[PATCH] HID: Add Wireless Radio Control feature for Chicony devices

[Jian-Hong Pan]

Some Chicony's keyboards support airplane mode hotkey (Fn+F2) with
"Wireless Radio Control" feature. For example, the wireless keyboard
[04f2:1236] shipped with ASUS all-in-one desktop.

After consulting Chicony for this hotkey, learned the device will send
with 0x11 as the report ID and 0x1 as the value when the key is pressed
down.

This patch maps the event as KEY_RFKILL.

Signed-off-by: Jian-Hong Pan <jhp@xxxxxxxxxxxxx>
---
 drivers/hid/hid-chicony.c | 58 +++++++++++++++++++++++++++++++++++++++
 drivers/hid/hid-ids.h     |  1 +
 2 files changed, 59 insertions(+)

diff --git a/drivers/hid/hid-chicony.c b/drivers/hid/hid-chicony.c
index 3f0ed6a95223..aca963aa0f1e 100644
--- a/drivers/hid/hid-chicony.c
+++ b/drivers/hid/hid-chicony.c
@@ -21,6 +21,42 @@
 
 #include "hid-ids.h"
 
+#define KEY_PRESSED			0x01
+#define CH_WIRELESS_CTL_REPORT_ID	0x11
+
+static int ch_report_wireless(struct hid_report *report, u8 *data, int size)
+{
+	struct hid_device *hdev = report->device;
+	struct input_dev *input;
+
+	if (report->id != CH_WIRELESS_CTL_REPORT_ID ||
+	    report->maxfield != 1 ||
+	    *report->field[0]->value != KEY_PRESSED)
+		return 0;
+
+	input = report->field[0]->hidinput->input;
+	if (!input) {
+		hid_warn(hdev, "can't find wireless radio control's input");
+		return 0;
+	}
+
+	input_report_key(input, KEY_RFKILL, 1);
+	input_sync(input);
+	input_report_key(input, KEY_RFKILL, 0);
+	input_sync(input);
+
+	return 1;
+}
+
+static int ch_raw_event(struct hid_device *hdev,
+		struct hid_report *report, u8 *data, int size)
+{
+	if (report->application == HID_GD_WIRELESS_RADIO_CTLS)
+		return ch_report_wireless(report, data, size);
+
+	return 0;
+}
+
 #define ch_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
 					EV_KEY, (c))
 static int ch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
@@ -77,10 +113,30 @@ static __u8 *ch_switch12_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 	return rdesc;
 }
 
+static int ch_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+
+	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "Chicony hid parse failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "Chicony hw start failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
 
 static const struct hid_device_id ch_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TACTICAL_PAD) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS3) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_ACER_SWITCH12) },
 	{ }
 };
@@ -91,6 +147,8 @@ static struct hid_driver ch_driver = {
 	.id_table = ch_devices,
 	.report_fixup = ch_switch12_report_fixup,
 	.input_mapping = ch_input_mapping,
+	.probe = ch_probe,
+	.raw_event = ch_raw_event,
 };
 module_hid_driver(ch_driver);
 
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 4c5f23640f9c..06d90301a3dc 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -270,6 +270,7 @@
 #define USB_DEVICE_ID_CHICONY_PIXART_USB_OPTICAL_MOUSE	0x1053
 #define USB_DEVICE_ID_CHICONY_PIXART_USB_OPTICAL_MOUSE2	0x0939
 #define USB_DEVICE_ID_CHICONY_WIRELESS2	0x1123
+#define USB_DEVICE_ID_CHICONY_WIRELESS3	0x1236
 #define USB_DEVICE_ID_ASUS_AK1D		0x1125
 #define USB_DEVICE_ID_CHICONY_TOSHIBA_WT10A	0x1408
 #define USB_DEVICE_ID_CHICONY_ACER_SWITCH12	0x1421
-- 
2.29.2