diff mbox

[v7,04/10] i2c: i2c-smbus: add of_i2c_setup_smbus_alert

Message ID 1497535178-12001-5-git-send-email-preid@electromag.com.au
State Superseded
Headers show

Commit Message

Phil Reid June 15, 2017, 1:59 p.m. UTC
This commit adds of_i2c_setup_smbus_alert which allows the smbalert
driver to be attached to an i2c adapter via the device tree.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/i2c/i2c.txt |  4 ++--
 drivers/i2c/i2c-smbus.c                       | 34 ++++++++++++++++++++++++---
 include/linux/i2c-smbus.h                     |  9 +++++++
 3 files changed, 42 insertions(+), 5 deletions(-)

Comments

Wolfram Sang June 19, 2017, 3:27 p.m. UTC | #1
On Thu, Jun 15, 2017 at 09:59:32PM +0800, Phil Reid wrote:
> This commit adds of_i2c_setup_smbus_alert which allows the smbalert
> driver to be attached to an i2c adapter via the device tree.
> 
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> Acked-by: Rob Herring <robh@kernel.org>

CCing Benjamin

> ---
>  Documentation/devicetree/bindings/i2c/i2c.txt |  4 ++--
>  drivers/i2c/i2c-smbus.c                       | 34 ++++++++++++++++++++++++---
>  include/linux/i2c-smbus.h                     |  9 +++++++
>  3 files changed, 42 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> index cee9d50..1126398 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> @@ -59,8 +59,8 @@ wants to support one of the below features, it should adapt the bindings below.
>  	interrupts used by the device.
>  
>  - interrupt-names
> -	"irq" and "wakeup" names are recognized by I2C core, other names are
> -	left to individual drivers.
> +	"irq", "wakeup" and "smbus_alert" names are recognized by I2C core,
> +	other names are	left to individual drivers.
>  
>  - host-notify
>  	device uses SMBus host notify protocol instead of interrupt line.
> diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
> index d4af270..0ad7f7f 100644
> --- a/drivers/i2c/i2c-smbus.c
> +++ b/drivers/i2c/i2c-smbus.c
> @@ -21,6 +21,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/of_irq.h>
>  #include <linux/slab.h>
>  #include <linux/workqueue.h>
>  
> @@ -131,7 +132,7 @@ static int smbalert_probe(struct i2c_client *ara,
>  {
>  	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
>  	struct i2c_smbus_alert *alert;
> -	struct i2c_adapter *adapter = ara->adapter;
> +	struct i2c_adapter *adap = ara->adapter;
>  	int res, irq;
>  
>  	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
> @@ -139,7 +140,14 @@ static int smbalert_probe(struct i2c_client *ara,
>  	if (!alert)
>  		return -ENOMEM;
>  
> -	irq = setup->irq;
> +	if (setup) {
> +		irq = setup->irq;
> +	} else {
> +		irq = of_irq_get_byname(adap->dev.of_node, "smbus_alert");
> +		if (irq <= 0)
> +			return irq;
> +	}
> +
>  	INIT_WORK(&alert->alert, smbalert_work);
>  	alert->ara = ara;
>  
> @@ -153,7 +161,7 @@ static int smbalert_probe(struct i2c_client *ara,
>  	}
>  
>  	i2c_set_clientdata(ara, alert);
> -	dev_info(&adapter->dev, "supports SMBALERT#\n");
> +	dev_info(&adap->dev, "supports SMBALERT#\n");
>  
>  	return 0;
>  }
> @@ -214,6 +222,26 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
>  }
>  EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
>  
> +int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
