[PATCH 6/6] Input: elantech - add v3 hardware support

[JJ Ding <jj_ding@emc.com.tw>]

v3 hardware's packet format is almost identical to v2 (one/three finger touch),
except when sensing two finger touch, the hardware sends 12 bytes of data.

Signed-off-by: JJ Ding <jj_ding@emc.com.tw>
---
 Documentation/input/elantech.txt |  104 ++++++++++++++++--
 drivers/input/mouse/elantech.c   |  218 ++++++++++++++++++++++++++++++++++---
 drivers/input/mouse/elantech.h   |   11 ++
 3 files changed, 303 insertions(+), 30 deletions(-)

diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
index bce9941..ce578bd 100644
--- a/Documentation/input/elantech.txt
+++ b/Documentation/input/elantech.txt
@@ -16,15 +16,22 @@ Contents
 
  1. Introduction
  2. Extra knobs
- 3. Hardware version 1
-    3.1 Registers
-    3.2 Native relative mode 4 byte packet format
-    3.3 Native absolute mode 4 byte packet format
- 4. Hardware version 2
+ 3. Differentiating hardware versions
+ 4. Hardware version 1
     4.1 Registers
-    4.2 Native absolute mode 6 byte packet format
-        4.2.1 One finger touch
-        4.2.2 Two finger touch
+    4.2 Native relative mode 4 byte packet format
+    4.3 Native absolute mode 4 byte packet format
+ 5. Hardware version 2
+    5.1 Registers
+    5.2 Native absolute mode 6 byte packet format
+        5.2.1 Parity checking and packet re-synchronization
+        5.2.2 One/Three finger touch
+        5.2.3 Two finger touch
+ 6. Hardware version 3
+    6.1 Registers
+    6.2 Native absolute mode 6 byte packet format
+        6.2.1 One/Three finger touch
+        6.2.2 Two finger touch
 
 
 
@@ -375,7 +382,7 @@ For all the other ones, there are just a few constant bits:
 
 In case an error is detected, all the packets are shifted by one (and packet[0] is discarded).
 
-5.2.1 One/Three finger touch
+5.2.2 One/Three finger touch
       ~~~~~~~~~~~~~~~~
 
 byte 0:
@@ -384,7 +391,7 @@ byte 0:
 	 n1  n0  w3  w2   .   .   R   L
 
          L, R = 1 when Left, Right mouse button pressed
-         n1..n0 = numbers of fingers on touchpad
+         n1..n0 = number of fingers on touchpad
 
 byte 1:
 
@@ -432,7 +439,7 @@ byte 5:
          y11..y0 = absolute y value (vertical)
 
 
-4.2.2 Two finger touch
+5.2.3 Two finger touch
       ~~~~~~~~~~~~~~~~
 
 Note that the two pairs of coordinates are not exactly the coordinates of the
@@ -446,7 +453,7 @@ byte 0:
         n1  n0  ay8 ax8  .   .   R   L
 
          L, R = 1 when Left, Right mouse button pressed
-         n1..n0 = numbers of fingers on touchpad
+         n1..n0 = number of fingers on touchpad
 
 byte 1:
 
