HID: wacom: leds: handle the switch of the LEDs directly in the kernel

The EKR switches the LED directly, and there is no point in having
userspace handling the switch it self when it's easy enough to do
in the kernel.

The other benefit is that now userspace does not need to have root access
to the LED but need only to read them with user privileges.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 1c882bb70f14..00e0c80be6d5 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2763,11 +2763,64 @@ static void wacom_setup_numbered_buttons(struct input_dev *input_dev,
 		__set_bit(BTN_BASE + (i-16), input_dev->keybit);
 }
 
+static bool wacom_is_led_toggled(struct wacom *wacom, int button_count,
+				 int mask, int group)
+{
+	int button_per_group;
+
+	button_per_group = button_count/wacom->led.count;
+
+	return mask & (1 << (group * button_per_group));
+}
+
+static void wacom_update_led(struct wacom *wacom, int button_count, int mask,
+			     int group)
+{
+	struct wacom_led *led, *next_led;
+	int cur;
+	bool pressed;
+
+	pressed = wacom_is_led_toggled(wacom, button_count, mask, group);
+	cur = wacom->led.groups[group].select;
+
+	led = wacom_led_find(wacom, group, cur);
+	if (!led) {
+		hid_err(wacom->hdev, "can't find current LED %d in group %d\n",
+			cur, group);
+		return;
+	}
+
+	if (!pressed) {
+		led->held = false;
+		return;
+	}
+
+	if (led->held && pressed)
+		return;
+
+	next_led = wacom_led_next(wacom, led);
+	if (!next_led) {
+		hid_err(wacom->hdev, "can't find next LED in group %d\n",
+			group);
+		return;
+	}
+	if (next_led == led)
+		return;
+
+	next_led->held = true;
+	led_trigger_event(&next_led->trigger,
+			  wacom_leds_brightness_get(next_led));
+}
+
 static void wacom_report_numbered_buttons(struct input_dev *input_dev,
 				int button_count, int mask)
 {
+	struct wacom *wacom = input_get_drvdata(input_dev);
 	int i;
 
+	for (i = 0; i < wacom->led.count; i++)
+		wacom_update_led(wacom,  button_count, mask, i);
+
 	for (i = 0; i < button_count && i < 10; i++)
 		input_report_key(input_dev, BTN_0 + i, mask & (1 << i));
 	for (i = 10; i < button_count && i < 16; i++)