[PATCH 14/18] of: export new of_cdev_find helper

[Marco Felsch]

On 23-05-31, Ahmad Fatoum wrote:
> __of_find_path goes throught the hassle of determining the cdev, only to
> discard it again and return either zero or an error code.
> 
> Follow up commits will need to get the cdev corresponding to a path in
> the DT. So let's make that easier by exporting a suitable helper function.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

Reviewed-by: Marco Felsch <m.felsch at pengutronix.de>

> ---
>  drivers/of/of_path.c | 59 ++++++++++++++++++++++++++++++--------------
>  include/of.h         |  1 +
>  2 files changed, 41 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/of/of_path.c b/drivers/of/of_path.c
> index 059690e9b8e8..4d9f7b6005af 100644
> --- a/drivers/of/of_path.c
> +++ b/drivers/of/of_path.c
> @@ -27,21 +27,17 @@ struct device *of_find_device_by_node_path(const char *path)
>  }
>  
>  /**
> - * __of_find_path
> + * __of_cdev_find
>   *
>   * @node: The node to find the cdev for, can be the device or a
>   *        partition in the device
>   * @part: Optionally, a description of a partition of @node.  See of_find_path
> - * @outpath: if this function returns 0 outpath will contain the path belonging
> - *           to the input path description. Must be freed with free().
> - * @flags: use OF_FIND_PATH_FLAGS_BB to return the .bb device if available
>   *
>   */
> -static int __of_find_path(struct device_node *node, const char *part, char **outpath, unsigned flags)
> +static struct cdev *__of_cdev_find(struct device_node *node, const char *part)
>  {
>  	struct device *dev;
>  	struct cdev *cdev;
> -	bool add_bb = false;
>  
>  	of_partition_ensure_probed(node);
>  
> @@ -56,24 +52,17 @@ static int __of_find_path(struct device_node *node, const char *part, char **out
>  
>  			/* when partuuid is specified short-circuit the search for the cdev */
>  			ret = of_property_read_string(node, "partuuid", &uuid);
> -			if (!ret) {
> -				cdev = cdev_by_partuuid(uuid);
> -				if (!cdev)
> -					return -ENODEV;
> -
> -				*outpath = basprintf("/dev/%s", cdev->name);
> -
> -				return 0;
> -			}
> +			if (!ret)
> +				return cdev_by_partuuid(uuid) ?: ERR_PTR(-ENODEV);
>  		}
>  
>  		dev = of_find_device_by_node_path(devnode->full_name);
>  		if (!dev)
> -			return -ENODEV;
> +			return ERR_PTR(-ENODEV);
>  	}
>  
>  	if (dev->bus && !dev->driver)
> -		return -EPROBE_DEFER;
> +		return ERR_PTR(-EPROBE_DEFER);
>  
>  	device_detect(dev);
>  
> @@ -82,8 +71,40 @@ static int __of_find_path(struct device_node *node, const char *part, char **out
>  	else
>  		cdev = cdev_by_device_node(node);
>  
> -	if (!cdev)
> -		return -ENOENT;
> +	return cdev ?: ERR_PTR(-ENOENT);
> +}
> +
> +/**
> + * of_cdev_find
> + *
> + * @node: The node to find the cdev for, can be the device or a
> + *        partition in the device
> + *
> + */
> +struct cdev *of_cdev_find(struct device_node *node)
> +{
> +	return __of_cdev_find(node, NULL);
> +}
> +
> +/**
> + * __of_find_path
> + *
> + * @node: The node to find the cdev for, can be the device or a
> + *        partition in the device
> + * @part: Optionally, a description of a partition of @node.  See of_find_path
> + * @outpath: if this function returns 0 outpath will contain the path belonging
> + *           to the input path description. Must be freed with free().
> + * @flags: use OF_FIND_PATH_FLAGS_BB to return the .bb device if available
> + *
> + */
> +static int __of_find_path(struct device_node *node, const char *part, char **outpath, unsigned flags)
> +{
> +	bool add_bb = false;
> +	struct cdev *cdev;
> +
> +	cdev = __of_cdev_find(node, part);
> +	if (IS_ERR(cdev))
> +		return PTR_ERR(cdev);
>  
>  	if ((flags & OF_FIND_PATH_FLAGS_BB) && cdev->mtd &&
>  	    mtd_can_have_bb(cdev->mtd))
> diff --git a/include/of.h b/include/of.h
> index c716f9283316..2b75ce63e185 100644
> --- a/include/of.h
> +++ b/include/of.h
> @@ -331,6 +331,7 @@ int of_add_memory_bank(struct device_node *node, bool dump, int r,
>  struct device *of_find_device_by_node_path(const char *path);
>  #define OF_FIND_PATH_FLAGS_BB 1		/* return .bb device if available */
>  int of_find_path(struct device_node *node, const char *propname, char **outpath, unsigned flags);
> +struct cdev *of_cdev_find(struct device_node *node);
>  int of_find_path_by_node(struct device_node *node, char **outpath, unsigned flags);
>  struct device_node *of_find_node_by_devpath(struct device_node *root, const char *path);
>  int of_register_fixup(int (*fixup)(struct device_node *, void *), void *context);
> -- 
> 2.39.2
> 
> 
>