[PATCH 1/4] platform/x86: Add Asus Wireless Radio Control driver

["João Paulo Rechi Vita" <jprvita@gmail.com>]

Some Asus notebooks like the Asus E202SA and the Asus X555UB have a
separate ACPI device for notifications from the airplane mode hotkey.
This device is called "Wireless Radio Control" in Asus websites and ASHS
in the DSDT, and its ACPI _HID is ATK4002 in the two models mentioned
above.

For these models, when the airplane mode hotkey (Fn+F2) is pressed, a
query 0x0B is started in the Embedded Controller, and all this query does
is a notify ASHS with the value 0x88 (for acpi_osi >= "Windows 2012"):

	Scope (_SB.PCI0.SBRG.EC0)
	{
		(...)
		Method (_Q0B, 0, NotSerialized)  // _Qxx: EC Query
		{
			If ((MSOS () >= OSW8))
			{
				Notify (ASHS, 0x88) // Device-Specific
			}
			Else
			{
				(...)
			}
		}
	}

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
---
 MAINTAINERS                     |   6 ++
 drivers/platform/x86/Kconfig    |  15 +++++
 drivers/platform/x86/Makefile   |   1 +
 drivers/platform/x86/asus-wrc.c | 118 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 140 insertions(+)
 create mode 100644 drivers/platform/x86/asus-wrc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9bff63c..b9849ea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1791,6 +1791,12 @@ S:	Maintained
 F:	drivers/platform/x86/asus*.c
 F:	drivers/platform/x86/eeepc*.c
 
+ASUS WIRELESS RADIO CONTROL DRIVER
+M:	João Paulo Rechi Vita <jprvita@gmail.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+F:	drivers/platform/x86/asus-wrc.c
+
 ASYNCHRONOUS TRANSFERS/TRANSFORMS (IOAT) API
 R:	Dan Williams <dan.j.williams@intel.com>
 W:	http://sourceforge.net/projects/xscaleiop
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 1089eaa..edd5de4 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -587,6 +587,21 @@ config EEEPC_WMI
 	  If you have an ACPI-WMI compatible Eee PC laptop (>= 1000), say Y or M
 	  here.
 
+config ASUS_WRC
+	tristate "Asus Wireless Radio Control Driver"
+	depends on ACPI
+	depends on INPUT
+	select INPUT_SPARSEKMAP
+	---help---
+	  The Asus Wireless Radio Control handles the airplane mode hotkey
+	  present on some Asus laptops, known as ASHS in the DSDT.
+
+	  Say Y or M here if you have an ASUS notebook with an airplane mode
+	  hotkey.
+
+	  If you choose to compile this driver as a module the module will be
+	  called asus-wrc.
+
 config ACPI_WMI
 	tristate "WMI"
 	depends on ACPI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 3ca78a3..98b5c2d 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_ASUS_LAPTOP)	+= asus-laptop.o
 obj-$(CONFIG_ASUS_WMI)		+= asus-wmi.o
 obj-$(CONFIG_ASUS_NB_WMI)	+= asus-nb-wmi.o
+obj-$(CONFIG_ASUS_WRC)		+= asus-wrc.o
 obj-$(CONFIG_EEEPC_LAPTOP)	+= eeepc-laptop.o
 obj-$(CONFIG_EEEPC_WMI)		+= eeepc-wmi.o
 obj-$(CONFIG_MSI_LAPTOP)	+= msi-laptop.o
diff --git a/drivers/platform/x86/asus-wrc.c b/drivers/platform/x86/asus-wrc.c
new file mode 100644
index 0000000..13a2022
--- /dev/null
+++ b/drivers/platform/x86/asus-wrc.c
@@ -0,0 +1,118 @@
+/*
+ * Asus Wireless Radio Control Driver
+ *
+ * Copyright (C) 2015 Endless Mobile, Inc.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/acpi.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+
+#define ASUS_WRC_MODULE_NAME "Asus Wireless Radio Control Driver"
+
+struct asus_wrc_data {
+	struct input_dev *inputdev;
+};
+
+static const struct key_entry asus_wrc_keymap[] = {
+	{ KE_KEY, 0x88, { KEY_RFKILL } },
+	{ KE_END, 0 }
+};
+
+static void asus_wrc_notify(struct acpi_device *device, u32 event)
+{
+	struct asus_wrc_data *data = acpi_driver_data(device);
+
+	pr_debug("event=0x%X\n", event);
+
+	if (!sparse_keymap_report_event(data->inputdev, event, 1, true))
+		pr_info("Unknown ASHS event: 0x%X\n", event);
+}
+
+static int asus_wrc_add(struct acpi_device *device)
+{
+	struct asus_wrc_data *data;
+	int err = -ENOMEM;
+
+	pr_info(ASUS_WRC_MODULE_NAME"\n");
+
+	data = kzalloc(sizeof(struct asus_wrc_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->inputdev = input_allocate_device();
+	if (!data->inputdev)
+		goto fail;
+
+	data->inputdev->name = "Asus Wireless Radio Control";
+	data->inputdev->phys = "asus-wrc/input0";
+	data->inputdev->id.bustype = BUS_HOST;
+	data->inputdev->dev.parent = &device->dev;
+	set_bit(EV_REP, data->inputdev->evbit);
+
+	err = sparse_keymap_setup(data->inputdev, asus_wrc_keymap, NULL);
+	if (err)
+		goto fail;
+
+	err = input_register_device(data->inputdev);
+	if (err)
+		goto fail;
+
+	device->driver_data = data;
+	return 0;
+
+fail:
+	device->driver->ops.remove(device);
+	return err;
+}
+
+static int asus_wrc_remove(struct acpi_device *device)
+{
+	struct asus_wrc_data *data = acpi_driver_data(device);
+
+	pr_info("Removing "ASUS_WRC_MODULE_NAME"\n");
+
+	if (data) {
+		if (data->inputdev) {
+			sparse_keymap_free(data->inputdev);
+			input_unregister_device(data->inputdev);
+			data->inputdev = NULL;
+		}
+
+		kfree(data);
+		data = NULL;
+	}
+	return 0;
+}
+
+static const struct acpi_device_id device_ids[] = {
+	{"ATK4002", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, device_ids);
+
+static struct acpi_driver asus_wrc_driver = {
+	.name = ASUS_WRC_MODULE_NAME,
+	.class = "hotkey",
+	.ids = device_ids,
+	.ops = {
+		.add = asus_wrc_add,
+		.remove = asus_wrc_remove,
+		.notify = asus_wrc_notify,
+	},
+};
+module_acpi_driver(asus_wrc_driver);
+
+MODULE_DESCRIPTION(ASUS_WRC_MODULE_NAME);
+MODULE_AUTHOR("João Paulo Rechi Vita <jprvita@gmail.com>");
+MODULE_LICENSE("GPL");
-- 
2.5.0