[PATCH 2/5] Input: ads7846 - simplify sample filtering

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

The filter and filter_data members of struct ads7846, along with the
generic signature of ads7846_debounce_filter(), are leftovers from
custom filter callbacks that were removed in commit 937f5d5ec642
("Input: ads7846 - remove custom filter handling functions from pdata").

Drop the filter and filter_data function pointers, remove the unused
ads7846_no_filter() stub, simplify ads7846_debounce_filter() to take
struct ads7846 and the sample value directly, and call it without
pointer indirection.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/touchscreen/ads7846.c | 72 ++++++++++++-----------------
 1 file changed, 30 insertions(+), 42 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 9bcb2ef129cd..f1827684c902 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -135,8 +135,6 @@ struct ads7846 {
 	bool			suspended;	/* P: lock */
 
 	void			(*read_state)(struct ads7846 *ts);
-	int			(*filter)(void *data, int data_idx, int *val);
-	void			*filter_data;
 	struct gpio_desc	*gpio_pendown;
 	struct gpio_desc	*gpio_hsync;
 };
@@ -631,11 +629,12 @@ ATTRIBUTE_GROUPS(ads784x);
 
 /*--------------------------------------------------------------------------*/
 
-static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
+static enum ads7846_filter ads7846_debounce_filter(struct ads7846 *ts, int val)
 {
-	struct ads7846 *ts = ads;
+	if (!ts->debounce_max)
+		return ADS7846_FILTER_OK;
 
-	if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
+	if (!ts->read_cnt || abs(ts->last_read - val) > ts->debounce_tol) {
 		/* Start over collecting consistent readings. */
 		ts->read_rep = 0;
 		/*
@@ -643,39 +642,34 @@ static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 		 * wasn't consistent enough.
 		 */
 		if (ts->read_cnt < ts->debounce_max) {
-			ts->last_read = *val;
-			ts->read_cnt++;
-			return ADS7846_FILTER_REPEAT;
-		} else {
-			/*
-			 * Maximum number of debouncing reached and still
-			 * not enough number of consistent readings. Abort
-			 * the whole sample, repeat it in the next sampling
-			 * period.
-			 */
-			ts->read_cnt = 0;
-			return ADS7846_FILTER_IGNORE;
-		}
-	} else {
-		if (++ts->read_rep > ts->debounce_rep) {
-			/*
-			 * Got a good reading for this coordinate,
-			 * go for the next one.
-			 */
-			ts->read_cnt = 0;
-			ts->read_rep = 0;
-			return ADS7846_FILTER_OK;
-		} else {
-			/* Read more values that are consistent. */
+			ts->last_read = val;
 			ts->read_cnt++;
 			return ADS7846_FILTER_REPEAT;
 		}
+
+		/*
+		 * Maximum number of debouncing reached and still
+		 * not enough number of consistent readings. Abort
+		 * the whole sample, repeat it in the next sampling
+		 * period.
+		 */
+		ts->read_cnt = 0;
+		return ADS7846_FILTER_IGNORE;
 	}
-}
 
-static int ads7846_no_filter(void *ads, int data_idx, int *val)
-{
-	return ADS7846_FILTER_OK;
+	if (++ts->read_rep > ts->debounce_rep) {
+		/*
+		 * Got a good reading for this coordinate,
+		 * go for the next one.
+		 */
+		ts->read_cnt = 0;
+		ts->read_rep = 0;
+		return ADS7846_FILTER_OK;
+	}
+
+	/* Read more values that are consistent. */
+	ts->read_cnt++;
+	return ADS7846_FILTER_REPEAT;
 }
 
 static int ads7846_get_value(struct ads7846_buf *buf)
@@ -759,7 +753,7 @@ static int ads7846_filter_cmd(struct ads7846 *ts, unsigned int cmd_idx)
 	for (b = l->skip; b < l->count; b++) {
 		int val = ads7846_get_value(&packet->rx[l->offset + b]);
 
-		switch (ts->filter(ts->filter_data, cmd_idx, &val)) {
+		switch (ads7846_debounce_filter(ts, val)) {
 		case ADS7846_FILTER_REPEAT:
 			if (b == l->count - 1)
 				return -EAGAIN;
@@ -1367,14 +1361,8 @@ static int ads7846_probe(struct spi_device *spi)
 	device_property_read_u16(dev, "ti,debounce-tol", &ts->debounce_tol);
 	device_property_read_u16(dev, "ti,debounce-rep", &ts->debounce_rep);
 
-	if (ts->debounce_max) {
-		if (ts->debounce_max < 2)
-			ts->debounce_max = 2;
-		ts->filter = ads7846_debounce_filter;
-		ts->filter_data = ts;
-	} else {
-		ts->filter = ads7846_no_filter;
-	}
+	if (ts->debounce_max && ts->debounce_max < 2)
+		ts->debounce_max = 2;
 
 	err = ads7846_setup_pendown(ts);
 	if (err)
-- 
2.56.0.567.gdb80ae8cd5-goog