diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-extcon | 22 | ||||
| -rw-r--r-- | drivers/extcon/extcon_class.c | 123 | ||||
| -rw-r--r-- | include/linux/extcon.h | 28 |
3 files changed, 160 insertions, 13 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon index 19b18e986a5..20ab361bd8c 100644 --- a/Documentation/ABI/testing/sysfs-class-extcon +++ b/Documentation/ABI/testing/sysfs-class-extcon @@ -15,6 +15,10 @@ Description: may have both HDMI and Charger attached, or analog audio, video, and USB cables attached simulteneously. + If there are cables mutually exclusive with each other, + such binary relations may be expressed with extcon_dev's + mutually_exclusive array. + What: /sys/class/extcon/.../name Date: February 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> @@ -73,3 +77,21 @@ Description: state of cable "x" (integer between 0 and 31) of an extcon device. The state value is either 0 (detached) or 1 (attached). + +What: /sys/class/extcon/.../mutually_exclusive/... +Date: December 2011 +Contact: MyungJoo Ham <myungjoo.ham@samsung.com> +Description: + Shows the relations of mutually exclusiveness. For example, + if the mutually_exclusive array of extcon_dev is + {0x3, 0x5, 0xC, 0x0}, the, the output is: + # ls mutually_exclusive/ + 0x3 + 0x5 + 0xc + # + + Note that mutually_exclusive is a sub-directory of the extcon + device and the file names under the mutually_exclusive + directory show the mutually-exclusive sets, not the contents + of the files. diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c index 403933bc3e9..3bc4b8af46c 100644 --- a/drivers/extcon/extcon_class.c +++ b/drivers/extcon/extcon_class.c @@ -72,6 +72,39 @@ static struct class_compat *switch_class; static LIST_HEAD(extcon_dev_list); static DEFINE_MUTEX(extcon_dev_list_lock); +/** + * check_mutually_exclusive - Check if new_state violates mutually_exclusive + * condition. + * @edev: the extcon device + * @new_state: new cable attach status for @edev + * + * Returns 0 if nothing violates. Returns the index + 1 for the first + * violated condition. + */ +static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state) +{ + int i = 0; + + if (!edev->mutually_exclusive) + return 0; + + for (i = 0; edev->mutually_exclusive[i]; i++) { + int count = 0, j; + u32 correspondants = new_state & edev->mutually_exclusive[i]; + u32 exp = 1; + + for (j = 0; j < 32; j++) { + if (exp & correspondants) + count++; + if (count > 1) + return i + 1; + exp <<= 1; + } + } + + return 0; +} + static ssize_t state_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -100,7 +133,7 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr, return count; } -void extcon_set_state(struct extcon_dev *edev, u32 state); +int extcon_set_state(struct extcon_dev *edev, u32 state); static ssize_t state_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -112,7 +145,7 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr, if (ret == 0) ret = -EINVAL; else - extcon_set_state(edev, state); + ret = extcon_set_state(edev, state); if (ret < 0) return ret; @@ -191,7 +224,7 @@ static ssize_t cable_state_store(struct device *dev, * Note that the notifier provides which bits are changed in the state * variable with the val parameter (second) to the callback. */ -void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) +int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) { char name_buf[120]; char state_buf[120]; @@ -206,6 +239,12 @@ void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) if (edev->state != ((edev->state & ~mask) | (state & mask))) { u32 old_state = edev->state; + if (check_mutually_exclusive(edev, (edev->state & ~mask) | + (state & mask))) { + spin_unlock_irqrestore(&edev->lock, flags); + return -EPERM; + } + edev->state &= ~mask; edev->state |= state & mask; @@ -247,6 +286,8 @@ void extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) /* No changes */ spin_unlock_irqrestore(&edev->lock, flags); } + + return 