[PATCH v3 1/1] Input: Improve the performance of alps v5-protocol's touchpad

[Yunkang Tang <tommywill2011@gmail.com>]

Hi all,

Here is the 3rd version of supporting ALPS v5 protocol's device

Change since v2:
- Merge two patches into one patch because they're all for improving v5 device.
- Modify the source code according to Kevin's suggestions.
  1) Simplify the alps_process_bitmap() function by using ffs() and fls().
  2) Simplify the alps_decode_dolphin() function by using u64 for the palm data.
  3) Reuse the alps_process_touchpad_packet_v3() for v5 device.
  4) Add an sample for calculating touchpad's x_max&y_max by using sensor line number.

Signed-off-by: Yunkang Tang <yunkang.tang@cn.alps.com>
---
 drivers/input/mouse/alps.c | 201 ++++++++++++++++++++++++++++++++++++---------
 drivers/input/mouse/alps.h |   7 +-
 2 files changed, 169 insertions(+), 39 deletions(-)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index ca7a26f..7cd0ac0 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -257,6 +257,50 @@ static void alps_process_packet_v1_v2(struct psmouse *psmouse)
 }
 
 /*
+ * Process bitmap data for V5 protocols. Return value is null.
+ *
+ * The bitmaps don't have enough data to track fingers, so this function
+ * only generates points representing a bounding box of at most two contacts.
+ * These two points are returned in x1, y1, x2, and y2.
+ */
+static void alps_process_bitmap_dolphin(struct alps_data *priv,
+					struct alps_fields *fields,
+					int *x1, int *y1, int *x2, int *y2)
+{
+	int box_middle_x, box_middle_y;
+	unsigned int x_map, y_map;
+	unsigned char start_bit, end_bit;
+
+	x_map = fields->x_map;
+	y_map = fields->y_map;
+
+	if (!x_map || !y_map)
+		return;
+
+	/* Most-significant bit should never exceed max sensor line number */
+	if (fls(x_map) > priv->x_bits || fls(y_map) > priv->y_bits)
+		return;
+
+	*x1 = *y1 = *x2 = *y2 = 0;
+
+	if (fields->fingers > 1) {
+		start_bit = priv->x_bits - fls(x_map);
+		end_bit = priv->x_bits - ffs(x_map);
+		box_middle_x = (priv->x_max * (start_bit + end_bit)) /
+				(2 * (priv->x_bits - 1));
+
+		start_bit = ffs(y_map) - 1;
+		end_bit = fls(y_map) - 1;
+		box_middle_y = (priv->y_max * (start_bit + end_bit)) /
+				(2 * (priv->y_bits - 1));
+		*x1 = fields->x;
+		*y1 = fields->y;
+		*x2 = 2 * box_middle_x - *x1;
+		*y2 = 2 * box_middle_y - *y1;
+	}
+}
+
+/*
  * Process bitmap data from v3 and v4 protocols. Returns the number of
  * fingers detected. A return value of 0 means at least one of the
  * bitmaps was empty.
@@ -461,7 +505,8 @@ static void alps_decode_buttons_v3(struct alps_fields *f, unsigned char *p)
 	f->ts_middle = !!(p[3] & 0x40);
 }
 
-static void alps_decode_pinnacle(struct alps_fields *f, unsigned char *p)
+static void alps_decode_pinnacle(struct alps_fields *f, unsigned char *p,
+				 struct psmouse *psmouse)
 {
 	f->first_mp = !!(p[4] & 0x40);
 	f->is_mp = !!(p[0] & 0x40);
@@ -482,48 +527,61 @@ static void alps_decode_pinnacle(struct alps_fields *f, unsigned char *p)
 	alps_decode_buttons_v3(f, p);
 }
 
-static void alps_decode_rushmore(struct alps_fields *f, unsigned char *p)
+static void alps_decode_rushmore(struct alps_fields *f, unsigned char *p,
+				 struct psmouse *psmouse)
 {
-	alps_decode_pinnacle(f, p);
+	alps_decode_pinnacle(f, p, psmouse);
 
 	f->x_map |= (p[5] & 0x10) << 11;
 	f->y_map |= (p[5] & 0x20) << 6;
 }
 
-static void alps_decode_dolphin(struct alps_fields *f, unsigned char *p)
+static void alps_decode_dolphin(struct alps_fields *f, unsigned char *p,
+				struct psmouse *psmouse)
 {
+	u64 palm_data = 0;
+	struct alps_data *priv = psmouse->private;
+
 	f->first_mp = !!(p[0] & 0x02);
 	f->is_mp = !!(p[0] & 0x20);
 
