On Fri, Sep 09, 2022 at 09:40:50AM +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@xxxxxxxxxxxxxx>
> ---
> drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++++
> include/of.h | 8 ++++++++
> test/self/of_manipulation.c | 2 +-
> 3 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 212b226eb55c..e208949b08bd 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2378,6 +2378,41 @@ 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;
> + int orig_len;
> + const void *orig_buf;
> + void *buf;
> +
> + if (!np)
> + return -ENOENT;
> +
> + pp = of_find_property(np, name, NULL);
> + if (!pp) {
> + of_new_property(np, name, val, len);
> + return 0;
> + }
> +
> + orig_len = pp->length;
> + buf = realloc(pp->value, orig_len + len);
> + if (!buf)
> + return -ENOMEM;
> +
> + orig_buf = pp->value_const ?: buf;
> + if (orig_buf) {
orig_buf is always non NULL here.
> + memmove(buf + len, orig_buf, orig_len);
> + pp->value_const = NULL;
> + }
> +
> + memcpy(buf, val, len);
> +
> + pp->value = buf;
> + pp->length += len;
> +
> + return 0;
> +}
How about a bit more straight forward variant like this:
int of_prepend_property(struct device_node *np, const char *name, const void *val, int len)
{
struct property *pp;
int oldlen = 0;
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;
}
Sascha
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