Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/input/input-poller.c b/drivers/input/input-poller.c
new file mode 100644
index 0000000..1b3d289
--- /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,
+};