-	f->fingers = ((p[0] & 0x6) >> 1 |
+	if (!f->is_mp) {
+		f->x = ((p[1] & 0x7f) | ((p[4] & 0x0f) << 7));
+		f->y = ((p[2] & 0x7f) | ((p[4] & 0xf0) << 3));
+		f->z = (p[0] & 4) ? 0 : p[5] & 0x7f;
+		alps_decode_buttons_v3(f, p);
+	} else {
+		f->fingers = ((p[0] & 0x6) >> 1 |
 		     (p[0] & 0x10) >> 2);
-	f->x_map = ((p[2] & 0x60) >> 5) |
-		   ((p[4] & 0x7f) << 2) |
-		   ((p[5] & 0x7f) << 9) |
-		   ((p[3] & 0x07) << 16) |
-		   ((p[3] & 0x70) << 15) |
-		   ((p[0] & 0x01) << 22);
-	f->y_map = (p[1] & 0x7f) |
-		   ((p[2] & 0x1f) << 7);
-
-	f->x = ((p[1] & 0x7f) | ((p[4] & 0x0f) << 7));
-	f->y = ((p[2] & 0x7f) | ((p[4] & 0xf0) << 3));
-	f->z = (p[0] & 4) ? 0 : p[5] & 0x7f;
 
-	alps_decode_buttons_v3(f, p);
+		palm_data = (p[1] & 0x7f) |
+			    ((p[2] & 0x7f) << 7) |
+			    ((p[4] & 0x7f) << 14) |
+			    ((p[5] & 0x7f) << 21) |
+			    ((p[3] & 0x07) << 28) |
+			    (((u64)p[3] & 0x70) << 27) |
+			    (((u64)p[0] & 0x01) << 34);
+
+		/* Y-profile is stored in P(0) to p(n-1), n = y_bits; */
+		f->y_map = palm_data & (BIT(priv->y_bits) - 1);
+
+		/* X-profile is stored in p(n) to p(n+m-1), m = x_bits; */
+		f->x_map = (palm_data >> priv->y_bits) &
+			   (BIT(priv->x_bits) - 1);
+	}
 }
 
-static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
+static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
 	unsigned char *packet = psmouse->packet;
 	struct input_dev *dev = psmouse->dev;
 	struct input_dev *dev2 = priv->dev2;
 	int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
-	int fingers = 0, bmap_fingers;
-	struct alps_fields f;
+	int fingers = 0, bmap_fn;
+	struct alps_fields f = {0};
 
-	priv->decode_fields(&f, packet);
+	priv->decode_fields(&f, packet, psmouse);
 
 	/*
 	 * There's no single feature of touchpad position and bitmap packets
@@ -540,19 +598,27 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
 		 */
 		if (f.is_mp) {
 			fingers = f.fingers;
-			bmap_fingers = alps_process_bitmap(priv,
-							   f.x_map, f.y_map,
-							   &x1, &y1, &x2, &y2);
-
-			/*
-			 * We shouldn't report more than one finger if
-			 * we don't have two coordinates.
-			 */
-			if (fingers > 1 && bmap_fingers < 2)
-				fingers = bmap_fingers;
+			if (priv->proto_version == ALPS_PROTO_V3) {
+				bmap_fn = alps_process_bitmap(priv, f.x_map,
+							      f.y_map, &x1, &y1,
+							      &x2, &y2);
+
+				/*
+				 * We shouldn't report more than one finger if
+				 * we don't have two coordinates.
+				 */
+				if (fingers > 1 && bmap_fn < 2)
+					fingers = bmap_fn;
+			} else {
+				/* Since Dolphin's finger number is reliable,
+				 * there is no need to compare with bmap_fn.
+				 */
+				alps_process_bitmap_dolphin(priv, &f, &x1, &y1,
+							    &x2, &y2);
+			}
 
 			/* Now process position packet */
-			priv->decode_fields(&f, priv->multi_data);
+			priv->decode_fields(&f, priv->multi_data, psmouse);
 		} else {
 			priv->multi_packet = 0;
 		}
@@ -642,7 +708,7 @@ static void alps_process_packet_v3(struct psmouse *psmouse)
 		return;
 	}
 
-	alps_process_touchpad_packet_v3(psmouse);
+	alps_process_touchpad_packet_v3_v5(psmouse);
 }
 
 static void alps_process_packet_v4(struct psmouse *psmouse)
@@ -742,6 +808,17 @@ static void alps_process_packet_v4(struct psmouse *psmouse)
 	input_sync(dev);
 }
 
+static void alps_process_packet_v5(struct psmouse *psmouse)
+{
+	unsigned char *packet = psmouse->packet;
+
+	/* Ignore stick point data */
+	if (packet[0] == 0xD8)
+		return;
+
+	alps_process_touchpad_packet_v3_v5(psmouse);
+}
+
 static void alps_report_bare_ps2_packet(struct psmouse *psmouse,
 					unsigned char packet[],
 					bool report_buttons)
@@ -1519,6 +1596,52 @@ error:
 	return -1;
 }
 
