sensors: LEGO EV3 Color: add 4th value on RGB-RAW mode

The LEGO EV3 Color sensor actually sends 4 values in the RGB-RAW
mode instead of the reported 3, so add some hacks to enable access
to this extra value.

Author: dlech

brickpi3/brickpi3_ports_in.c

@@ -247,18 +247,20 @@ static void brickpi3_in_port_poll_work(struct work_struct *work)
 		break;
 	case BRICKPI3_SENSOR_TYPE_EV3_COLOR_COLOR_COMPONENTS:
 		ret = brickpi3_read_sensor(data->bp, data->address, data->index,
-					   data->sensor_type, msg, 6);
+					   data->sensor_type, msg, 8);
 		if (ret < 0)
 			return;
 
-		// 3 16-bit values
+		// 4 16-bit values
 		if (raw_data) {
 			raw_data[0] = msg[1];
 			raw_data[1] = msg[0];
 			raw_data[2] = msg[3];
 			raw_data[3] = msg[2];
 			raw_data[4] = msg[5];
 			raw_data[5] = msg[4];
+			raw_data[6] = msg[7];
+			raw_data[7] = msg[6];
 		}
 		break;
 	case BRICKPI3_SENSOR_TYPE_EV3_INFRARED_SEEK:

sensors/ev3_uart_sensor_defs.c

@@ -100,10 +100,10 @@ const struct ev3_uart_sensor_info ev3_uart_sensor_defs[] = {
 				 * @value0: Red (0 to 1020???)
 				 * @value1: Green (0 to 1020???)
 				 * @value2: Blue (0 to 1020???)
-				 * @units_description: color
+				 * @value3: Ambient? (0 to 1020???)
 				 */
 				.name		= "RGB-RAW",
-				.data_sets	= 3,
+				.data_sets	= 4,
 				.data_type	= LEGO_SENSOR_DATA_S16,
 			},
 			[5] = {

sensors/ev3_uart_sensor_ld.c

@@ -834,7 +834,11 @@ static int ev3_uart_receive_buf2(struct tty_struct *tty,
 					port->last_err = "Received duplicate format INFO.";
 					goto err_invalid_state;
 				}
-				port->mode_info[mode].data_sets = message[2];
+				/* LEGO EV3 Color sensor reports wrong value for RGB-RAW mode */
+				if (port->type_id == EV3_UART_TYPE_ID_COLOR && mode == 4)
+					port->mode_info[mode].data_sets = 4;
+				else
+					port->mode_info[mode].data_sets = message[2];
 				if (!port->mode_info[mode].data_sets) {
 					port->last_err = "Invalid number of data sets.";
 					goto err_invalid_state;