> +{
> +	struct i2c_client *client;
> +	int irq;
> +
> +	irq = of_property_match_string(adap->dev.of_node, "interrupt-names",
> +				       "smbus_alert");
> +	if (irq == -EINVAL || irq == -ENODATA)
> +		return 0;
> +	else if (irq < 0)
> +		return irq;
> +
> +	client = i2c_setup_smbus_alert(adap, NULL);
> +	if (!client)
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
> +
>  /**
>   * i2c_handle_smbus_alert - Handle an SMBus alert
>   * @ara: the ARA client on the relevant adapter
> diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
> index 19efbd1..b5261c1 100644
> --- a/include/linux/i2c-smbus.h
> +++ b/include/linux/i2c-smbus.h
> @@ -49,4 +49,13 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
>  					 struct i2c_smbus_alert_setup *setup);
>  int i2c_handle_smbus_alert(struct i2c_client *ara);
>  
> +#if IS_ENABLED(CONFIG_I2C_SMBUS)
> +int of_i2c_setup_smbus_alert(struct i2c_adapter *adap);
> +#else
> +static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
> +{
> +	return 0;
> +}
> +#endif
> +
>  #endif /* _LINUX_I2C_SMBUS_H */
> -- 
> 1.8.3.1
>
Benjamin Tissoires June 23, 2017, 12:15 p.m. UTC | #2
On Jun 19 2017 or thereabouts, Wolfram Sang wrote:
> On Thu, Jun 15, 2017 at 09:59:32PM +0800, Phil Reid wrote:
> > This commit adds of_i2c_setup_smbus_alert which allows the smbalert
> > driver to be attached to an i2c adapter via the device tree.
> > 
> > Signed-off-by: Phil Reid <preid@electromag.com.au>
> > Acked-by: Rob Herring <robh@kernel.org>
> 
> CCing Benjamin
> 
> > ---
> >  Documentation/devicetree/bindings/i2c/i2c.txt |  4 ++--
> >  drivers/i2c/i2c-smbus.c                       | 34 ++++++++++++++++++++++++---
> >  include/linux/i2c-smbus.h                     |  9 +++++++
> >  3 files changed, 42 insertions(+), 5 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
> > index cee9d50..1126398 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
> > @@ -59,8 +59,8 @@ wants to support one of the below features, it should adapt the bindings below.
> >  	interrupts used by the device.
> >  
> >  - interrupt-names
> > -	"irq" and "wakeup" names are recognized by I2C core, other names are
> > -	left to individual drivers.
> > +	"irq", "wakeup" and "smbus_alert" names are recognized by I2C core,
> > +	other names are	left to individual drivers.
> >  
> >  - host-notify
> >  	device uses SMBus host notify protocol instead of interrupt line.
> > diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
> > index d4af270..0ad7f7f 100644
> > --- a/drivers/i2c/i2c-smbus.c
> > +++ b/drivers/i2c/i2c-smbus.c
> > @@ -21,6 +21,7 @@
> >  #include <linux/interrupt.h>
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> > +#include <linux/of_irq.h>
> >  #include <linux/slab.h>
> >  #include <linux/workqueue.h>
> >  
> > @@ -131,7 +132,7 @@ static int smbalert_probe(struct i2c_client *ara,
> >  {
> >  	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
> >  	struct i2c_smbus_alert *alert;
> > -	struct i2c_adapter *adapter = ara->adapter;
> > +	struct i2c_adapter *adap = ara->adapter;

I am not a big fan of this rename (even for consistency with the rest of
the file). It makes the patch bigger of 2 hunks for nothing :/

(Wolfram might have a different opinion)

