diff options
Diffstat (limited to 'drivers/input/misc/input-polldev.c')
| -rw-r--r-- | drivers/input/misc/input-polldev.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/input/misc/input-polldev.c b/drivers/input/misc/input-polldev.c new file mode 100644 index 000000000000..1b2b9c9c5d88 --- /dev/null +++ b/drivers/input/misc/input-polldev.c @@ -0,0 +1,171 @@ +/* + * Generic implementation of a polled input device + + * Copyright (c) 2007 Dmitry Torokhov + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/jiffies.h> +#include <linux/mutex.h> +#include <linux/input-polldev.h> + +static DEFINE_MUTEX(polldev_mutex); +static int polldev_users; +static struct workqueue_struct *polldev_wq; + +static int input_polldev_start_workqueue(void) +{ + int retval; + + retval = mutex_lock_interruptible(&polldev_mutex); + if (retval) + return retval; + + if (!polldev_users) { + polldev_wq = create_singlethread_workqueue("ipolldevd"); + if (!polldev_wq) { + printk(KERN_ERR "input-polldev: failed to create " + "ipolldevd workqueue\n"); + retval = -ENOMEM; + goto out; + } + } + + polldev_users++; + + out: + mutex_unlock(&polldev_mutex); + return retval; +} + +static void input_polldev_stop_workqueue(void) +{ + mutex_lock(&polldev_mutex); + + if (!--polldev_users) + destroy_workqueue(polldev_wq); + + mutex_unlock(&polldev_mutex); +} + +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); + queue_delayed_work(polldev_wq, &dev->work, + msecs_to_jiffies(dev->poll_interval)); +} + +static int input_open_polled_device(struct input_dev *input) +{ + struct input_polled_dev *dev = input->private; + int error; + + error = input_polldev_start_workqueue(); + if (error) + return error; + + if (dev->flush) + dev->flush(dev); + + queue_delayed_work(polldev_wq, &dev->work, + msecs_to_jiffies(dev->poll_interval)); + + return 0; +} + +static void input_close_polled_device(struct input_dev *input) +{ + struct input_polled_dev *dev = input->private; + + cancel_rearming_delayed_workqueue(polldev_wq, &dev->work); + input_polldev_stop_workqueue(); +} + +/** + * input_allocate_polled_device - allocated memory 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); + +/** + * 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 (if present). + */ +void input_free_polled_device(struct input_polled_dev *dev) +{ + if (dev) { + input_free_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 + * corresponing input_dev structure. + */ +int input_register_polled_device(struct input_polled_dev *dev) +{ + struct input_dev *input = dev->input; + + INIT_DELAYED_WORK(&dev->work, input_polled_device_work); + if (!dev->poll_interval) + dev->poll_interval = 500; + input->private = dev; + input->open = input_open_polled_device; + input->close = input_close_polled_device; + + return input_register_device(input); +} +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(). + * Callers should not attempt to access dev->input pointer + * after calling this function. + */ +void input_unregister_polled_device(struct input_polled_dev *dev) +{ + input_unregister_device(dev->input); + dev->input = NULL; +} +EXPORT_SYMBOL(input_unregister_polled_device); + |