0; } EXPORT_SYMBOL_GPL(extcon_update_state); @@ -258,9 +299,9 @@ EXPORT_SYMBOL_GPL(extcon_update_state); * Note that notifier provides which bits are changed in the state * variable with the val parameter (second) to the callback. */ -void extcon_set_state(struct extcon_dev *edev, u32 state) +int extcon_set_state(struct extcon_dev *edev, u32 state) { - extcon_update_state(edev, 0xffffffff, state); + return extcon_update_state(edev, 0xffffffff, state); } EXPORT_SYMBOL_GPL(extcon_set_state); @@ -334,8 +375,7 @@ int extcon_set_cable_state_(struct extcon_dev *edev, return -EINVAL; state = cable_state ? (1 << index) : 0; - extcon_update_state(edev, 1 << index, state); - return 0; + return extcon_update_state(edev, 1 << index, state); } EXPORT_SYMBOL_GPL(extcon_set_cable_state_); @@ -511,6 +551,14 @@ static void extcon_cleanup(struct extcon_dev *edev, bool skip) if (!skip && get_device(edev->dev)) { int index; + if (edev->mutually_exclusive && edev->max_supported) { + for (index = 0; edev->mutually_exclusive[index]; + index++) + kfree(edev->d_attrs_muex[index].attr.name); + kfree(edev->d_attrs_muex); + kfree(edev->attrs_muex); + } + for (index = 0; index < edev->max_supported; index++) kfree(edev->cables[index].attr_g.name); @@ -533,6 +581,7 @@ static void extcon_dev_release(struct device *dev) extcon_cleanup(edev, true); } +static const char *muex_name = "mutually_exclusive"; static void dummy_sysfs_dev_release(struct device *dev) { } @@ -625,10 +674,58 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev) } } + if (edev->max_supported && edev->mutually_exclusive) { + char buf[80]; + char *name; + + /* Count the size of mutually_exclusive array */ + for (index = 0; edev->mutually_exclusive[index]; index++) + ; + + edev->attrs_muex = kzalloc(sizeof(struct attribute *) * + (index + 1), GFP_KERNEL); + if (!edev->attrs_muex) { + ret = -ENOMEM; + goto err_muex; + } + + edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) * + index, GFP_KERNEL); + if (!edev->d_attrs_muex) { + ret = -ENOMEM; + kfree(edev->attrs_muex); + goto err_muex; + } + + for (index = 0; edev->mutually_exclusive[index]; index++) { + sprintf(buf, "0x%x", edev->mutually_exclusive[index]); + name = kzalloc(sizeof(char) * (strlen(buf) + 1), + GFP_KERNEL); + if (!name) { + for (index--; index >= 0; index--) { + kfree(edev->d_attrs_muex[index].attr. + name); + } + kfree(edev->d_attrs_muex); + kfree(edev->attrs_muex); + ret = -ENOMEM; + goto err_muex; + } + strcpy(name, buf); + edev->d_attrs_muex[index].attr.name = name; + edev->d_attrs_muex[index].attr.mode = 0000; + edev->attrs_muex[index] = &edev->d_attrs_muex[index] + .attr; + } + edev->attr_g_muex.name = muex_name; + edev->attr_g_muex.attrs = edev->attrs_muex; + + } + if (edev->max_supported) { edev->extcon_dev_type.groups = kzalloc(sizeof(struct attribute_group *) * - (edev->max_supported + 1), GFP_KERNEL); + (edev->max_supported + 2), GFP_KERNEL); if (!edev->extcon_dev_type.groups) { ret = -ENOMEM; goto err_alloc_groups; @@ -640,6 +737,9 @@ int extcon_dev_register(struct extcon_dev *edev, struct device *dev) for (index = 0; index < edev->max_supported; index++) edev->extcon_dev_type.groups[index] = &edev->cables[index].attr_g; + if (edev->mutually_exclusive) + edev->extcon_dev_type.groups[index] = + &edev->attr_g_muex; edev->dev->type = &edev->extcon_dev_type; } @@ -672,6 +772,13 @@ err_dev: if (edev->max_supported) kfree(edev->extcon_dev_type.groups); err_alloc_groups: + if (edev->max_supported && edev->mutually_exclusive) { + for (index = 0; edev->mutually_exclusive[index]; index++) + kfree(edev->d_attrs_muex[index].attr.name); + kfree(edev->d_attrs_muex); + kfree(edev->attrs_muex); + } +err_muex: for (index = 0; index < edev->max_supported; index++) kfree(edev->cables[index].attr_g.name); err_alloc_cables: diff --git a/include/linux/extcon.h b/include/linux/extcon.h index 20e24b32a17..6495f773140 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) |