1 files changed, 365 insertions, 0 deletions
diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
new file mode 100644
index 000000000..78df5a748
--- /dev/null
+++ b/drivers/input/input-polldev.c
@@ -0,0 +1,365 @@
+/*
+ * 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.
+ */
+
+#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);