[PATCH] psmouse: added BYD touchpad driver

[PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

This adds proper single-touch support for BYD touchpads to the psmouse input
driver.

This patch is against commit b82dde0230439215b55e545880e90337ee16f51a (Merge tag
'please-pull-copy_file_range' of
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux ) of Linus' kernel
branch.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
---
 Kconfig        |    9
 Makefile       |    1
 byd.c          |  586 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 byd.h          |   33 +++
 psmouse-base.c |   17 +
 psmouse.h      |    1
 6 files changed, 647 insertions(+)
diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 17f97e5..63d5349 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -161,6 +161,15 @@ config MOUSE_PS2_VMMOUSE

   If unsure, say N.

+config MOUSE_PS2_BYD
+ bool "BYD PS/2 protocol extension"
+ depends on MOUSE_PS2
+ help
+  Say Y here if you have a BYD PS/2 touchpad
+  connected to your system.
+
+  If unsure, say N.
+
 config MOUSE_SERIAL
  tristate "Serial mouse"
  select SERIO
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index ee6a6e9..67f22cc 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -37,6 +37,7 @@ psmouse-$(CONFIG_MOUSE_PS2_TRACKPOINT) += trackpoint.o
 psmouse-$(CONFIG_MOUSE_PS2_TOUCHKIT) += touchkit_ps2.o
 psmouse-$(CONFIG_MOUSE_PS2_CYPRESS) += cypress_ps2.o
 psmouse-$(CONFIG_MOUSE_PS2_VMMOUSE) += vmmouse.o
+psmouse-$(CONFIG_MOUSE_PS2_BYD) += byd.o

