[PATCH] input: pwm-beeper: Add devicetree probing support

[PATCH] input: pwm-beeper: Add devicetree probing support

[Sascha Hauer]

A very simple binding, the only property is the phandle to the PWM.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
 drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt

diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
new file mode 100644
index 0000000..7388b82
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
@@ -0,0 +1,7 @@
+* PWM beeper device tree bindings
+
+Registers a PWM device as beeper.
+
+Required properties:
+- compatible: should be "pwm-beeper"
+- pwms: phandle to the physical pwm device
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index fc84c8a..a6aa48c 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
 	if (!beeper)
 		return -ENOMEM;
 
-	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
+	if (pdev->dev.platform_data)
+		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
+	else
+		beeper->pwm = pwm_get(&pdev->dev, NULL);
 
 	if (IS_ERR(beeper->pwm)) {
 		error = PTR_ERR(beeper->pwm);
@@ -171,6 +174,11 @@ static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
 #define PWM_BEEPER_PM_OPS NULL
 #endif
 
+static const struct of_device_id pwm_beeper_match[] = {
+	{ .compatible = "pwm-beeper", },
+	{ },
+};
+
 static struct platform_driver pwm_beeper_driver = {
 	.probe	= pwm_beeper_probe,
 	.remove = __devexit_p(pwm_beeper_remove),
@@ -178,6 +186,7 @@ static struct platform_driver pwm_beeper_driver = {
 		.name	= "pwm-beeper",
 		.owner	= THIS_MODULE,
 		.pm	= PWM_BEEPER_PM_OPS,
+		.of_match_table = pwm_beeper_match,
 	},
 };
 module_platform_driver(pwm_beeper_driver);
-- 
1.7.10.4

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Rob Herring]

On 09/24/2012 02:37 AM, Sascha Hauer wrote:
> A very simple binding, the only property is the phandle to the PWM.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Acked-by: Rob Herring <rob.herring@calxeda.com>

> ---
>  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
>  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
>  2 files changed, 17 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> new file mode 100644
> index 0000000..7388b82
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> @@ -0,0 +1,7 @@
> +* PWM beeper device tree bindings
> +
> +Registers a PWM device as beeper.
> +
> +Required properties:
> +- compatible: should be "pwm-beeper"
> +- pwms: phandle to the physical pwm device
> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> index fc84c8a..a6aa48c 100644
> --- a/drivers/input/misc/pwm-beeper.c
> +++ b/drivers/input/misc/pwm-beeper.c
> @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
>  	if (!beeper)
>  		return -ENOMEM;
>  
> -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> +	if (pdev->dev.platform_data)
> +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> +	else
> +		beeper->pwm = pwm_get(&pdev->dev, NULL);
>  
>  	if (IS_ERR(beeper->pwm)) {
>  		error = PTR_ERR(beeper->pwm);
> @@ -171,6 +174,11 @@ static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
>  #define PWM_BEEPER_PM_OPS NULL
>  #endif
>  
> +static const struct of_device_id pwm_beeper_match[] = {
> +	{ .compatible = "pwm-beeper", },
> +	{ },
> +};
> +
>  static struct platform_driver pwm_beeper_driver = {
>  	.probe	= pwm_beeper_probe,
>  	.remove = __devexit_p(pwm_beeper_remove),
> @@ -178,6 +186,7 @@ static struct platform_driver pwm_beeper_driver = {
>  		.name	= "pwm-beeper",
>  		.owner	= THIS_MODULE,
>  		.pm	= PWM_BEEPER_PM_OPS,
> +		.of_match_table = pwm_beeper_match,
>  	},
>  };
>  module_platform_driver(pwm_beeper_driver);
> 

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Dmitry Torokhov]

On Mon, Sep 24, 2012 at 07:55:38AM -0500, Rob Herring wrote:
> On 09/24/2012 02:37 AM, Sascha Hauer wrote:
> > A very simple binding, the only property is the phandle to the PWM.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> 
> Acked-by: Rob Herring <rob.herring@calxeda.com>
> 
> > ---
> >  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
> >  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
> >  2 files changed, 17 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> > new file mode 100644
> > index 0000000..7388b82
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> > @@ -0,0 +1,7 @@
> > +* PWM beeper device tree bindings
> > +
> > +Registers a PWM device as beeper.
> > +
> > +Required properties:
> > +- compatible: should be "pwm-beeper"
> > +- pwms: phandle to the physical pwm device
> > diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> > index fc84c8a..a6aa48c 100644
> > --- a/drivers/input/misc/pwm-beeper.c
> > +++ b/drivers/input/misc/pwm-beeper.c
> > @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
> >  	if (!beeper)
> >  		return -ENOMEM;
> >  
> > -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> > +	if (pdev->dev.platform_data)
> > +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> > +	else
> > +		beeper->pwm = pwm_get(&pdev->dev, NULL);

Hmm, pwm_id == 0 is a valid ID I think, but your change makes it go into
DT branch, potentially breaking it.

Thanks.

-- 
Dmitry

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Lars-Peter Clausen]

On 09/24/2012 05:56 PM, Dmitry Torokhov wrote:
> On Mon, Sep 24, 2012 at 07:55:38AM -0500, Rob Herring wrote:
>> On 09/24/2012 02:37 AM, Sascha Hauer wrote:
>>> A very simple binding, the only property is the phandle to the PWM.
>>>
>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>
>> Acked-by: Rob Herring <rob.herring@calxeda.com>
>>
>>> ---
>>>  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
>>>  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
>>>  2 files changed, 17 insertions(+), 1 deletion(-)
>>>  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
>>> new file mode 100644
>>> index 0000000..7388b82
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
>>> @@ -0,0 +1,7 @@
>>> +* PWM beeper device tree bindings
>>> +
>>> +Registers a PWM device as beeper.
>>> +
>>> +Required properties:
>>> +- compatible: should be "pwm-beeper"
>>> +- pwms: phandle to the physical pwm device
>>> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
>>> index fc84c8a..a6aa48c 100644
>>> --- a/drivers/input/misc/pwm-beeper.c
>>> +++ b/drivers/input/misc/pwm-beeper.c
>>> @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
>>>  	if (!beeper)
>>>  		return -ENOMEM;
>>>  
>>> -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
>>> +	if (pdev->dev.platform_data)
>>> +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
>>> +	else
>>> +		beeper->pwm = pwm_get(&pdev->dev, NULL);
> 
> Hmm, pwm_id == 0 is a valid ID I think, but your change makes it go into
> DT branch, potentially breaking it.

Yes, this a bit tricky, but we only have a single in-tree user of the
pwm-beeper which uses a id != 0. And now that all the PWM providers have
been converted to the new generic PWM framework the old legacy API will go
away soon anyway. So this if () else branch should hopefully only be
necessary for a transitional period of 1-2 releases. So I think this change
should be OK.

But I think the patch is missing a change to the Kconfig entry to allow the
driver to be selected if the generic PWM framework is available.

--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -444,7 +444,7 @@ config INPUT_PCF8574

 config INPUT_PWM_BEEPER
 	tristate "PWM beeper support"
-	depends on HAVE_PWM
+	depends on HAVE_PWM || PWM
 	help
 	  Say Y here to get support for PWM based beeper devices.


- Lars

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Sascha Hauer]

On Mon, Sep 24, 2012 at 06:22:33PM +0200, Lars-Peter Clausen wrote:
> On 09/24/2012 05:56 PM, Dmitry Torokhov wrote:
> > On Mon, Sep 24, 2012 at 07:55:38AM -0500, Rob Herring wrote:
> >> On 09/24/2012 02:37 AM, Sascha Hauer wrote:
> >>> A very simple binding, the only property is the phandle to the PWM.
> >>>
> >>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> >>
> >> Acked-by: Rob Herring <rob.herring@calxeda.com>
> >>
> >>> ---
> >>>  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
> >>>  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
> >>>  2 files changed, 17 insertions(+), 1 deletion(-)
> >>>  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>> new file mode 100644
> >>> index 0000000..7388b82
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>> @@ -0,0 +1,7 @@
> >>> +* PWM beeper device tree bindings
> >>> +
> >>> +Registers a PWM device as beeper.
> >>> +
> >>> +Required properties:
> >>> +- compatible: should be "pwm-beeper"
> >>> +- pwms: phandle to the physical pwm device
> >>> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> >>> index fc84c8a..a6aa48c 100644
> >>> --- a/drivers/input/misc/pwm-beeper.c
> >>> +++ b/drivers/input/misc/pwm-beeper.c
> >>> @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
> >>>  	if (!beeper)
> >>>  		return -ENOMEM;
> >>>  
> >>> -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> >>> +	if (pdev->dev.platform_data)
> >>> +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> >>> +	else
> >>> +		beeper->pwm = pwm_get(&pdev->dev, NULL);
> > 
> > Hmm, pwm_id == 0 is a valid ID I think, but your change makes it go into
> > DT branch, potentially breaking it.

