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authorMyungJoo Ham <myungjoo.ham@samsung.com>2012-04-20 09:16:26 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-04-20 20:24:03 +0400
commitbde68e60b18208978c50c6fb9bdf29826d2887f3 (patch)
tree62b48807d48c2454c374bede680c9e9c6cf71a0d /include/linux/extcon.h
parent806d9dd71ff52ef09764585baaeec23afbb98560 (diff)
downloadlinux-bde68e60b18208978c50c6fb9bdf29826d2887f3.tar.xz
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 <neilb@suse.de> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> -- Changes from V5: - Updated sysfs format Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/extcon.h')
-rw-r--r--include/linux/extcon.h28
1 files changed, 23 insertions, 5 deletions
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)