 elan_i2c-objs := elan_i2c_core.o
 elan_i2c-$(CONFIG_MOUSE_ELAN_I2C_I2C) += elan_i2c_i2c.o
diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
new file mode 100644
index 0000000..a880adb
--- /dev/null
+++ b/drivers/input/mouse/byd.c
@@ -0,0 +1,586 @@
+/*
+ * BYD BTP-10463 touchpad PS/2 mouse driver
+ *
+ * Copyright (C) 2015, Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015, Martin Wimpress
+ * Copyright (C) 2015, Jay Kuri
+ * Copyright (C) 2015, Richard Pospesel
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
+ *
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+#include <linux/libps2.h>
+
+#include "psmouse.h"
+#include "byd.h"
+
+#define BYD_MODEL_ID_LEN        2
+#define BYD_CMD_PAIR(c) ((1 << 12) | (c))
+#define BYD_CMD_PAIR_R(r, c) ((1 << 12) | (r << 8) | (c))
+
+/* BYD pad constants */
+
+/*
+ * true device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm
+ * absolute coordinate packets are in the range 0-255 for both X and y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm
+ */
+
+#define BYD_CONST_PAD_WIDTH                     11264
+#define BYD_CONST_PAD_HEIGHT                    6656
+#define BYD_CONST_PAD_RESOLUTION                111
+
+
+/* BYD commands reverse engineered from windows driver */
+
+/*
+ * swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
+/*
+ * tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
+/*
+ * physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
+/*
+ * absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
+/*
+ * two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
+/*
+ * handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS                  0xd3
+/*
+ * tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP                         0xd4
+/*
+ * tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG                    0xd5
+/*
+ * touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
+/*
+ * one finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
+/*
+ * one finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
+/*
+ * sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED               0xda
+/*
+ * edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION                 0xdb
+/*
+ * left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
+/*
+ * top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
+/*
+ * disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK                  0xde
+/* right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
+/*
+ * bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
+/*
+ * multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH                  0xe3
+/*
+ * edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
+/*
+ * two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5
+
+/* BYD Packets */
+
+#define BYD_PKT_RELATIVE                        0x00
+#define BYD_PKT_ABSOLUTE                        0xf8
+#define BYD_PKT_PINCH_IN                        0xd8
+#define BYD_PKT_PINCH_OUT                       0x28
+#define BYD_PKT_ROTATE_CLOCKWISE                0x29
+#define BYD_PKT_ROTATE_ANTICLOCKWISE            0xd7
+#define BYD_PKT_TWO_FINGER_SCROLL_RIGHT         0x2a
+#define BYD_PKT_TWO_FINGER_SCROLL_DOWN          0x2b
+#define BYD_PKT_TWO_FINGER_SCROLL_UP            0xd5
+#define BYD_PKT_TWO_FINGER_SCROLL_LEFT          0xd6
+#define BYD_PKT_THREE_FINGER_SWIPE_RIGHT        0x2c
+#define BYD_PKT_THREE_FINGER_SWIPE_DOWN         0x2d
+#define BYD_PKT_THREE_FINGER_SWIPE_UP           0xd3
+#define BYD_PKT_THREE_FINGER_SWIPE_LEFT         0xd4
+#define BYD_PKT_FOUR_FINGER_DOWN                0x33
+#define BYD_PKT_FOUR_FINGER_UP                  0xcd
+#define BYD_PKT_REGION_SCROLL_RIGHT             0x35
+#define BYD_PKT_REGION_SCROLL_DOWN              0x36
+#define BYD_PKT_REGION_SCROLL_UP                0xca
+#define BYD_PKT_REGION_SCROLL_LEFT              0xcb
+#define BYD_PKT_RIGHT_CORNER_CLICK              0xd2
+#define BYD_PKT_LEFT_CORNER_CLICK               0x2e
+#define BYD_PKT_LEFT_AND_RIGHT_CORNER_CLICK     0x2f
+#define BYD_PKT_ONTO_PAD_SWIPE_RIGHT            0x37
+#define BYD_PKT_ONTO_PAD_SWIPE_DOWN             0x30
+#define BYD_PKT_ONTO_PAD_SWIPE_UP               0xd0
+#define BYD_PKT_ONTO_PAD_SWIPE_LEFT             0xc9
+
+struct byd_init_command_pair {
+ uint8_t command;
+ uint8_t  value;
+};
+
+static const struct byd_init_command_pair init_commands[] = {
+ {BYD_CMD_SET_HANDEDNESS, 0x01},
+ {BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04},
+ {BYD_CMD_SET_TAP, 0x02},
+ {BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04},
+ {BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04},
+ {BYD_CMD_SET_EDGE_MOTION, 0x01},
+ {BYD_CMD_SET_PALM_CHECK, 0x00},
+ {BYD_CMD_SET_MULTITOUCH, 0x02},
+ {BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04},
+ {BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04},
+ {BYD_CMD_SET_LEFT_EDGE_REGION, 0x00},
+ {BYD_CMD_SET_TOP_EDGE_REGION, 0x00},
+ {BYD_CMD_SET_RIGHT_EDGE_REGION, 0x0},
+ {BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00},
+ {BYD_CMD_SET_ABSOLUTE_MODE, 0x02},
+};
+
+struct byd_model_info {
+ char name[16];
+ char id[BYD_MODEL_ID_LEN];
+};
+
+static struct byd_model_info byd_model_data[] = {
+ { "BTP10463", { 0x03, 0x64 } }
+};
+
+struct byd_data {
+ struct timer_list timer;
+ int32_t abs_x;
+ int32_t abs_y;
+ uint32_t last_touch_time;
+ uint32_t button_left      : 1;
+ uint32_t button_right     : 1;
+ uint32_t touch            : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+ struct byd_data *priv = (struct byd_data *)psmouse->private;
+ struct input_dev *dev = psmouse->dev;
+
+ input_report_abs(dev, ABS_X, priv->abs_x);
+ input_report_abs(dev, ABS_Y, priv->abs_y);
+ input_report_key(dev, BTN_LEFT, priv->button_left);
+ input_report_key(dev, BTN_RIGHT, priv->button_right);
+ input_report_key(dev, BTN_TOUCH, priv->touch);
+ input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+
+ input_sync(dev);
+}
+
+static void byd_clear_touch(unsigned long data)
+{
+ struct psmouse *psmouse = (struct psmouse *)data;
+ struct byd_data *priv = psmouse->private;
+
+ serio_pause_rx(psmouse->ps2dev.serio);
+
+ priv->touch = 0;
+ /*
+ * move cursor back to center of pad when we lose touch
+ * this specifically improves user experiencce when moving
+ * cursor with one finger, and pressing butoton with other
+ */
+ priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
+ priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
+
+ byd_report_input(psmouse);
+
+ serio_continue_rx(psmouse->ps2dev.serio);
+}
+
+static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
+{
+ struct byd_data *priv = psmouse->private;
+ unsigned char *packet = psmouse->packet;
+ uint32_t now_msecs = jiffies_to_msecs(jiffies);
+
+
+ if (psmouse->pktcnt < psmouse->pktsize)
+ return PSMOUSE_GOOD_DATA;
+
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "process: packet = %x %x %x %x\n",
+ packet[0], packet[1], packet[2], packet[3]);
+#endif
+
+ switch (packet[3]) {
+ case BYD_PKT_ABSOLUTE:
+ /* on first touch, use the absolute packet to determine our start location */
+ if (priv->touch == 0) {
+ priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
+ priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
+
+ /* needed to detect tap */
+ if (now_msecs - priv->last_touch_time > 64) {
+ priv->touch = 1;
+ }
+ }
+ break;
+ case BYD_PKT_RELATIVE:
+ {
+ int32_t rel_x, rel_y;
+
+ /* same as regular PS/2 psmouse protocoal */
+ rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) & 0x100) : 0;
+ rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int) packet[2] : 0;
+
+ /*
+ * experiments show relative mouse packets come in increments of
+ * 1 unit / 11 msecs (regardless of time delta between relative packets)
+ */
+ priv->abs_x += rel_x * 11;
+ priv->abs_y += rel_y * 11;
+
+ priv->touch = 1;
+ }
+ break;
+ default:
+ /* shoudn't be sending anything else, but ignore just in-case */
+ return PSMOUSE_FULL_PACKET;
+ }
+
+ /* both ABS and REL packets report button states */
+ priv->button_left = packet[0] & 1;
+ priv->button_right = (packet[0] >> 1) & 1;
+
+ byd_report_input(psmouse);
+
+ /* reset time since last touch */
+ if (priv->touch == 1) {
+ priv->last_touch_time = now_msecs;
+ mod_timer(&priv->timer, jiffies + msecs_to_jiffies(64));
+ }
+
+ return PSMOUSE_FULL_PACKET;
+}
+
+int byd_init(struct psmouse *psmouse)
+{
+ struct byd_data *priv;
+ struct ps2dev *ps2dev = &psmouse->ps2dev;
+ unsigned char param[4];
+ int cmd, error = 0;
+ int i = 0;
+
+ /* it needs to be initialised like an intellimouse to get 4-byte packets */
+ psmouse_reset(psmouse);
+ param[0] = 200;
+ ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+ param[0] = 100;
+ ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+ param[0] =  80;
+ ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+ ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
+
+ if (param[0] != 3)
+ return -1;
+
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: init sequence\n");
+#endif
+
+ /* activate the mouse to initialise it */
+ psmouse_activate(psmouse);
+
+ /* enter command mode */
+ param[0] = 0x00;
+ if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe2))) {
+ error = -EIO;
+ goto init_fail;
+ }
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: entered command mode\n");
+#endif
+
+ /* send second identification command */
+ param[0] = 0x02;
+ if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe0))) {
+ error = -EIO;
+ goto init_fail;
+ }
+
+ param[0] = 0x01;
+ if (ps2_command(ps2dev, param, BYD_CMD_PAIR_R(4, 0xe0))) {
+ error = -EIO;
+ goto init_fail;
+ }
+
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: magic %x %x %x %x\n",
+ param[0], param[1], param[2], param[3]);
+#endif
+
+ /* magic identifier the vendor driver reads */
+ if (param[0] != 0x08 || param[1] != 0x01 ||
+    param[2] != 0x01 || param[3] != 0x31) {
+#ifdef BYD_DEBUG
+ psmouse_err(psmouse, "unknown magic, expected: 08 01 01 31\n");
+#endif
+ error = -EINVAL;
+ goto init_fail;
+ }
+
+ /*
+ * send the byd vendor commands
+ * these appear to be pairs of (command, param)
+ */
+ for (i = 0; i < ARRAY_SIZE(init_commands); i++) {
+ param[0] = init_commands[i].value;
+ cmd = BYD_CMD_PAIR(init_commands[i].command);
+ if (ps2_command(ps2dev, param, cmd)) {
+ error = -EIO;
+ goto init_fail;
+ }
+ }
+
+ /* confirm/finalize the above vender command table */
+ param[0] = 0x00;
+ if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe0))) {
+ error = -EIO;
+ goto init_fail;
+ }
+
+ /* exit command mode */
+ param[0] = 0x01;
+ if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe2))) {
+ error = -ENOMEM;
+ goto init_fail;
+ }
+
+ /* alloc space for byd_data */
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ error = -ENOMEM;
+ goto init_fail;
+ }
+
+ /* init struct and timer */
+ memset(priv, 0x00, sizeof(*priv));
+ /* signal touch end after not receiving movement packets for 32 ms */
+ setup_timer(&priv->timer, byd_clear_touch, (unsigned long)psmouse);
+ psmouse->private = priv;
+
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: exit command mode\n");
+#endif
+
+ return 0;
+
+init_fail:
+ psmouse_deactivate(psmouse);
+ return error;
+}
+
+static void byd_disconnect(struct psmouse *psmouse)
+{
+ if (psmouse->private) {
+ struct byd_data *priv = psmouse->private;
+
+ del_timer(&priv->timer);
+ kfree(psmouse->private);
+ psmouse->private = NULL;
+ }
+}
+
+static int byd_reconnect(struct psmouse *psmouse)
+{
+ if (byd_detect(psmouse, 0)) {
+ return -1;
+ }
+
+ if (byd_init(psmouse)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+ struct ps2dev *ps2dev = &psmouse->ps2dev;
+ unsigned char param[4];
+ int i;
+
+ /* reset the mouse */
+ psmouse_reset(psmouse);
+
+ /* magic knock - identify the mouse (as per. the datasheet) */
+ param[0] = 0x03;
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
+ return -EIO;
+ }
+
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: model id: %x %x %x\n",
+ param[0], param[1], param[2]);
+#endif
+
+ /*
+ * match the device - the first byte, param[0], appears to be set
+ * to some unknown value based on the state of the mouse and cannot
+ * be used for identification after suspend.
+ */
+ for (i = 0; i < ARRAY_SIZE(byd_model_data); i++) {
+ if (!memcmp(param + 1, &byd_model_data[i].id, BYD_MODEL_ID_LEN)) {
+ break;
+ }
+ }
+
+ /* no match found */
+ if (i == ARRAY_SIZE(byd_model_data)) {
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: no match found\n");
+#endif
+ return -EINVAL;
+ } else {
+#ifdef BYD_DEBUG
+ psmouse_dbg(psmouse, "detect: matched %s\n",
+ byd_model_data[i].name);
+#endif
+ }
+
+ if (set_properties) {
+ struct input_dev *dev = psmouse->dev;
+
+ __set_bit(INPUT_PROP_POINTER, dev->propbit);
+
+ /* touchpad */
+ __set_bit(BTN_TOUCH, dev->keybit);
+ __set_bit(BTN_TOOL_FINGER, dev->keybit);
+
+ /* buttons */
+ __set_bit(BTN_LEFT, dev->keybit);
+ __set_bit(BTN_RIGHT, dev->keybit);
+ __clear_bit(BTN_MIDDLE, dev->keybit);
+
+ /* absolute position */
+ __set_bit(EV_ABS, dev->evbit);
+
+ input_set_abs_params(dev, ABS_X, 0, BYD_CONST_PAD_WIDTH, 0, 0);
+ input_set_abs_params(dev, ABS_Y, 0, BYD_CONST_PAD_HEIGHT, 0, 0);
+ input_abs_set_res(dev, ABS_X, BYD_CONST_PAD_RESOLUTION);
+ input_abs_set_res(dev, ABS_Y, BYD_CONST_PAD_RESOLUTION);
+
+ /* no relative support */
+ __clear_bit(EV_REL, dev->evbit);
+ __clear_bit(REL_X, dev->relbit);
+ __clear_bit(REL_Y, dev->relbit);
+
+ psmouse->vendor = "BYD";
+ psmouse->name = "TouchPad";
+ psmouse->protocol_handler = byd_process_byte;
+ psmouse->pktsize = 4;
+ psmouse->private = NULL;
+ psmouse->disconnect = byd_disconnect;
+ psmouse->reconnect = byd_reconnect;
+ }
+
+ return 0;
+}
diff --git a/drivers/input/mouse/byd.h b/drivers/input/mouse/byd.h
new file mode 100644
index 0000000..75e4295
--- /dev/null
+++ b/drivers/input/mouse/byd.h
@@ -0,0 +1,33 @@
+/*
+ * BYD BTP-10463 touchpad PS/2 mouse driver
+ *
+ * Copyright (C) 2015, Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015, Martin Wimpress
+ * Copyright (C) 2015, Jay Kuri
+ * Copyright (C) 2016, Richard Pospesel
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef __BYD_H
+#define __BYD_H
+
+#ifdef CONFIG_MOUSE_PS2_BYD
+int byd_detect(struct psmouse *psmouse, bool set_properties);
+int byd_init(struct psmouse *psmouse);
+#else
+static inline int byd_detect(struct psmouse *psmouse,
+      bool set_properties)
+{
+ return -ENOSYS;
+}
+static inline int byd_init(struct psmouse *psmouse)
+{
+ return -ENOSYS;
+}
+
+#endif /* CONFIG_MOUSE_PS2_BYD */
+
+#endif /* !__BYD_H */
diff --git a/drivers/input/mouse/psmouse-base.c
b/drivers/input/mouse/psmouse-base.c
index b9e4ee3..abc2234 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -32,6 +32,7 @@
 #include "lifebook.h"
 #include "trackpoint.h"
 #include "touchkit_ps2.h"
+#include "byd.h"
 #include "elantech.h"
 #include "sentelic.h"
 #include "cypress_ps2.h"
@@ -842,6 +843,15 @@ static const struct psmouse_protocol
psmouse_protocols[] = {
  .init = vmmouse_init,
  },
 #endif
+#ifdef CONFIG_MOUSE_PS2_BYD
+ {
+ .type = PSMOUSE_BYD,
+ .name = "BYDPS/2",
+ .alias = "byd",
+ .detect = byd_detect,
+ .init       = byd_init,
+ },
+#endif
  {
  .type = PSMOUSE_AUTO,
  .name = "auto",
@@ -1089,6 +1099,13 @@ static int psmouse_extensions(struct psmouse *psmouse,
  return PSMOUSE_ELANTECH;
  }