My bad, I missed that platform_data is casted to an unsigned long. I
thought I would test for a pointer.
The obvious clean way would be to use a pointer for platform_data, but
given that this will vanish anyway soon, I think we could just test for
existence of dev->of_node instead of dev->platform_data.

> 
> Yes, this a bit tricky, but we only have a single in-tree user of the
> pwm-beeper which uses a id != 0. And now that all the PWM providers have
> been converted to the new generic PWM framework the old legacy API will go
> away soon anyway. So this if () else branch should hopefully only be
> necessary for a transitional period of 1-2 releases. So I think this change
> should be OK.
> 
> But I think the patch is missing a change to the Kconfig entry to allow the
> driver to be selected if the generic PWM framework is available.
> 
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -444,7 +444,7 @@ config INPUT_PCF8574
> 
>  config INPUT_PWM_BEEPER
>  	tristate "PWM beeper support"
> -	depends on HAVE_PWM
> +	depends on HAVE_PWM || PWM

Is this the preferred way to do this? Instead of doing the above I added
a 'select HAVE_PWM' to the pwm framework instead. I found a patch for that,
but there were comments to it that this is not good

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Lars-Peter Clausen]

On 09/24/2012 08:49 PM, Sascha Hauer wrote:
> On Mon, Sep 24, 2012 at 06:22:33PM +0200, Lars-Peter Clausen wrote:
>> On 09/24/2012 05:56 PM, Dmitry Torokhov wrote:
>>> On Mon, Sep 24, 2012 at 07:55:38AM -0500, Rob Herring wrote:
>>>> On 09/24/2012 02:37 AM, Sascha Hauer wrote:
>>>>> A very simple binding, the only property is the phandle to the PWM.
>>>>>
>>>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>>>
>>>> Acked-by: Rob Herring <rob.herring@calxeda.com>
>>>>
>>>>> ---
>>>>>  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
>>>>>  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
>>>>>  2 files changed, 17 insertions(+), 1 deletion(-)
>>>>>  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
>>>>> new file mode 100644
>>>>> index 0000000..7388b82
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
>>>>> @@ -0,0 +1,7 @@
>>>>> +* PWM beeper device tree bindings
>>>>> +
>>>>> +Registers a PWM device as beeper.
>>>>> +
>>>>> +Required properties:
>>>>> +- compatible: should be "pwm-beeper"
>>>>> +- pwms: phandle to the physical pwm device
>>>>> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
>>>>> index fc84c8a..a6aa48c 100644
>>>>> --- a/drivers/input/misc/pwm-beeper.c
>>>>> +++ b/drivers/input/misc/pwm-beeper.c
>>>>> @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
>>>>>  	if (!beeper)
>>>>>  		return -ENOMEM;
>>>>>  
>>>>> -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
>>>>> +	if (pdev->dev.platform_data)
>>>>> +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
>>>>> +	else
>>>>> +		beeper->pwm = pwm_get(&pdev->dev, NULL);
>>>
>>> Hmm, pwm_id == 0 is a valid ID I think, but your change makes it go into
>>> DT branch, potentially breaking it.
> 
> My bad, I missed that platform_data is casted to an unsigned long. I
> thought I would test for a pointer.
> The obvious clean way would be to use a pointer for platform_data, but
> given that this will vanish anyway soon, I think we could just test for
> existence of dev->of_node instead of dev->platform_data.

I think the plan is to convert the existing board file platforms to pwm_table
and then remove the old pwm_request API. So this wouldn't work too well if we'd
test for of_node. Maybe we can just run pwm_get unconditionally and fallback to
pwm_request if it failed. That's also what the PWM backlight driver currently does.

