function to retrive of_device_id data

function to retrive of_device_id data

[Joachim Eastwood]

Hi DT maintainers,

A common driver pattern for retrieving the data field in a of_device_id struct seems to be:

    const struct of_device_id *match;
    match = of_match_device(driver_of_match, &pdev->dev);
    driver->data = match->data;

I was looking for a simple function to perform the above action but couldn't find one.

What do you think about the following patch to add such a function?

---
 drivers/of/device.c       | 12 ++++++++++++
 include/linux/of_device.h |  7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 46d6c75c1404..fd07bc55194a 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -79,6 +79,18 @@ void of_device_unregister(struct platform_device *ofdev)
 }
 EXPORT_SYMBOL(of_device_unregister);
 
+const void *of_device_get_data(const struct device *dev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match)
+		return NULL;
+
+	return match->data;
+}
+EXPORT_SYMBOL(of_device_get_data);
+
 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 {
 	const char *compat;
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index ef370210ffb2..78fddff259a0 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -33,6 +33,8 @@ extern int of_device_add(struct platform_device *pdev);
 extern int of_device_register(struct platform_device *ofdev);
 extern void of_device_unregister(struct platform_device *ofdev);
 
+extern const void *of_device_get_data(const struct device *dev);
+
 extern ssize_t of_device_get_modalias(struct device *dev,
 					char *str, ssize_t len);
 
@@ -64,6 +66,11 @@ static inline int of_driver_match_device(struct device *dev,
 static inline void of_device_uevent(struct device *dev,
 			struct kobj_uevent_env *env) { }
 
+static const void *of_device_get_data(const struct device *dev)
+{
+	return NULL;
+}
+
 static inline int of_device_get_modalias(struct device *dev,
 				   char *str, ssize_t len)
 {
-- 
1.8.0

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Re: function to retrive of_device_id data

[Rob Herring]

On Sun, May 3, 2015 at 4:19 PM, Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi DT maintainers,
>
> A common driver pattern for retrieving the data field in a of_device_id struct seems to be:
>
>     const struct of_device_id *match;
>     match = of_match_device(driver_of_match, &pdev->dev);
>     driver->data = match->data;
>
> I was looking for a simple function to perform the above action but couldn't find one.
>
> What do you think about the following patch to add such a function?

Looks fine to me. I'd prefer it be called of_device_get_match_data() though.

Rob

> ---
>  drivers/of/device.c       | 12 ++++++++++++
>  include/linux/of_device.h |  7 +++++++
>  2 files changed, 19 insertions(+)
>
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 46d6c75c1404..fd07bc55194a 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -79,6 +79,18 @@ void of_device_unregister(struct platform_device *ofdev)
>  }
>  EXPORT_SYMBOL(of_device_unregister);
>
> +const void *of_device_get_data(const struct device *dev)
> +{
> +       const struct of_device_id *match;
> +
> +       match = of_match_device(dev->driver->of_match_table, dev);
> +       if (!match)
> +               return NULL;
> +
> +       return match->data;
> +}
> +EXPORT_SYMBOL(of_device_get_data);
> +
>  ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
>  {
>         const char *compat;
> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
> index ef370210ffb2..78fddff259a0 100644
> --- a/include/linux/of_device.h
> +++ b/include/linux/of_device.h
> @@ -33,6 +33,8 @@ extern int of_device_add(struct platform_device *pdev);
>  extern int of_device_register(struct platform_device *ofdev);
>  extern void of_device_unregister(struct platform_device *ofdev);
>
> +extern const void *of_device_get_data(const struct device *dev);
> +
>  extern ssize_t of_device_get_modalias(struct device *dev,
>                                         char *str, ssize_t len);
>
> @@ -64,6 +66,11 @@ static inline int of_driver_match_device(struct device *dev,
>  static inline void of_device_uevent(struct device *dev,
>                         struct kobj_uevent_env *env) { }
>
> +static const void *of_device_get_data(const struct device *dev)
> +{
> +       return NULL;
> +}
> +
>  static inline int of_device_get_modalias(struct device *dev,
>                                    char *str, ssize_t len)
>  {
> --
> 1.8.0
>
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Re: function to retrive of_device_id data

[Joachim Eastwood]

On 5 May 2015 at 00:24, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Sun, May 3, 2015 at 4:19 PM, Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> Hi DT maintainers,
>>
>> A common driver pattern for retrieving the data field in a of_device_id struct seems to be:
>>
>>     const struct of_device_id *match;
>>     match = of_match_device(driver_of_match, &pdev->dev);
>>     driver->data = match->data;
>>
>> I was looking for a simple function to perform the above action but couldn't find one.
>>
>> What do you think about the following patch to add such a function?
>
> Looks fine to me. I'd prefer it be called of_device_get_match_data() though.

I'll rename it and post a proper patch with a change log, tomorrow.

regards,
Joachim Eastwood
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