+ /* Try BYD touchpad. */
+ if (max_proto > PSMOUSE_IMEX &&
+ psmouse_try_protocol(psmouse, PSMOUSE_BYD,
+ &max_proto, set_properties, true)) {
+ return PSMOUSE_BYD;
+ }
+
  if (max_proto > PSMOUSE_IMEX) {
  if (psmouse_try_protocol(psmouse, PSMOUSE_GENPS,
  &max_proto, set_properties, true))
diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
index ad5a5a1..e0ca6cd 100644
--- a/drivers/input/mouse/psmouse.h
+++ b/drivers/input/mouse/psmouse.h
@@ -104,6 +104,7 @@ enum psmouse_type {
  PSMOUSE_CYPRESS,
  PSMOUSE_FOCALTECH,
  PSMOUSE_VMMOUSE,
+ PSMOUSE_BYD,
  PSMOUSE_AUTO /* This one should always be last */
 };

Re: [PATCH] psmouse: added BYD touchpad driver

[Chris Diamand]

Hi Richard,

> This adds proper single-touch support for BYD touchpads to the psmouse input
> driver.

I posted a driver for the same touchpad a few weeks ago, which has been merged
into linux-next. There's some stuff in this patch which is missing in my driver
though, so we should definitely try and include that, and I'm very curious
about the pseudo-absolute mode.

> This patch is against commit b82dde0230439215b55e545880e90337ee16f51a (Merge tag
> 'please-pull-copy_file_range' of
> git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux ) of Linus' kernel
> branch.

Can you rebase against
'git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input'?

> +/* BYD commands reverse engineered from windows driver */
> +
> +/*
> + * swipe gesture from off-pad to on-pad
> + *  0 : disable
> + *  1 : enable
> + */
> +#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
> +/*
> + * tap and drag delay time
> + *  0 : disable
> + *  1 - 8 : least to most delay
> + */
> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
> +/*
> + * physical buttons function mapping
> + *  0 : enable
> + *  4 : normal
> + *  5 : left button custom command
> + *  6 : right button custom command
> + *  8 : disable
> + */
> +#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
> +/*
> + * absolute mode (1 byte X/Y resolution)
> + *  0 : disable
> + *  2 : enable
> + */
> +#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
> +/*
> + * two finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
> +/*
> + * handedness
> + *  1 : right handed
> + *  2 : left handed
> + */
> +#define BYD_CMD_SET_HANDEDNESS                  0xd3
> +/*
> + * tap to click
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_TAP                         0xd4
> +/*
> + * tap and drag
> + *  1 : tap and hold to drag
> + *  2 : tap and hold to drag + lock
> + *  3 : disable
> + */
> +#define BYD_CMD_SET_TAP_DRAG                    0xd5
> +/*
> + * touch sensitivity
> + *  1 - 7 : least to most sensitive
> + */
> +#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
> +/*
> + * one finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
> +/*
> + * one finger scrolling function
> + *  1 : free scrolling
> + *  2 : edge motion
> + *  3 : free scrolling + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
> +/*
> + * sliding speed
> + *  1 - 5 : slowest to fastest
> + */
> +#define BYD_CMD_SET_SLIDING_SPEED               0xda
> +/*
> + * edge motion
> + *  1 : disable
> + *  2 : enable when dragging
> + *  3 : enable when dragging and pointing
> + */
> +#define BYD_CMD_SET_EDGE_MOTION                 0xdb
> +/*
> + * left edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
> +/*
> + * top edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
> +/*
> + * disregard palm press as clicks
> + *  1 - 6 : smallest to largest
> + */
> +#define BYD_CMD_SET_PALM_CHECK                  0xde
> +/* right edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
> +/*
> + * bottom edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
> +/*
> + * multitouch gestures
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_MULTITOUCH                  0xe3
> +/*
> + * edge motion speed
> + *  0 : control with finger pressure
> + *  1 - 9 : slowest to fastest
> + */
> +#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
> +/*
> + * two finger scolling function
> + *  0 : free scrolling
> + *  1 : free scrolling (with momentum)
> + *  2 : edge motion
> + *  3 : free scrolling (with momentum) + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5

These are definitely worth merging into the existing driver - I never got the
time to figure out all of the different settings.

> +
> +struct byd_data {
> + struct timer_list timer;
> + int32_t abs_x;
> + int32_t abs_y;
> + uint32_t last_touch_time;
> + uint32_t button_left      : 1;
> + uint32_t button_right     : 1;
> + uint32_t touch            : 1;
> +};
> +

It looks like whatever email client you used has broken the formatting - when
you resend, can you use something which will preserve whitespace properly? See
'Documentation/email-clients.txt'.

> +static void byd_report_input(struct psmouse *psmouse)
> +{
> + struct byd_data *priv = (struct byd_data *)psmouse->private;
> + struct input_dev *dev = psmouse->dev;
> +
> + input_report_abs(dev, ABS_X, priv->abs_x);
> + input_report_abs(dev, ABS_Y, priv->abs_y);
> + input_report_key(dev, BTN_LEFT, priv->button_left);
> + input_report_key(dev, BTN_RIGHT, priv->button_right);
> + input_report_key(dev, BTN_TOUCH, priv->touch);
> + input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
> +
> + input_sync(dev);
> +}

Could you explain generally why you're reporting in absolute mode? What
advantage does it have over using relative reporting and turning off the
absolute packets in the touchpad init sequence?

