+/* drivers/input/keyreset.c
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/input.h>
+#include <linux/keyreset.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+
+struct keyreset_state {
+ struct input_handler input_handler;
+ unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
+ unsigned long upbit[BITS_TO_LONGS(KEY_CNT)];
+ unsigned long key[BITS_TO_LONGS(KEY_CNT)];
+ spinlock_t lock;
+ int key_down_target;
+ int key_down;
+ int key_up;
+ int restart_disabled;
+};
+
+int restart_requested;
+static void deferred_restart(struct work_struct *dummy)
+{
+ restart_requested = 2;
+ sys_sync();
+ restart_requested = 3;
+ kernel_restart(NULL);
+}
+static DECLARE_WORK(restart_work, deferred_restart);
+
+static void keyreset_event(struct input_handle *handle, unsigned int type,
+ unsigned int code, int value)
+{
+ unsigned long flags;
+ struct keyreset_state *state = handle->private;
+
+ if (type != EV_KEY)
+ return;
+
+ if (code >= KEY_MAX)
+ return;
+
+ if (!test_bit(code, state->keybit))
+ return;
+
+ spin_lock_irqsave(&state->lock, flags);
+ if (!test_bit(code, state->key) == !value)
+ goto done;
+ __change_bit(code, state->key);
+ if (test_bit(code, state->upbit)) {
+ if (value) {
+ state->restart_disabled = 1;
+ state->key_up++;
+ } else
+ state->key_up--;
+ } else {
+ if (value)
+ state->key_down++;
+ else
+ state->key_down--;
+ }
+ if (state->key_down == 0 && state->key_up == 0)
+ state->restart_disabled = 0;
+
+ pr_debug("reset key changed %d %d new state %d-%d-%d\n", code, value,
+ state->key_down, state->key_up, state->restart_disabled);
+
+ if (value && !state->restart_disabled &&
+ state->key_down == state->key_down_target) {
+ state->restart_disabled = 1;
+ if (restart_requested)
+ panic("keyboard reset failed, %d", restart_requested);
+ pr_info("keyboard reset\n");
+ schedule_work(&restart_work);
+ restart_requested = 1;
+ }
+done:
+ spin_unlock_irqrestore(&state->lock, flags);
+}
+
+static int keyreset_connect(struct input_handler *handler,
+ struct input_dev *dev,
+ const struct input_device_id *id)
+{
+ int i;
+ int ret;
+ struct input_handle *handle;
+ struct keyreset_state *state =
+ container_of(handler, struct keyreset_state, input_handler);
+
+ for (i = 0; i < KEY_MAX; i++) {
+ if (test_bit(i, state->keybit) && test_bit(i, dev->keybit))
+ break;
+ }
+ if (i == KEY_MAX)
+ return -ENODEV;
+
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle)
+ return -ENOMEM;
+
+ handle->dev = dev;
+ handle->handler = handler;
+ handle->name = "keyreset";
+ handle->private = state;
+
+ ret = input_register_handle(handle);
+ if (ret)
+ goto err_input_register_handle;
+
+ ret = input_open_device(handle);
+ if (ret)
+ goto err_input_open_device;
+
+ pr_info("using input dev %s for key reset\n", dev->name);
+
+ return 0;
+
+err_input_open_device:
+ input_unregister_handle(handle);
+err_input_register_handle:
+ kfree(handle);
+ return ret;
+}
+
+static void keyreset_disconnect(struct input_handle *handle)
+{
+ input_close_device(handle);
+ input_unregister_handle(handle);
+ kfree(handle);
+}
+
+static const struct input_device_id keyreset_ids[] = {
+ {
+ .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+ .evbit = { BIT_MASK(EV_KEY) },
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(input, keyreset_ids);
+
+static int keyreset_probe(struct platform_device *pdev)
+{
+ int ret;
+ int key, *keyp;
+ struct keyreset_state *state;
+ struct keyreset_platform_data *pdata = pdev->dev.platform_data;
+
+ if (!pdata)
+ return -EINVAL;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return -ENOMEM;
+
+ spin_lock_init(&state->lock);
+ keyp = pdata->keys_down;
+ while ((key = *keyp++)) {
+ if (key >= KEY_MAX)
+ continue;
+ state->key_down_target++;
+ __set_bit(key, state->keybit);
+ }
+ if (pdata->keys_up) {
+ keyp = pdata->keys_up;
+ while ((key = *keyp++)) {
+ if (key >= KEY_MAX)
+ continue;
+ __set_bit(key, state->keybit);
+ __set_bit(key, state->upbit);
+ }
+ }
+ state->input_handler.event = keyreset_event;
+ state->input_handler.connect = keyreset_connect;
+ state->input_handler.disconnect = keyreset_disconnect;
+ state->input_handler.name = KEYRESET_NAME;
+ state->input_handler.id_table = keyreset_ids;
+ ret = input_register_handler(&state->input_handler);
+ if (ret) {
+ kfree(state);
+ return ret;
+ }
+ platform_set_drvdata(pdev, state);
+ return 0;
+}
+
+int keyreset_remove(struct platform_device *pdev)
+{
+ struct keyreset_state *state = platform_get_drvdata(pdev);
+ input_unregister_handler(&state->input_handler);
+ kfree(state);
+ return 0;
+}
+
+
+struct platform_driver keyreset_driver = {
+ .driver.name = KEYRESET_NAME,
+ .probe = keyreset_probe,
+ .remove = keyreset_remove,
+};
+
+static int __init keyreset_init(void)
+{
+ return platform_driver_register(&keyreset_driver);
+}
+
+static void __exit keyreset_exit(void)
+{
+ return platform_driver_unregister(&keyreset_driver);
+}
+
+module_init(keyreset_init);
+module_exit(keyreset_exit);