Gupta wrote:
> * DT binding for arc-uart
> * With alll the bits in place we can now use DT probing.
> 
> Note that there's a bit of kludge right now because earlyprintk portion
> of driver can't use the DT infrastrcuture to get resoures/plat_data.
> This requires some infrastructre changes to of_flat_ framework
> 
> Signed-off-by: Vineet Gupta 
> Cc: Grant Likely 
> Cc: Arnd Bergmann 
> Cc: linux-ser...@vger.kernel.org
> Cc: Alan Cox 
> Cc: Greg Kroah-Hartman 
> Cc: devicetree-disc...@lists.ozlabs.org
> Cc: Rob Herring 
> Cc: Rob Landley 
> Cc: linux-ser...@vger.kernel.org

Acked-by: Arnd Bergmann 

Quick question about the name though: is this UART only used
on ARC, or is it something that synopsys licenses to other
parties as well? If the latter is true, we might want to 
add a more generic "compatible" value for those that use
it on another architecture.

Arnd
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Arnd Bergmann 
On Friday 11 January 2013, Vineet Gupta wrote:
 * DT binding for arc-uart
 * With alll the bits in place we can now use DT probing.
 
 Note that there's a bit of kludge right now because earlyprintk portion
 of driver can't use the DT infrastrcuture to get resoures/plat_data.
 This requires some infrastructre changes to of_flat_ framework
 
 Signed-off-by: Vineet Gupta vgu...@synopsys.com
 Cc: Grant Likely grant.lik...@secretlab.ca
 Cc: Arnd Bergmann a...@arndb.de
 Cc: linux-ser...@vger.kernel.org
 Cc: Alan Cox a...@linux.intel.com
 Cc: Greg Kroah-Hartman gre...@linuxfoundation.org
 Cc: devicetree-disc...@lists.ozlabs.org
 Cc: Rob Herring rob.herr...@calxeda.com
 Cc: Rob Landley r...@landley.net
 Cc: linux-ser...@vger.kernel.org

Acked-by: Arnd Bergmann a...@arndb.de

Quick question about the name though: is this UART only used
on ARC, or is it something that synopsys licenses to other
parties as well? If the latter is true, we might want to 
add a more generic compatible value for those that use
it on another architecture.

Arnd
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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Vineet Gupta 
On Friday 11 January 2013 05:03 PM, Arnd Bergmann wrote:
 On Friday 11 January 2013, Vineet Gupta wrote:
 * DT binding for arc-uart
 * With alll the bits in place we can now use DT probing.

 Note that there's a bit of kludge right now because earlyprintk portion
 of driver can't use the DT infrastrcuture to get resoures/plat_data.
 This requires some infrastructre changes to of_flat_ framework

 Signed-off-by: Vineet Gupta vgu...@synopsys.com
 Cc: Grant Likely grant.lik...@secretlab.ca
 Cc: Arnd Bergmann a...@arndb.de
 Cc: linux-ser...@vger.kernel.org
 Cc: Alan Cox a...@linux.intel.com
 Cc: Greg Kroah-Hartman gre...@linuxfoundation.org
 Cc: devicetree-disc...@lists.ozlabs.org
 Cc: Rob Herring rob.herr...@calxeda.com
 Cc: Rob Landley r...@landley.net
 Cc: linux-ser...@vger.kernel.org
 Acked-by: Arnd Bergmann a...@arndb.de

 Quick question about the name though: is this UART only used
 on ARC, or is it something that synopsys licenses to other
 parties as well? If the latter is true, we might want to 
 add a more generic compatible value for those that use
 it on another architecture.

It's not licensed as standalone IP - since its not a standard 8250. It is only
(but actively) used on the internal FPGA flows from ARC days.

Thx,
Vineet

   Arnd

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Re: [PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-11 Thread Arnd Bergmann 
On Friday 11 January 2013, Vineet Gupta wrote:
 On Friday 11 January 2013 05:03 PM, Arnd Bergmann wrote:

  Quick question about the name though: is this UART only used
  on ARC, or is it something that synopsys licenses to other
  parties as well? If the latter is true, we might want to 
  add a more generic compatible value for those that use
  it on another architecture.
 
