--- /dev/null
+/*
+ Dell Airplane Mode Switch driver
+ Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ 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/module.h>
+#include <linux/acpi.h>
+#include <linux/rfkill.h>
+#include <linux/input.h>
+
+enum rbtn_type {
+ RBTN_UNKNOWN,
+ RBTN_TOGGLE,
+ RBTN_SLIDER,
+};
+
+struct rbtn_data {
+ enum rbtn_type type;
+ struct rfkill *rfkill;
+ struct input_dev *input_dev;
+};
+
+
+/*
+ * acpi functions
+ */
+
+static enum rbtn_type rbtn_check(struct acpi_device *device)
+{
+ unsigned long long output;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(device->handle, "CRBT", NULL, &output);
+ if (ACPI_FAILURE(status))
+ return RBTN_UNKNOWN;
+
+ switch (output) {
+ case 0:
+ case 1:
+ return RBTN_TOGGLE;
+ case 2:
+ case 3:
+ return RBTN_SLIDER;
+ default:
+ return RBTN_UNKNOWN;
+ }
+}
+
+static int rbtn_get(struct acpi_device *device)
+{
+ unsigned long long output;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(device->handle, "GRBT", NULL, &output);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+
+ return !output;
+}
+
+static int rbtn_acquire(struct acpi_device *device, bool enable)
+{
+ struct acpi_object_list input;
+ union acpi_object param;
+ acpi_status status;
+
+ param.type = ACPI_TYPE_INTEGER;
+ param.integer.value = enable;
+ input.count = 1;
+ input.pointer = ¶m;
+
+ status = acpi_evaluate_object(device->handle, "ARBT", &input, NULL);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+
+ return 0;
+}
+
+
+/*
+ * rfkill device
+ */
+
+static void rbtn_rfkill_query(struct rfkill *rfkill, void *data)
+{
+ struct acpi_device *device = data;
+ int state;
+
+ state = rbtn_get(device);
+ if (state < 0)
+ return;
+
+ rfkill_set_states(rfkill, state, state);
+}
+
+static int rbtn_rfkill_set_block(void *data, bool blocked)
+{
+ /* NOTE: setting soft rfkill state is not supported */
+ return -EINVAL;
+}
+
+static struct rfkill_ops rbtn_ops = {
+ .query = rbtn_rfkill_query,
+ .set_block = rbtn_rfkill_set_block,
+};
+
+static int rbtn_rfkill_init(struct acpi_device *device)
+{
+ struct rbtn_data *rbtn_data = device->driver_data;
+ int ret;
+
+ if (rbtn_data->rfkill)
+ return 0;
+
+ /*
+ * NOTE: rbtn controls all radio devices, not only WLAN
+ * but rfkill interface does not support "ANY" type
+ * so "WLAN" type is used
+ */
+ rbtn_data->rfkill = rfkill_alloc("dell-rbtn", &device->dev,
+ RFKILL_TYPE_WLAN, &rbtn_ops, device);
+ if (!rbtn_data->rfkill)
+ return -ENOMEM;
+
+ ret = rfkill_register(rbtn_data->rfkill);
+ if (ret) {
+ rfkill_destroy(rbtn_data->rfkill);
+ rbtn_data->rfkill = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+static void rbtn_rfkill_exit(struct acpi_device *device)
+{
+ struct rbtn_data *rbtn_data = device->driver_data;
+
+ if (!rbtn_data->rfkill)
+ return;
+
+ rfkill_unregister(rbtn_data->rfkill);
+ rfkill_destroy(rbtn_data->rfkill);
+ rbtn_data->rfkill = NULL;
+}
+
+static void rbtn_rfkill_event(struct acpi_device *device)
+{
+ struct rbtn_data *rbtn_data = device->driver_data;
+
+ if (rbtn_data->rfkill)
+ rbtn_rfkill_query(rbtn_data->rfkill, device);
+}
+
+
+/*
+ * input device
+ */
+
+static int rbtn_input_init(struct rbtn_data *rbtn_data)
+{
+ int ret;
+
+ rbtn_data->input_dev = input_allocate_device();
+ if (!rbtn_data->input_dev)
+ return -ENOMEM;
+
+ rbtn_data->input_dev->name = "DELL Wireless hotkeys";
+ rbtn_data->input_dev->phys = "dellabce/input0";
+ rbtn_data->input_dev->id.bustype = BUS_HOST;
+ rbtn_data->input_dev->evbit[0] = BIT(EV_KEY);
+ set_bit(KEY_RFKILL, rbtn_data->input_dev->keybit);
+
+ ret = input_register_device(rbtn_data->input_dev);
+ if (ret) {
+ input_free_device(rbtn_data->input_dev);
+ rbtn_data->input_dev = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+static void rbtn_input_exit(struct rbtn_data *rbtn_data)
+{
+ input_unregister_device(rbtn_data->input_dev);
+ rbtn_data->input_dev = NULL;
+}
+
+static void rbtn_input_event(struct rbtn_data *rbtn_data)
+{
+ input_report_key(rbtn_data->input_dev, KEY_RFKILL, 1);
+ input_sync(rbtn_data->input_dev);
+ input_report_key(rbtn_data->input_dev, KEY_RFKILL, 0);
+ input_sync(rbtn_data->input_dev);
+}
+
+
+/*
+ * acpi driver
+ */
+
+static int rbtn_add(struct acpi_device *device);
+static int rbtn_remove(struct acpi_device *device);
+static void rbtn_notify(struct acpi_device *device, u32 event);
+
+static const struct acpi_device_id rbtn_ids[] = {
+ { "DELRBTN", 0 },
+ { "DELLABCE", 0 },
+ { "", 0 },
+};
+
+static struct acpi_driver rbtn_driver = {
+ .name = "dell-rbtn",
+ .ids = rbtn_ids,
+ .ops = {
+ .add = rbtn_add,
+ .remove = rbtn_remove,
+ .notify = rbtn_notify,
+ },
+ .owner = THIS_MODULE,
+};
+
+
+/*
+ * notifier export functions
+ */
+
+static bool auto_remove_rfkill = true;
+
+static ATOMIC_NOTIFIER_HEAD(rbtn_chain_head);
+
+static int rbtn_inc_count(struct device *dev, void *data)
+{
+ struct acpi_device *device = to_acpi_device(dev);
+ struct rbtn_data *rbtn_data = device->driver_data;
+ int *count = data;
+
+ if (rbtn_data->type == RBTN_SLIDER)
+ (*count)++;
+
+ return 0;
+}
+
+static int rbtn_switch_dev(struct device *dev, void *data)
+{
+ struct acpi_device *device = to_acpi_device(dev);
+ struct rbtn_data *rbtn_data = device->driver_data;
+ bool enable = data;
+
+ if (rbtn_data->type != RBTN_SLIDER)
+ return 0;
+
+ if (enable)
+ rbtn_rfkill_init(device);
+ else
+ rbtn_rfkill_exit(device);
+
+ return 0;
+}
+
+int dell_rbtn_notifier_register(struct notifier_block *nb)
+{
+ bool first;
+ int count;
+ int ret;
+
+ count = 0;
+ ret = driver_for_each_device(&rbtn_driver.drv, NULL, &count,
+ rbtn_inc_count);
+ if (ret || count == 0)
+ return -ENODEV;
+
+ first = !rbtn_chain_head.head;
+
+ ret = atomic_notifier_chain_register(&rbtn_chain_head, nb);
+ if (ret != 0)
+ return ret;
+
+ if (auto_remove_rfkill && first)
+ ret = driver_for_each_device(&rbtn_driver.drv, NULL,
+ (void *)false, rbtn_switch_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dell_rbtn_notifier_register);
+
+int dell_rbtn_notifier_unregister(struct notifier_block *nb)
+{
+ int ret;
+
+ ret = atomic_notifier_chain_unregister(&rbtn_chain_head, nb);
+ if (ret != 0)
+ return ret;
+
+ if (auto_remove_rfkill && !rbtn_chain_head.head)
+ ret = driver_for_each_device(&rbtn_driver.drv, NULL,
+ (void *)true, rbtn_switch_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dell_rbtn_notifier_unregister);
+
+
+/*
+ * acpi driver functions
+ */
+
+static int rbtn_add(struct acpi_device *device)
+{
+ struct rbtn_data *rbtn_data;
+ enum rbtn_type type;
+ int ret = 0;
+
+ type = rbtn_check(device);
+ if (type == RBTN_UNKNOWN) {
+ dev_info(&device->dev, "Unknown device type\n");
+ return -EINVAL;
+ }
+
+ ret = rbtn_acquire(device, true);
+ if (ret < 0) {
+ dev_err(&device->dev, "Cannot enable device\n");
+ return ret;
+ }
+
+ rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
+ if (!rbtn_data)
+ return -ENOMEM;
+
+ rbtn_data->type = type;
+ device->driver_data = rbtn_data;
+
+ switch (rbtn_data->type) {
+ case RBTN_TOGGLE:
+ ret = rbtn_input_init(rbtn_data);
+ break;
+ case RBTN_SLIDER:
+ if (auto_remove_rfkill && rbtn_chain_head.head)
+ ret = 0;
+ else
+ ret = rbtn_rfkill_init(device);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+
+}
+
+static int rbtn_remove(struct acpi_device *device)
+{
+ struct rbtn_data *rbtn_data = device->driver_data;
+
+ switch (rbtn_data->type) {
+ case RBTN_TOGGLE:
+ rbtn_input_exit(rbtn_data);
+ break;
+ case RBTN_SLIDER:
+ rbtn_rfkill_exit(device);
+ break;
+ default:
+ break;
+ }
+
+ rbtn_acquire(device, false);
+ device->driver_data = NULL;
+
+ return 0;
+}
+
+static void rbtn_notify(struct acpi_device *device, u32 event)
+{
+ struct rbtn_data *rbtn_data = device->driver_data;
+
+ if (event != 0x80) {
+ dev_info(&device->dev, "Received unknown event (0x%x)\n",
+ event);
+ return;
+ }
+
+ switch (rbtn_data->type) {
+ case RBTN_TOGGLE:
+ rbtn_input_event(rbtn_data);
+ break;
+ case RBTN_SLIDER:
+ rbtn_rfkill_event(device);
+ atomic_notifier_call_chain(&rbtn_chain_head, event, device);
+ break;
+ default:
+ break;
+ }
+}
+
+
+/*
+ * module functions
+ */
+
+module_acpi_driver(rbtn_driver);
+
+module_param(auto_remove_rfkill, bool, 0444);
+
+MODULE_PARM_DESC(auto_remove_rfkill, "Automatically remove rfkill devices when "
+ "other modules start receiving events "
+ "from this module and re-add them when "
+ "the last module stops receiving events "
+ "(default true)");
+MODULE_DEVICE_TABLE(acpi, rbtn_ids);
+MODULE_DESCRIPTION("Dell Airplane Mode Switch driver");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff