| Message ID | 20241211-power-supply-extensions-v6-1-9d9dc3f3d387@weissschuh.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | power: supply: extension API | expand |
Am 11.12.24 um 20:57 schrieb Thomas Weißschuh: > Various drivers, mostly in platform/x86 extend the ACPI battery driver > with additional sysfs attributes to implement more UAPIs than are > exposed through ACPI by using various side-channels, like WMI, > nonstandard ACPI or EC communication. > > While the created sysfs attributes look similar to the attributes > provided by the powersupply core, there are various deficiencies: > > * They don't show up in uevent payload. > * They can't be queried with the standard in-kernel APIs. > * They don't work with triggers. > * The extending driver has to reimplement all of the parsing, > formatting and sysfs display logic. > * Writing a extension driver is completely different from writing a > normal power supply driver. > > This extension API avoids all of these issues. > An extension is just a "struct power_supply_ext" with the same kind of > callbacks as in a normal "struct power_supply_desc". > > The API is meant to be used via battery_hook_register(), the same way as > the current extensions. Reviewed-by: Armin Wolf <W_Armin@gmx.de> > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > --- > drivers/power/supply/power_supply.h | 17 ++++ > drivers/power/supply/power_supply_core.c | 162 ++++++++++++++++++++++++++++-- > drivers/power/supply/power_supply_sysfs.c | 26 ++++- > include/linux/power_supply.h | 33 ++++++ > 4 files changed, 228 insertions(+), 10 deletions(-) > > diff --git a/drivers/power/supply/power_supply.h b/drivers/power/supply/power_supply.h > index 5dabbd895538003096b62d03fdd0201b82b090e6..531785516d2ac31f9a7f73a58e15e64cb81820ed 100644 > --- a/drivers/power/supply/power_supply.h > +++ b/drivers/power/supply/power_supply.h > @@ -9,6 +9,8 @@ > * Modified: 2004, Oct Szabolcs Gyurko > */ > > +#include <linux/lockdep.h> > + > struct device; > struct device_type; > struct power_supply; > @@ -17,6 +19,21 @@ extern int power_supply_property_is_writeable(struct power_supply *psy, > enum power_supply_property psp); > extern bool power_supply_has_property(struct power_supply *psy, > enum power_supply_property psp); > +extern bool power_supply_ext_has_property(const struct power_supply_ext *ext, > + enum power_supply_property psp); > + > +struct power_supply_ext_registration { > + struct list_head list_head; > + const struct power_supply_ext *ext; > + void *data; > +}; > + > +/* Make sure that the macro is a single expression */ > +#define power_supply_for_each_extension(pos, psy) \ > + if ( ({ lockdep_assert_held(&(psy)->extensions_sem); 0; }) ) \ > + ; \ > + else \ > + list_for_each_entry(pos, &(psy)->extensions, list_head) \ > > #ifdef CONFIG_SYSFS > > diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c > index 502b07468b93dfb7f5a6c2092588d931a7d015f2..bc22edbd0e6a02c27500132075f5c98d814a7330 100644 > --- a/drivers/power/supply/power_supply_core.c > +++ b/drivers/power/supply/power_supply_core.c > @@ -81,6 +81,7 @@ static int __power_supply_changed_work(struct device *dev, void *data) > > static void power_supply_changed_work(struct work_struct *work) > { > + int ret; > unsigned long flags; > struct power_supply *psy = container_of(work, struct power_supply, > changed_work); > @@ -88,6 +89,16 @@ static void power_supply_changed_work(struct work_struct *work) > dev_dbg(&psy->dev, "%s\n", __func__); > > spin_lock_irqsave(&psy->changed_lock, flags); > + > + if (unlikely(psy->update_groups)) { > + psy->update_groups = false; > + spin_unlock_irqrestore(&psy->changed_lock, flags); > + ret = sysfs_update_groups(&psy->dev.kobj, power_supply_dev_type.groups); > + if (ret) > + dev_warn(&psy->dev, "failed to update sysfs groups: %pe\n", ERR_PTR(ret)); > + spin_lock_irqsave(&psy->changed_lock, flags); > + } > + > /* > * Check 'changed' here to