 It's not licensed as standalone IP - since its not a standard 8250. It is only
 (but actively) used on the internal FPGA flows from ARC days.
 
Ok, thanks for the confirmation.

Arnd
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[PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-10 Thread Vineet Gupta 
* DT binding for arc-uart
* With alll the bits in place we can now use DT probing.

Note that there's a bit of kludge right now because earlyprintk portion
of driver can't use the DT infrastrcuture to get resoures/plat_data.
This requires some infrastructre changes to of_flat_ framework

Signed-off-by: Vineet Gupta 
Cc: Grant Likely 
Cc: Arnd Bergmann 
Cc: linux-ser...@vger.kernel.org
Cc: Alan Cox 
Cc: Greg Kroah-Hartman 
Cc: devicetree-disc...@lists.ozlabs.org
Cc: Rob Herring 
Cc: Rob Landley 
Cc: linux-ser...@vger.kernel.org
---
 .../devicetree/bindings/tty/serial/arc-uart.txt|   26 
 drivers/tty/serial/arc_uart.c  |   43 ++-
 2 files changed, 66 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/tty/serial/arc-uart.txt

diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt 
b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
new file mode 100644
index 000..c3bd8f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
@@ -0,0 +1,26 @@
+* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
+
+Required properties:
+- compatible   : "snps,arc-uart"
+- reg  : offset and length of the register set for the device.
+- interrupts   : device interrupt
+- clock-frequency  : the input clock frequency for the UART
+- baud : baud rate for UART
+
+e.g.
+
+arcuart0: serial@c0fc1000 {
+   compatible = "snps,arc-uart";
+   reg = <0xc0fc1000 0x100>;
+   interrupts = <5>;
+   clock-frequency = <8000>;
+   baud = <115200>;
+   status = "okay";
+};
+
+Note: Each port should have an alias correctly numbered in "aliases" node.
+
+e.g.
+aliases {
+   serial0 = 
+};
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 2db6410..b468601 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -37,6 +37,8 @@
 #include 
 #include 
 #include 
+#include 
+#include 
 
 /*
  * ARC UART Hardware Specs
@@ -537,8 +539,26 @@ arc_uart_init_one(struct platform_device *pdev, int dev_id)
return -ENODEV;
 
uart->is_emulated = !!plat_data[0]; /* workaround ISS bug */
-   uart->port.uartclk = plat_data[1];
-   uart->baud = plat_data[2];
+
+   if (is_early_platform_device(pdev)) {
+   uart->port.uartclk = plat_data[1];
+   uart->baud = plat_data[2];
+   } else {
+   struct device_node *np = pdev->dev.of_node;
+   u32 val;
+
+   if (of_property_read_u32(np, "clock-frequency", )) {
+   dev_err(>dev, "clock-frequency property 
NOTset\n");
+   return -EINVAL;
+   }
+   uart->port.uartclk = val;
+
+   if (of_property_read_u32(np, "baud", )) {
+   dev_err(>dev, "baud property NOT set\n");
+   return -EINVAL;
+   }
+   uart->baud = val;
+   }
 
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
@@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
platform_device *pdev)
 static int arc_serial_probe(struct platform_device *pdev)
 {
int rc, dev_id;
+   struct device_node *np = pdev->dev.of_node;
+
+   /* no device tree device */
+   if (!np)
+   return -ENODEV;
+
+   dev_id = of_alias_get_id(np, "serial");
+   if (dev_id < 0) {
+   dev_err(>dev, "failed to get alias id: %d\n", dev_id);
+   return dev_id;
+   }
 
-   dev_id = pdev->id < 0 ? 0 : pdev->id;
rc = arc_uart_init_one(pdev, dev_id);
if (rc)
return rc;
@@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device *pdev)
return 0;
 }
 
+static const struct of_device_id arc_uart_dt_ids[] = {
+   { .compatible = "snps,arc-uart" },
+   { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
+
 static struct platform_driver arc_platform_driver = {
.probe = arc_serial_probe,
.remove = arc_serial_remove,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
+   .of_match_table  = arc_uart_dt_ids,
 },
 };
 
-- 
1.7.4.1

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[PATCH 4/4] serial/arc-uart: switch to devicetree based probing

2013-01-10 Thread Vineet Gupta 
* DT binding for arc-uart
* With alll the bits in place we can now use DT probing.

