From bde68e60b18208978c50c6fb9bdf29826d2887f3 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Fri, 20 Apr 2012 14:16:26 +0900 Subject: Extcon: support mutually exclusive relation between cables. There could be cables that t recannot be attaches simulatenously. Extcon device drivers may express such information via mutually_exclusive in struct extcon_dev. For example, for an extcon device with 16 cables (bits 0 to 15 are available), if mutually_exclusive = { 0x7, 0xC0, 0x81, 0 }, then, the following attachments are prohibitted. {0, 1} {0, 2} {1, 2} {6, 7} {0, 7} and every attachment set that are superset of one of the above. For the detail, please refer to linux/include/linux/extcon.h. The concept is suggested by NeilBrown Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park -- Changes from V5: - Updated sysfs format Signed-off-by: Greg Kroah-Hartman --- include/linux/extcon.h | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) (limited to 'include/linux/extcon.h') diff --git a/include/linux/extcon.h b/include/linux/extcon.h index 20e24b32a17d..6495f7731400 100644 --- a/include/linux/extcon.h +++ b/include/linux/extcon.h @@ -78,6 +78,14 @@ struct extcon_cable; * @supported_cable Array of supported cable name ending with NULL. * If supported_cable is NULL, cable name related APIs * are disabled. + * @mutually_exclusive Array of mutually exclusive set of cables that cannot + * be attached simultaneously. The array should be + * ending with NULL or be NULL (no mutually exclusive + * cables). For example, if it is { 0x7, 0x30, 0}, then, + * {0, 1}, {0, 1, 2}, {0, 2}, {1, 2}, or {4, 5} cannot + * be attached simulataneously. {0x7, 0} is equivalent to + * {0x3, 0x6, 0x5, 0}. If it is {0xFFFFFFFF, 0}, there + * can be no simultaneous connections. * @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 @@ -103,6 +111,7 @@ struct extcon_dev { /* --- Optional user initializing data --- */ const char *name; const char **supported_cable; + const u32 *mutually_exclusive; /* --- Optional callbacks to override class functions --- */ ssize_t (*print_name)(struct extcon_dev *edev, char *buf); @@ -119,6 +128,10 @@ struct extcon_dev { /* /sys/class/extcon/.../cable.n/... */ struct device_type extcon_dev_type; struct extcon_cable *cables; + /* /sys/class/extcon/.../mutually_exclusive/... */ + struct attribute_group attr_g_muex; + struct attribute **attrs_muex; + struct device_attribute *d_attrs_muex; }; /** @@ -179,8 +192,8 @@ 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); +extern int extcon_set_state(struct extcon_dev *edev, u32 state); +extern int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state); /* * get/set_cable_state access each bit of the 32b encoded state value. @@ -235,11 +248,16 @@ static inline u32 extcon_get_state(struct extcon_dev *edev) return 0; } -static inline void extcon_set_state(struct extcon_dev *edev, u32 state) { } +static inline int extcon_set_state(struct extcon_dev *edev, u32 state) +{ + return 0; +} -static inline void extcon_update_state(struct extcon_dev *edev, u32 mask, +static inline int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) -{ } +{ + return 0; +} static inline int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name) -- cgit v1.2.3-58-ga151