Hi Bartosz,
On Fri, 2018-03-23 at 10:36 +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
> introduced reset control lookup mechanism for boards that still use
> board files.
>
> The routine used to register lookup entries takes the corresponding
> reset_controlled_dev structure as argument.
>
> It's been determined however that for the first user of this new
> interface - davinci psc driver - it will be easier to register the
> lookup entries using the reset controller device name.
Thank you, this is what I expected in the first place.
> This patch changes the way lookup entries are added.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
> drivers/reset/core.c | 33 +++++++++++++++++++++++++++++----
> include/linux/reset-controller.h | 8 +++++---
> 2 files changed, 34 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 06fa4907afc4..f37048e55336 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
>
> /**
> * reset_controller_add_lookup - register a set of lookup entries
> - * @rcdev: initialized reset controller device owning the reset line
> + * @provider: name of the reset controller provider
> * @lookup: array of reset lookup entries
> * @num_entries: number of entries in the lookup array
> */
> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> +void reset_controller_add_lookup(const char *provider,
Is there any reason not to drop the provider parameter completely?
I'd just let the user add the provider device id to the lookup, see
below.
> struct reset_control_lookup *lookup,
> unsigned int num_entries)
> {
> @@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> continue;
> }
>
> - entry->rcdev = rcdev;
> + entry->provider = provider;
> list_add_tail(&entry->list, &reset_lookup_list);
> }
> mutex_unlock(&reset_lookup_mutex);
> @@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
> }
> EXPORT_SYMBOL_GPL(__of_reset_control_get);
>
> +static struct reset_controller_dev *
> +__reset_controller_by_name(const char *name)
> +{
> + struct reset_controller_dev *rcdev;
> +
> + lockdep_assert_held(&reset_list_mutex);
> +
> + list_for_each_entry(rcdev, &reset_controller_list, list) {
> + if (!rcdev->dev)
> + continue;
> +
> + if (!strcmp(name, dev_name(rcdev->dev)))
> + return rcdev;
> + }
> +
> + return NULL;
> +}
> +
> static struct reset_control *
> __reset_control_get_from_lookup(struct device *dev, const char *con_id,
> bool shared, bool optional)
> {
> const struct reset_control_lookup *lookup;
> + struct reset_controller_dev *rcdev;
> const char *dev_id = dev_name(dev);
> struct reset_control *rstc = NULL;
>
> @@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
> ((con_id && lookup->con_id) &&
> !strcmp(con_id, lookup->con_id))) {
> mutex_lock(&reset_list_mutex);
> - rstc = __reset_control_get_internal(lookup->rcdev,
> + rcdev = __reset_controller_by_name(lookup->provider);
> + if (!rcdev) {
> + mutex_unlock(&reset_list_mutex);
> + continue;
What is the reason to continue here? If we've found a matching lookup
that contains a rcdev dev_id for which there is no reset controller,
shouldn't we just return an error?
> + }
> +
> + rstc = __reset_control_get_internal(rcdev,
> lookup->index,
> shared);
> mutex_unlock(&reset_list_mutex);
> diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
> index 25698f6c1fae..1a6c25d825d3 100644
> --- a/include/linux/reset-controller.h
> +++ b/include/linux/reset-controller.h
> @@ -30,14 +30,14 @@ struct of_phandle_args;
> * struct reset_control_lookup - represents a single lookup entry
> *
> * @list: internal list of all reset lookup entries
> - * @rcdev: reset controller device controlling this reset line
> + * @provider: name of the reset controller device controlling this reset line
> * @index: ID of the reset controller in the reset controller device
> * @dev_id: name of the device associated with this reset line
> * @con_id name of the reset line (can be NULL)
> */
> struct reset_control_lookup {
> struct list_head list;
> - struct reset_controller_dev *rcdev;
> + const char *provider;
Looks good to me, but I'd also extend RESET_LOOKUP to set the provider
instead of passing it to the reset_controller_add_lookup function,
similarly to PWM_LOOKUP:
#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id)
> unsigned int index;
> const char *dev_id;
> const char *con_id;
> @@ -57,6 +57,7 @@ struct reset_control_lookup {
> * @owner: kernel module of the reset controller driver
> * @list: internal list of reset controller devices
> * @reset_control_head: head of internal list of requested reset controls
> + * @dev: corresponding driver model device struct
> * @of_node: corresponding device tree node as phandle target
> * @of_reset_n_cells: number of cells in reset line specifiers
> * @of_xlate: translation function to translate from specifier as found in the
> @@ -68,6 +69,7 @@ struct reset_controller_dev {
> struct module *owner;
> struct list_head list;
> struct list_head reset_control_head;
> + struct device *dev;
> struct device_node *of_node;
> int of_reset_n_cells;
> int (*of_xlate)(struct reset_controller_dev *rcdev,
> @@ -82,7 +84,7 @@ struct device;
> int devm_reset_controller_register(struct device *dev,
> struct reset_controller_dev *rcdev);
>
> -void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
> +void reset_controller_add_lookup(const char *provider,
> struct reset_control_lookup *lookup,
> unsigned int num_entries);
>
regards
Philipp
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