+static int alps_dolphin_get_device_area(struct psmouse *psmouse,
+					struct alps_data *priv)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[4] = {0};
+	int num_x_electrode, num_y_electrode;
+
+	if (alps_enter_command_mode(psmouse))
+		return -1;
+
+	if (ps2_command(ps2dev, NULL, 0x00EC) ||
+	    ps2_command(ps2dev, NULL, 0x00F0) ||
+	    ps2_command(ps2dev, NULL, 0x00F0) ||
+	    ps2_command(ps2dev, NULL, 0x00F3) ||
+	    ps2_command(ps2dev, NULL, 0x000A) ||
+	    ps2_command(ps2dev, NULL, 0x00F3) ||
+	    ps2_command(ps2dev, NULL, 0x000A))
+		return -1;
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	/* Dolphin's sensor line number is not fixed. It can be calculated
+	 * by adding the device's register value with DOLPHIN_PROFILE_X/YOFFSET.
+	 * Further more, we can get device's x_max and y_max by multiplying
+	 * sensor line number with DOLPHIN_COUNT_PER_ELECTRODE.
+	 *
+	 * e.g. When we get register's sensor_x = 11 & sensor_y = 8,
+	 *	real sensor line number X = 11 + 8 = 19, and
+	 *	real sensor line number Y = 8 + 1 = 9.
+	 *	So, x_max = (19 - 1) * 64 = 1152, and
+	 *	    y_max = (9 - 1) * 64 = 512.
+	 */
+	num_x_electrode = DOLPHIN_PROFILE_XOFFSET + (param[2] & 0x0F);
+	num_y_electrode = DOLPHIN_PROFILE_YOFFSET + ((param[2] >> 4) & 0x0F);
+	priv->x_bits = num_x_electrode;
+	priv->y_bits = num_y_electrode;
+	priv->x_max = (num_x_electrode - 1) * DOLPHIN_COUNT_PER_ELECTRODE;
+	priv->y_max = (num_y_electrode - 1) * DOLPHIN_COUNT_PER_ELECTRODE;
+
+	if (alps_exit_command_mode(psmouse))
+		return -1;
+
+	return 0;
+}
+
 static int alps_hw_init_dolphin_v1(struct psmouse *psmouse)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
@@ -1571,7 +1694,7 @@ static void alps_set_defaults(struct alps_data *priv)
 		break;
 	case ALPS_PROTO_V5:
 		priv->hw_init = alps_hw_init_dolphin_v1;
-		priv->process_packet = alps_process_packet_v3;
+		priv->process_packet = alps_process_packet_v5;
 		priv->decode_fields = alps_decode_dolphin;
 		priv->set_abs_params = alps_set_abs_params_mt;
 		priv->nibble_commands = alps_v3_nibble_commands;
@@ -1645,11 +1768,13 @@ static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
 	if (alps_match_table(psmouse, priv, e7, ec) == 0) {
 		return 0;
 	} else if (e7[0] == 0x73 && e7[1] == 0x03 && e7[2] == 0x50 &&
-		   ec[0] == 0x73 && ec[1] == 0x01) {
+		   ec[0] == 0x73 && (ec[1] == 0x01 || ec[1] == 0x02)) {
 		priv->proto_version = ALPS_PROTO_V5;
 		alps_set_defaults(priv);
-
-		return 0;
+		if (alps_dolphin_get_device_area(psmouse, priv))
+			return -EIO;
+		else
+			return 0;
 	} else if (ec[0] == 0x88 && ec[1] == 0x08) {
 		priv->proto_version = ALPS_PROTO_V3;
 		alps_set_defaults(priv);
diff --git a/drivers/input/mouse/alps.h b/drivers/input/mouse/alps.h
index eee5985..c5c53f4 100644
--- a/drivers/input/mouse/alps.h
+++ b/drivers/input/mouse/alps.h
@@ -18,6 +18,10 @@
 #define ALPS_PROTO_V4	4
 #define ALPS_PROTO_V5	5
 
+#define DOLPHIN_COUNT_PER_ELECTRODE	64
+#define DOLPHIN_PROFILE_XOFFSET		8	/* x-electrode offset */
+#define DOLPHIN_PROFILE_YOFFSET		1	/* y-electrode offset */
+
 /**
  * struct alps_model_info - touchpad ID table
  * @signature: E7 response string to match.
@@ -145,7 +149,8 @@ struct alps_data {
 
 	int (*hw_init)(struct psmouse *psmouse);
 	void (*process_packet)(struct psmouse *psmouse);
-	void (*decode_fields)(struct alps_fields *f, unsigned char *p);
+	void (*decode_fields)(struct alps_fields *f, unsigned char *p,
+			      struct psmouse *psmouse);
 	void (*set_abs_params)(struct alps_data *priv, struct input_dev *dev1);
 
 	int prev_fin;
-- 
1.8.1.2