Messages in this thread Patch in this message | | | From | Charles Keepax <> | Subject | [RFC PATCH] regulator: core: Add ability to create a lookup alias for supply | Date | Wed, 2 Oct 2013 13:16:59 +0100 |
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These patches add the ability to create an alternative device on which a lookup for a certain supply should be conducted.
A common use-case for this would be devices that are logically represented as a collection of drivers within Linux but are are presented as a single device from device tree. It this case it is necessary for each sub device to locate their supply data on the main device.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> ---
Hi Mark,
Following our discussions around the Arizona regulator bindings here is an effort at putting a mechanism into the regulator core to alias registering of a supply from one device to another.
I have a couple of patches that update the Arizona driver to use this that I will send in if you think this looks along the lines of what you were suggesting.
Thanks, Charles
drivers/regulator/core.c | 93 ++++++++++++++++++++++++++++++++++++ include/linux/regulator/consumer.h | 17 +++++++ 2 files changed, 110 insertions(+), 0 deletions(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 6333080..e9f11f0 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -53,6 +53,7 @@ static DEFINE_MUTEX(regulator_list_mutex); static LIST_HEAD(regulator_list); static LIST_HEAD(regulator_map_list); static LIST_HEAD(regulator_ena_gpio_list); +static LIST_HEAD(regulator_supply_alias_list); static bool has_full_constraints; static struct dentry *debugfs_root; @@ -82,6 +83,18 @@ struct regulator_enable_gpio { unsigned int ena_gpio_invert:1; }; +/* + * struct regulator_supply_alias + * + * Used to map lookups for a supply onto an alternative device. + */ +struct regulator_supply_alias { + struct list_head list; + struct device *dev; + const char *supply; + struct device *alias; +}; + static int _regulator_is_enabled(struct regulator_dev *rdev); static int _regulator_disable(struct regulator_dev *rdev); static int _regulator_get_voltage(struct regulator_dev *rdev); @@ -1208,6 +1221,28 @@ static int _regulator_get_enable_time(struct regulator_dev *rdev) return rdev->desc->ops->enable_time(rdev); } +static inline int regulator_supply_alias_match(struct device *dev, + const char *supply, + struct regulator_supply_alias *map) +{ + return map->dev == dev && strcmp(map->supply, supply) == 0; +} + +static struct device *regulator_supply_alias(struct device *dev, + const char *supply) +{ + struct regulator_supply_alias *map; + + list_for_each_entry(map, ®ulator_supply_alias_list, list) + if (regulator_supply_alias_match(dev, supply, map)) { + dev_dbg(dev, "Mapping supply %s to %s\n", + supply, dev_name(map->alias)); + return map->alias; + } + + return dev; +} + static struct regulator_dev *regulator_dev_lookup(struct device *dev, const char *supply, int *ret) @@ -1217,6 +1252,8 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev, struct regulator_map *map; const char *devname = NULL; + dev = regulator_supply_alias(dev, supply); + /* first do a dt based lookup */ if (dev && dev->of_node) { node = of_get_regulator(dev, supply); @@ -1470,6 +1507,62 @@ void regulator_put(struct regulator *regulator) } EXPORT_SYMBOL_GPL(regulator_put); +/** + * regulator_register_supply_alias - Provide device alias for supply lookup + * @dev: device that will be given as the regulator "consumer" + * @id: Supply name or regulator ID. + * @alias: device that should be used to lookup the supply + * + * All lookups for id on dev will instead be conducted on for id on alias. + */ +int regulator_register_supply_alias(struct device *dev, const char *id, + struct device *alias) +{ + struct regulator_supply_alias *map; + + list_for_each_entry(map, ®ulator_supply_alias_list, list) + if (regulator_supply_alias_match(dev, id, map)) + return -EEXIST; + + map = kzalloc(sizeof(struct regulator_supply_alias), GFP_KERNEL); + if (!map) + return -ENOMEM; + + map->dev = dev; + map->supply = id; + map->alias = alias; + + list_add(&map->list, ®ulator_supply_alias_list); + + pr_info("Adding alias for supply %s: %s -> %s\n", + id, dev_name(dev), dev_name(alias)); + + return 0; +} +EXPORT_SYMBOL_GPL(regulator_register_supply_alias); + +/** + * regulator_unregister_supply_alias - Remove device alias + * @dev: device that will be given as the regulator "consumer" + * @id: Supply name or regulator ID. + * + * Remove a lookup alias if one exists for id on dev. + */ +int regulator_unregister_supply_alias(struct device *dev, const char *id) +{ + struct regulator_supply_alias *map; + + list_for_each_entry(map, ®ulator_supply_alias_list, list) + if (regulator_supply_alias_match(dev, id, map)) { + list_del(&map->list); + kfree(map); + return 0; + } + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(regulator_unregister_supply_alias); + /* Manage enable GPIO list. Same GPIO pin can be shared among regulators */ static int regulator_ena_gpio_request(struct regulator_dev *rdev, const struct regulator_config *config) diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h index 27be915..622d81e 100644 --- a/include/linux/regulator/consumer.h +++ b/include/linux/regulator/consumer.h @@ -146,6 +146,10 @@ struct regulator *__must_check devm_regulator_get_optional(struct device *dev, void regulator_put(struct regulator *regulator); void devm_regulator_put(struct regulator *regulator); +int regulator_register_supply_alias(struct device *dev, const char *id, + struct device *alias); +int regulator_unregister_supply_alias(struct device *dev, const char *id); + /* regulator output control and status */ int __must_check regulator_enable(struct regulator *regulator); int regulator_disable(struct regulator *regulator); @@ -250,6 +254,19 @@ static inline void devm_regulator_put(struct regulator *regulator) { } +static inline int regulator_register_supply_alias(struct device *dev, + const char *id, + struct device *alias) +{ + return 0; +} + +static inline int regulator_unregister_supply_alias(struct device *dev, + const char *id) +{ + return 0; +} + static inline int regulator_enable(struct regulator *regulator) { return 0; -- 1.7.2.5
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