| Message ID | 20200605173335.13753-8-andrzej.p@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/7] Input: add input_device_enabled() | expand |
Hi, On 6/5/20 7:33 PM, Andrzej Pietrasiewicz wrote: > From: Patrik Fimml <patrikf@chromium.org> > > Userspace might want to implement a policy to temporarily disregard input > from certain devices, including not treating them as wakeup sources. > > An example use case is a laptop, whose keyboard can be folded under the > screen to create tablet-like experience. The user then must hold the laptop > in such a way that it is difficult to avoid pressing the keyboard keys. It > is therefore desirable to temporarily disregard input from the keyboard, > until it is folded back. This obviously is a policy which should be kept > out of the kernel, but the kernel must provide suitable means to implement > such a policy. > > This patch adds a sysfs interface for exactly this purpose. > > To implement the said interface it adds an "inhibited" property to struct > input_dev, and effectively creates four states a device can be in: closed > uninhibited, closed inhibited, open uninhibited, open inhibited. It also > defers calling driver's ->open() and ->close() to until they are actually > needed, e.g. it makes no sense to prepare the underlying device for > generating events (->open()) if the device is inhibited. > > uninhibit > closed <------------ closed > uninhibited ------------> inhibited > | ^ inhibit | ^ > 1st | | 1st | | > open | | open | | > | | | | > | | last | | last > | | close | | close > v | uninhibit v | > open <------------ open > uninhibited ------------> inhibited > > The top inhibit/uninhibit transition happens when users == 0. > The bottom inhibit/uninhibit transition happens when users > 0. > The left open/close transition happens when !inhibited. > The right open/close transition happens when inhibited. > Due to all transitions being serialized with dev->mutex, it is impossible > to have "diagonal" transitions between closed uninhibited and open > inhibited or between open uninhibited and closed inhibited. > > No new callbacks are added to drivers, because their open() and close() > serve exactly the purpose to tell the driver to start/stop providing > events to the input core. Consequently, open() and close() - if provided > - are called in both inhibit and uninhibit paths. > > Signed-off-by: Patrik Fimml <patrikf@chromium.org> > Co-developed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> > Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> > --- > drivers/input/input.c | 115 +++++++++++++++++++++++++++++++++++++++--- > include/linux/input.h | 12 ++++- > 2 files changed, 118 insertions(+), 9 deletions(-) > > diff --git a/drivers/input/input.c b/drivers/input/input.c > index 41377bfa142d..4110b5797219 100644 > --- a/drivers/input/input.c > +++ b/drivers/input/input.c > @@ -284,8 +284,11 @@ static int input_get_disposition(struct input_dev *dev, > case EV_KEY: > if (is_event_supported(code, dev->keybit, KEY_MAX)) { > > - /* auto-repeat bypasses state updates */ > - if (value == 2) { > + /* > + * auto-repeat bypasses state updates but repeat > + * events are ignored if the key is not pressed > + */ > + if (value == 2 && test_bit(code, dev->key)) { > disposition = INPUT_PASS_TO_HANDLERS; > break; > } > @@ -367,8 +370,13 @@ static int input_get_disposition(struct input_dev *dev, > static void input_handle_event(struct input_dev *dev, > unsigned int type, unsigned int code, int value) > { > - int disposition = input_get_disposition(dev, type, code, &value); > + int disposition; > + > + /* filter-out events from inhibited devices */ > + if (dev->inhibited) > + return; > > + disposition = input_get_disposition(dev, type, code, &value); > if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN) > add_input_randomness(type, code, value); > > @@ -612,7 +620,7 @@ int input_open_device(struct input_handle *handle) > > handle->open++; > > - if (dev->users++) { > + if (dev->users++ || dev->inhibited) { > /* > * Device is already opened, so we can exit immediately and > * report success. It seems the comment which is part of the context here may need some updating because of the inhibit changes ? Otherwise this patch and the rest of the series looks good to me now. Thank you very much for your work on this. Regards, Hans > @@ -675,10 +683,9 @@ void input_close_device(struct input_handle *handle) > > __input_release_device(handle); > > - if (!--dev->users) { > + if (!dev->inhibited && !