[RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[Grygorii Strashko]

The commit 9ec36cafe43bf835f8f29273597a5b0cbc8267ef
"of/irq: do irq resolution in platform_get_irq" from Rob Herring -
moves resolving of the interrupt resources in platform_get_irq().
But this solution isn't complete because platform_get_irq_byname()
need to be modified the same way.

Hence, fix it by adding interrupt resolution code at the
platform_get_irq_byname() function too.

Cc: Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
Cc: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Cc: Grant Likely <grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Signed-off-by: Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>
---
 drivers/base/platform.c |    7 +++++--
 drivers/of/irq.c        |   25 +++++++++++++++++++++++++
 include/linux/of_irq.h  |    5 +++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 5b47210..9e9227e 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -131,9 +131,12 @@ EXPORT_SYMBOL_GPL(platform_get_resource_byname);
  */
 int platform_get_irq_byname(struct platform_device *dev, const char *name)
 {
-	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
-							  name);
+	struct resource *r;
+
+	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node)
+		return of_irq_get_byname(dev->dev.of_node, name);
 
+	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
 	return r ? r->start : -ENXIO;
 }
 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 5aeb894..6419de9 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -406,6 +406,31 @@ int of_irq_get(struct device_node *dev, int index)
 }
 
 /**
+ * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
+ * @dev: pointer to device tree node
+ * @name: zero-based index of the irq
+ *
+ * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
+ * is not yet created, or errorno in case of failure.
+ *
+ */
+int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	const char *name_irq = NULL;
+	int index = 0;
+
+	if (unlikely(!name))
+		return -EINVAL;
+
+	while (!of_property_read_string_index(dev, "interrupt-names",
+					      index, &name_irq))
+		if (!strcmp(name, name_irq))
+			return of_irq_get(dev, index);
+
+	return -ENXIO;
+}
+
+/**
  * of_irq_count - Count the number of IRQs a node uses
  * @dev: pointer to device tree node
  */
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 6404253..bfec136 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -45,6 +45,7 @@ extern void of_irq_init(const struct of_device_id *matches);
 #ifdef CONFIG_OF_IRQ
 extern int of_irq_count(struct device_node *dev);
 extern int of_irq_get(struct device_node *dev, int index);
+extern int of_irq_get_byname(struct device_node *dev, const char *name);
 #else
 static inline int of_irq_count(struct device_node *dev)
 {
@@ -54,6 +55,10 @@ static inline int of_irq_get(struct device_node *dev, int index)
 {
 	return 0;
 }
+static inline int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	return 0;
+}
 #endif
 
 #if defined(CONFIG_OF)
-- 
1.7.9.5

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Re: [RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[Thierry Reding]

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On Mon, May 19, 2014 at 04:30:59PM +0300, Grygorii Strashko wrote:
[...]
> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
[...]
>  /**
> + * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
> + * @dev: pointer to device tree node
> + * @name: zero-based index of the irq

This is a name, not an index.

> + *
> + * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
> + * is not yet created, or errorno in case of failure.

s/errorno/error code/? Also EPROBE_DEFER is also an error code, so I'm
not sure if it's worth a special case in the description here.

> + *
> + */
> +int of_irq_get_byname(struct device_node *dev, const char *name)
> +{
> +	const char *name_irq = NULL;
> +	int index = 0;
> +
> +	if (unlikely(!name))
> +		return -EINVAL;
> +
> +	while (!of_property_read_string_index(dev, "interrupt-names",
> +					      index, &name_irq))
> +		if (!strcmp(name, name_irq))
> +			return of_irq_get(dev, index);

Isn't this missing an index++ somewhere? Otherwise it seems like this
would loop infinitely if there was no match on the first entry.