> >  	int res, irq;
> >  
> >  	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
> > @@ -139,7 +140,14 @@ static int smbalert_probe(struct i2c_client *ara,
> >  	if (!alert)
> >  		return -ENOMEM;
> >  
> > -	irq = setup->irq;
> > +	if (setup) {
> > +		irq = setup->irq;
> > +	} else {
> > +		irq = of_irq_get_byname(adap->dev.of_node, "smbus_alert");
> > +		if (irq <= 0)
> > +			return irq;
> > +	}
> > +
> >  	INIT_WORK(&alert->alert, smbalert_work);
> >  	alert->ara = ara;
> >  
> > @@ -153,7 +161,7 @@ static int smbalert_probe(struct i2c_client *ara,
> >  	}
> >  
> >  	i2c_set_clientdata(ara, alert);
> > -	dev_info(&adapter->dev, "supports SMBALERT#\n");
> > +	dev_info(&adap->dev, "supports SMBALERT#\n");
> >  
> >  	return 0;
> >  }
> > @@ -214,6 +222,26 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
> >  }
> >  EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
> >  
> > +int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
> > +{
> > +	struct i2c_client *client;
> > +	int irq;
> > +
> > +	irq = of_property_match_string(adap->dev.of_node, "interrupt-names",
> > +				       "smbus_alert");
> > +	if (irq == -EINVAL || irq == -ENODATA)
> > +		return 0;
> > +	else if (irq < 0)
> > +		return irq;
> > +
> > +	client = i2c_setup_smbus_alert(adap, NULL);
> > +	if (!client)
> > +		return -ENODEV;
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
> > +
> >  /**
> >   * i2c_handle_smbus_alert - Handle an SMBus alert
> >   * @ara: the ARA client on the relevant adapter
> > diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
> > index 19efbd1..b5261c1 100644
> > --- a/include/linux/i2c-smbus.h
> > +++ b/include/linux/i2c-smbus.h
> > @@ -49,4 +49,13 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
> >  					 struct i2c_smbus_alert_setup *setup);
> >  int i2c_handle_smbus_alert(struct i2c_client *ara);
> >  
> > +#if IS_ENABLED(CONFIG_I2C_SMBUS)

Can't we have:
#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(*whatever OF config symbol is*)

Because otherwise, even if the code works from what I understand, we
will pull in i2c-smbus from i2c-core all the time.

Besides those nitpicks, the patch is OK IMO.

Cheers,
Benjamin

> > +int of_i2c_setup_smbus_alert(struct i2c_adapter *adap);
> > +#else
> > +static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
> > +{
> > +	return 0;
> > +}
> > +#endif
> > +
> >  #endif /* _LINUX_I2C_SMBUS_H */
> > -- 
> > 1.8.3.1
> >
Phil Reid June 28, 2017, 6:48 a.m. UTC | #3
On 23/06/2017 20:15, Benjamin Tissoires wrote:
> On Jun 19 2017 or thereabouts, Wolfram Sang wrote:
>> On Thu, Jun 15, 2017 at 09:59:32PM +0800, Phil Reid wrote:
>>> This commit adds of_i2c_setup_smbus_alert which allows the smbalert
>>> driver to be attached to an i2c adapter via the device tree.
>>>
>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>>> Acked-by: Rob Herring <robh@kernel.org>
>>
>> CCing Benjamin
>>
>>> ---
>>>   Documentation/devicetree/bindings/i2c/i2c.txt |  4 ++--
>>>   drivers/i2c/i2c-smbus.c                       | 34 ++++++++++++++++++++++++---
>>>   include/linux/i2c-smbus.h                     |  9 +++++++
>>>   3 files changed, 42 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
>>> index cee9d50..1126398 100644
>>> --- a/Documentation/devicetree/bindings/i2c/i2c.txt
>>> +++ b/Documentation/devicetree/bindings/i2c/i2c.txt
>>> @@ -59,8 +59,8 @@ wants to support one of the below features, it should adapt the bindings below.
>>>   	interrupts used by the device.
>>>   
>>>   - interrupt-names
>>> -	"irq" and "wakeup" names are recognized by I2C core, other names are
>>> -	left to individual drivers.
>>> +	"irq", "wakeup" and "smbus_alert" names are recognized by I2C core,
>>> +	other names are	left to individual drivers.
>>>   
>>>   - host-notify
>>>   	device uses SMBus host notify protocol instead of interrupt line.
>>> diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
>>> index d4af270..0ad7f7f 100644
>>> --- a/drivers/i2c/i2c-smbus.c
>>> +++ b/drivers/i2c/i2c-smbus.c
>>> @@ -21,6 +21,7 @@
>>>   #include <linux/interrupt.h>
>>>   #include <linux/kernel.h>
>>>   #include <linux/module.h>
>>> +#include <linux/of_irq.h>
>>>   #include <linux/slab.h>
>>>   #include <linux/workqueue.h>
>>>   
>>> @@ -131,7 +132,7 @@ static int smbalert_probe(struct i2c_client *ara,
>>>   {
>>>   	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
>>>   	struct i2c_smbus_alert *alert;
>>> -	struct i2c_adapter *adapter = ara->adapter;
>>> +	struct i2c_adapter *adap = ara->adapter;
> 
> I am not a big fan of this rename (even for consistency with the rest of
> the file). It makes the patch bigger of 2 hunks for nothing :/
> 
> (Wolfram might have a different opinion)

Fair enough I'll remove the rename.