> +
> +static void byd_clear_touch(unsigned long data)
> +{
> + struct psmouse *psmouse = (struct psmouse *)data;
> + struct byd_data *priv = psmouse->private;
> +
> + serio_pause_rx(psmouse->ps2dev.serio);
> +
> + priv->touch = 0;
> + /*
> + * move cursor back to center of pad when we lose touch
> + * this specifically improves user experiencce when moving
> + * cursor with one finger, and pressing butoton with other
> + */
> + priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
> + priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
> +
> + byd_report_input(psmouse);

serio_pause_rx() takes a spinlock - might be worth checking that
byd_report_input() doesn't do anything that might sleep.

> + switch (packet[3]) {
> + case BYD_PKT_ABSOLUTE:
> + /* on first touch, use the absolute packet to determine our start location */
> + if (priv->touch == 0) {
> + priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
> + priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
> +
> + /* needed to detect tap */
> + if (now_msecs - priv->last_touch_time > 64) {
> + priv->touch = 1;
> + }
> + }
> + break;
> + case BYD_PKT_RELATIVE:
> + {
> + int32_t rel_x, rel_y;
> +
> + /* same as regular PS/2 psmouse protocoal */
> + rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) & 0x100) : 0;
> + rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int) packet[2] : 0;
> +
> + /*
> + * experiments show relative mouse packets come in increments of
> + * 1 unit / 11 msecs (regardless of time delta between relative packets)
> + */
> + priv->abs_x += rel_x * 11;
> + priv->abs_y += rel_y * 11;
> +
> + priv->touch = 1;
> + }

So can this not handle gestures/multitouch?

Cheers!
Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Hi Chris,

Reporting absolute position allows the synaptics and libinput xorg
drivers to treat the BYD touchpad as a touchpad, rather than a mouse.
This allows edge scrolling, tap to click, natural scrolling and any
other location based single touch gesture to work.

I opted to completely disable the hardware multitouch gesture
recognition (including two finger scroll) for a couple of reasons:

1.  time delta between gesture packets was very large resulting in a
rather jerky scrolling experience, especially compared to touchpad
with real multitouch reporting.
2.  Reporting absolute position and touch support enables the users to
configure the touchpad in the touchpad settings section of gnome,
cinnamon, etc because those applets configure synaptics and libinput.
Otherwise xorg thinks it's just a mouse.
3.  Enabling multitouch gesture recognition results in the mouse
cursor freezing up when the user uses two fingers, one to move the
mouse cursor and another to click.  This is because movement packets
stop getting sent while a gesture (such as pinch, rotate, etc) is
being detected and/or reported.  Disabling all hardware gesture
detection, including two finger scroll, provides the most fluid user
experience.

Regarding serio_pause_rx(), I was following a pattern similar to
another touchpad driver in psmouse.  That whole callback mechanism is
required to report the touch had ended, since the BYD hardware only
sends packets when a touch is occurring.  Is there a better way?

I'll try to rebase and post an updated patch tonight.

best,
Richard

On Tue, Feb 2, 2016 at 4:41 PM, Chris Diamand <chris@diamand.org> wrote:
> Hi Richard,
>
>> This adds proper single-touch support for BYD touchpads to the psmouse input
>> driver.
>
> I posted a driver for the same touchpad a few weeks ago, which has been merged
> into linux-next. There's some stuff in this patch which is missing in my driver
> though, so we should definitely try and include that, and I'm very curious
> about the pseudo-absolute mode.
>
>> This patch is against commit b82dde0230439215b55e545880e90337ee16f51a (Merge tag
>> 'please-pull-copy_file_range' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux ) of Linus' kernel
>> branch.
>
> Can you rebase against
> 'git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input'?
>
>> +/* BYD commands reverse engineered from windows driver */
>> +
>> +/*
>> + * swipe gesture from off-pad to on-pad
>> + *  0 : disable
>> + *  1 : enable
>> + */
>> +#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
>> +/*
>> + * tap and drag delay time
>> + *  0 : disable
>> + *  1 - 8 : least to most delay
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
>> +/*
>> + * physical buttons function mapping
>> + *  0 : enable
>> + *  4 : normal
>> + *  5 : left button custom command
>> + *  6 : right button custom command
>> + *  8 : disable
>> + */
>> +#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
>> +/*
>> + * absolute mode (1 byte X/Y resolution)
>> + *  0 : disable
>> + *  2 : enable
>> + */
>> +#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
>> +/*
>> + * two finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
>> +/*
>> + * handedness
>> + *  1 : right handed
>> + *  2 : left handed
>> + */
>> +#define BYD_CMD_SET_HANDEDNESS                  0xd3
>> +/*
>> + * tap to click
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_TAP                         0xd4
>> +/*
>> + * tap and drag
>> + *  1 : tap and hold to drag
>> + *  2 : tap and hold to drag + lock
>> + *  3 : disable
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG                    0xd5
>> +/*
>> + * touch sensitivity
>> + *  1 - 7 : least to most sensitive
>> + */
>> +#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
>> +/*
>> + * one finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
>> +/*
>> + * one finger scrolling function
>> + *  1 : free scrolling
>> + *  2 : edge motion
>> + *  3 : free scrolling + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
>> +/*
>> + * sliding speed
>> + *  1 - 5 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_SLIDING_SPEED               0xda
>> +/*
>> + * edge motion
>> + *  1 : disable
>> + *  2 : enable when dragging
>> + *  3 : enable when dragging and pointing
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION                 0xdb
>> +/*
>> + * left edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
>> +/*
>> + * top edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
>> +/*
>> + * disregard palm press as clicks
>> + *  1 - 6 : smallest to largest
>> + */
>> +#define BYD_CMD_SET_PALM_CHECK                  0xde
>> +/* right edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
>> +/*
>> + * bottom edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
>> +/*
>> + * multitouch gestures
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_MULTITOUCH                  0xe3
>> +/*
>> + * edge motion speed
>> + *  0 : control with finger pressure
>> + *  1 - 9 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
>> +/*
>> + * two finger scolling function
>> + *  0 : free scrolling
>> + *  1 : free scrolling (with momentum)
>> + *  2 : edge motion
>> + *  3 : free scrolling (with momentum) + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5
>
> These are definitely worth merging into the existing driver - I never got the
> time to figure out all of the different settings.
>
>> +
>> +struct byd_data {
>> + struct timer_list timer;
>> + int32_t abs_x;
>> + int32_t abs_y;
>> + uint32_t last_touch_time;
>> + uint32_t button_left      : 1;
>> + uint32_t button_right     : 1;
>> + uint32_t touch            : 1;
>> +};
>> +
>
> It looks like whatever email client you used has broken the formatting - when
> you resend, can you use something which will preserve whitespace properly? See
> 'Documentation/email-clients.txt'.
>
>> +static void byd_report_input(struct psmouse *psmouse)
>> +{
>> + struct byd_data *priv = (struct byd_data *)psmouse->private;
>> + struct input_dev *dev = psmouse->dev;
>> +
>> + input_report_abs(dev, ABS_X, priv->abs_x);
>> + input_report_abs(dev, ABS_Y, priv->abs_y);
>> + input_report_key(dev, BTN_LEFT, priv->button_left);
>> + input_report_key(dev, BTN_RIGHT, priv->button_right);
>> + input_report_key(dev, BTN_TOUCH, priv->touch);
>> + input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
>> +
>> + input_sync(dev);
>> +}
>
> Could you explain generally why you're reporting in absolute mode? What
> advantage does it have over using relative reporting and turning off the
> absolute packets in the touchpad init sequence?
>
>> +
>> +static void byd_clear_touch(unsigned long data)
>> +{
>> + struct psmouse *psmouse = (struct psmouse *)data;
>> + struct byd_data *priv = psmouse->private;
>> +
>> + serio_pause_rx(psmouse->ps2dev.serio);
>> +
>> + priv->touch = 0;
>> + /*
>> + * move cursor back to center of pad when we lose touch
>> + * this specifically improves user experiencce when moving
>> + * cursor with one finger, and pressing butoton with other
>> + */
>> + priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
>> + priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
>> +
>> + byd_report_input(psmouse);
>
> serio_pause_rx() takes a spinlock - might be worth checking that
> byd_report_input() doesn't do anything that might sleep.
>
>> + switch (packet[3]) {
>> + case BYD_PKT_ABSOLUTE:
>> + /* on first touch, use the absolute packet to determine our start location */
>> + if (priv->touch == 0) {
>> + priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
>> + priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
>> +
>> + /* needed to detect tap */
>> + if (now_msecs - priv->last_touch_time > 64) {
>> + priv->touch = 1;
>> + }
>> + }
>> + break;
>> + case BYD_PKT_RELATIVE:
>> + {
>> + int32_t rel_x, rel_y;
>> +
>> + /* same as regular PS/2 psmouse protocoal */
>> + rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) & 0x100) : 0;
>> + rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int) packet[2] : 0;
>> +
>> + /*
>> + * experiments show relative mouse packets come in increments of
>> + * 1 unit / 11 msecs (regardless of time delta between relative packets)
>> + */
>> + priv->abs_x += rel_x * 11;
>> + priv->abs_y += rel_y * 11;
>> +
>> + priv->touch = 1;
>> + }
>
> So can this not handle gestures/multitouch?
>
> Cheers!
> Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Hi Chris,

Reporting absolute position allows the synaptics and libinput xorg
drivers to treat the BYD touchpad as a touchpad, rather than a mouse.
This allows edge scrolling, tap to click, natural scrolling and any
other location based single touch gesture to work.