--dev->users) { > if (dev->poller) > input_dev_poller_stop(dev->poller); > - > if (dev->close) > dev->close(dev); > } > @@ -1416,12 +1423,49 @@ static ssize_t input_dev_show_properties(struct device *dev, > } > static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL); > > +static int input_inhibit_device(struct input_dev *dev); > +static int input_uninhibit_device(struct input_dev *dev); > + > +static ssize_t inhibited_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct input_dev *input_dev = to_input_dev(dev); > + > + return scnprintf(buf, PAGE_SIZE, "%d\n", input_dev->inhibited); > +} > + > +static ssize_t inhibited_store(struct device *dev, > + struct device_attribute *attr, const char *buf, > + size_t len) > +{ > + struct input_dev *input_dev = to_input_dev(dev); > + ssize_t rv; > + bool inhibited; > + > + if (strtobool(buf, &inhibited)) > + return -EINVAL; > + > + if (inhibited) > + rv = input_inhibit_device(input_dev); > + else > + rv = input_uninhibit_device(input_dev); > + > + if (rv != 0) > + return rv; > + > + return len; > +} > + > +static DEVICE_ATTR_RW(inhibited); > + > static struct attribute *input_dev_attrs[] = { > &dev_attr_name.attr, > &dev_attr_phys.attr, > &dev_attr_uniq.attr, > &dev_attr_modalias.attr, > &dev_attr_properties.attr, > + &dev_attr_inhibited.attr, > NULL > }; > > @@ -1703,6 +1747,63 @@ void input_reset_device(struct input_dev *dev) > } > EXPORT_SYMBOL(input_reset_device); > > +static int input_inhibit_device(struct input_dev *dev) > +{ > + int ret = 0; > + > + mutex_lock(&dev->mutex); > + > + if (dev->inhibited) > + goto out; > + > + if (dev->users) { > + if (dev->close) > + dev->close(dev); > + if (dev->poller) > + input_dev_poller_stop(dev->poller); > + } > + > + spin_lock_irq(&dev->event_lock); > + input_dev_release_keys(dev); > + input_dev_toggle(dev, false); > + spin_unlock_irq(&dev->event_lock); > + > + dev->inhibited = true; > + > +out: > + mutex_unlock(&dev->mutex); > + return ret; > +} > + > +static int input_uninhibit_device(struct input_dev *dev) > +{ > + int ret = 0; > + > + mutex_lock(&dev->mutex); > + > + if (!dev->inhibited) > + goto out; > + > + if (dev->users) { > + if (dev->open) { > + ret = dev->open(dev); > + if (ret) > + goto out; > + } > + if (dev->poller) > + input_dev_poller_start(dev->poller); > + } > + > + dev->inhibited = false; > + spin_lock_irq(&dev->event_lock); > + input_dev_toggle(dev, true); > + spin_unlock_irq(&dev->event_lock); > + > +out: > + mutex_unlock(&dev->mutex); > + return ret; > +} > + > #ifdef CONFIG_PM_SLEEP > static int input_dev_suspend(struct device *dev) > { > @@ -2131,7 +2232,7 @@ bool input_device_enabled(struct input_dev *dev) > { > lockdep_assert_held(&dev->mutex); > > - return dev->users > 0; > + return !dev->inhibited && dev->users > 0; > } > EXPORT_SYMBOL_GPL(input_device_enabled); > > diff --git a/include/linux/input.h b/include/linux/input.h > index eda4587dba67..0354b298d874 100644 > --- a/include/linux/input.h > +++ b/include/linux/input.h > @@ -90,9 +90,11 @@ enum input_clock_type { > * @open: this method is called when the very first user calls > * input_open_device(). The driver must prepare the device > * to start generating events (start polling thread, > - * request an IRQ, submit URB, etc.) > + * request an IRQ, submit URB, etc.). The meaning of open() is > + * to start providing events to the input core. > * @close: this method is called when the very last user calls > - * input_close_device(). > + * input_close_device(). The meaning of close() is to stop > + * providing events to the input core. > * @flush: purges the device. Most commonly used to get rid of force > * feedback effects loaded into the device when disconnecting > * from it > @@ -127,6 +129,10 @@ enum input_clock_type { > * and needs not be explicitly unregistered or freed. > * @timestamp: storage for a timestamp set by input_set_timestamp called > * by a driver > + * @inhibited: indicates that the input device is inhibited. If that is > + * the case then input core ignores any events generated by the device. > + * Device's close() is called when it is being inhibited and its open() > + * is called when it is being uninhibited. > */ > struct input_dev { > const char *name; > @@ -201,6 +207,8 @@ struct input_dev { > bool devres_managed; > > ktime_t timestamp[INPUT_CLK_MAX]; > + > + bool inhibited; > }; > #define to_input_dev(d) container_of(d, struct input_dev, dev) > >