> 
>>>   	int res, irq;
>>>   
>>>   	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
>>> @@ -139,7 +140,14 @@ static int smbalert_probe(struct i2c_client *ara,
>>>   	if (!alert)
>>>   		return -ENOMEM;
>>>   
>>> -	irq = setup->irq;
>>> +	if (setup) {
>>> +		irq = setup->irq;
>>> +	} else {
>>> +		irq = of_irq_get_byname(adap->dev.of_node, "smbus_alert");
>>> +		if (irq <= 0)
>>> +			return irq;
>>> +	}
>>> +
>>>   	INIT_WORK(&alert->alert, smbalert_work);
>>>   	alert->ara = ara;
>>>   
>>> @@ -153,7 +161,7 @@ static int smbalert_probe(struct i2c_client *ara,
>>>   	}
>>>   
>>>   	i2c_set_clientdata(ara, alert);
>>> -	dev_info(&adapter->dev, "supports SMBALERT#\n");
>>> +	dev_info(&adap->dev, "supports SMBALERT#\n");
>>>   
>>>   	return 0;
>>>   }
>>> @@ -214,6 +222,26 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
>>>   }
>>>   EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
>>>   
>>> +int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
>>> +{
>>> +	struct i2c_client *client;
>>> +	int irq;
>>> +
>>> +	irq = of_property_match_string(adap->dev.of_node, "interrupt-names",
>>> +				       "smbus_alert");
>>> +	if (irq == -EINVAL || irq == -ENODATA)
>>> +		return 0;
>>> +	else if (irq < 0)
>>> +		return irq;
>>> +
>>> +	client = i2c_setup_smbus_alert(adap, NULL);
>>> +	if (!client)
>>> +		return -ENODEV;
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
>>> +
>>>   /**
>>>    * i2c_handle_smbus_alert - Handle an SMBus alert
>>>    * @ara: the ARA client on the relevant adapter
>>> diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
>>> index 19efbd1..b5261c1 100644
>>> --- a/include/linux/i2c-smbus.h
>>> +++ b/include/linux/i2c-smbus.h
>>> @@ -49,4 +49,13 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
>>>   					 struct i2c_smbus_alert_setup *setup);
>>>   int i2c_handle_smbus_alert(struct i2c_client *ara);
>>>   
>>> +#if IS_ENABLED(CONFIG_I2C_SMBUS)
> 
> Can't we have:
> #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(*whatever OF config symbol is*)
> 
> Because otherwise, even if the code works from what I understand, we
> will pull in i2c-smbus from i2c-core all the time.

Sorry I'm lost here.
CONFIG_I2C_SMBUS looks to the be symbol that enables i2c-smbus in the makefile.
I thought this would be enough to keep it out of the core.
Benjamin Tissoires June 28, 2017, 12:42 p.m. UTC | #4
On Jun 28 2017 or thereabouts, Phil Reid wrote:
> > > > diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
> > > > index 19efbd1..b5261c1 100644
> > > > --- a/include/linux/i2c-smbus.h
> > > > +++ b/include/linux/i2c-smbus.h
> > > > @@ -49,4 +49,13 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
> > > >   					 struct i2c_smbus_alert_setup *setup);
> > > >   int i2c_handle_smbus_alert(struct i2c_client *ara);
> > > > +#if IS_ENABLED(CONFIG_I2C_SMBUS)
> > 
> > Can't we have:
> > #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(*whatever OF config symbol is*)
> > 
> > Because otherwise, even if the code works from what I understand, we
> > will pull in i2c-smbus from i2c-core all the time.
> 
> Sorry I'm lost here.
> CONFIG_I2C_SMBUS looks to the be symbol that enables i2c-smbus in the makefile.
> I thought this would be enough to keep it out of the core.
> 

