Re: [PATCH v5 3/4] of: overlay: add per overlay sysfs attributes

[Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Wed, Sep 16, 2015 at 11:09 AM, Pantelis Antoniou
<pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org> wrote:
> The two default overlay attributes are:
>
> * A targets sysfs attribute listing the targets of the installed
> overlay. The targets list the path on the kernel's device tree
> where each overlay fragment is applied to
>
> * A per overlay can_remove sysfs attribute that reports whether
> the overlay can be removed or not due to another overlapping overlay.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
> ---

How about an answer to my v4 questions?

Rob

>  drivers/of/overlay.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
>
> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> index 62cfb99..cff3c05 100644
> --- a/drivers/of/overlay.c
> +++ b/drivers/of/overlay.c
> @@ -373,8 +373,61 @@ static const struct attribute *overlay_global_attrs[] = {
>         NULL
>  };
>
> +static ssize_t can_remove_show(struct kobject *kobj,
> +               struct kobj_attribute *attr, char *buf)
> +{
> +       struct of_overlay *ov = kobj_to_overlay(kobj);
> +
> +       return snprintf(buf, PAGE_SIZE, "%d\n", overlay_removal_is_ok(ov));
> +}
> +
> +static ssize_t targets_show(struct kobject *kobj,
> +               struct kobj_attribute *attr, char *buf)
> +{
> +       struct of_overlay *ov = kobj_to_overlay(kobj);
> +       struct of_overlay_info *ovinfo;
> +       char *s, *e;
> +       ssize_t ret;
> +       int i, len;
> +
> +       s = buf;
> +       e = buf + PAGE_SIZE;
> +
> +       mutex_lock(&of_mutex);
> +
> +       /* targets */
> +       for (i = 0; i < ov->count; i++) {
> +               ovinfo = &ov->ovinfo_tab[i];
> +
> +               len = snprintf(s, e - s, "%s\n",
> +                               of_node_full_name(ovinfo->target));
> +               if (len == 0) {
> +                       ret = -ENOSPC;
> +                       goto err;
> +               }
> +               s += len;
> +       }
> +
> +       /* the buffer is zero terminated */
> +       ret = s - buf;
> +err:
> +       mutex_unlock(&of_mutex);
> +       return ret;
> +}
> +
> +static struct kobj_attribute can_remove_attr = __ATTR_RO(can_remove);
> +static struct kobj_attribute targets_attr = __ATTR_RO(targets);
> +
> +static struct attribute *overlay_attrs[] = {
> +       &can_remove_attr.attr,
> +       &targets_attr.attr,
> +       NULL
> +};
> +
>  static struct kobj_type of_overlay_ktype = {
>         .release = of_overlay_release,
> +       .sysfs_ops = &kobj_sysfs_ops,   /* default kobj sysfs ops */
> +       .default_attrs = overlay_attrs,
>  };
>
>  static struct kset *ov_kset;
> --
> 1.7.12
>