> 
>>
>> Yes, this a bit tricky, but we only have a single in-tree user of the
>> pwm-beeper which uses a id != 0. And now that all the PWM providers have
>> been converted to the new generic PWM framework the old legacy API will go
>> away soon anyway. So this if () else branch should hopefully only be
>> necessary for a transitional period of 1-2 releases. So I think this change
>> should be OK.
>>
>> But I think the patch is missing a change to the Kconfig entry to allow the
>> driver to be selected if the generic PWM framework is available.
>>
>> --- a/drivers/input/misc/Kconfig
>> +++ b/drivers/input/misc/Kconfig
>> @@ -444,7 +444,7 @@ config INPUT_PCF8574
>>
>>  config INPUT_PWM_BEEPER
>>  	tristate "PWM beeper support"
>> -	depends on HAVE_PWM
>> +	depends on HAVE_PWM || PWM
> 
> Is this the preferred way to do this? Instead of doing the above I added
> a 'select HAVE_PWM' to the pwm framework instead. I found a patch for that,
> but there were comments to it that this is not good
> 

Thierry said that this is his preferred solution. Given that HAVE_PWM will be
extinct soon anyway I think it is fine.

- Lars

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Sascha Hauer]

On Mon, Sep 24, 2012 at 09:05:59PM +0200, Lars-Peter Clausen wrote:
> On 09/24/2012 08:49 PM, Sascha Hauer wrote:
> > 
> > My bad, I missed that platform_data is casted to an unsigned long. I
> > thought I would test for a pointer.
> > The obvious clean way would be to use a pointer for platform_data, but
> > given that this will vanish anyway soon, I think we could just test for
> > existence of dev->of_node instead of dev->platform_data.
> 
> I think the plan is to convert the existing board file platforms to pwm_table
> and then remove the old pwm_request API. So this wouldn't work too well if we'd
> test for of_node. Maybe we can just run pwm_get unconditionally and fallback to
> pwm_request if it failed. That's also what the PWM backlight driver currently does.

Fine with me.

> 
> > 
> >>
> >> Yes, this a bit tricky, but we only have a single in-tree user of the
> >> pwm-beeper which uses a id != 0. And now that all the PWM providers have
> >> been converted to the new generic PWM framework the old legacy API will go
> >> away soon anyway. So this if () else branch should hopefully only be
> >> necessary for a transitional period of 1-2 releases. So I think this change
> >> should be OK.
> >>
> >> But I think the patch is missing a change to the Kconfig entry to allow the
> >> driver to be selected if the generic PWM framework is available.
> >>
> >> --- a/drivers/input/misc/Kconfig
> >> +++ b/drivers/input/misc/Kconfig
> >> @@ -444,7 +444,7 @@ config INPUT_PCF8574
> >>
> >>  config INPUT_PWM_BEEPER
> >>  	tristate "PWM beeper support"
> >> -	depends on HAVE_PWM
> >> +	depends on HAVE_PWM || PWM
> > 
> > Is this the preferred way to do this? Instead of doing the above I added
> > a 'select HAVE_PWM' to the pwm framework instead. I found a patch for that,
> > but there were comments to it that this is not good
> > 
> 
> Thierry said that this is his preferred solution. Given that HAVE_PWM will be
> extinct soon anyway I think it is fine.

Ok. Will send an updated patch tomorrow.

Thanks
 Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH] input: pwm-beeper: Add devicetree probing support

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 5019 bytes --]

