rtc: rtc-hid-sensor-time: allow full years (16bit) in HID reports

The draft for HID-sensors (HUTRR39) currently doesn't define the range
for the attribute year.  Asking one of the authors revealed that full
years (e.g.  2013 instead of just 13) were meant.

So we now allow both, 8 bit and 16 bit values for the attribute year and
assuming full years when the value is 16 bits wide.

We will still support 8 bit values until the specification gets final
(and maybe defines a way to set the time too).

Signed-off-by: Alexander Holler <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Jingoo Han <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/rtc/rtc-hid-sensor-time.c

@@ -85,10 +85,13 @@ static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
 
 	switch (usage_id) {
 	case HID_USAGE_SENSOR_TIME_YEAR:
-		time_buf->tm_year = *(u8 *)raw_data;
-		if (time_buf->tm_year < 70)
-			/* assume we are in 1970...2069 */
-			time_buf->tm_year += 100;
+		if (raw_len == 1) {
+			time_buf->tm_year = *(u8 *)raw_data;
+			if (time_buf->tm_year < 70)
+				/* assume we are in 1970...2069 */
+				time_buf->tm_year += 100;
+		} else
+			time_buf->tm_year = *(u16 *)raw_data-1900;
 		break;
 	case HID_USAGE_SENSOR_TIME_MONTH:
 		/* sensor sending the month as 1-12, we need 0-11 */
@@ -151,11 +154,27 @@ static int hid_time_parse_report(struct platform_device *pdev,
 			return -EINVAL;
 		}
 		if (time_state->info[i].size != 1) {
-			dev_err(&pdev->dev,
-				"attribute '%s' not 8 bits wide!\n",
+			/*
+			 * The draft for HID-sensors (HUTRR39) currently
+			 * doesn't define the range for the year attribute.
+			 * Therefor we support both 8 bit (0-99) and 16 bit
+			 * (full) as size for the year.
+			 */
+			if (time_state->info[i].attrib_id !=
+				HID_USAGE_SENSOR_TIME_YEAR) {
+				dev_err(&pdev->dev,
+					"attribute '%s' not 8 bits wide!\n",
 				hid_time_attrib_name(
 					time_state->info[i].attrib_id));
-			return -EINVAL;
+				return -EINVAL;
+			}
+			if (time_state->info[i].size != 2) {
+				dev_err(&pdev->dev,
+					"attribute '%s' not 8 or 16 bits wide!\n",
+				hid_time_attrib_name(
+					time_state->info[i].attrib_id));
+				return -EINVAL;
+			}
 		}
 		if (time_state->info[i].units !=
 				HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&