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author | MyungJoo Ham <myungjoo.ham@samsung.com> | 2012-04-20 05:16:25 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-20 16:23:37 (GMT) |
commit | 806d9dd71ff52ef09764585baaeec23afbb98560 (patch) | |
tree | e81291b139bac10e08d1cb376a22cac5c89a3b65 /include | |
parent | 74c5d09bd562edc220d6e076b8f1e118819c178f (diff) | |
download | linux-fsl-qoriq-806d9dd71ff52ef09764585baaeec23afbb98560.tar.xz |
Extcon: support multiple states at a device.
One switch device (e.g., MUIC(MAX8997, MAX77686, ...), and some 30-pin
devices) may have multiple cables attached. For example, one
30-pin port may inhabit a USB cable, an HDMI cable, and a mic.
Thus, one switch device requires multiple state bits each representing
a type of cable.
For such purpose, we use the 32bit state variable; thus, up to 32
different type of cables may be defined for a switch device. The list of
possible cables is defined by the array of cable names in the switch_dev
struct given to the class.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
--
Changes from V7
- Bugfixed in _call_per_cable() (incorrect nb) (Chanwoo Choi)
- Compiler error in header for !CONFIG_EXTCON (Chanwoo Choi)
Changes from V5
- Sysfs style reformed: subdirectory per cable.
- Updated standard cable names
- Removed unnecessary printf
- Bugfixes after testing
Changes from V4
- Bugfixes after more testing at Exynos4412 boards with userspace
processses.
Changes from V3
- Bugfixes after more testing at Exynos4412 boards.
Changes from V2
- State can be stored by user
- Documentation updated
Changes from RFC
- Switch is renamed to extcon
- Added kerneldoc comments
- Added APIs to support "standard" cable names
- Added helper APIs to support notifier block registration with cable
name.
- Regrouped function list in the header file.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/extcon.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/include/linux/extcon.h b/include/linux/extcon.h index c9c9afe..20e24b3 100644 --- a/include/linux/extcon.h +++ b/include/linux/extcon.h @@ -24,10 +24,60 @@ #define __LINUX_EXTCON_H__ #include <linux/notifier.h> + +#define SUPPORTED_CABLE_MAX 32 +#define CABLE_NAME_MAX 30 + +/* + * The standard cable name is to help support general notifier + * and notifee device drivers to share the common names. + * Please use standard cable names unless your notifier device has + * a very unique and abnormal cable or + * the cable type is supposed to be used with only one unique + * pair of notifier/notifee devices. + * + * Please add any other "standard" cables used with extcon dev. + * + * You may add a dot and number to specify version or specification + * of the specific cable if it is required. (e.g., "Fast-charger.18" + * and "Fast-charger.10" for 1.8A and 1.0A chargers) + * However, the notifee and notifier should be able to handle such + * string and if the notifee can negotiate the protocol or idenify, + * you don't need such convention. This convention is helpful when + * notifier can distinguish but notifiee cannot. + */ +enum extcon_cable_name { + EXTCON_USB = 0, + EXTCON_USB_HOST, + EXTCON_TA, /* Travel Adaptor */ + EXTCON_FAST_CHARGER, + EXTCON_SLOW_CHARGER, + EXTCON_CHARGE_DOWNSTREAM, /* Charging an external device */ + EXTCON_HDMI, + EXTCON_MHL, + EXTCON_DVI, + EXTCON_VGA, + EXTCON_DOCK, + EXTCON_LINE_IN, + EXTCON_LINE_OUT, + EXTCON_MIC_IN, + EXTCON_HEADPHONE_OUT, + EXTCON_SPDIF_IN, + EXTCON_SPDIF_OUT, + EXTCON_VIDEO_IN, + EXTCON_VIDEO_OUT, +}; +extern const char *extcon_cable_name[]; + +struct extcon_cable; + /** * struct extcon_dev - An extcon device represents one external connector. * @name The name of this extcon device. Parent device name is used * if NULL. + * @supported_cable Array of supported cable name ending with NULL. + * If supported_cable is NULL, cable name related APIs + * are disabled. * @print_name An optional callback to override the method to print the * name of the extcon device. * @print_state An optional callback to override the method to print the @@ -38,6 +88,11 @@ * @nh Notifier for the state change events from this extcon * @entry To support list of extcon devices so that uses can search * for extcon devices based on the extcon name. + * @lock + * @max_supported Internal value to store the number of cables. + * @extcon_dev_type Device_type struct to provide attribute_groups + * customized for each extcon device. + * @cables Sysfs subdirectories. Each represents one cable. * * In most cases, users only need to provide "User initializing data" of * this struct when registering an extcon. In some exceptional cases, @@ -47,6 +102,7 @@ struct extcon_dev { /* --- Optional user initializing data --- */ const char *name; + const char **supported_cable; /* --- Optional callbacks to override class functions --- */ ssize_t (*print_name)(struct extcon_dev *edev, char *buf); @@ -57,6 +113,49 @@ struct extcon_dev { u32 state; struct raw_notifier_head nh; struct list_head entry; + spinlock_t lock; /* could be called by irq handler */ + int max_supported; + + /* /sys/class/extcon/.../cable.n/... */ + struct device_type extcon_dev_type; + struct extcon_cable *cables; +}; + +/** + * struct extcon_cable - An internal data for each cable of extcon device. + * @edev The extcon device + * @cable_index Index of this cable in the edev + * @attr_g Attribute group for the cable + * @attr_name "name" sysfs entry + * @attr_state "state" sysfs entry + * @attrs Array pointing to attr_name and attr_state for attr_g + */ +struct extcon_cable { + struct extcon_dev *edev; + int cable_index; + + struct attribute_group attr_g; + struct device_attribute attr_name; + struct device_attribute attr_state; + + struct attribute *attrs[3]; /* to be fed to attr_g.attrs */ +}; + +/** + * struct extcon_specific_cable_nb - An internal data for + * extcon_register_interest(). + * @internal_nb a notifier block bridging extcon notifier and cable notifier. + * @user_nb user provided notifier block for events from a specific cable. + * @cable_index the target cable. + * @edev the target extcon device. + * @previous_value the saved previous event value. + */ +struct extcon_specific_cable_nb { + struct notifier_block internal_nb; + struct notifier_block *user_nb; + int cable_index; + struct extcon_dev *edev; + unsigned long previous_value; }; #if IS_ENABLED(CONFIG_EXTCON) @@ -69,16 +168,54 @@ extern int extcon_dev_register(struct extcon_dev *edev, struct device *dev); extern void extcon_dev_unregister(struct extcon_dev *edev); extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name); +/* + * get/set/update_state access the 32b encoded state value, which represents + * states of all possible cables of the multistate port. For example, if one + * calls extcon_set_state(edev, 0x7), it may mean that all the three cables + * are attached to the port. + */ static inline u32 extcon_get_state(struct extcon_dev *edev) { return edev->state; } extern void extcon_set_state(struct extcon_dev *edev, u32 state); +extern void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state); + +/* + * get/set_cable_state access each bit of the 32b encoded state value. + * They are used to access the status of each cable based on the cable_name + * or cable_index, which is retrived by extcon_find_cable_index + */ +extern int extcon_find_cable_index(struct extcon_dev *sdev, + const char *cable_name); +extern int extcon_get_cable_state_(struct extcon_dev *edev, int cable_index); +extern int extcon_set_cable_state_(struct extcon_dev *edev, int cable_index, + bool cable_state); + +extern int extcon_get_cable_state(struct extcon_dev *edev, + const char *cable_name); +extern int extcon_set_cable_state(struct extcon_dev *edev, + const char *cable_name, bool cable_state); + +/* + * Following APIs are for notifiees (those who want to be notified) + * to register a callback for events from a specific cable of the extcon. + * Notifiees are the connected device drivers wanting to get notified by + * a specific external port of a connection device. + */ +extern int extcon_register_interest(struct extcon_specific_cable_nb *obj, + const char *extcon_name, + const char *cable_name, + struct notifier_block *nb); +extern int extcon_unregister_interest(struct extcon_specific_cable_nb *nb); /* * Following APIs are to monitor every action of a notifier. * Registerer gets notified for every external port of a connection device. + * Probably this could be used to debug an action of notifier; however, + * we do not recommend to use this at normal 'notifiee' device drivers who + * want to be notified by a specific external port of the notifier. */ extern int extcon_register_notifier(struct extcon_dev *edev, struct notifier_block *nb); @@ -99,6 +236,41 @@ static inline u32 extcon_get_state(struct extcon_dev *edev) } static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { } + +static inline void extcon_update_state(struct extcon_dev *edev, u32 mask, + u32 state) +{ } + +static inline int extcon_find_cable_index(struct extcon_dev *edev, + const char *cable_name) +{ + return 0; +} + +static inline int extcon_get_cable_state_(struct extcon_dev *edev, + int cable_index) +{ + return 0; +} + +static inline int extcon_set_cable_state_(struct extcon_dev *edev, + int cable_index, bool cable_state) +{ + return 0; +} + +static inline int extcon_get_cable_state(struct extcon_dev *edev, + const char *cable_name) +{ + return 0; +} + +static inline int extcon_set_cable_state(struct extcon_dev *edev, + const char *cable_name, int state) +{ + return 0; +} + static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) { return NULL; @@ -116,5 +288,18 @@ static inline int extcon_unregister_notifier(struct extcon_dev *edev, return 0; } +static inline int extcon_register_interest(struct extcon_specific_cable_nb *obj, + const char *extcon_name, + const char *cable_name, + struct notifier_block *nb) +{ + return 0; +} + +static inline int extcon_unregister_interest(struct extcon_specific_cable_nb + *obj) +{ + return 0; +} #endif /* CONFIG_EXTCON */ #endif /* __LINUX_EXTCON_H__ */ |