I opted to completely disable the hardware multitouch gesture
recognition (including two finger scroll) for a couple of reasons:

1.  time delta between gesture packets was very large resulting in a
rather jerky scrolling experience, especially compared to touchpad
with real multitouch reporting.
2.  Reporting absolute position and touch support enables the users to
configure the touchpad in the touchpad settings section of gnome,
cinnamon, etc because those applets configure synaptics and libinput.
Otherwise xorg thinks it's just a mouse.
3.  Enabling multitouch gesture recognition results in the mouse
cursor freezing up when the user uses two fingers, one to move the
mouse cursor and another to click.  This is because movement packets
stop getting sent while a gesture (such as pinch, rotate, etc) is
being detected and/or reported.  Disabling all hardware gesture
detection, including two finger scroll, provides the most fluid user
experience.

Regarding serio_pause_rx(), I was following a pattern similar to
another touchpad driver in psmouse.  That whole callback mechanism is
required to report the touch had ended, since the BYD hardware only
sends packets when a touch is occurring.  Is there a better way?

I'll try to rebase and post an updated patch tonight.

best,
Richard

On Tue, Feb 2, 2016 at 4:41 PM, Chris Diamand <chris@diamand.org> wrote:
> Hi Richard,
>
>> This adds proper single-touch support for BYD touchpads to the psmouse input
>> driver.
>
> I posted a driver for the same touchpad a few weeks ago, which has been merged
> into linux-next. There's some stuff in this patch which is missing in my driver
> though, so we should definitely try and include that, and I'm very curious
> about the pseudo-absolute mode.
>
>> This patch is against commit b82dde0230439215b55e545880e90337ee16f51a (Merge tag
>> 'please-pull-copy_file_range' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux ) of Linus' kernel
>> branch.
>
> Can you rebase against
> 'git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input'?
>
>> +/* BYD commands reverse engineered from windows driver */
>> +
>> +/*
>> + * swipe gesture from off-pad to on-pad
>> + *  0 : disable
>> + *  1 : enable
>> + */
>> +#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
>> +/*
>> + * tap and drag delay time
>> + *  0 : disable
>> + *  1 - 8 : least to most delay
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
>> +/*
>> + * physical buttons function mapping
>> + *  0 : enable
>> + *  4 : normal
>> + *  5 : left button custom command
>> + *  6 : right button custom command
>> + *  8 : disable
>> + */
>> +#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
>> +/*
>> + * absolute mode (1 byte X/Y resolution)
>> + *  0 : disable
>> + *  2 : enable
>> + */
>> +#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
>> +/*
>> + * two finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
>> +/*
>> + * handedness
>> + *  1 : right handed
>> + *  2 : left handed
>> + */
>> +#define BYD_CMD_SET_HANDEDNESS                  0xd3
>> +/*
>> + * tap to click
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_TAP                         0xd4
>> +/*
>> + * tap and drag
>> + *  1 : tap and hold to drag
>> + *  2 : tap and hold to drag + lock
>> + *  3 : disable
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG                    0xd5
>> +/*
>> + * touch sensitivity
>> + *  1 - 7 : least to most sensitive
>> + */
>> +#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
>> +/*
>> + * one finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
>> +/*
>> + * one finger scrolling function
>> + *  1 : free scrolling
>> + *  2 : edge motion
>> + *  3 : free scrolling + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
>> +/*
>> + * sliding speed
>> + *  1 - 5 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_SLIDING_SPEED               0xda
>> +/*
>> + * edge motion
>> + *  1 : disable
>> + *  2 : enable when dragging
>> + *  3 : enable when dragging and pointing
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION                 0xdb
>> +/*
>> + * left edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
>> +/*
>> + * top edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
>> +/*
>> + * disregard palm press as clicks
>> + *  1 - 6 : smallest to largest
>> + */
>> +#define BYD_CMD_SET_PALM_CHECK                  0xde
>> +/* right edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
>> +/*
>> + * bottom edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
>> +/*
>> + * multitouch gestures
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_MULTITOUCH                  0xe3
>> +/*
>> + * edge motion speed
>> + *  0 : control with finger pressure
>> + *  1 - 9 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
>> +/*
>> + * two finger scolling function
>> + *  0 : free scrolling
>> + *  1 : free scrolling (with momentum)
>> + *  2 : edge motion
>> + *  3 : free scrolling (with momentum) + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5
>
> These are definitely worth merging into the existing driver - I never got the
> time to figure out all of the different settings.
>
>> +
>> +struct byd_data {
>> + struct timer_list timer;
>> + int32_t abs_x;
>> + int32_t abs_y;
>> + uint32_t last_touch_time;
>> + uint32_t button_left      : 1;
>> + uint32_t button_right     : 1;
>> + uint32_t touch            : 1;
>> +};
>> +
>
> It looks like whatever email client you used has broken the formatting - when
> you resend, can you use something which will preserve whitespace properly? See
> 'Documentation/email-clients.txt'.
>
>> +static void byd_report_input(struct psmouse *psmouse)
>> +{
>> + struct byd_data *priv = (struct byd_data *)psmouse->private;
>> + struct input_dev *dev = psmouse->dev;
>> +
>> + input_report_abs(dev, ABS_X, priv->abs_x);
>> + input_report_abs(dev, ABS_Y, priv->abs_y);
>> + input_report_key(dev, BTN_LEFT, priv->button_left);
>> + input_report_key(dev, BTN_RIGHT, priv->button_right);
>> + input_report_key(dev, BTN_TOUCH, priv->touch);
>> + input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
>> +
>> + input_sync(dev);
>> +}
>
> Could you explain generally why you're reporting in absolute mode? What
> advantage does it have over using relative reporting and turning off the
> absolute packets in the touchpad init sequence?
>
>> +
>> +static void byd_clear_touch(unsigned long data)
>> +{
>> + struct psmouse *psmouse = (struct psmouse *)data;
>> + struct byd_data *priv = psmouse->private;
>> +
>> + serio_pause_rx(psmouse->ps2dev.serio);
>> +
>> + priv->touch = 0;
>> + /*
>> + * move cursor back to center of pad when we lose touch
>> + * this specifically improves user experiencce when moving
>> + * cursor with one finger, and pressing butoton with other
>> + */
>> + priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
>> + priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
>> +
>> + byd_report_input(psmouse);
>
> serio_pause_rx() takes a spinlock - might be worth checking that
> byd_report_input() doesn't do anything that might sleep.
>
>> + switch (packet[3]) {
>> + case BYD_PKT_ABSOLUTE:
>> + /* on first touch, use the absolute packet to determine our start location */
>> + if (priv->touch == 0) {
>> + priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
>> + priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
>> +
>> + /* needed to detect tap */
>> + if (now_msecs - priv->last_touch_time > 64) {
>> + priv->touch = 1;
>> + }
>> + }
>> + break;
>> + case BYD_PKT_RELATIVE:
>> + {
>> + int32_t rel_x, rel_y;
>> +
>> + /* same as regular PS/2 psmouse protocoal */
>> + rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) & 0x100) : 0;
>> + rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int) packet[2] : 0;
>> +
>> + /*
>> + * experiments show relative mouse packets come in increments of
>> + * 1 unit / 11 msecs (regardless of time delta between relative packets)
>> + */
>> + priv->abs_x += rel_x * 11;
>> + priv->abs_y += rel_y * 11;
>> +
>> + priv->touch = 1;
>> + }
>
> So can this not handle gestures/multitouch?
>
> Cheers!
> Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

