HID: plantronics: Workaround for double volume key presses

Plantronics Blackwire 3220 Series (047f:c056) sends HID reports twice
for each volume key press. This patch adds a quirk to hid-plantronics
for this product ID, which will ignore the second volume key press if
it happens within 5 ms from the last one that was handled.

The patch was tested on the mentioned model only, it shouldn't affect
other models, however, this quirk might be needed for them too.
Auto-repeat (when a key is held pressed) is not affected, because the
rate is about 3 times per second, which is far less frequent than once
in 5 ms.

Fixes: 81bb773faed7 ("HID: plantronics: Update to map volume up/down controls")
Signed-off-by: Maxim Mikityanskiy <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/hid-ids.h

···
 #define USB_DEVICE_ID_ORTEK_IHOME_IMAC_A210S	0x8003
 
 #define USB_VENDOR_ID_PLANTRONICS	0x047f
+#define USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3220_SERIES	0xc056
 
 #define USB_VENDOR_ID_PANASONIC		0x04da
 #define USB_DEVICE_ID_PANABOARD_UBT780	0x1044

drivers/hid/hid-plantronics.c

···
 
 #include <linux/hid.h>
 #include <linux/module.h>
+#include <linux/jiffies.h>
 
 #define PLT_HID_1_0_PAGE	0xffa00000
 #define PLT_HID_2_0_PAGE	0xffa20000
···
 #define PLT_ALLOW_CONSUMER (field->application == HID_CP_CONSUMERCONTROL && \
 			    (usage->hid & HID_USAGE_PAGE) == HID_UP_CONSUMER)
 
+#define PLT_QUIRK_DOUBLE_VOLUME_KEYS BIT(0)
+
+#define PLT_DOUBLE_KEY_TIMEOUT 5 /* ms */
+
+struct plt_drv_data {
+	unsigned long device_type;
+	unsigned long last_volume_key_ts;
+	u32 quirks;
+};
+
 static int plantronics_input_mapping(struct hid_device *hdev,
 				     struct hid_input *hi,
 				     struct hid_field *field,
···
 				     unsigned long **bit, int *max)
 {
 	unsigned short mapped_key;
-	unsigned long plt_type = (unsigned long)hid_get_drvdata(hdev);
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long plt_type = drv_data->device_type;
 
 	/* special case for PTT products */
 	if (field->application == HID_GD_JOYSTICK)
···
 	return 1;
 }
 
+static int plantronics_event(struct hid_device *hdev, struct hid_field *field,
+			     struct hid_usage *usage, __s32 value)
+{
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+
+	if (drv_data->quirks & PLT_QUIRK_DOUBLE_VOLUME_KEYS) {
+		unsigned long prev_ts, cur_ts;
+
+		/* Usages are filtered in plantronics_usages. */
+
+		if (!value) /* Handle key presses only. */
+			return 0;
+
+		prev_ts = drv_data->last_volume_key_ts;
+		cur_ts = jiffies;
+		if (jiffies_to_msecs(cur_ts - prev_ts) <= PLT_DOUBLE_KEY_TIMEOUT)
+			return 1; /* Ignore the repeated key. */
+
+		drv_data->last_volume_key_ts = cur_ts;
+	}
+
+	return 0;
+}
+
 static unsigned long plantronics_device_type(struct hid_device *hdev)
 {
 	unsigned i, col_page;
···
 static int plantronics_probe(struct hid_device *hdev,
 			     const struct hid_device_id *id)
 {
+	struct plt_drv_data *drv_data;
 	int ret;
+
+	drv_data = devm_kzalloc(&hdev->dev, sizeof(*drv_data), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
 
 	ret = hid_parse(hdev);
 	if (ret) {
···
 		goto err;
 	}
 
-	hid_set_drvdata(hdev, (void *)plantronics_device_type(hdev));
+	drv_data->device_type = plantronics_device_type(hdev);
+	drv_data->quirks = id->driver_data;
+	drv_data->last_volume_key_ts = jiffies - msecs_to_jiffies(PLT_DOUBLE_KEY_TIMEOUT);
+
+	hid_set_drvdata(hdev, drv_data);
 
 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT |
 		HID_CONNECT_HIDINPUT_FORCE | HID_CONNECT_HIDDEV_FORCE);
···
 }
 
 static const struct hid_device_id plantronics_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
+					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3220_SERIES),
+		.driver_data = PLT_QUIRK_DOUBLE_VOLUME_KEYS },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS, HID_ANY_ID) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, plantronics_devices);
 
+static const struct hid_usage_id plantronics_usages[] = {
+	{ HID_CP_VOLUMEUP, EV_KEY, HID_ANY_ID },
+	{ HID_CP_VOLUMEDOWN, EV_KEY, HID_ANY_ID },
+	{ HID_TERMINATOR, HID_TERMINATOR, HID_TERMINATOR }
+};
+
 static struct hid_driver plantronics_driver = {
 	.name = "plantronics",
 	.id_table = plantronics_devices,
+	.usage_table = plantronics_usages,
 	.input_mapping = plantronics_input_mapping,
+	.event = plantronics_event,
 	.probe = plantronics_probe,
 };
 module_hid_driver(plantronics_driver);

include/linux/hid.h

···
 #define HID_CP_SELECTION	0x000c0080
 #define HID_CP_MEDIASELECTION	0x000c0087
 #define HID_CP_SELECTDISC	0x000c00ba
+#define HID_CP_VOLUMEUP		0x000c00e9
+#define HID_CP_VOLUMEDOWN	0x000c00ea
 #define HID_CP_PLAYBACKSPEED	0x000c00f1
 #define HID_CP_PROXIMITY	0x000c0109
 #define HID_CP_SPEAKERSYSTEM	0x000c0160