[PATCH v2] of: implement of_prepend_property

[Sascha Hauer]

On Mon, Sep 12, 2022 at 05:54:36PM +0200, Ahmad Fatoum wrote:
> Like of_append_property for adding at the end of properties, implement
> of_prepend_property for placing data into the front.
> 
> This is especially useful to fixup most-specific compatibles into
> existing nodes.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
> v1 -> v2:
>   - simplify with malloc/memcpy instead of realloc/memmove (Sascha)
> ---
>  drivers/of/base.c           | 30 ++++++++++++++++++++++++++++++
>  include/of.h                |  8 ++++++++
>  test/self/of_manipulation.c |  2 +-
>  3 files changed, 39 insertions(+), 1 deletion(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 212b226eb55c..ea2a88764bb2 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2378,6 +2378,36 @@ int of_append_property(struct device_node *np, const char *name, const void *val
>  	return 0;
>  }
>  
> +int of_prepend_property(struct device_node *np, const char *name, const void *val, int len)
> +{
> +	struct property *pp;
> +	const void *oldval;
> +	void *buf;
> +	int oldlen;
> +
> +	pp = of_find_property(np, name, &oldlen);
> +	if (!pp) {
> +		of_new_property(np, name, val, len);
> +		return 0;
> +	}
> +
> +	oldval = of_property_get_value(pp);
> +
> +	buf = malloc(len + oldlen);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	memcpy(buf, val, len);
> +	memcpy(buf + len, oldval, oldlen);
> +
> +	free(pp->value);
> +	pp->value = buf;
> +	pp->length = len + oldlen;
> +	pp->value_const = NULL;
> +
> +	return 0;
> +}
> +
>  int of_property_sprintf(struct device_node *np,
>  			const char *propname, const char *fmt, ...)
>  {
> diff --git a/include/of.h b/include/of.h
> index 153e75d3e51d..052d5fcad84c 100644
> --- a/include/of.h
> +++ b/include/of.h
> @@ -135,6 +135,8 @@ extern int of_set_property(struct device_node *node, const char *p,
>  			const void *val, int len, int create);
>  extern int of_append_property(struct device_node *np, const char *p,
>  			      const void *val, int len);
> +extern int of_prepend_property(struct device_node *np, const char *name,
> +			       const void *val, int len);
>  extern struct property *of_new_property(struct device_node *node,
>  				const char *name, const void *data, int len);
>  extern struct property *of_new_property_const(struct device_node *node,
> @@ -536,6 +538,12 @@ static inline int of_append_property(struct device_node *np, const char *p,
>  	return -ENOSYS;
>  }
>  
> +static inline int of_prepend_property(struct device_node *np, const char *name,
> +				      const void *val, int len)
> +{
> +	return -ENOSYS;
> +}
> +
>  static inline struct property *of_new_property(struct device_node *node,
>  				const char *name, const void *data, int len)
>  {
> diff --git a/test/self/of_manipulation.c b/test/self/of_manipulation.c
> index 7e30a60ca687..f7f95fa269af 100644
> --- a/test/self/of_manipulation.c
> +++ b/test/self/of_manipulation.c
> @@ -103,9 +103,9 @@ static void test_of_property_strings(struct device_node *root)
>  
>  	of_append_property(np4, "property-single", "ayy", 4);
>  
> -	of_append_property(np4, "property-multi", "ayy", 4);
>  	of_append_property(np4, "property-multi", "bee", 4);
>  	of_append_property(np4, "property-multi", "sea", 4);
> +	of_prepend_property(np4, "property-multi", "ayy", 4);
>  
>  	assert_equal(np3, np4);
>  }
> -- 
> 2.30.2
> 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |