Input: wacom - add Intuos5 Touch Ring LED support

The Touch Ring LEDs on Intuos5 tablets use a different report
format which supports only 4 levels of brightness. We remap
the 7-bit value obtained from sysfs to an appropriate value
for the tablet. Control of the crop mark LEDs (new to the I5)
is left for a later patch.
Signed-off-by: Jason Gerecke <killertofu@gmail.com>
Reviewed-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Documentation/ABI/testing/sysfs-driver-wacom

@@ -15,9 +15,10 @@ Contact:	linux-input@vger.kernel.org
 Description:
 		Attribute group for control of the status LEDs and the OLEDs.
 		This attribute group is only available for Intuos 4 M, L,
-		and XL (with LEDs and OLEDs) and Cintiq 21UX2 and Cintiq 24HD
-		(LEDs only). Therefore its presence implicitly signifies the
-		presence of said LEDs and OLEDs on the tablet device.
+		and XL (with LEDs and OLEDs), Intuos 5 (LEDs only), and Cintiq
+		21UX2 and Cintiq 24HD (LEDs only). Therefore its presence
+		implicitly signifies the presence of said LEDs and OLEDs on the
+		tablet device.
 
 What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status0_luminance
 Date:		August 2011
@@ -40,10 +41,10 @@ What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status_led0
 Date:		August 2011
 Contact:	linux-input@vger.kernel.org
 Description:
-		Writing to this file sets which one of the four (for Intuos 4)
-		or of the right four (for Cintiq 21UX2 and Cintiq 24HD) status
-		LEDs is active (0..3). The other three LEDs on the same side are
-		always inactive.
+		Writing to this file sets which one of the four (for Intuos 4
+		and Intuos 5) or of the right four (for Cintiq 21UX2 and Cintiq
+		24HD) status LEDs is active (0..3). The other three LEDs on the
+		same side are always inactive.
 
 What:		/sys/bus/usb/devices/<busnum>-<devnum>:<cfg>.<intf>/wacom_led/status_led1_select
 Date:		September 2011

drivers/input/tablet/wacom_sys.c

@@ -574,23 +574,39 @@ static void wacom_remove_shared_data(struct wacom_wac *wacom)
 static int wacom_led_control(struct wacom *wacom)
 {
 	unsigned char *buf;
-	int retval, led = 0;
+	int retval;
 
 	buf = kzalloc(9, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
+	if (wacom->wacom_wac.features.type >= INTUOS5S &&
+	    wacom->wacom_wac.features.type <= INTUOS5L)	{
+		/*
+		 * Touch Ring and crop mark LED luminance may take on
+		 * one of four values:
+		 *    0 = Low; 1 = Medium; 2 = High; 3 = Off
+		 */
+		int ring_led = wacom->led.select[0] & 0x03;
+		int ring_lum = (((wacom->led.llv & 0x60) >> 5) - 1) & 0x03;
+		int crop_lum = 0;
+
+		buf[0] = WAC_CMD_LED_CONTROL;
+		buf[1] = (crop_lum << 4) | (ring_lum << 2) | (ring_led);
+	}
+	else {
+		int led = wacom->led.select[0] | 0x4;
+
 		if (wacom->wacom_wac.features.type == WACOM_21UX2 ||
 		    wacom->wacom_wac.features.type == WACOM_24HD)
-		led = (wacom->led.select[1] << 4) | 0x40;
-
-	led |=  wacom->led.select[0] | 0x4;
+			led |= (wacom->led.select[1] << 4) | 0x40;
 
 		buf[0] = WAC_CMD_LED_CONTROL;
 		buf[1] = led;
 		buf[2] = wacom->led.llv;
 		buf[3] = wacom->led.hlv;
 		buf[4] = wacom->led.img_lum;
+	}
 
 	retval = wacom_set_report(wacom->intf, 0x03, WAC_CMD_LED_CONTROL,
 				  buf, 9, WAC_CMD_RETRIES);
@@ -783,6 +799,17 @@ static struct attribute_group intuos4_led_attr_group = {
 	.attrs = intuos4_led_attrs,
 };
 
+static struct attribute *intuos5_led_attrs[] = {
+	&dev_attr_status0_luminance.attr,
+	&dev_attr_status_led0_select.attr,
+	NULL
+};
+
+static struct attribute_group intuos5_led_attr_group = {
+	.name = "wacom_led",
+	.attrs = intuos5_led_attrs,
+};
+
 static int wacom_initialize_leds(struct wacom *wacom)
 {
 	int error;
@@ -812,6 +839,19 @@ static int wacom_initialize_leds(struct wacom *wacom)
 					   &cintiq_led_attr_group);
 		break;
 
+	case INTUOS5S:
+	case INTUOS5:
+	case INTUOS5L:
+		wacom->led.select[0] = 0;
+		wacom->led.select[1] = 0;
+		wacom->led.llv = 32;
+		wacom->led.hlv = 0;
+		wacom->led.img_lum = 0;
+
+		error = sysfs_create_group(&wacom->intf->dev.kobj,
+					   &intuos5_led_attr_group);
+		break;
+
 	default:
 		return 0;
 	}
@@ -840,6 +880,13 @@ static void wacom_destroy_leds(struct wacom *wacom)
 		sysfs_remove_group(&wacom->intf->dev.kobj,
 				   &cintiq_led_attr_group);
 		break;
+
+	case INTUOS5S:
+	case INTUOS5:
+	case INTUOS5L:
+		sysfs_remove_group(&wacom->intf->dev.kobj,
+				   &intuos5_led_attr_group);
+		break;
 	}
 }