On Mon, Sep 24, 2012 at 09:05:59PM +0200, Lars-Peter Clausen wrote:
> On 09/24/2012 08:49 PM, Sascha Hauer wrote:
> > On Mon, Sep 24, 2012 at 06:22:33PM +0200, Lars-Peter Clausen wrote:
> >> On 09/24/2012 05:56 PM, Dmitry Torokhov wrote:
> >>> On Mon, Sep 24, 2012 at 07:55:38AM -0500, Rob Herring wrote:
> >>>> On 09/24/2012 02:37 AM, Sascha Hauer wrote:
> >>>>> A very simple binding, the only property is the phandle to the PWM.
> >>>>>
> >>>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> >>>>
> >>>> Acked-by: Rob Herring <rob.herring@calxeda.com>
> >>>>
> >>>>> ---
> >>>>>  Documentation/devicetree/bindings/input/pwm-beeper.txt |    7 +++++++
> >>>>>  drivers/input/misc/pwm-beeper.c                        |   11 ++++++++++-
> >>>>>  2 files changed, 17 insertions(+), 1 deletion(-)
> >>>>>  create mode 100644 Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>>>>
> >>>>> diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>>>> new file mode 100644
> >>>>> index 0000000..7388b82
> >>>>> --- /dev/null
> >>>>> +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
> >>>>> @@ -0,0 +1,7 @@
> >>>>> +* PWM beeper device tree bindings
> >>>>> +
> >>>>> +Registers a PWM device as beeper.
> >>>>> +
> >>>>> +Required properties:
> >>>>> +- compatible: should be "pwm-beeper"
> >>>>> +- pwms: phandle to the physical pwm device
> >>>>> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> >>>>> index fc84c8a..a6aa48c 100644
> >>>>> --- a/drivers/input/misc/pwm-beeper.c
> >>>>> +++ b/drivers/input/misc/pwm-beeper.c
> >>>>> @@ -75,7 +75,10 @@ static int __devinit pwm_beeper_probe(struct platform_device *pdev)
> >>>>>  	if (!beeper)
> >>>>>  		return -ENOMEM;
> >>>>>  
> >>>>> -	beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> >>>>> +	if (pdev->dev.platform_data)
> >>>>> +		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
> >>>>> +	else
> >>>>> +		beeper->pwm = pwm_get(&pdev->dev, NULL);
> >>>
> >>> Hmm, pwm_id == 0 is a valid ID I think, but your change makes it go into
> >>> DT branch, potentially breaking it.
> > 
> > My bad, I missed that platform_data is casted to an unsigned long. I
> > thought I would test for a pointer.
> > The obvious clean way would be to use a pointer for platform_data, but
> > given that this will vanish anyway soon, I think we could just test for
> > existence of dev->of_node instead of dev->platform_data.
> 
> I think the plan is to convert the existing board file platforms to pwm_table
> and then remove the old pwm_request API. So this wouldn't work too well if we'd
> test for of_node. Maybe we can just run pwm_get unconditionally and fallback to
> pwm_request if it failed. That's also what the PWM backlight driver currently does.

I agree. Calling pwm_get() will automatically switch to using the
entries from a PWM table if the board adds it.

> >> Yes, this a bit tricky, but we only have a single in-tree user of the
> >> pwm-beeper which uses a id != 0. And now that all the PWM providers have
> >> been converted to the new generic PWM framework the old legacy API will go
> >> away soon anyway. So this if () else branch should hopefully only be
> >> necessary for a transitional period of 1-2 releases. So I think this change
> >> should be OK.
> >>
> >> But I think the patch is missing a change to the Kconfig entry to allow the
> >> driver to be selected if the generic PWM framework is available.
> >>
> >> --- a/drivers/input/misc/Kconfig
> >> +++ b/drivers/input/misc/Kconfig
> >> @@ -444,7 +444,7 @@ config INPUT_PCF8574
> >>
> >>  config INPUT_PWM_BEEPER
> >>  	tristate "PWM beeper support"
> >> -	depends on HAVE_PWM
> >> +	depends on HAVE_PWM || PWM
> > 
> > Is this the preferred way to do this? Instead of doing the above I added
> > a 'select HAVE_PWM' to the pwm framework instead. I found a patch for that,
> > but there were comments to it that this is not good
> > 
> 
> Thierry said that this is his preferred solution. Given that HAVE_PWM will be
> extinct soon anyway I think it is fine.

The reason is that some platforms, actually the majority, do not define
HAVE_PWM property. We ran into that problem when the PWM tree was first
added to linux-next because builds would break on PowerPC, which is one
of the architectures that doesn't define HAVE_PWM.

Conceptually what we're saying here is that either the legacy PWM API
(HAVE_PWM) or the new PWM framework (PWM) can satisfy the dependency.
Note that if you make the change above, it is no longer enough to depend
on HAVE_PWM because that doesn't provide the pwm_get() function.

Also we should be able to remove HAVE_PWM for 3.7 already as all legacy
implementations have been moved. The plan is to get rid of pwm_request()
and pwm_free() for 3.8. All that's required is converting all the board
files to use PWM lookup tables.

Thierry

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