New patch vs 98ee377144935857d8ad5d7d70cdab1da4ede32e on 
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input follows. 
Confirmed builds and works as expected with that kernel branch.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
---
diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..a880adb 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -1,337 +1,586 @@
  /*
- * BYD TouchPad PS/2 mouse driver
+ * BYD BTP-10463 touchpad PS/2 mouse driver
   *
- * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015, Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015, Martin Wimpress
+ * Copyright (C) 2015, Jay Kuri
+ * Copyright (C) 2015, Richard Pospesel
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as 
published by
   * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
+ *
   */
+#include <linux/types.h>
+#include <linux/kernel.h>

-#include <linux/delay.h>
  #include <linux/input.h>
-#include <linux/libps2.h>
  #include <linux/serio.h>
+#include <linux/slab.h>
+#include <linux/libps2.h>

  #include "psmouse.h"
  #include "byd.h"

-#define PS2_Y_OVERFLOW	BIT_MASK(7)
-#define PS2_X_OVERFLOW	BIT_MASK(6)
-#define PS2_Y_SIGN	BIT_MASK(5)
-#define PS2_X_SIGN	BIT_MASK(4)
-#define PS2_ALWAYS_1	BIT_MASK(3)
-#define PS2_MIDDLE	BIT_MASK(2)
-#define PS2_RIGHT	BIT_MASK(1)
-#define PS2_LEFT	BIT_MASK(0)
+#define BYD_MODEL_ID_LEN        2
+#define BYD_CMD_PAIR(c)		((1 << 12) | (c))
+#define BYD_CMD_PAIR_R(r, c)	((1 << 12) | (r << 8) | (c))
+
+/* BYD pad constants */

  /*
- * The touchpad reports gestures in the last byte of each packet. It 
can take
- * any of the following values:
+ * true device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm
+ * absolute coordinate packets are in the range 0-255 for both X and y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm
   */

-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP		0xCA
-#define BYD_SCROLLDOWN		0x36
-#define BYD_SCROLLLEFT		0xCB
-#define BYD_SCROLLRIGHT		0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN		0x2B
-#define BYD_2UP			0xD5
-#define BYD_2LEFT		0xD6
-#define BYD_2RIGHT		0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT		0xD8
-#define BYD_ZOOMIN		0x28
-/* Three-finger swipe. */
-#define BYD_3UP			0xD3
-#define BYD_3DOWN		0x2D
-#define BYD_3LEFT		0xD4
-#define BYD_3RIGHT		0x2C
-/* Four-finger swipe. */
-#define BYD_4UP			0xCD
-#define BYD_4DOWN		0x33
+#define BYD_CONST_PAD_WIDTH                     11264
+#define BYD_CONST_PAD_HEIGHT                    6656
+#define BYD_CONST_PAD_RESOLUTION                111

-int byd_detect(struct psmouse *psmouse, bool set_properties)
+
+/* BYD commands reverse engineered from windows driver */
+
+/*
+ * swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
+/*
+ * tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
+/*
+ * physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
+/*
+ * absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
+/*
+ * two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
+/*
+ * handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS                  0xd3
+/*
+ * tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP                         0xd4
+/*
+ * tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG                    0xd5
+/*
+ * touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
+/*
+ * one finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
+/*
+ * one finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
+/*
+ * sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED               0xda
+/*
+ * edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION                 0xdb
+/*
+ * left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
+/*
+ * top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
+/*
+ * disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK                  0xde
+/* right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
+/*
+ * bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
+/*
+ * multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH                  0xe3
+/*
+ * edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
+/*
+ * two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5
+
+/* BYD Packets */
+
+#define BYD_PKT_RELATIVE                        0x00
+#define BYD_PKT_ABSOLUTE                        0xf8
+#define BYD_PKT_PINCH_IN                        0xd8
+#define BYD_PKT_PINCH_OUT                       0x28
+#define BYD_PKT_ROTATE_CLOCKWISE                0x29
+#define BYD_PKT_ROTATE_ANTICLOCKWISE            0xd7
+#define BYD_PKT_TWO_FINGER_SCROLL_RIGHT         0x2a
+#define BYD_PKT_TWO_FINGER_SCROLL_DOWN          0x2b
+#define BYD_PKT_TWO_FINGER_SCROLL_UP            0xd5
+#define BYD_PKT_TWO_FINGER_SCROLL_LEFT          0xd6
+#define BYD_PKT_THREE_FINGER_SWIPE_RIGHT        0x2c
+#define BYD_PKT_THREE_FINGER_SWIPE_DOWN         0x2d
+#define BYD_PKT_THREE_FINGER_SWIPE_UP           0xd3
+#define BYD_PKT_THREE_FINGER_SWIPE_LEFT         0xd4
+#define BYD_PKT_FOUR_FINGER_DOWN                0x33
+#define BYD_PKT_FOUR_FINGER_UP                  0xcd
+#define BYD_PKT_REGION_SCROLL_RIGHT             0x35
+#define BYD_PKT_REGION_SCROLL_DOWN              0x36
+#define BYD_PKT_REGION_SCROLL_UP                0xca
+#define BYD_PKT_REGION_SCROLL_LEFT              0xcb
+#define BYD_PKT_RIGHT_CORNER_CLICK              0xd2
+#define BYD_PKT_LEFT_CORNER_CLICK               0x2e
+#define BYD_PKT_LEFT_AND_RIGHT_CORNER_CLICK     0x2f
+#define BYD_PKT_ONTO_PAD_SWIPE_RIGHT            0x37
+#define BYD_PKT_ONTO_PAD_SWIPE_DOWN             0x30
+#define BYD_PKT_ONTO_PAD_SWIPE_UP               0xd0
+#define BYD_PKT_ONTO_PAD_SWIPE_LEFT             0xc9
+
+struct byd_init_command_pair {
+	uint8_t command;
+	uint8_t  value;
+};
+
+static const struct byd_init_command_pair init_commands[] = {
+	{BYD_CMD_SET_HANDEDNESS, 0x01},
+	{BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04},
+	{BYD_CMD_SET_TAP, 0x02},
+	{BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04},
+	{BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04},
+	{BYD_CMD_SET_EDGE_MOTION, 0x01},
+	{BYD_CMD_SET_PALM_CHECK, 0x00},
+	{BYD_CMD_SET_MULTITOUCH, 0x02},
+	{BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04},
+	{BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04},
+	{BYD_CMD_SET_LEFT_EDGE_REGION, 0x00},
+	{BYD_CMD_SET_TOP_EDGE_REGION, 0x00},
+	{BYD_CMD_SET_RIGHT_EDGE_REGION, 0x0},
+	{BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00},
+	{BYD_CMD_SET_ABSOLUTE_MODE, 0x02},
+};
+
+struct byd_model_info {
+	char name[16];
+	char id[BYD_MODEL_ID_LEN];
+};
+
+static struct byd_model_info byd_model_data[] = {
+	{ "BTP10463", { 0x03, 0x64 } }
+};
+
+struct byd_data {
+	struct timer_list timer;
+	int32_t abs_x;
+	int32_t abs_y;
+	uint32_t last_touch_time;
+	uint32_t button_left      : 1;
+	uint32_t button_right     : 1;
+	uint32_t touch            : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
  {
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	unsigned char param[4];
+	struct byd_data *priv = (struct byd_data *)psmouse->private;
+	struct input_dev *dev = psmouse->dev;

-	param[0] = 0x03;
-	param[1] = 0x00;
-	param[2] = 0x00;
-	param[3] = 0x00;
+	input_report_abs(dev, ABS_X, priv->abs_x);
+	input_report_abs(dev, ABS_Y, priv->abs_y);
+	input_report_key(dev, BTN_LEFT, priv->button_left);
+	input_report_key(dev, BTN_RIGHT, priv->button_right);
+	input_report_key(dev, BTN_TOUCH, priv->touch);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);

