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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/input/input-polldev.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/input/input-polldev.c')
-rw-r--r-- | drivers/input/input-polldev.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c new file mode 100644 index 000000000..9bf1c9aeb --- /dev/null +++ b/drivers/input/input-polldev.c @@ -0,0 +1,362 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic implementation of a polled input device + + * Copyright (c) 2007 Dmitry Torokhov + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/jiffies.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/workqueue.h> +#include <linux/module.h> +#include <linux/input-polldev.h> + +MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); +MODULE_DESCRIPTION("Generic implementation of a polled input device"); +MODULE_LICENSE("GPL v2"); + +static void input_polldev_queue_work(struct input_polled_dev *dev) +{ + unsigned long delay; + + delay = msecs_to_jiffies(dev->poll_interval); + if (delay >= HZ) + delay = round_jiffies_relative(delay); + + queue_delayed_work(system_freezable_wq, &dev->work, delay); +} + +static void input_polled_device_work(struct work_struct *work) +{ + struct input_polled_dev *dev = + container_of(work, struct input_polled_dev, work.work); + + dev->poll(dev); + input_polldev_queue_work(dev); +} + +static int input_open_polled_device(struct input_dev *input) +{ + struct input_polled_dev *dev = input_get_drvdata(input); + + if (dev->open) + dev->open(dev); + + /* Only start polling if polling is enabled */ + if (dev->poll_interval > 0) { + dev->poll(dev); + input_polldev_queue_work(dev); + } + + return 0; +} + +static void input_close_polled_device(struct input_dev *input) +{ + struct input_polled_dev *dev = input_get_drvdata(input); + + cancel_delayed_work_sync(&dev->work); + + if (dev->close) + dev->close(dev); +} + +/* SYSFS interface */ + +static ssize_t input_polldev_get_poll(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct input_polled_dev *polldev = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", polldev->poll_interval); +} + +static ssize_t input_polldev_set_poll(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t count) +{ + struct input_polled_dev *polldev = dev_get_drvdata(dev); + struct input_dev *input = polldev->input; + unsigned int interval; + int err; + + err = kstrtouint(buf, 0, &interval); + if (err) + return err; + + if (interval < polldev->poll_interval_min) + return -EINVAL; + + if (interval > polldev->poll_interval_max) + return -EINVAL; + + mutex_lock(&input->mutex); + + polldev->poll_interval = interval; + + if (input->users) { + cancel_delayed_work_sync(&polldev->work); + if (polldev->poll_interval > 0) + input_polldev_queue_work(polldev); + } + + mutex_unlock(&input->mutex); + + return count; +} + +static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll, + input_polldev_set_poll); + + +static ssize_t input_polldev_get_max(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct input_polled_dev *polldev = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", polldev->poll_interval_max); +} + +static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL); + +static ssize_t input_polldev_get_min(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct input_polled_dev *polldev = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", polldev->poll_interval_min); +} + +static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL); + +static struct attribute *sysfs_attrs[] = { + &dev_attr_poll.attr, + &dev_attr_max.attr, + &dev_attr_min.attr, + NULL +}; + +static struct attribute_group input_polldev_attribute_group = { + .attrs = sysfs_attrs +}; + +static const struct attribute_group *input_polldev_attribute_groups[] = { + &input_polldev_attribute_group, + NULL +}; + +/** + * input_allocate_polled_device - allocate memory for polled device + * + * The function allocates memory for a polled device and also + * for an input device associated with this polled device. + */ +struct input_polled_dev *input_allocate_polled_device(void) +{ + struct input_polled_dev *dev; + + dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL); + if (!dev) + return NULL; + + dev->input = input_allocate_device(); + if (!dev->input) { + kfree(dev); + return NULL; + } + + return dev; +} +EXPORT_SYMBOL(input_allocate_polled_device); + +struct input_polled_devres { + struct input_polled_dev *polldev; +}; + +static int devm_input_polldev_match(struct device *dev, void *res, void *data) +{ + struct input_polled_devres *devres = res; + + return devres->polldev == data; +} + +static void devm_input_polldev_release(struct device *dev, void *res) +{ + struct input_polled_devres *devres = res; + struct input_polled_dev *polldev = devres->polldev; + + dev_dbg(dev, "%s: dropping reference/freeing %s\n", + __func__, dev_name(&polldev->input->dev)); + + input_put_device(polldev->input); + kfree(polldev); +} + +static void devm_input_polldev_unregister(struct device *dev, void *res) +{ + struct input_polled_devres *devres = res; + struct input_polled_dev *polldev = devres->polldev; + + dev_dbg(dev, "%s: unregistering device %s\n", + __func__, dev_name(&polldev->input->dev)); + input_unregister_device(polldev->input); + + /* + * Note that we are still holding extra reference to the input + * device so it will stick around until devm_input_polldev_release() + * is called. + */ +} + +/** + * devm_input_allocate_polled_device - allocate managed polled device + * @dev: device owning the polled device being created + * + * Returns prepared &struct input_polled_dev or %NULL. + * + * Managed polled input devices do not need to be explicitly unregistered + * or freed as it will be done automatically when owner device unbinds + * from * its driver (or binding fails). Once such managed polled device + * is allocated, it is ready to be set up and registered in the same + * fashion as regular polled input devices (using + * input_register_polled_device() function). + * + * If you want to manually unregister and free such managed polled devices, + * it can be still done by calling input_unregister_polled_device() and + * input_free_polled_device(), although it is rarely needed. + * + * NOTE: the owner device is set up as parent of input device and users + * should not override it. + */ +struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev) +{ + struct input_polled_dev *polldev; + struct input_polled_devres *devres; + + devres = devres_alloc(devm_input_polldev_release, sizeof(*devres), + GFP_KERNEL); + if (!devres) + return NULL; + + polldev = input_allocate_polled_device(); + if (!polldev) { + devres_free(devres); + return NULL; + } + + polldev->input->dev.parent = dev; + polldev->devres_managed = true; + + devres->polldev = polldev; + devres_add(dev, devres); + + return polldev; +} +EXPORT_SYMBOL(devm_input_allocate_polled_device); + +/** + * input_free_polled_device - free memory allocated for polled device + * @dev: device to free + * + * The function frees memory allocated for polling device and drops + * reference to the associated input device. + */ +void input_free_polled_device(struct input_polled_dev *dev) +{ + if (dev) { + if (dev->devres_managed) + WARN_ON(devres_destroy(dev->input->dev.parent, + devm_input_polldev_release, + devm_input_polldev_match, + dev)); + input_put_device(dev->input); + kfree(dev); + } +} +EXPORT_SYMBOL(input_free_polled_device); + +/** + * input_register_polled_device - register polled device + * @dev: device to register + * + * The function registers previously initialized polled input device + * with input layer. The device should be allocated with call to + * input_allocate_polled_device(). Callers should also set up poll() + * method and set up capabilities (id, name, phys, bits) of the + * corresponding input_dev structure. + */ +int input_register_polled_device(struct input_polled_dev *dev) +{ + struct input_polled_devres *devres = NULL; + struct input_dev *input = dev->input; + int error; + + if (dev->devres_managed) { + devres = devres_alloc(devm_input_polldev_unregister, + sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + devres->polldev = dev; + } + + input_set_drvdata(input, dev); + INIT_DELAYED_WORK(&dev->work, input_polled_device_work); + + if (!dev->poll_interval) + dev->poll_interval = 500; + if (!dev->poll_interval_max) + dev->poll_interval_max = dev->poll_interval; + + input->open = input_open_polled_device; + input->close = input_close_polled_device; + + input->dev.groups = input_polldev_attribute_groups; + + error = input_register_device(input); + if (error) { + devres_free(devres); + return error; + } + + /* + * Take extra reference to the underlying input device so + * that it survives call to input_unregister_polled_device() + * and is deleted only after input_free_polled_device() + * has been invoked. This is needed to ease task of freeing + * sparse keymaps. + */ + input_get_device(input); + + if (dev->devres_managed) { + dev_dbg(input->dev.parent, "%s: registering %s with devres.\n", + __func__, dev_name(&input->dev)); + devres_add(input->dev.parent, devres); + } + + return 0; +} +EXPORT_SYMBOL(input_register_polled_device); + +/** + * input_unregister_polled_device - unregister polled device + * @dev: device to unregister + * + * The function unregisters previously registered polled input + * device from input layer. Polling is stopped and device is + * ready to be freed with call to input_free_polled_device(). + */ +void input_unregister_polled_device(struct input_polled_dev *dev) +{ + if (dev->devres_managed) + WARN_ON(devres_destroy(dev->input->dev.parent, + devm_input_polldev_unregister, + devm_input_polldev_match, + dev)); + + input_unregister_device(dev->input); +} +EXPORT_SYMBOL(input_unregister_polled_device); |