[PATCH v2] device property: Add helpers to count items in an array

[PATCH v2] device property: Add helpers to count items in an array

[Andy Shevchenko]

The usual pattern to allocate the necessary space for an array of properties is
to count them first by calling:

  count = device_property_read_uXX_array(dev, propname, NULL, 0);
  if (count < 0)
	return count;

Introduce helpers device_property_count_uXX() to count items by supplying hard
coded last two parameters to device_property_readXX_array().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
- gathered tags
- rephrase a bit the commit message and fix a typo (Sakari)
 include/linux/property.h | 44 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/include/linux/property.h b/include/linux/property.h
index a29369c89e6e..65e31c090f9f 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -144,6 +144,26 @@ static inline int device_property_read_u64(struct device *dev,
 	return device_property_read_u64_array(dev, propname, val, 1);
 }
 
+static inline int device_property_count_u8(struct device *dev, const char *propname)
+{
+	return device_property_read_u8_array(dev, propname, NULL, 0);
+}
+
+static inline int device_property_count_u16(struct device *dev, const char *propname)
+{
+	return device_property_read_u16_array(dev, propname, NULL, 0);
+}
+
+static inline int device_property_count_u32(struct device *dev, const char *propname)
+{
+	return device_property_read_u32_array(dev, propname, NULL, 0);
+}
+
+static inline int device_property_count_u64(struct device *dev, const char *propname)
+{
+	return device_property_read_u64_array(dev, propname, NULL, 0);
+}
+
 static inline bool fwnode_property_read_bool(const struct fwnode_handle *fwnode,
 					     const char *propname)
 {
@@ -174,6 +194,30 @@ static inline int fwnode_property_read_u64(const struct fwnode_handle *fwnode,
 	return fwnode_property_read_u64_array(fwnode, propname, val, 1);
 }
 
+static inline int fwnode_property_count_u8(const struct fwnode_handle *fwnode,
+					   const char *propname)
+{
+	return fwnode_property_read_u8_array(fwnode, propname, NULL, 0);
+}
+
+static inline int fwnode_property_count_u16(const struct fwnode_handle *fwnode,
+					    const char *propname)
+{
+	return fwnode_property_read_u16_array(fwnode, propname, NULL, 0);
+}
+
+static inline int fwnode_property_count_u32(const struct fwnode_handle *fwnode,
+					    const char *propname)
+{
+	return fwnode_property_read_u32_array(fwnode, propname, NULL, 0);
+}
+
+static inline int fwnode_property_count_u64(const struct fwnode_handle *fwnode,
+					    const char *propname)
+{
+	return fwnode_property_read_u64_array(fwnode, propname, NULL, 0);
+}
+
 /**
  * struct property_entry - "Built-in" device property representation.
  * @name: Name of the property.
-- 
2.20.1

Re: [PATCH v2] device property: Add helpers to count items in an array

[Andy Shevchenko]

On Mon, May 20, 2019 at 04:50:04PM +0300, Andy Shevchenko wrote:
> The usual pattern to allocate the necessary space for an array of properties is
> to count them first by calling:
> 
>   count = device_property_read_uXX_array(dev, propname, NULL, 0);
>   if (count < 0)
> 	return count;
> 
> Introduce helpers device_property_count_uXX() to count items by supplying hard
> coded last two parameters to device_property_readXX_array().
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Rafael, can be this applied if you have no objections?

> ---
> - gathered tags
> - rephrase a bit the commit message and fix a typo (Sakari)
>  include/linux/property.h | 44 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/include/linux/property.h b/include/linux/property.h
> index a29369c89e6e..65e31c090f9f 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -144,6 +144,26 @@ static inline int device_property_read_u64(struct device *dev,
>  	return device_property_read_u64_array(dev, propname, val, 1);
>  }
>  
> +static inline int device_property_count_u8(struct device *dev, const char *propname)
> +{
> +	return device_property_read_u8_array(dev, propname, NULL, 0);
> +}
> +
> +static inline int device_property_count_u16(struct device *dev, const char *propname)
> +{
> +	return device_property_read_u16_array(dev, propname, NULL, 0);
> +}
> +
> +static inline int device_property_count_u32(struct device *dev, const char *propname)
> +{
> +	return device_property_read_u32_array(dev, propname, NULL, 0);
> +}
> +
> +static inline int device_property_count_u64(struct device *dev, const char *propname)
> +{
> +	return device_property_read_u64_array(dev, propname, NULL, 0);
> +}
> +
>  static inline bool fwnode_property_read_bool(const struct fwnode_handle *fwnode,
>  					     const char *propname)
>  {
> @@ -174,6 +194,30 @@ static inline int fwnode_property_read_u64(const struct fwnode_handle *fwnode,
>  	return fwnode_property_read_u64_array(fwnode, propname, val, 1);
>  }
>  
> +static inline int fwnode_property_count_u8(const struct fwnode_handle *fwnode,
> +					   const char *propname)
> +{
> +	return fwnode_property_read_u8_array(fwnode, propname, NULL, 0);
> +}
> +
> +static inline int fwnode_property_count_u16(const struct fwnode_handle *fwnode,
> +					    const char *propname)
> +{
> +	return fwnode_property_read_u16_array(fwnode, propname, NULL, 0);
> +}
> +
> +static inline int fwnode_property_count_u32(const struct fwnode_handle *fwnode,
> +					    const char *propname)
> +{
> +	return fwnode_property_read_u32_array(fwnode, propname, NULL, 0);
> +}
> +
> +static inline int fwnode_property_count_u64(const struct fwnode_handle *fwnode,
> +					    const char *propname)
> +{
> +	return fwnode_property_read_u64_array(fwnode, propname, NULL, 0);
> +}
> +
>  /**
>   * struct property_entry - "Built-in" device property representation.
>   * @name: Name of the property.
> -- 
> 2.20.1
> 

-- 
With Best Regards,
Andy Shevchenko