Note that there's a bit of kludge right now because earlyprintk portion
of driver can't use the DT infrastrcuture to get resoures/plat_data.
This requires some infrastructre changes to of_flat_ framework

Signed-off-by: Vineet Gupta vgu...@synopsys.com
Cc: Grant Likely grant.lik...@secretlab.ca
Cc: Arnd Bergmann a...@arndb.de
Cc: linux-ser...@vger.kernel.org
Cc: Alan Cox a...@linux.intel.com
Cc: Greg Kroah-Hartman gre...@linuxfoundation.org
Cc: devicetree-disc...@lists.ozlabs.org
Cc: Rob Herring rob.herr...@calxeda.com
Cc: Rob Landley r...@landley.net
Cc: linux-ser...@vger.kernel.org
---
 .../devicetree/bindings/tty/serial/arc-uart.txt|   26 
 drivers/tty/serial/arc_uart.c  |   43 ++-
 2 files changed, 66 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/tty/serial/arc-uart.txt

diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt 
b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
new file mode 100644
index 000..c3bd8f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
@@ -0,0 +1,26 @@
+* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
+
+Required properties:
+- compatible   : snps,arc-uart
+- reg  : offset and length of the register set for the device.
+- interrupts   : device interrupt
+- clock-frequency  : the input clock frequency for the UART
+- baud : baud rate for UART
+
+e.g.
+
+arcuart0: serial@c0fc1000 {
+   compatible = snps,arc-uart;
+   reg = 0xc0fc1000 0x100;
+   interrupts = 5;
+   clock-frequency = 8000;
+   baud = 115200;
+   status = okay;
+};
+
+Note: Each port should have an alias correctly numbered in aliases node.
+
+e.g.
+aliases {
+   serial0 = arcuart0;
+};
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 2db6410..b468601 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -37,6 +37,8 @@
 #include linux/tty_flip.h
 #include linux/serial_core.h
 #include linux/io.h
+#include linux/of.h
+#include linux/of_platform.h
 
 /*
  * ARC UART Hardware Specs
@@ -537,8 +539,26 @@ arc_uart_init_one(struct platform_device *pdev, int dev_id)
return -ENODEV;
 
uart-is_emulated = !!plat_data[0]; /* workaround ISS bug */
-   uart-port.uartclk = plat_data[1];
-   uart-baud = plat_data[2];
+
+   if (is_early_platform_device(pdev)) {
+   uart-port.uartclk = plat_data[1];
+   uart-baud = plat_data[2];
+   } else {
+   struct device_node *np = pdev-dev.of_node;
+   u32 val;
+
+   if (of_property_read_u32(np, clock-frequency, val)) {
+   dev_err(pdev-dev, clock-frequency property 
NOTset\n);
+   return -EINVAL;
+   }
+   uart-port.uartclk = val;
+
+   if (of_property_read_u32(np, baud, val)) {
+   dev_err(pdev-dev, baud property NOT set\n);
+   return -EINVAL;
+   }
+   uart-baud = val;
+   }
 
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
@@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct 
platform_device *pdev)
 static int arc_serial_probe(struct platform_device *pdev)
 {
int rc, dev_id;
+   struct device_node *np = pdev-dev.of_node;
+
+   /* no device tree device */
+   if (!np)
+   return -ENODEV;
+
+   dev_id = of_alias_get_id(np, serial);
+   if (dev_id  0) {
+   dev_err(pdev-dev, failed to get alias id: %d\n, dev_id);
+   return dev_id;
+   }
 
-   dev_id = pdev-id  0 ? 0 : pdev-id;
rc = arc_uart_init_one(pdev, dev_id);
if (rc)
return rc;
@@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device *pdev)
return 0;
 }
 
+static const struct of_device_id arc_uart_dt_ids[] = {
+   { .compatible = snps,arc-uart },
+   { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
+
 static struct platform_driver arc_platform_driver = {
.probe = arc_serial_probe,
.remove = arc_serial_remove,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
+   .of_match_table  = arc_uart_dt_ids,
 },
 };
 
-- 
1.7.4.1

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