avoid issues due to race between > * power_supply_changed() and this routine. In worst case > @@ -1196,15 +1207,34 @@ static bool psy_desc_has_property(const struct power_supply_desc *psy_desc, > return found; > } > > +bool power_supply_ext_has_property(const struct power_supply_ext *psy_ext, > + enum power_supply_property psp) > +{ > + int i; > + > + for (i = 0; i < psy_ext->num_properties; i++) > + if (psy_ext->properties[i] == psp) > + return true; > + > + return false; > +} > + > bool power_supply_has_property(struct power_supply *psy, > enum power_supply_property psp) > { > + struct power_supply_ext_registration *reg; > + > if (psy_desc_has_property(psy->desc, psp)) > return true; > > if (power_supply_battery_info_has_prop(psy->battery_info, psp)) > return true; > > + power_supply_for_each_extension(reg, psy) { > + if (power_supply_ext_has_property(reg->ext, psp)) > + return true; > + } > + > return false; > } > > @@ -1212,12 +1242,21 @@ int power_supply_get_property(struct power_supply *psy, > enum power_supply_property psp, > union power_supply_propval *val) > { > + struct power_supply_ext_registration *reg; > + > if (atomic_read(&psy->use_cnt) <= 0) { > if (!psy->initialized) > return -EAGAIN; > return -ENODEV; > } > > + scoped_guard(rwsem_read, &psy->extensions_sem) { > + power_supply_for_each_extension(reg, psy) { > + if (power_supply_ext_has_property(reg->ext, psp)) > + return reg->ext->get_property(psy, reg->ext, reg->data, psp, val); > + } > + } > + > if (psy_desc_has_property(psy->desc, psp)) > return psy->desc->get_property(psy, psp, val); > else if (power_supply_battery_info_has_prop(psy->battery_info, psp)) > @@ -1231,7 +1270,24 @@ int power_supply_set_property(struct power_supply *psy, > enum power_supply_property psp, > const union power_supply_propval *val) > { > - if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->set_property) > + struct power_supply_ext_registration *reg; > + > + if (atomic_read(&psy->use_cnt) <= 0) > + return -ENODEV; > + > + scoped_guard(rwsem_read, &psy->extensions_sem) { > + power_supply_for_each_extension(reg, psy) { > + if (power_supply_ext_has_property(reg->ext, psp)) { > + if (reg->ext->set_property) > + return reg->ext->set_property(psy, reg->ext, reg->data, > + psp, val); > + else > + return -ENODEV; > + } > + } > + } > + > + if (!psy->desc->set_property) > return -ENODEV; > > return psy->desc->set_property(psy, psp, val); > @@ -1241,7 +1297,22 @@ EXPORT_SYMBOL_GPL(power_supply_set_property); > int power_supply_property_is_writeable(struct power_supply *psy, > enum power_supply_property psp) > { > - return psy->desc->property_is_writeable && psy->desc->property_is_writeable(psy, psp); > + struct power_supply_ext_registration *reg; > + > + power_supply_for_each_extension(reg, psy) { > + if (power_supply_ext_has_property(reg->ext, psp)) { > + if (reg->ext->property_is_writeable) > + return reg->ext->property_is_writeable(psy, reg->ext, > + reg->data, psp); > + else > + return 0; > + } > + } > + > + if (!psy->desc->property_is_writeable) > + return 0; > + > + return psy->desc->property_is_writeable(psy, psp); > } > > void power_supply_external_power_changed(struct power_supply *psy) > @@ -1260,6 +1331,76 @@ int power_supply_powers(struct power_supply *psy, struct device *dev) > } > EXPORT_SYMBOL_GPL(power_supply_powers); > > +static int power_supply_update_sysfs_and_hwmon(struct power_supply *psy) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&psy->changed_lock, flags); > + psy->update_groups = true; > + spin_unlock_irqrestore(&psy->changed_lock, flags); > + > + power_supply_changed(psy); > + > + power_supply_remove_hwmon_sysfs(psy); > + return power_supply_add_hwmon_sysfs(psy); > +} > + > +int power_supply_register_extension(struct power_supply *psy, const struct power_supply_ext *ext, > + void *data) > +{ > + struct power_supply_ext_registration *reg; > + size_t i; > + int ret; > + > + if (!psy || !ext || !ext->properties || !ext->num_properties) > + return -EINVAL; > + > + guard(rwsem_write)(&psy->extensions_sem); > + > + for (i = 0; i < ext->num_properties; i++) > + if (power_supply_has_property(psy, ext->properties[i])) > + return -EEXIST; > + > + reg = kmalloc(sizeof(*reg), GFP_KERNEL); > + if (!reg) > + return -ENOMEM; > + > + reg->ext = ext; > + reg->data = data; > + list_add(®->list_head, &psy->extensions); > + > + ret = power_supply_update_sysfs_and_hwmon(psy); > + if (ret) > + goto sysfs_hwmon_failed; > + > + return 0; > + > +sysfs_hwmon_failed: > + list_del(®->list_head); > + kfree(reg); > + return ret; > +} > +EXPORT_SYMBOL_GPL(power_supply_register_extension); > + > +void power_supply_unregister_extension(struct power_supply *psy, const struct power_supply_ext *ext) > +{ > + struct power_supply_ext_registration *reg; > + > + guard(rwsem_write)(&psy->extensions_sem); > + > + power_supply_for_each_extension(reg, psy) { > + if (reg->ext == ext) { > + list_del(®->list_head); > + kfree(reg); > + power_supply_update_sysfs_and_hwmon(psy); > + return; > + } > + } > + > + dev_warn(&psy->dev, "Trying to unregister invalid extension"); > +} > +EXPORT_SYMBOL_GPL(power_supply_unregister_extension); > + > static void power_supply_dev_release(struct device *dev) > { > struct power_supply *psy = to_power_supply(dev); > @@ -1414,6 +1555,9 @@ __power_supply_register(struct device *parent, > } > > spin_lock_init(&psy->changed_lock); > + init_rwsem(&psy->extensions_sem); > + INIT_LIST_HEAD(&psy->extensions); > + > rc = device_add(dev); > if (rc) > goto device_add_failed; > @@ -1426,13 +1570,15 @@ __power_supply_register(struct device *parent, > if (rc) > goto register_thermal_failed; > > - rc = power_supply_create_triggers(psy); > - if (rc) > - goto create_triggers_failed; > + scoped_guard(rwsem_read, &psy->extensions_sem) { > + rc = power_supply_create_triggers(psy); > + if (rc) > + goto create_triggers_failed; > > - rc = power_supply_add_hwmon_sysfs(psy); > - if (rc) > - goto add_hwmon_sysfs_failed; > + rc = power_supply_add_hwmon_sysfs(psy); > + if (rc) > + goto add_hwmon_sysfs_failed; > + } > > /* > * Update use_cnt after any uevents (most notably from device_add()). > diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c > index 99bfe1f03eb8326d38c4e2831c9670313b42e425..927ddb9d83bb7259809ba695cb9398d1ad654b46 100644 > --- a/drivers/power/supply/power_supply_sysfs.c > +++ b/drivers/power/supply/power_supply_sysfs.c > @@ -268,6 +268,27 @@ static ssize_t power_supply_show_enum_with_available( > return count; > } > > +static ssize_t power_supply_show_charge_behaviour(struct device *dev, > + struct power_supply *psy, > + union power_supply_propval *value, > + char *buf) > +{ > + struct power_supply_ext_registration *reg; > + > + scoped_guard(rwsem_read, &psy->extensions_sem) { > + power_supply_for_each_extension(reg, psy) { > + if (power_supply_ext_has_property(reg->ext, > + POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR)) > + return power_supply_charge_behaviour_show(dev, > + reg->ext->charge_behaviours, > + value->intval, buf); > + } > + } > + > + return power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours, > + value->intval, buf); > +} > + > static ssize_t power_supply_format_property(struct device *dev, > bool uevent, > struct device_attribute *attr, > @@ -307,8 +328,7 @@ static ssize_t power_supply_format_property(struct device *dev, > case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR: > if (uevent) /* no possible values in uevents */ > goto default_format; > - ret = power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours, > - value.intval, buf); > + ret = power_supply_show_charge_behaviour(dev, psy, &value, buf); > break; > case POWER_SUPPLY_PROP_MODEL_NAME ... POWER_SUPPLY_PROP_SERIAL_NUMBER: > ret = sysfs_emit(buf, "%s\n", value.strval); > @@ -385,6 +405,8 @@ static umode_t power_supply_attr_is_visible(struct kobject *kobj, > if (attrno == POWER_SUPPLY_PROP_TYPE) > return mode; > > + guard(rwsem_read)(&psy->extensions_sem); > + > if (power_supply_has_property(psy, attrno)) { > if (power_supply_property_is_writeable(psy, attrno) > 0) > mode |= S_IWUSR; > diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h > index b98106e1a90f34bce5129317a099f363248342b9..e434516086f032cdb4698005bb1a99eda303a307 100644 > --- a/include/linux/power_supply.h > +++ b/include/linux/power_supply.h > @@ -15,6 +15,8 @@ > #include <linux/device.h> > #include <linux/workqueue.h> > #include <linux/leds.h> > +#include <linux/rwsem.h> > +#include <linux/list.h> > #include <linux/spinlock.h> > #include <linux/notifier.h> > > @@ -281,6 +283,27 @@ struct power_supply_desc { > int use_for_apm; > }; > > +struct power_supply_ext { > + u8 charge_behaviours; > + const enum power_supply_property *properties; > + size_t num_properties; > + > + int (*get_property)(struct power_supply *psy, > + const struct power_supply_ext *ext, > + void *data, > + enum power_supply_property psp, > + union power_supply_propval *val); > + int (*set_property)(struct power_supply *psy, > + const struct power_supply_ext *ext, > + void *data, > + enum power_supply_property psp, > + const union power_supply_propval *val); > + int (*property_is_writeable)(struct power_supply *psy, > + const struct power_supply_ext *ext, > + void *data, > + enum power_supply_property psp); > +}; > + > struct power_supply { > const struct power_supply_desc *desc; > > @@ -300,10 +323,13 @@ struct power_supply { > struct delayed_work deferred_register_work; > spinlock_t changed_lock; > bool changed; > + bool update_groups; > bool initialized; > bool removing; > atomic_t use_cnt; > struct power_supply_battery_info *battery_info; > + struct rw_semaphore extensions_sem; /* protects "extensions" */ > + struct list_head extensions; > #ifdef CONFIG_THERMAL > struct thermal_zone_device *tzd; > struct thermal_cooling_device *tcd; > @@ -878,6 +904,13 @@ devm_power_supply_register(struct device *parent, > extern void power_supply_unregister(struct power_supply *psy); > extern int power_supply_powers(struct power_supply *psy, struct device *dev); > > +extern int __must_check > +power_supply_register_extension(struct power_supply *psy, > + const struct power_supply_ext *ext, > + void *data); > +extern void power_supply_unregister_extension(struct power_supply *psy, > + const struct power_supply_ext *ext); > + > #define to_power_supply(device) container_of(device, struct power_supply, dev) > > extern void *power_supply_get_drvdata(struct power_supply *psy); >
diff --git a/drivers/power/supply/power_supply.h b/drivers/power/supply/power_supply.h index 5dabbd895538003096b62d03fdd0201b82b090e6..531785516d2ac31f9a7f73a58e15e64cb81820ed 100644 --- a/drivers/power/supply/power_supply.h +++ b/drivers/power/supply/power_supply.h @@ -9,6 +9,8 @@ * Modified: 2004, Oct Szabolcs Gyurko */ +#include <linux/lockdep.h> + struct device; struct device_type; struct power_supply; @@ -17,6 +19,21 @@ extern int power_supply_property_is_writeable(struct power_supply *psy, enum power_supply_property psp); extern bool power_supply_has_property(struct power_supply *psy, enum power_supply_property psp); +extern bool power_supply_ext_has_property(const struct power_supply_ext *ext, + enum power_supply_property psp); + +struct power_supply_ext_registration { + struct list_head list_head; + const struct power_supply_ext *ext; + void *data; +}; + +/* Make sure that the macro is a single expression */ +#define power_supply_for_each_extension(pos, psy) \ + if ( ({ lockdep_assert_held(&(psy)->extensions_sem); 0; }) ) \ + ; \ + else \ + list_for_each_entry(pos, &(psy)->extensions, list_head) \ #ifdef CONFIG_SYSFS diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 502b07468b93dfb7f5a6c2092588d931a7d015f2..bc22edbd0e6a02c27500132075f5c98d814a7330 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -81,6 +81,7 @@ static int __power_supply_changed_work(struct device *dev, void *data) static void power_supply_changed_work(struct work_struct *work) { + int ret; unsigned long flags; struct power_supply *psy = container_of(work, struct power_supply, changed_work); @@ -88,6 +89,16 @@ static void power_supply_changed_work(struct work_struct *work) dev_dbg(&psy->dev, "%s\n", __func__); spin_lock_irqsave(&psy->changed_lock, flags); + + if (unlikely(psy->update_groups)) { + psy->update_groups = false; + spin_unlock_irqrestore(&psy->changed_lock, flags); + ret = sysfs_update_groups(&psy->dev.kobj, power_supply_dev_type.groups); + if (ret) + dev_warn(&psy->dev, "failed to update sysfs groups: %pe\n", ERR_PTR(ret)); + spin_lock_irqsave(&psy->changed_lock, flags); + } + /* * Check 'changed' here to avoid issues due to race between * power_supply_changed() and this routine. In worst case @@ -1196,15 +1207,34 @@ static bool psy_desc_has_property(const struct power_supply_desc *psy_desc, return found; } +bool power_supply_ext_has_property(const struct power_supply_ext *psy_ext, + enum power_supply_property psp) +{ + int i; + + for (i = 0; i < psy_ext->num_properties; i++) + if (psy_ext->properties[i] == psp) + return true; + + return false; +} + bool power_supply_has_property(struct power_supply *psy, enum power_supply_property psp) { + struct power_supply_ext_registration *reg; + if (psy_desc_has_property(psy->desc, psp)) return true; if (power_supply_battery_info_has_prop(psy->battery_info, psp)) return true; + power_supply_for_each_extension(reg, psy) { + if (power_supply_ext_has_property(reg->ext, psp)) + return true; + } + return false; } @@ -1212,12 +1242,21 @@ int power_supply_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { + struct power_supply_ext_registration *reg; + if (atomic_read(&psy->use_cnt) <= 0) { if (!psy->initialized) return -EAGAIN; return -ENODEV; } + scoped_guard(rwsem_read, &psy->extensions_sem) { + power_supply_for_each_extension(reg, psy) { + if (power_supply_ext_has_property(reg->ext, psp)) + return reg->ext->get_property(psy, reg->ext, reg->data, psp, val); + } + } + if (psy_desc_has_property(psy->desc, psp)) return psy->desc->get_property(psy, psp, val); else if (power_supply_battery_info_has_prop(psy->battery_info, psp)) @@ -1231,7 +1270,24 @@ int power_supply_set_property(struct power_supply *psy, enum power_supply_property psp, const union power_supply_propval *val) { - if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->set_property) + struct power_supply_ext_registration *reg; + + if (atomic_read(&psy->use_cnt) <= 0) + return -ENODEV; + + scoped_guard(rwsem_read, &psy->extensions_sem) { + power_supply_for_each_extension(reg, psy) { + if (power_supply_ext_has_property(reg->ext, psp)) { + if (reg->ext->set_property) + return reg->ext->set_property(psy, reg->ext, reg->data, + psp, val); + else + return -ENODEV; + } + } + } + + if (!psy->desc->set_property) return -ENODEV; return psy->desc->set_property(psy, psp, val); @@ -1241,7 +1297,22 @@ EXPORT_SYMBOL_GPL(power_supply_set_property); int power_supply_property_is_writeable(struct power_supply *psy, enum power_supply_property psp) { - return psy->desc->property_is_writeable && psy->desc->property_is_writeable(psy, psp); + struct power_supply_ext_registration *reg; + + power_supply_for_each_extension(reg, psy) { + if (power_supply_ext_has_property(reg->ext, psp)) { + if (reg->ext->property_is_writeable) + return reg->ext->property_is_writeable(psy, reg->ext, + reg->data, psp); + else + return 0; + } + } + + if (!psy->desc->property_is_writeable) + return 0; + + return psy->desc->property_is_writeable(psy, psp); } void power_supply_external_power_changed(struct power_supply *psy) @@ -1260,6 +1331,76 @@ int power_supply_powers(struct power_supply *psy, struct device *dev) } EXPORT_SYMBOL_GPL(power_supply_powers); +static int power_supply_update_sysfs_and_hwmon(struct power_supply *psy) +{ + unsigned long flags; + + spin_lock_irqsave(&psy->changed_lock, flags); + psy->update_groups = true; + spin_unlock_irqrestore(&psy->changed_lock, flags); + + power_supply_changed(psy); + + power_supply_remove_hwmon_sysfs(psy); + return power_supply_add_hwmon_sysfs(psy); +} + +int power_supply_register_extension(struct power_supply *psy, const struct power_supply_ext *ext, + void *data) +{ + struct power_supply_ext_registration *reg; + size_t i; + int ret; + + if (!psy || !ext || !ext->properties || !ext->num_properties) + return -EINVAL; + + guard(rwsem_write)(&psy->extensions_sem); + + for (i = 0; i < ext->num_properties; i++) + if (power_supply_has_property(psy, ext->properties[i])) + return -EEXIST; + + reg = kmalloc(sizeof(*reg), GFP_KERNEL); + if (!reg) + return -ENOMEM; + + reg->ext = ext; + reg->data = data; + list_add(®->list_head, &psy->extensions); + + ret = power_supply_update_sysfs_and_hwmon(psy); + if (ret) + goto sysfs_hwmon_failed; + + return 0; + +sysfs_hwmon_failed: + list_del(®->list_head); + kfree(reg); + return ret; +} +EXPORT_SYMBOL_GPL(power_supply_register_extension); + +void power_supply_unregister_extension(struct power_supply *psy, const struct power_supply_ext *ext) +{ + struct power_supply_ext_registration *reg; + + guard(rwsem_write)(&psy->extensions_sem); + + power_supply_for_each_extension(reg, psy) { + if (reg->ext == ext) { + list_del(®->list_head); + kfree(reg); + power_supply_update_sysfs_and_hwmon(psy); + return; + } + } + + dev_warn(&psy->dev, "Trying to unregister invalid extension"); +} +EXPORT_SYMBOL_GPL(power_supply_unregister_extension); + static void power_supply_dev_release(struct device *dev) { struct power_supply *psy = to_power_supply(dev); @@ -1414,6 +1555,9 @@ __power_supply_register(struct device *parent, } spin_lock_init(&psy->changed_lock); + init_rwsem(&psy->extensions_sem); + INIT_LIST_HEAD(&psy->extensions); + rc = device_add(dev); if (rc) goto device_add_failed; @@ -1426,13 +1570,15 @@ __power_supply_register(struct device *parent, if (rc) goto register_thermal_failed; - rc = power_supply_create_triggers(psy); - if (rc) - goto create_triggers_failed; + scoped_guard(rwsem_read, &psy->extensions_sem) { + rc = power_supply_create_triggers(psy); + if (rc) + goto create_triggers_failed; - rc = power_supply_add_hwmon_sysfs(psy); - if (rc) - goto add_hwmon_sysfs_failed; + rc = power_supply_add_hwmon_sysfs(psy); + if (rc) + goto add_hwmon_sysfs_failed; + } /* * Update use_cnt after any uevents (most notably from device_add()). diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c index 99bfe1f03eb8326d38c4e2831c9670313b42e425..927ddb9d83bb7259809ba695cb9398d1ad654b46 100644 --- a/drivers/power/supply/power_supply_sysfs.c +++ b/drivers/power/supply/power_supply_sysfs.c @@ -268,6 +268,27 @@ static ssize_t power_supply_show_enum_with_available( return count; } +static ssize_t power_supply_show_charge_behaviour(struct device *dev, + struct power_supply *psy, + union power_supply_propval *value, + char *buf) +{ + struct power_supply_ext_registration *reg; + + scoped_guard(rwsem_read, &psy->extensions_sem) { + power_supply_for_each_extension(reg, psy) { + if (power_supply_ext_has_property(reg->ext, + POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR)) + return power_supply_charge_behaviour_show(dev, + reg->ext->charge_behaviours, + value->intval, buf); + } + } + + return power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours, + value->intval, buf); +} + static ssize_t power_supply_format_property(struct device *dev, bool uevent, struct device_attribute *attr, @@ -307,8 +328,7 @@ static ssize_t power_supply_format_property(struct device *dev, case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR: if (uevent) /* no possible values in uevents */ goto default_format; - ret = power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours, - value.intval, buf); + ret = power_supply_show_charge_behaviour(dev, psy, &value, buf); break; case POWER_SUPPLY_PROP_MODEL_NAME ... POWER_SUPPLY_PROP_SERIAL_NUMBER: ret = sysfs_emit(buf, "%s\n", value.strval); @@ -385,6 +405,8 @@ static umode_t power_supply_attr_is_visible(struct kobject *kobj, if (attrno == POWER_SUPPLY_PROP_TYPE) return mode; + guard(rwsem_read)(&psy->extensions_sem); + if (power_supply_has_property(psy, attrno)) { if (power_supply_property_is_writeable(psy, attrno) > 0) mode |= S_IWUSR; diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index b98106e1a90f34bce5129317a099f363248342b9..e434516086f032cdb4698005bb1a99eda303a307 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -15,6 +15,8 @@ #include <linux/device.h> #include <linux/workqueue.h> #include <linux/leds.h> +#include <linux/rwsem.h> +#include <linux/list.h> #include <linux/spinlock.h> #include <linux/notifier.h> @@ -281,6 +283,27 @@ struct power_supply_desc { int use_for_apm; }; +struct power_supply_ext { + u8 charge_behaviours; + const enum power_supply_property *properties; + size_t num_properties; + + int (*get_property)(struct power_supply *psy, + const struct power_supply_ext *ext, + void *data, + enum power_supply_property psp, + union power_supply_propval *val); + int (*set_property)(struct power_supply *psy, + const struct power_supply_ext *ext, + void *data, + enum power_supply_property psp, + const union power_supply_propval *val); + int (*property_is_writeable)(struct power_supply *psy, + const struct power_supply_ext *ext, + void *data, + enum power_supply_property psp); +}; + struct power_supply { const struct power_supply_desc *desc; @@ -300,10 +323,13 @@ struct power_supply { struct delayed_work deferred_register_work; spinlock_t changed_lock; bool changed; + bool update_groups; bool initialized; bool removing; atomic_t use_cnt; struct power_supply_battery_info *battery_info; + struct rw_semaphore extensions_sem; /* protects "extensions" */ + struct list_head extensions; #ifdef CONFIG_THERMAL struct thermal_zone_device *tzd; struct thermal_cooling_device *tcd; @@ -878,6 +904,13 @@ devm_power_supply_register(struct device *parent, extern void power_supply_unregister(struct power_supply *psy); extern int power_supply_powers(struct power_supply *psy, struct device *dev); +extern int __must_check +power_supply_register_extension(struct power_supply *psy, + const struct power_supply_ext *ext, + void *data); +extern void power_supply_unregister_extension(struct power_supply *psy, + const struct power_supply_ext *ext); + #define to_power_supply(device) container_of(device, struct power_supply, dev) extern void *power_supply_get_drvdata(struct power_supply *psy);
Various drivers, mostly in platform/x86 extend the ACPI battery driver with additional sysfs attributes to implement more UAPIs than are exposed through ACPI by using various side-channels, like WMI, nonstandard ACPI or EC communication. While the created sysfs attributes look similar to the attributes provided by the powersupply core, there are various deficiencies: * They don't show up in uevent payload. * They can't be queried with the standard in-kernel APIs. * They don't work with triggers. * The extending driver has to reimplement all of the parsing, formatting and sysfs display logic. * Writing a extension driver is completely different from writing a normal power supply driver. This extension API avoids all of these issues. An extension is just a "struct power_supply_ext" with the same kind of callbacks as in a normal "struct power_supply_desc". The API is meant to be used via battery_hook_register(), the same way as the current extensions. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- drivers/power/supply/power_supply.h | 17 ++++ drivers/power/supply/power_supply_core.c | 162 ++++++++++++++++++++++++++++-- drivers/power/supply/power_supply_sysfs.c | 26 ++++- include/linux/power_supply.h | 33 ++++++ 4 files changed, 228 insertions(+), 10 deletions(-)