Assuming CONFIG_I2C_SMBUS is set, my concerns are regarding the fact
that i2c-smbus.ko will now be pulled in by i2c-core.ko no matter what.
There is nothing wrong per se in the code, just that now i2c-core
depends on i2c_smbus given that you call i2c_setup_smbus_alert() in
i2c-core. So that makes the whole point of having a separate module
for i2c-smbus moot.

If of_i2c_setup_smbus_alert() is masked by IS_ENABLED(OF), then the call
for i2c_setup_smbus_alert() will only be done with OF enabled, meaning
that i2c-smbus.ko will only be pulled in by i2c-core when OF is in use.

But maybe that is too much of thinking from my part :)

Cheers,
Benjamin
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
index cee9d50..1126398 100644
--- a/Documentation/devicetree/bindings/i2c/i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c.txt
@@ -59,8 +59,8 @@  wants to support one of the below features, it should adapt the bindings below.
 	interrupts used by the device.
 
 - interrupt-names
-	"irq" and "wakeup" names are recognized by I2C core, other names are
-	left to individual drivers.
+	"irq", "wakeup" and "smbus_alert" names are recognized by I2C core,
+	other names are	left to individual drivers.
 
 - host-notify
 	device uses SMBus host notify protocol instead of interrupt line.
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index d4af270..0ad7f7f 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -21,6 +21,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_irq.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
@@ -131,7 +132,7 @@  static int smbalert_probe(struct i2c_client *ara,
 {
 	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
 	struct i2c_smbus_alert *alert;
-	struct i2c_adapter *adapter = ara->adapter;
+	struct i2c_adapter *adap = ara->adapter;
 	int res, irq;
 
 	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
@@ -139,7 +140,14 @@  static int smbalert_probe(struct i2c_client *ara,
 	if (!alert)
 		return -ENOMEM;
 
-	irq = setup->irq;
+	if (setup) {
+		irq = setup->irq;
+	} else {
+		irq = of_irq_get_byname(adap->dev.of_node, "smbus_alert");
+		if (irq <= 0)
+			return irq;
+	}
+
 	INIT_WORK(&alert->alert, smbalert_work);
 	alert->ara = ara;
 
@@ -153,7 +161,7 @@  static int smbalert_probe(struct i2c_client *ara,
 	}
 
 	i2c_set_clientdata(ara, alert);
-	dev_info(&adapter->dev, "supports SMBALERT#\n");
+	dev_info(&adap->dev, "supports SMBALERT#\n");
 
 	return 0;
 }
@@ -214,6 +222,26 @@  struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
 }
 EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
 
+int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
+{
+	struct i2c_client *client;
+	int irq;
+
+	irq = of_property_match_string(adap->dev.of_node, "interrupt-names",
+				       "smbus_alert");
+	if (irq == -EINVAL || irq == -ENODATA)
+		return 0;
+	else if (irq < 0)
+		return irq;
+
+	client = i2c_setup_smbus_alert(adap, NULL);
+	if (!client)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
+
 /**
  * i2c_handle_smbus_alert - Handle an SMBus alert
  * @ara: the ARA client on the relevant adapter
diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h
index 19efbd1..b5261c1 100644
--- a/include/linux/i2c-smbus.h
+++ b/include/linux/i2c-smbus.h
@@ -49,4 +49,13 @@  struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
 					 struct i2c_smbus_alert_setup *setup);
 int i2c_handle_smbus_alert(struct i2c_client *ara);
 
+#if IS_ENABLED(CONFIG_I2C_SMBUS)
+int of_i2c_setup_smbus_alert(struct i2c_adapter *adap);
+#else
+static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
+{
+	return 0;
+}
+#endif
+
 #endif /* _LINUX_I2C_SMBUS_H */