@@ -480,3 +487,76 @@ byte 5:
         by7 by8 by5 by4 by3 by2 by1 by0
 
          by8..by0 = upper-right finger absolute y value
+
+/////////////////////////////////////////////////////////////////////////////
+
+6. Hardware version 3
+   ==================
+
+6.1 Registers
+    ~~~~~~~~~
+* reg_10
+
+   bit   7   6   5   4   3   2   1   0
+         0   0   0   0   0   0   0   A
+
+         A: 1 = enable absolute tracking
+
+6.2 Native absolute mode 6 byte packet format
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+1 and 3 finger touch shares the same 6-byte packet format, except that
+3 finger touch only reports the position of the center of all three fingers.
+
+Firmware would send 12 bytes of data for 2 finger touch.
+
+6.2.1 One/Three finger touch
+      ~~~~~~~~~~~~~~~~~~~~~~
+
+byte 0:
+
+   bit   7   6   5   4   3   2   1   0
+        n1  n0  w3  w2   0   1   R   L
+
+        L, R = 1 when Left, Right mouse button pressed
+        n1..n0 = number of fingers on touchpad
+
+byte 1:
+
+   bit   7   6   5   4   3   2   1   0
+        p7  p6  p5  p4 x11 x10  x9  x8
+
+byte 2:
+
+   bit   7   6   5   4   3   2   1   0
+        x7  x6  x5  x4  x3  x2  x1  x0
+
+        x11..x0 = absolute x value (horizontal)
+
+byte 3:
+
+   bit   7   6   5   4   3   2   1   0
+         0   0  w1  w0   0   0   1   0
+
+         w3..w0 = width of the finger touch
+
+byte 4:
+
+   bit   7   6   5   4   3   2   1   0
+        p3  p1  p2  p0  y11 y10 y9  y8
+
+        p7..p0 = pressure
+
+byte 5:
+
+   bit   7   6   5   4   3   2   1   0
+        y7  y6  y5  y4  y3  y2  y1  y0
+
+        y11..y0 = absolute y value (vertical)
+
+6.2.2 Two finger touch
+      ~~~~~~~~~~~~~~~~
+
+The packet format is exactly the same for two finger touch, except the hardware
+sends two 6 byte packets. The first packet contains data for the first finger,
+the second packet has data for the second finger. So for two finger touch a
+total of 12 bytes are sent.
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index ddd40eb..e13a719 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -108,6 +108,16 @@ static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
 			rc = -1;
 		}
 		break;
+
+	case 3:
+		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+		    elantech_ps2_command(psmouse, NULL, reg) ||
+		    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
+			rc = -1;
+		}
+		break;
 	}
 
 	if (rc)
@@ -154,6 +164,18 @@ static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
 			rc = -1;
 		}
 		break;
+
+	case 3:
+		if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+		    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+		    elantech_ps2_command(psmouse, NULL, reg) ||
+		    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+		    elantech_ps2_command(psmouse, NULL, val) ||
+		    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
+			rc = -1;
+		}
+		break;
 	}
 
 	if (rc)
@@ -352,6 +374,94 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
 	input_sync(dev);
 }
 
+/*
+ * firmware tells us there's noise.
+ */
+static inline int debounce(unsigned int x, unsigned int y)
+{
+	return (x == 0xfff) && (y == 0xfff);
+}
+
+/*
+ * Interpret complete data packets and report absolute mode input events for
+ * hardware version 3. (12 byte packets for two fingers)
+ */
+static void elantech_report_absolute_v3(struct psmouse *psmouse,
+					int packet_type)
+{
+	struct input_dev *dev = psmouse->dev;
+	struct elantech_data *etd = psmouse->private;
+	unsigned char *packet = psmouse->packet;
+	unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
+	unsigned int width = 0, pres = 0;
+
+	/* byte 0: n1  n0   .   .   .   .   R   L */
+	fingers = (packet[0] & 0xc0) >> 6;
+
+	switch (fingers) {
+	case 3:
+	case 1:
+		/*
+		 * byte 1:  .   .   .   .  x11 x10 x9  x8
+		 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
+		 */
+		x1 = ((packet[1] & 0x0f) << 8) | packet[2];
+		/*
+		 * byte 4:  .   .   .   .  y11 y10 y9  y8
+		 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
+		 */
+		y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
+
+		if (fingers == 3 && debounce(x1, y1))
+			return;
+
+		break;
+
+	case 2:
+		if (packet_type == PACKET_V3_HEAD) {
+			/*
+			 * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
+			 * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
+			 */
+			etd->prev_x = ((packet[1] & 0x0f) << 8) | packet[2];
+			/*
+			 * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