-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
-		return -1;
+	input_sync(dev);
+}

-	if (param[1] != 0x03 || param[2] != 0x64)
-		return -ENODEV;
+static void byd_clear_touch(unsigned long data)
+{
+	struct psmouse *psmouse = (struct psmouse *)data;
+	struct byd_data *priv = psmouse->private;

-	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+	serio_pause_rx(psmouse->ps2dev.serio);

-	if (set_properties) {
-		psmouse->vendor = "BYD";
-		psmouse->name = "TouchPad";
-	}
+	priv->touch = 0;
+	/*
+	 * move cursor back to center of pad when we lose touch
+	 * this specifically improves user experiencce when moving
+	 * cursor with one finger, and pressing butoton with other
+	 */
+	priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
+	priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;

-	return 0;
+	byd_report_input(psmouse);
+
+	serio_continue_rx(psmouse->ps2dev.serio);
  }

  static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
  {
-	struct input_dev *dev = psmouse->dev;
-	u8 *pkt = psmouse->packet;
+	struct byd_data *priv = psmouse->private;
+	unsigned char *packet = psmouse->packet;
+	uint32_t now_msecs = jiffies_to_msecs(jiffies);

-	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
-		psmouse_warn(psmouse, "Always_1 bit not 1. pkt[0] = %02x\n",
-			     pkt[0]);
-		return PSMOUSE_BAD_DATA;
-	}

  	if (psmouse->pktcnt < psmouse->pktsize)
  		return PSMOUSE_GOOD_DATA;

-	/* Otherwise, a full packet has been received */
-	switch (pkt[3]) {
-	case 0: {
-		/* Standard packet */
-		/* Sign-extend if a sign bit is set. */
-		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
-		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
-		int dx = signx | (int) pkt[1];
-		int dy = signy | (int) pkt[2];
-
-		input_report_rel(psmouse->dev, REL_X, dx);
-		input_report_rel(psmouse->dev, REL_Y, -dy);
-
-		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
-		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
-		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "process: packet = %x %x %x %x\n",
+			packet[0], packet[1], packet[2], packet[3]);
+#endif
+
+	switch (packet[3]) {
+	case BYD_PKT_ABSOLUTE:
+		/* on first touch, use the absolute packet to determine our start 
location */
+		if (priv->touch == 0) {
+			priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
+			priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
+
+			/* needed to detect tap */
+			if (now_msecs - priv->last_touch_time > 64) {
+				priv->touch = 1;
+			}
+		}
  		break;
-	}
-
-	case BYD_SCROLLDOWN:
-	case BYD_2DOWN:
-		input_report_rel(dev, REL_WHEEL, -1);
-		break;
-
-	case BYD_SCROLLUP:
-	case BYD_2UP:
-		input_report_rel(dev, REL_WHEEL, 1);
-		break;
-
-	case BYD_SCROLLLEFT:
-	case BYD_2LEFT:
-		input_report_rel(dev, REL_HWHEEL, -1);
+	case BYD_PKT_RELATIVE:
+		{
+			int32_t rel_x, rel_y;
+
+			/* same as regular PS/2 psmouse protocoal */
+			rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) & 
0x100) : 0;
+			rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int) 
packet[2] : 0;
+
+			/*
+			 * experiments show relative mouse packets come in increments of
+			 * 1 unit / 11 msecs (regardless of time delta between relative packets)
+			 */
+			priv->abs_x += rel_x * 11;
+			priv->abs_y += rel_y * 11;
+
+			priv->touch = 1;
+		}
  		break;
+	default:
+		/* shoudn't be sending anything else, but ignore just in-case */
+		return PSMOUSE_FULL_PACKET;
+	}

-	case BYD_SCROLLRIGHT:
-	case BYD_2RIGHT:
-		input_report_rel(dev, REL_HWHEEL, 1);
-		break;
+	/* both ABS and REL packets report button states */
+	priv->button_left = packet[0] & 1;
+	priv->button_right = (packet[0] >> 1) & 1;

-	case BYD_ZOOMOUT:
-	case BYD_ZOOMIN:
-	case BYD_3UP:
-	case BYD_3DOWN:
-	case BYD_3LEFT:
-	case BYD_3RIGHT:
-	case BYD_4UP:
-	case BYD_4DOWN:
-		break;
+	byd_report_input(psmouse);

-	default:
-		psmouse_warn(psmouse,
-			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
-			     psmouse->packet[0], psmouse->packet[1],
-			     psmouse->packet[2], psmouse->packet[3]);
-		return PSMOUSE_BAD_DATA;
+	/* reset time since last touch */
+	if (priv->touch == 1) {
+		priv->last_touch_time = now_msecs;
+		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(64));
  	}

-	input_sync(dev);
-
  	return PSMOUSE_FULL_PACKET;
  }

-/* Send a sequence of bytes, where each is ACKed before the next is 
sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, 
size_t len)
+int byd_init(struct psmouse *psmouse)
  {
-	unsigned int i;
+	struct byd_data *priv;
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[4];
+	int cmd, error = 0;
+	int i = 0;
+
+	/* it needs to be initialised like an intellimouse to get 4-byte 
packets */
+	psmouse_reset(psmouse);
+	param[0] = 200;
+	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+	param[0] = 100;
+	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+	param[0] =  80;
+	ps2_command(ps2dev, param, PSMOUSE_CMD_SETRATE);
+	ps2_command(ps2dev, param, PSMOUSE_CMD_GETID);
+
+	if (param[0] != 3)
+		return -1;
+
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "detect: init sequence\n");
+#endif

-	for (i = 0; i < len; ++i) {
-		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
-			return -1;
+	/* activate the mouse to initialise it */
+	psmouse_activate(psmouse);
+
+	/* enter command mode */
+	param[0] = 0x00;
+	if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe2))) {
+		error = -EIO;
+		goto init_fail;
+	}
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "detect: entered command mode\n");
+#endif
+
+	/* send second identification command */
+	param[0] = 0x02;
+	if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe0))) {
+		error = -EIO;
+		goto init_fail;
  	}
-	return 0;
-}

-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL		0x01
-#define SCROLL_NO_INERTIAL	0x02
+	param[0] = 0x01;
+	if (ps2_command(ps2dev, param, BYD_CMD_PAIR_R(4, 0xe0))) {
+		error = -EIO;
+		goto init_fail;
+	}

-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH		0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY	0x02
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "detect: magic %x %x %x %x\n",
+			param[0], param[1], param[2], param[3]);
+#endif
+
+	/* magic identifier the vendor driver reads */
+	if (param[0] != 0x08 || param[1] != 0x01 ||
+	    param[2] != 0x01 || param[3] != 0x31) {
+#ifdef BYD_DEBUG
+		psmouse_err(psmouse, "unknown magic, expected: 08 01 01 31\n");
+#endif
+		error = -EINVAL;
+		goto init_fail;
+	}

-static int byd_enable(struct psmouse *psmouse)
-{
-	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
-	const u8 seq2[] = {
-		0xD3, 0x01,
-		0xD0, 0x00,
-		0xD0, 0x04,
-		/* Whether clicking is done by tapping or pressing. */
-		0xD4, CLICK_PRESS_ONLY,
-		0xD5, 0x01,
-		0xD7, 0x03,
-		/* Vertical and horizontal one-finger scroll zone inertia. */
-		0xD8, SCROLL_INERTIAL,
-		0xDA, 0x05,
-		0xDB, 0x02,
-		0xE4, 0x05,
-		0xD6, 0x01,
-		0xDE, 0x04,
-		0xE3, 0x01,
-		0xCF, 0x00,
-		0xD2, 0x03,
-		/* Vertical and horizontal two-finger scrolling inertia. */
-		0xE5, SCROLL_INERTIAL,
-		0xD9, 0x02,
-		0xD9, 0x07,
-		0xDC, 0x03,
-		0xDD, 0x03,
-		0xDF, 0x03,
-		0xE1, 0x03,
-		0xD1, 0x00,
-		0xCE, 0x00,
-		0xCC, 0x00,
-		0xE0, 0x00,
-		0xE2, 0x01
-	};
-	u8 param[4];
-
-	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
-		return -1;
+	/*
+	 * send the byd vendor commands
+	 * these appear to be pairs of (command, param)
+	 */
+	for (i = 0; i < ARRAY_SIZE(init_commands); i++) {
+		param[0] = init_commands[i].value;
+		cmd = BYD_CMD_PAIR(init_commands[i].command);
+		if (ps2_command(ps2dev, param, cmd)) {
+			error = -EIO;
+			goto init_fail;
+		}
+	}

