diff options
| -rw-r--r-- | drivers/reset/core.c | 96 | ||||
| -rw-r--r-- | include/linux/reset-controller.h | 30 |
2 files changed, 125 insertions, 1 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c index da4292e9de97..6488292e129c 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -23,6 +23,9 @@ static DEFINE_MUTEX(reset_list_mutex); static LIST_HEAD(reset_controller_list); +static DEFINE_MUTEX(reset_lookup_mutex); +static LIST_HEAD(reset_lookup_list); + /** * struct reset_control - a reset control * @rcdev: a pointer to the reset controller device @@ -148,6 +151,33 @@ int devm_reset_controller_register(struct device *dev, } EXPORT_SYMBOL_GPL(devm_reset_controller_register); +/** + * reset_controller_add_lookup - register a set of lookup entries + * @lookup: array of reset lookup entries + * @num_entries: number of entries in the lookup array + */ +void reset_controller_add_lookup(struct reset_control_lookup *lookup, + unsigned int num_entries) +{ + struct reset_control_lookup *entry; + unsigned int i; + + mutex_lock(&reset_lookup_mutex); + for (i = 0; i < num_entries; i++) { + entry = &lookup[i]; + + if (!entry->dev_id || !entry->provider) { + pr_warn("%s(): reset lookup entry badly specified, skipping\n", + __func__); + continue; + } + + list_add_tail(&entry->list, &reset_lookup_list); + } + mutex_unlock(&reset_lookup_mutex); +} +EXPORT_SYMBOL_GPL(reset_controller_add_lookup); + static inline struct reset_control_array * rstc_to_array(struct reset_control *rstc) { return container_of(rstc, struct reset_control_array, base); @@ -493,6 +523,70 @@ 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; + + if (!dev) + return ERR_PTR(-EINVAL); + + mutex_lock(&reset_lookup_mutex); + + list_for_each_entry(lookup, &reset_lookup_list, list) { + if (strcmp(lookup->dev_id, dev_id)) + continue; + + if ((!con_id && !lookup->con_id) || + ((con_id && lookup->con_id) && + !strcmp(con_id, lookup->con_id))) { + mutex_lock(&reset_list_mutex); + rcdev = __reset_controller_by_name(lookup->provider); + if (!rcdev) { + mutex_unlock(&reset_list_mutex); + mutex_unlock(&reset_lookup_mutex); + /* Reset provider may not be ready yet. */ + return ERR_PTR(-EPROBE_DEFER); + } + + rstc = __reset_control_get_internal(rcdev, + lookup->index, + shared); + mutex_unlock(&reset_list_mutex); + break; + } + } + + mutex_unlock(&reset_lookup_mutex); + + if (!rstc) + return optional ? NULL : ERR_PTR(-ENOENT); + + return rstc; +} + struct reset_control *__reset_control_get(struct device *dev, const char *id, int index, bool shared, bool optional) { @@ -500,7 +594,7 @@ struct reset_control *__reset_control_get(struct device *dev, const char *id, return __of_reset_control_get(dev->of_node, id, index, shared, optional); - return optional ? NULL : ERR_PTR(-EINVAL); + return __reset_control_get_from_lookup(dev, id, shared, optional); } EXPORT_SYMBOL_GPL(__reset_control_get); diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index adb88f8cefbc..9326d671b6e6 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -27,12 +27,38 @@ struct device_node; struct of_phandle_args; /** + * struct reset_control_lookup - represents a single lookup entry + * + * @list: internal list of all reset lookup entries + * @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; + const char *provider; + unsigned int index; + const char *dev_id; + const char *con_id; +}; + +#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id) \ + { \ + .provider = _provider, \ + .index = _index, \ + .dev_id = _dev_id, \ + .con_id = _con_id, \ + } + +/** * struct reset_controller_dev - reset controller entity that might * provide multiple reset controls * @ops: a pointer to device specific struct reset_control_ops * @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 @@ -44,6 +70,7 @@ 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, @@ -58,4 +85,7 @@ struct device; int devm_reset_controller_register(struct device *dev, struct reset_controller_dev *rcdev); +void reset_controller_add_lookup(struct reset_control_lookup *lookup, + unsigned int num_entries); + #endif |