diff --git a/drivers/input/input.c b/drivers/input/input.c index 41377bfa142d..4110b5797219 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -284,8 +284,11 @@ static int input_get_disposition(struct input_dev *dev, case EV_KEY: if (is_event_supported(code, dev->keybit, KEY_MAX)) { - /* auto-repeat bypasses state updates */ - if (value == 2) { + /* + * auto-repeat bypasses state updates but repeat + * events are ignored if the key is not pressed + */ + if (value == 2 && test_bit(code, dev->key)) { disposition = INPUT_PASS_TO_HANDLERS; break; } @@ -367,8 +370,13 @@ static int input_get_disposition(struct input_dev *dev, static void input_handle_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { - int disposition = input_get_disposition(dev, type, code, &value); + int disposition; + + /* filter-out events from inhibited devices */ + if (dev->inhibited) + return; + disposition = input_get_disposition(dev, type, code, &value); if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN) add_input_randomness(type, code, value); @@ -612,7 +620,7 @@ int input_open_device(struct input_handle *handle) handle->open++; - if (dev->users++) { + if (dev->users++ || dev->inhibited) { /* * Device is already opened, so we can exit immediately and * report success. @@ -675,10 +683,9 @@ void input_close_device(struct input_handle *handle) __input_release_device(handle); - if (!--dev->users) { + if (!dev->inhibited && !--dev->users) { if (dev->poller) input_dev_poller_stop(dev->poller); - if (dev->close) dev->close(dev); } @@ -1416,12 +1423,49 @@ static ssize_t input_dev_show_properties(struct device *dev, } static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL); +static int input_inhibit_device(struct input_dev *dev); +static int input_uninhibit_device(struct input_dev *dev); + +static ssize_t inhibited_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct input_dev *input_dev = to_input_dev(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", input_dev->inhibited); +} + +static ssize_t inhibited_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t len) +{ + struct input_dev *input_dev = to_input_dev(dev); + ssize_t rv; + bool inhibited; + + if (strtobool(buf, &inhibited)) + return -EINVAL; + + if (inhibited) + rv = input_inhibit_device(input_dev); + else + rv = input_uninhibit_device(input_dev); + + if (rv != 0) + return rv; + + return len; +} + +static DEVICE_ATTR_RW(inhibited); + static struct attribute *input_dev_attrs[] = { &dev_attr_name.attr, &dev_attr_phys.attr, &dev_attr_uniq.attr, &dev_attr_modalias.attr, &dev_attr_properties.attr, + &dev_attr_inhibited.attr, NULL }; @@ -1703,6 +1747,63 @@ void input_reset_device(struct input_dev *dev) } EXPORT_SYMBOL(input_reset_device); +static int input_inhibit_device(struct input_dev *dev) +{ + int ret = 0; + + mutex_lock(&dev->mutex); + + if (dev->inhibited) + goto out; + + if (dev->users) { + if (dev->close) + dev->close(dev); + if (dev->poller) + input_dev_poller_stop(dev->poller); + } + + spin_lock_irq(&dev->event_lock); + input_dev_release_keys(dev); + input_dev_toggle(dev, false); + spin_unlock_irq(&dev->event_lock); + + dev->inhibited = true; + +out: + mutex_unlock(&dev->mutex); + return ret; +} + +static int input_uninhibit_device(struct input_dev *dev) +{ + int ret = 0; + + mutex_lock(&dev->mutex); + + if (!dev->inhibited) + goto out; + + if (dev->users) { + if (dev->open) { + ret = dev->open(dev); + if (ret) + goto out; + } + if (dev->poller) + input_dev_poller_start(dev->poller); + } + + dev->inhibited = false; + spin_lock_irq(&dev->event_lock); + input_dev_toggle(dev, true); + spin_unlock_irq(&dev->event_lock); + +out: + mutex_unlock(&dev->mutex); + return ret; +} + #ifdef CONFIG_PM_SLEEP static int input_dev_suspend(struct device *dev) { @@ -2131,7 +2232,7 @@ bool input_device_enabled(struct input_dev *dev) { lockdep_assert_held(&dev->mutex); - return dev->users > 0; + return !dev->inhibited && dev->users > 0; } EXPORT_SYMBOL_GPL(input_device_enabled); diff --git a/include/linux/input.h b/include/linux/input.h index eda4587dba67..0354b298d874 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -90,9 +90,11 @@ enum input_clock_type { * @open: this method is called when the very first user calls * input_open_device(). The driver must prepare the device * to start generating events (start polling thread, - * request an IRQ, submit URB, etc.) + * request an IRQ, submit URB, etc.). The meaning of open() is + * to start providing events to the input core. * @close: this method is called when the very last user calls - * input_close_device(). + * input_close_device(). The meaning of close() is to stop + * providing events to the input core. * @flush: purges the device. Most commonly used to get rid of force * feedback effects loaded into the device when disconnecting * from it @@ -127,6 +129,10 @@ enum input_clock_type { * and needs not be explicitly unregistered or freed. * @timestamp: storage for a timestamp set by input_set_timestamp called * by a driver + * @inhibited: indicates that the input device is inhibited. If that is + * the case then input core ignores any events generated by the device. + * Device's close() is called when it is being inhibited and its open() + * is called when it is being uninhibited. */ struct input_dev { const char *name; @@ -201,6 +207,8 @@ struct input_dev { bool devres_managed; ktime_t timestamp[INPUT_CLK_MAX]; + + bool inhibited; }; #define to_input_dev(d) container_of(d, struct input_dev, dev)