driver:ucb1400: Add debug messages

drivers/input/touchscreen/ucb1400_ts.c

@@ -211,7 +211,7 @@ static void ucb1400_poll_touch(struct ucb1400_ts *ucb, struct touch_data *data)
 
 	int hys_down = SECO_INF_DOWN_HYSTERESIS;
 
-	unsigned next_sleep = 0;
+	unsigned next_sleep = 0, timestamp = jiffies_to_msecs(jiffies);
 
 	/* Start with a small delay before checking pendown state */
 	msleep(UCB1400_TS_POLL_PERIOD);
@@ -234,6 +234,7 @@ static void ucb1400_poll_touch(struct ucb1400_ts *ucb, struct touch_data *data)
 
 		if (!penup) {
 			is_pendown = true;
+			is_penup = false;
 
 			ucb1400_adc_enable(ucb->ac97);
 			data->x = ucb1400_ts_read_xpos(ucb);
@@ -244,8 +245,15 @@ static void ucb1400_poll_touch(struct ucb1400_ts *ucb, struct touch_data *data)
 			if ((SECO_INVALID_VALUE == data->x) ||
 			    (SECO_INVALID_VALUE == data->y) ||
 			    (SECO_INVALID_VALUE == data->p)) {
+				++ucb->read_error_count;
+				dev_dbg(&ucb->ts_idev->dev, "Invalid value (%u)",
+					ucb->read_error_count);
 				retry = true;
 			}
+		} else if (is_pendown && !is_penup) {
+			is_penup = true;
+			dev_dbg(&ucb->ts_idev->dev, "Up: %u ms",
+				jiffies_to_msecs(jiffies)-timestamp);
 		}
 
 		/*
@@ -285,6 +293,10 @@ static void ucb1400_poll_touch(struct ucb1400_ts *ucb, struct touch_data *data)
 			hys_down--;
 			next_sleep = UCB1400_TS_SHORT_POLL_PERIOD;
 			continue;
+		} else if (!report_pendown) {
+			report_pendown = true;
+			dev_dbg(&ucb->ts_idev->dev, "Down: %u ms",
+				jiffies_to_msecs(jiffies)-timestamp);
 		}
 
 		ucb1400_ts_report_event(ucb->ts_idev, data);
@@ -402,6 +414,8 @@ static void ucb1400_ts_start(struct ucb1400_ts *ucb)
 				"Failed to create workqueue");
 		}
 	}
+
+	ucb->read_error_count = 0;
 }
 
 static int ucb1400_ts_open(struct input_dev *idev)

include/linux/ucb1400.h

@@ -115,6 +115,7 @@ struct ucb1400_ts {
 	struct seco_filter_data	filter_data;
 	struct delayed_work	ts_reader;
 	struct workqueue_struct	*ts_workq;
+	unsigned		read_error_count;
 };
 
 struct ucb1400 {