diff options
| -rw-r--r-- | drivers/input/Makefile | 2 | ||||
| -rw-r--r-- | drivers/input/input-poller.c | 213 | ||||
| -rw-r--r-- | drivers/input/input-poller.h | 18 | ||||
| -rw-r--r-- | drivers/input/input.c | 36 | ||||
| -rw-r--r-- | include/linux/input.h | 12 |
5 files changed, 273 insertions, 8 deletions
diff --git a/drivers/input/Makefile b/drivers/input/Makefile index 40de6a7be641..e35650930371 100644 --- a/drivers/input/Makefile +++ b/drivers/input/Makefile @@ -6,7 +6,7 @@ # Each configuration option enables a list of files. obj-$(CONFIG_INPUT) += input-core.o -input-core-y := input.o input-compat.o input-mt.o ff-core.o +input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o obj-$(CONFIG_INPUT_FF_MEMLESS) += ff-memless.o obj-$(CONFIG_INPUT_POLLDEV) += input-polldev.o diff --git a/drivers/input/input-poller.c b/drivers/input/input-poller.c new file mode 100644 index 000000000000..1b3d28964bb2 --- /dev/null +++ b/drivers/input/input-poller.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Support for polling mode for input devices. + */ + +#include <linux/device.h> +#include <linux/input.h> +#include <linux/jiffies.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/workqueue.h> +#include "input-poller.h" + +struct input_dev_poller { + void (*poll)(struct input_dev *dev); + + unsigned int poll_interval; /* msec */ + unsigned int poll_interval_max; /* msec */ + unsigned int poll_interval_min; /* msec */ + + struct input_dev *input; + struct delayed_work work; +}; + +static void input_dev_poller_queue_work(struct input_dev_poller *poller) +{ + unsigned long delay; + + delay = msecs_to_jiffies(poller->poll_interval); + if (delay >= HZ) + delay = round_jiffies_relative(delay); + + queue_delayed_work(system_freezable_wq, &poller->work, delay); +} + +static void input_dev_poller_work(struct work_struct *work) +{ + struct input_dev_poller *poller = + container_of(work, struct input_dev_poller, work.work); + + poller->poll(poller->input); + input_dev_poller_queue_work(poller); +} + +void input_dev_poller_finalize(struct input_dev_poller *poller) +{ + if (!poller->poll_interval) + poller->poll_interval = 500; + if (!poller->poll_interval_max) + poller->poll_interval_max = poller->poll_interval; +} + +void input_dev_poller_start(struct input_dev_poller *poller) +{ + /* Only start polling if polling is enabled */ + if (poller->poll_interval > 0) { + poller->poll(poller->input); + input_dev_poller_queue_work(poller); + } +} + +void input_dev_poller_stop(struct input_dev_poller *poller) +{ + cancel_delayed_work_sync(&poller->work); +} + +int input_setup_polling(struct input_dev *dev, + void (*poll_fn)(struct input_dev *dev)) +{ + struct input_dev_poller *poller; + + poller = kzalloc(sizeof(*poller), GFP_KERNEL); + if (!poller) { + /* + * We want to show message even though kzalloc() may have + * printed backtrace as knowing what instance of input + * device we were dealing with is helpful. + */ + dev_err(dev->dev.parent ?: &dev->dev, + "%s: unable to allocate poller structure\n", __func__); + return -ENOMEM; + } + + INIT_DELAYED_WORK(&poller->work, input_dev_poller_work); + poller->input = dev; + poller->poll = poll_fn; + + dev->poller = poller; + return 0; +} +EXPORT_SYMBOL(input_setup_polling); + +static bool input_dev_ensure_poller(struct input_dev *dev) +{ + if (!dev->poller) { + dev_err(dev->dev.parent ?: &dev->dev, + "poller structure has not been set up\n"); + return false; + } + + return true; +} + +void input_set_poll_interval(struct input_dev *dev, unsigned int interval) +{ + if (input_dev_ensure_poller(dev)) + dev->poller->poll_interval = interval; +} +EXPORT_SYMBOL(input_set_poll_interval); + +void input_set_min_poll_interval(struct input_dev *dev, unsigned int interval) +{ + if (input_dev_ensure_poller(dev)) + dev->poller->poll_interval_min = interval; +} +EXPORT_SYMBOL(input_set_min_poll_interval); + +void input_set_max_poll_interval(struct input_dev *dev, unsigned int interval) +{ + if (input_dev_ensure_poller(dev)) + dev->poller->poll_interval_max = interval; +} +EXPORT_SYMBOL(input_set_max_poll_interval); + +/* SYSFS interface */ + +static ssize_t input_dev_get_poll_interval(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct input_dev *input = to_input_dev(dev); + + return sprintf(buf, "%d\n", input->poller->poll_interval); +} + +static ssize_t input_dev_set_poll_interval(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct input_dev *input = to_input_dev(dev); + struct input_dev_poller *poller = input->poller; + unsigned int interval; + int err; + + err = kstrtouint(buf, 0, &interval); + if (err) + return err; + + if (interval < poller->poll_interval_min) + return -EINVAL; + + if (interval > poller->poll_interval_max) + return -EINVAL; + + mutex_lock(&input->mutex); + + poller->poll_interval = interval; + + if (input->users) { + cancel_delayed_work_sync(&poller->work); + if (poller->poll_interval > 0) + input_dev_poller_queue_work(poller); + } + + mutex_unlock(&input->mutex); + + return count; +} + +static DEVICE_ATTR(poll, 0644, + input_dev_get_poll_interval, input_dev_set_poll_interval); + +static