lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Extcon: support mutually exclusive relation between cables.

Browse Source 
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>
This commit is contained in:
MyungJoo Ham
2012-04-20 14:16:26 +09:00
committed by Greg Kroah-Hartman
parent 806d9dd71f
commit bde68e60b1
3 changed files with 160 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
include/linux/extcon.h
View File

@ -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)