On Wed, Jul 19, 2017 at 05:24:33PM -0700, Dmitry Torokhov wrote:
> Many drivers create additional driver-specific device attributes when
> binding to the device, and providing managed version of
> device_create_group() will simplify unbinding and error handling in probe
> path for such drivers.
>
> Without managed version driver writers either have to mix manual and
> managed resources, which is prone to errors, or open-code this function by
> providing a wrapper to device_add_group() and use it with devm_add_action()
> or devm_add_action_or_reset().
>
> Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
> ---
> drivers/base/core.c | 130
> +++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/device.h | 9 ++++
> 2 files changed, 139 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 14f8cf5c8b05..09723532725d 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1035,6 +1035,136 @@ void device_remove_groups(struct device *dev,
> }
> EXPORT_SYMBOL_GPL(device_remove_groups);
>
> +union device_attr_group_devres {
> + const struct attribute_group *group;
> + const struct attribute_group **groups;
> +};
> +
> +static int devm_attr_group_match(struct device *dev, void *res, void *data)
> +{
> + return ((union device_attr_group_devres *)res)->group == data;
> +}
> +
> +static void devm_attr_group_remove(struct device *dev, void *res)
> +{
> + union device_attr_group_devres *devres = res;
> + const struct attribute_group *group = devres->group;
> +
> + dev_dbg(dev, "%s: removing group %p\n", __func__, group);
> + sysfs_remove_group(&dev->kobj, group);
> +}
> +
> +static void devm_attr_groups_remove(struct device *dev, void *res)
> +{
> + union device_attr_group_devres *devres = res;
> + const struct attribute_group **groups = devres->groups;
> +
> + dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
> + sysfs_remove_groups(&dev->kobj, groups);
> +}
> +
> +/**
> + * devm_device_add_group - given a device, create a managed attribute group
> + * @dev: The device to create the group for
> + * @grp: The attribute group to create
> + *
> + * This function creates a group for the first time. It will explicitly
> + * warn and error if any of the attribute files being created already exist.
> + *
> + * Returns 0 on success or error code on failure.
> + */
> +int devm_device_add_group(struct device *dev, const struct attribute_group
> *grp)
> +{
> + union device_attr_group_devres *devres;
> + int error;
> +
> + devres = devres_alloc(devm_attr_group_remove,
> + sizeof(*devres), GFP_KERNEL);
> + if (!devres)
> + return -ENOMEM;
> +
> + error = sysfs_create_group(&dev->kobj, grp);
Minor nit, this can now call device_create_group(), right?
Same with below I think as well.
It's fine, these look great, I'll queue them up this afternoon...
Thanks for persisting with these, and sorry it took so long to convince
me I was wrong :)
greg k-h