+			 * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
+			 */
+			etd->prev_y = etd->y_max -
+				(((packet[4] & 0x0f) << 8) | packet[5]);
+			/*
+			 * wait for next packet
+			 */
+			return;
+		}
+
+		/* packet_type == PACKET_V3_TAIL */
+		x1 = etd->prev_x;
+		y1 = etd->prev_y;
+		x2 = ((packet[1] & 0x0f) << 8) | packet[2];
+		y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
+		break;
+	}
+
+	pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
+	width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
+
+	input_report_key(dev, BTN_TOUCH, fingers != 0);
+	input_report_abs(dev, ABS_X, x1);
+	input_report_abs(dev, ABS_Y, y1);
+	elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
+	input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
+	input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
+	input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
+	input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
+	input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
+	input_report_abs(dev, ABS_PRESSURE, pres);
+	input_report_abs(dev, ABS_TOOL_WIDTH, width);
+
+	input_sync(dev);
+}
+
 static int elantech_check_parity_v1(struct psmouse *psmouse)
 {
 	struct elantech_data *etd = psmouse->private;
@@ -396,11 +506,31 @@ static int packet_simple_check_v2(struct psmouse *psmouse)
 }
 
 /*
+ * We check the constant bits to determine what packet type we get,
+ * so packet checking is mandatory for v3 hardware.
+ */
+static int determine_packet_v3(struct psmouse *psmouse)
+{
+	unsigned char *packet = psmouse->packet;
+
+	if ((packet[0] & 0x0c) == 0x04 &&
+	    (packet[3] & 0xcf) == 0x02)
+		return PACKET_V3_HEAD;
+
+	if ((packet[0] & 0x0c) == 0x0c &&
+	    (packet[3] & 0xce) == 0x0c)
+		return PACKET_V3_TAIL;
+
+	return PACKET_UNKNOWN;
+}
+
+/*
  * Process byte stream from mouse and handle complete packets
  */
 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 {
 	struct elantech_data *etd = psmouse->private;
+	int packet_type;
 
 	if (psmouse->pktcnt < psmouse->pktsize)
 		return PSMOUSE_GOOD_DATA;
@@ -422,6 +552,14 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 
 		elantech_report_absolute_v2(psmouse);
 		break;
+
+	case 3:
+		packet_type = determine_packet_v3(psmouse);
+		if (packet_type == PACKET_UNKNOWN)
+			goto bad_packet;
+
+		elantech_report_absolute_v3(psmouse, packet_type);
+		break;
 	}
 
 	return PSMOUSE_FULL_PACKET;
@@ -459,10 +597,17 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
 		etd->reg_21 = 0x60;	/* 0x00 */
 		if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 		    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
-		    elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
+		    elantech_write_reg(psmouse, 0x21, etd->reg_21))
 			rc = -1;
-			break;
-		}
+
+		break;
+
+	case 3:
+		etd->reg_10 = 0x0b;
+		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
+			rc = -1;
+
+		break;
 	}
 
 	if (rc == 0) {
@@ -496,11 +641,12 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
 	return rc;
 }
 
-static void set_range(struct psmouse *psmouse, unsigned int *x_min,
+static int set_range(struct psmouse *psmouse, unsigned int *x_min,
 		     unsigned int *y_min, unsigned int *x_max,
 		     unsigned int *y_max, unsigned int *y_2ft_max)
 {
 	struct elantech_data *etd = psmouse->private;
+	unsigned char param[3];
 	int i;
 
 	switch (etd->hw_version) {
@@ -529,19 +675,30 @@ static void set_range(struct psmouse *psmouse, unsigned int *x_min,
 		*y_max = (etd->capabilities[2] - i) * 64;
 		*y_2ft_max = (*y_max - i) * 64 / 4;
 		break;
+
+	case 3:
+		if (synaptics_send_cmd(psmouse, ETP_FW_ID_QUERY, param))
+			return -1;
+
+		*x_max = (0x0f & param[0]) << 8 | param[1];
+		*y_max = (0xf0 & param[0]) << 4 | param[2];
+		break;
 	}
+
+	return 0;
 }
 
 /*
  * Set the appropriate event bits for the input subsystem
  */
-static void elantech_set_input_params(struct psmouse *psmouse)
+static int elantech_set_input_params(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
 	struct elantech_data *etd = psmouse->private;
 	unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, y_2ft_max = 0;
 
-	set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &y_2ft_max);
+	if (set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &y_2ft_max))
+		return -1;
 
 	__set_bit(EV_KEY, dev->evbit);
 	__set_bit(EV_ABS, dev->evbit);
@@ -582,10 +739,26 @@ static void elantech_set_input_params(struct psmouse *psmouse)
 		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
 		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
