Re: [PATCH v2 01/17] reset: add of_reset_control_get_by_index()

Philipp Zabel
2015-03-12T15:02:47Z

Hi Vince,

Am Donnerstag, den 12.03.2015, 20:15 +0800 schrieb Vince Hsu:
> Add of_reset_control_get_by_index() to allow the drivers to get reset device
> without knowing its name.

I see this is useful in the case of PM domain drivers that just need to
trigger a list of resets in whatever order.

> Signed-off-by: Vince Hsu <vinceh@nvidia.com>
>
> ---
> v2: minor changes according to Alex's comments
>
> drivers/reset/core.c | 44 +++++++++++++++++++++++++++++---------------
> include/linux/reset.h | 9 +++++++++
> 2 files changed, 38 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 7955e00d04d4..5e78866acd62 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -140,28 +140,15 @@ int reset_control_status(struct reset_control *rstc)
> }
> EXPORT_SYMBOL_GPL(reset_control_status);
>
> -/**
> - * of_reset_control_get - Lookup and obtain a reference to a reset controller.
> - * @node: device to be reset by the controller
> - * @id: reset line name
> - *
> - * Returns a struct reset_control or IS_ERR() condition containing errno.
> - *
> - * Use of id names is optional.
> - */
> -struct reset_control *of_reset_control_get(struct device_node *node,
> - const char *id)
> +struct reset_control *__of_reset_control_get(struct device_node *node,
> + int index)

static

> {
> struct reset_control *rstc = ERR_PTR(-EPROBE_DEFER);
> struct reset_controller_dev *r, *rcdev;
> struct of_phandle_args args;
> - int index = 0;
> int rstc_id;
> int ret;
>
> - if (id)
> - index = of_property_match_string(node,
> - "reset-names", id);
> ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
> index, &args);
> if (ret)
> @@ -202,6 +189,33 @@ struct reset_control *of_reset_control_get(struct device_node *node,
>
> return rstc;
> }
> +
> +struct reset_control *of_reset_control_get_by_index(struct device_node *node,
> + int index)
> +{
> + return __of_reset_control_get(node, index);
> +}
> +EXPORT_SYMBOL_GPL(of_reset_control_get_by_index);

This function is missing a kerneldoc comment, and please add a note that
this is only to be used if the order of the resets doesn't matter.

Actually, I see no reason not to just merge __of_reset_control_get into
of_reset_control_get_by_index and then just call that from
of_reset_control_get.

> +/**
> + * of_reset_control_get - Lookup and obtain a reference to a reset controller.
> + * @node: device to be reset by the controller
> + * @id: reset line name
> + *
> + * Returns a struct reset_control or IS_ERR() condition containing errno.
> + *
> + * Use of id names is optional.
> + */
> +struct reset_control *of_reset_control_get(struct device_node *node,
> + const char *id)
> +{
> + int index = 0;
> +
> + if (id)
> + index = of_property_match_string(node,
> + "reset-names", id);
> + return __of_reset_control_get(node, index);
> +}
> EXPORT_SYMBOL_GPL(of_reset_control_get);
[...]

regards
Philipp