ssize_t input_dev_get_poll_max(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct input_dev *input = to_input_dev(dev); + + return sprintf(buf, "%d\n", input->poller->poll_interval_max); +} + +static DEVICE_ATTR(max, 0444, input_dev_get_poll_max, NULL); + +static ssize_t input_dev_get_poll_min(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct input_dev *input = to_input_dev(dev); + + return sprintf(buf, "%d\n", input->poller->poll_interval_min); +} + +static DEVICE_ATTR(min, 0444, input_dev_get_poll_min, NULL); + +static umode_t input_poller_attrs_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct input_dev *input = to_input_dev(dev); + + return input->poller ? attr->mode : 0; +} + +static struct attribute *input_poller_attrs[] = { + &dev_attr_poll.attr, + &dev_attr_max.attr, + &dev_attr_min.attr, + NULL +}; + +struct attribute_group input_poller_attribute_group = { + .is_visible = input_poller_attrs_visible, + .attrs = input_poller_attrs, +}; diff --git a/drivers/input/input-poller.h b/drivers/input/input-poller.h new file mode 100644 index 000000000000..e3fca0be1d32 --- /dev/null +++ b/drivers/input/input-poller.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _INPUT_POLLER_H +#define _INPUT_POLLER_H + +/* + * Support for polling mode for input devices. + */ +#include <linux/sysfs.h> + +struct input_dev_poller; + +void input_dev_poller_finalize(struct input_dev_poller *poller); +void input_dev_poller_start(struct input_dev_poller *poller); +void input_dev_poller_stop(struct input_dev_poller *poller); + +extern struct attribute_group input_poller_attribute_group; + +#endif /* _INPUT_POLLER_H */ diff --git a/drivers/input/input.c b/drivers/input/input.c index 7494a0dede79..c08aa3596144 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -24,6 +24,7 @@ #include <linux/mutex.h> #include <linux/rcupdate.h> #include "input-compat.h" +#include "input-poller.h" MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>"); MODULE_DESCRIPTION("Input core"); @@ -603,20 +604,31 @@ int input_open_device(struct input_handle *handle) handle->open++; - if (!dev->users++ && dev->open) - retval = dev->open(dev); + if (dev->users++) { + /* + * Device is already opened, so we can exit immediately and + * report success. + */ + goto out; + } - if (retval) { - dev->users--; - if (!--handle->open) { + if (dev->open) { + retval = dev->open(dev); + if (retval) { + dev->users--; + handle->open--; /* * Make sure we are not delivering any more events * through this handle */ synchronize_rcu(); + goto out; } } + if (dev->poller) + input_dev_poller_start(dev->poller); + out: mutex_unlock(&dev->mutex); return retval; @@ -655,8 +667,13 @@ void input_close_device(struct input_handle *handle) __input_release_device(handle); - if (!--dev->users && dev->close) - dev->close(dev); + if (!--dev->users) { + if (dev->poller) + input_dev_poller_stop(dev->poller); + + if (dev->close) + dev->close(dev); + } if (!--handle->open) { /* @@ -1502,6 +1519,7 @@ static const struct attribute_group *input_dev_attr_groups[] = { &input_dev_attr_group, &input_dev_id_attr_group, &input_dev_caps_attr_group, + &input_poller_attribute_group, NULL }; @@ -1511,6 +1529,7 @@ static void input_dev_release(struct device *device) input_ff_destroy(dev); input_mt_destroy_slots(dev); + kfree(dev->poller); kfree(dev->absinfo); kfree(dev->vals); kfree(dev); @@ -2175,6 +2194,9 @@ int input_register_device(struct input_dev *dev) if (!dev->setkeycode) dev->setkeycode = input_default_setkeycode; + if (dev->poller) + input_dev_poller_finalize(dev->poller); + error = device_add(&dev->dev); if (error) goto err_free_vals; diff --git a/include/linux/input.h b/include/linux/input.h index e95a439d8bd5..94f277cd806a 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -21,6 +21,8 @@ #include <linux/timer.h> #include <linux/mod_devicetable.h> +struct input_dev_poller; + /** * struct input_value - input value representation * @type: type of value (EV_KEY, EV_ABS, etc) @@ -71,6 +73,8 @@ enum input_clock_type { * not sleep * @ff: force feedback structure associated with the device if device * supports force feedback effects + * @poller: poller structure associated with the device if device is + * set up to use polling mode * @repeat_key: stores key code of the last key pressed; used to implement * software autorepeat * @timer: timer for software autorepeat @@ -156,6 +160,8 @@ struct input_dev { struct ff_device *ff; + struct input_dev_poller *poller; + unsigned int repeat_key; struct timer_list timer; @@ -372,6 +378,12 @@ void input_unregister_device(struct input_dev *); void input_reset_device(struct input_dev *); +int input_setup_polling(struct input_dev *dev, + void (*poll_fn)(struct input_dev *dev)); +void input_set_poll_interval(struct input_dev *dev, unsigned int interval); +void input_set_min_poll_interval(struct input_dev *dev, unsigned int interval); +void input_set_max_poll_interval(struct input_dev *dev, unsigned int interval); + int __must_check input_register_handler(struct input_handler *); void input_unregister_handler(struct input_handler *); |