[PATCH v2 2/3] common: oftree: Add autoenable functionality

[Sascha Hauer]

On Thu, Nov 02, 2017 at 05:39:41PM +0100, Daniel Schultz wrote:
> This patch adds an API to automatically enable either hardware components
> with existing device drivers or i2c clients. All functions take a device
> tree path to find the hardware and will fix up the node status in the
> kernel device tree, if it's accessible.
> 
> Signed-off-by: Daniel Schultz <d.schultz at phytec.de>
> ---
> Changes:
> 	v2: Moved from standalone file to oftree.c
> 	    Added of_device_is_available, if a driver is disabled
> 	    Added of_property_read_u32
> 	    Removed Kconfig
> 	    Added of_ prefix to function names
> 	    Renamed of_autoenable_i2c_by_path to of_autoenable_i2c_by_component
> 
>  common/oftree.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/of.h    | 14 +++++++++
>  2 files changed, 106 insertions(+)
> 
> diff --git a/common/oftree.c b/common/oftree.c
> index 09a4455..3b77a7e 100644
> --- a/common/oftree.c
> +++ b/common/oftree.c
> @@ -11,6 +11,7 @@
>  #include <getopt.h>
>  #include <init.h>
>  #include <boot.h>
> +#include <i2c/i2c.h>
>  
>  #define MAX_LEVEL	32		/* how deeply nested we will go */
>  
> @@ -260,3 +261,94 @@ struct fdt_header *of_get_fixed_tree(struct device_node *node)
>  
>  	return fdt;
>  }
> +
> +/**
> + * of_autoenable_device_by_path() - Autoenable a device by a device tree path
> + * @param path Device tree path up from the root to the device
> + * @return 0 on success, -enodev on failure. If no device found in the device
> + * tree.
> + *
> + * This function will search for a device and will enable it in the kernel
> + * device tree, if it exists and is loaded.
> + */
> +int of_autoenable_device_by_path(char *path)
> +{
> +	struct device_d *device;
> +	struct device_node *node;
> +	int ret;
> +
> +	node = of_find_node_by_name(NULL, path);
> +	if (!node)
> +		node = of_find_node_by_path(path);
> +
> +	if (!node)
> +		return -ENODEV;
> +
> +	device = of_find_device_by_node(node);
> +	if (!device)
> +		if (!of_device_is_available(node))
> +			return -ENODEV;

Is the of_find_device_by_node(node) test still necessary? In which case?

Sascha

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