Thierry

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Re: [RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[Grant Likely]

On Mon, 19 May 2014 14:57:39 +0200, Thierry Reding <thierry.reding@gmail.com> wrote:
> On Mon, May 19, 2014 at 04:30:59PM +0300, Grygorii Strashko wrote:
> [...]
> > diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> [...]
> >  /**
> > + * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
> > + * @dev: pointer to device tree node
> > + * @name: zero-based index of the irq
> 
> This is a name, not an index.
> 
> > + *
> > + * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
> > + * is not yet created, or errorno in case of failure.
> 
> s/errorno/error code/? Also EPROBE_DEFER is also an error code, so I'm
> not sure if it's worth a special case in the description here.
> 
> > + *
> > + */
> > +int of_irq_get_byname(struct device_node *dev, const char *name)
> > +{
> > +	const char *name_irq = NULL;
> > +	int index = 0;
> > +
> > +	if (unlikely(!name))
> > +		return -EINVAL;
> > +
> > +	while (!of_property_read_string_index(dev, "interrupt-names",
> > +					      index, &name_irq))
> > +		if (!strcmp(name, name_irq))
> > +			return of_irq_get(dev, index);
> 
> Isn't this missing an index++ somewhere? Otherwise it seems like this
> would loop infinitely if there was no match on the first entry.

Better yet, use of_property_match_string().

g.

> 
> Thierry

Re: [RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[Grygorii Strashko]

Hi Grant,

On 05/20/2014 09:17 AM, Grant Likely wrote:
> On Mon, 19 May 2014 14:57:39 +0200, Thierry Reding <thierry.reding@gmail.com> wrote:
>> On Mon, May 19, 2014 at 04:30:59PM +0300, Grygorii Strashko wrote:
>> [...]
>>> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
>> [...]
>>>   /**
>>> + * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
>>> + * @dev: pointer to device tree node
>>> + * @name: zero-based index of the irq
>>
>> This is a name, not an index.
>>
>>> + *
>>> + * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
>>> + * is not yet created, or errorno in case of failure.
>>
>> s/errorno/error code/? Also EPROBE_DEFER is also an error code, so I'm
>> not sure if it's worth a special case in the description here.
>>
>>> + *
>>> + */
>>> +int of_irq_get_byname(struct device_node *dev, const char *name)
>>> +{
>>> +	const char *name_irq = NULL;
>>> +	int index = 0;
>>> +
>>> +	if (unlikely(!name))
>>> +		return -EINVAL;
>>> +
>>> +	while (!of_property_read_string_index(dev, "interrupt-names",
>>> +					      index, &name_irq))
>>> +		if (!strcmp(name, name_irq))
>>> +			return of_irq_get(dev, index);
>>
>> Isn't this missing an index++ somewhere? Otherwise it seems like this
>> would loop infinitely if there was no match on the first entry.
>
> Better yet, use of_property_match_string().

yep. Thanks. I've just come to the same idea. Patch re-sent.

Regards,
-grygorii

Re: [RFC PATCH] of/irq: do irq resolution in platform_get_irq_byname()

[Grygorii Strashko]

Hi Thierry,

On 05/19/2014 03:57 PM, Thierry Reding wrote:
> On Mon, May 19, 2014 at 04:30:59PM +0300, Grygorii Strashko wrote:
> [...]
>> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> [...]
>>   /**
>> + * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
>> + * @dev: pointer to device tree node
>> + * @name: zero-based index of the irq
> 
> This is a name, not an index.
> 
>> + *
>> + * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
>> + * is not yet created, or errorno in case of failure.
> 
> s/errorno/error code/? Also EPROBE_DEFER is also an error code, so I'm
> not sure if it's worth a special case in the description here.

>From my experience, It's very useful to know that function can return 
EPROBE_DEFER, otherwise, the code need to be traced till place where
EPROBE_DEFER is returned.

> 
>> + *
>> + */
>> +int of_irq_get_byname(struct device_node *dev, const char *name)
>> +{
>> +	const char *name_irq = NULL;
>> +	int index = 0;
>> +
>> +	if (unlikely(!name))
>> +		return -EINVAL;
>> +
>> +	while (!of_property_read_string_index(dev, "interrupt-names",
>> +					      index, &name_irq))
>> +		if (!strcmp(name, name_irq))
>> +			return of_irq_get(dev, index);
> 
> Isn't this missing an index++ somewhere? Otherwise it seems like this
> would loop infinitely if there was no match on the first entry.

Omg. You're right. It was bad day (

Thanks for your review. Patch re-sent.

Regards,
-grygorii