 		break;
+
+	case 3:
+		input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
+		input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
+		/* range of pressure and width is the same as v2 */
+		input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
+				     ETP_PMAX_V2, 0, 0);
+		input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
+				     ETP_WMAX_V2, 0, 0);
+		__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
+		input_mt_init_slots(dev, 2);
+		input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
+		input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
+		break;
 	}
 
 	etd->y_max = y_max;
 	etd->y_2ft_max = y_2ft_max;
+
+	return 0;
 }
 
 struct elantech_attr_data {
@@ -727,7 +900,8 @@ int elantech_detect(struct psmouse *psmouse, bool set_properties)
 	 * Report this in case there are Elantech models that use a different
 	 * set of magic numbers
 	 */
-	if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
+	if (param[0] != 0x3c || param[1] != 0x03 ||
+	    (param[2] != 0xc8 && param[2] != 0x00)) {
 		pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
 			 param[0], param[1], param[2]);
 		return -1;
@@ -793,16 +967,16 @@ static int elantech_reconnect(struct psmouse *psmouse)
 /*
  * determine hardware version and set some properties according to it.
  */
-static void elantech_set_properties(struct elantech_data *etd)
+static int elantech_set_properties(struct elantech_data *etd)
 {
-	/*
-	 * Assume every version greater than 0x020030 is new EeePC style
-	 * hardware with 6 byte packets, except 0x020600
-	 */
 	if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
 		etd->hw_version = 1;
-	else
+	else if (etd->fw_version < 0x150600)
 		etd->hw_version = 2;
+	else if ((etd->fw_version & 0x0f0000) >> 16 == 5)
+		etd->hw_version = 3;
+	else
+		return -1;
 
 	/*
 	 * Turn on packet checking by default.
@@ -817,13 +991,15 @@ static void elantech_set_properties(struct elantech_data *etd)
 	etd->jumpy_cursor =
 		(etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
 
-	if (etd->hw_version == 2) {
+	if (etd->hw_version > 1) {
 		/* For now show extra debug information */
 		etd->debug = 1;
 
 		if (etd->fw_version >= 0x020800)
 			etd->reports_pressure = true;
 	}
+
+	return 0;
 }
 
 /*
@@ -850,9 +1026,12 @@ int elantech_init(struct psmouse *psmouse)
 		pr_err("failed to query firmware version.\n");
 		goto init_fail;
 	}
-
 	etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
-	elantech_set_properties(etd);
+
+	if (elantech_set_properties(etd)) {
+		pr_err("unknown hardware version, aborting...\n");
+		goto init_fail;
+	}
 	pr_info("assuming hardware version %d "
 		"(with firmware version 0x%02x%02x%02x)\n",
 		etd->hw_version, param[0], param[1], param[2]);
@@ -871,7 +1050,10 @@ int elantech_init(struct psmouse *psmouse)
 		goto init_fail;
 	}
 
-	elantech_set_input_params(psmouse);
+	if (elantech_set_input_params(psmouse)) {
+		pr_err("failed to query touchpad range.\n");
+		goto init_fail;
+	}
 
 	error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
 				   &elantech_attr_group);
@@ -883,7 +1065,7 @@ int elantech_init(struct psmouse *psmouse)
 	psmouse->protocol_handler = elantech_process_byte;
 	psmouse->disconnect = elantech_disconnect;
 	psmouse->reconnect = elantech_reconnect;
-	psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
+	psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
 
 	return 0;
 
diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index 4b7447e..4f01fc6 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -16,6 +16,7 @@
 /*
  * Command values for Synaptics style queries
  */
+#define ETP_FW_ID_QUERY			0x00
 #define ETP_FW_VERSION_QUERY		0x01
 #define ETP_CAPABILITIES_QUERY		0x02
 
@@ -24,6 +25,7 @@
  */
 #define ETP_REGISTER_READ		0x10
 #define ETP_REGISTER_WRITE		0x11
+#define ETP_REGISTER_READWRITE		0x00
 
 /*
  * Hardware version 2 custom PS/2 command value
@@ -93,6 +95,13 @@
 #define ETP_2FT_YMIN			(  0 + ETP_2FT_FUZZ)
 #define ETP_2FT_YMAX			(192 - ETP_2FT_FUZZ)
 
+/*
+ * v3 hardware has 2 kinds of packet types.
+ */
+#define PACKET_UNKNOWN			0x01
+#define PACKET_V3_HEAD			0x02
+#define PACKET_V3_TAIL			0x03
+
 struct elantech_data {
 	unsigned char reg_10;
 	unsigned char reg_11;
@@ -113,6 +122,8 @@ struct elantech_data {
 	unsigned int single_finger_reports;
 	unsigned int y_max;
 	unsigned int y_2ft_max;
+	unsigned int prev_x;
+	unsigned int prev_y;
 	unsigned char parity[256];
 };
 
-- 
1.7.4.1