-	/* Send a 0x01 command, which should return 4 bytes. */
-	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
-		return -1;
+	/* confirm/finalize the above vender command table */
+	param[0] = 0x00;
+	if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe0))) {
+		error = -EIO;
+		goto init_fail;
+	}

-	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
-		return -1;
+	/* exit command mode */
+	param[0] = 0x01;
+	if (ps2_command(ps2dev, param, BYD_CMD_PAIR(0xe2))) {
+		error = -ENOMEM;
+		goto init_fail;
+	}
+
+	/* alloc space for byd_data */
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		error = -ENOMEM;
+		goto init_fail;
+	}
+
+	/* init struct and timer */
+	memset(priv, 0x00, sizeof(*priv));
+	/* signal touch end after not receiving movement packets for 32 ms */
+	setup_timer(&priv->timer, byd_clear_touch, (unsigned long)psmouse);
+	psmouse->private = priv;
+
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "detect: exit command mode\n");
+#endif

  	return 0;
+
+init_fail:
+	psmouse_deactivate(psmouse);
+	return error;
  }

-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static void byd_disconnect(struct psmouse *psmouse)
  {
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	u8 param[4];
-	int i;
-	const struct {
-		u16 command;
-		u8 arg;
-	} seq[] = {
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_GETINFO, 0 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_ENABLE, 0 }
-	};
-
-	memset(param, 0, sizeof(param));
-	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
-		param[0] = seq[i].arg;
-		if (ps2_command(ps2dev, param, seq[i].command))
-			return -1;
-	}
+	if (psmouse->private) {
+		struct byd_data *priv = psmouse->private;

-	return 0;
+		del_timer(&priv->timer);
+		kfree(psmouse->private);
+		psmouse->private = NULL;
+	}
  }

-static int byd_reset_touchpad(struct psmouse *psmouse)
+static int byd_reconnect(struct psmouse *psmouse)
  {
-	if (byd_send_intellimouse_sequence(psmouse))
-		return -EIO;
+	if (byd_detect(psmouse, 0)) {
+		return -1;
+	}

-	if (byd_enable(psmouse))
-		return -EIO;
+	if (byd_init(psmouse)) {
+		return -1;
+	}

  	return 0;
  }

-static int byd_reconnect(struct psmouse *psmouse)
+int byd_detect(struct psmouse *psmouse, bool set_properties)
  {
-	int retry = 0, error = 0;
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	unsigned char param[4];
+	int i;

-	psmouse_dbg(psmouse, "Reconnect\n");
-	do {
-		psmouse_reset(psmouse);
-		if (retry)
-			ssleep(1);
-		error = byd_detect(psmouse, 0);
-	} while (error && ++retry < 3);
+	/* reset the mouse */
+	psmouse_reset(psmouse);

-	if (error)
-		return error;
+	/* magic knock - identify the mouse (as per. the datasheet) */
+	param[0] = 0x03;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||
+	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
+		return -EIO;
+	}

-	psmouse_dbg(psmouse, "Reconnected after %d attempts\n", retry);
+#ifdef BYD_DEBUG
+	psmouse_dbg(psmouse, "detect: model id: %x %x %x\n",
+			param[0], param[1], param[2]);
+#endif
+
+	/*
+	 * match the device - the first byte, param[0], appears to be set
+	 * to some unknown value based on the state of the mouse and cannot
+	 * be used for identification after suspend.
+	 */
+	for (i = 0; i < ARRAY_SIZE(byd_model_data); i++) {
+		if (!memcmp(param + 1, &byd_model_data[i].id, BYD_MODEL_ID_LEN)) {
+			break;
+		}
+	}

-	error = byd_reset_touchpad(psmouse);
-	if (error) {
-		psmouse_err(psmouse, "Unable to initialize device\n");
-		return error;
+	/* no match found */
+	if (i == ARRAY_SIZE(byd_model_data)) {
+#ifdef BYD_DEBUG
+		psmouse_dbg(psmouse, "detect: no match found\n");
+#endif
+		return -EINVAL;
+	} else {
+#ifdef BYD_DEBUG
+		psmouse_dbg(psmouse, "detect: matched %s\n",
+				byd_model_data[i].name);
+#endif
  	}

-	return 0;
-}
+	if (set_properties) {
+		struct input_dev *dev = psmouse->dev;

-int byd_init(struct psmouse *psmouse)
-{
-	struct input_dev *dev = psmouse->dev;
+		__set_bit(INPUT_PROP_POINTER, dev->propbit);

-	if (psmouse_reset(psmouse))
-		return -EIO;
+		/* touchpad */
+		__set_bit(BTN_TOUCH, dev->keybit);
+		__set_bit(BTN_TOOL_FINGER, dev->keybit);

-	if (byd_reset_touchpad(psmouse))
-		return -EIO;
+		/* buttons */
+		__set_bit(BTN_LEFT, dev->keybit);
+		__set_bit(BTN_RIGHT, dev->keybit);
+		__clear_bit(BTN_MIDDLE, dev->keybit);
+
+		/* absolute position */
+		__set_bit(EV_ABS, dev->evbit);

-	psmouse->reconnect = byd_reconnect;
-	psmouse->protocol_handler = byd_process_byte;
-	psmouse->pktsize = 4;
-	psmouse->resync_time = 0;
+		input_set_abs_params(dev, ABS_X, 0, BYD_CONST_PAD_WIDTH, 0, 0);
+		input_set_abs_params(dev, ABS_Y, 0, BYD_CONST_PAD_HEIGHT, 0, 0);
+		input_abs_set_res(dev, ABS_X, BYD_CONST_PAD_RESOLUTION);
+		input_abs_set_res(dev, ABS_Y, BYD_CONST_PAD_RESOLUTION);

-	__set_bit(BTN_MIDDLE, dev->keybit);
-	__set_bit(REL_WHEEL, dev->relbit);
-	__set_bit(REL_HWHEEL, dev->relbit);
+		/* no relative support */
+		__clear_bit(EV_REL, dev->evbit);
+		__clear_bit(REL_X, dev->relbit);
+		__clear_bit(REL_Y, dev->relbit);
+
+		psmouse->vendor = "BYD";
+		psmouse->name = "TouchPad";
+		psmouse->protocol_handler = byd_process_byte;
+		psmouse->pktsize = 4;
+		psmouse->private = NULL;
+		psmouse->disconnect = byd_disconnect;
+		psmouse->reconnect = byd_reconnect;
+	}

  	return 0;
  }
diff --git a/drivers/input/mouse/byd.h b/drivers/input/mouse/byd.h
index d6c120c..86b4a0e 100644
--- a/drivers/input/mouse/byd.h
+++ b/drivers/input/mouse/byd.h
@@ -1,11 +1,25 @@
-#ifndef _BYD_H
-#define _BYD_H
+/*
+ * BYD BTP-10463 touchpad PS/2 mouse driver
+ *
+ * Copyright (C) 2015, Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015, Martin Wimpress
+ * Copyright (C) 2015, Jay Kuri
+ * Copyright (C) 2016, Richard Pospesel
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as 
published by
+ * the Free Software Foundation.
+ */
+
+#ifndef __BYD_H
+#define __BYD_H

  #ifdef CONFIG_MOUSE_PS2_BYD
  int byd_detect(struct psmouse *psmouse, bool set_properties);
  int byd_init(struct psmouse *psmouse);
  #else
-static inline int byd_detect(struct psmouse *psmouse, bool set_properties)
+static inline int byd_detect(struct psmouse *psmouse,
+				      bool set_properties)
  {
  	return -ENOSYS;
  }
@@ -13,6 +27,7 @@ static inline int byd_init(struct psmouse *psmouse)
  {
  	return -ENOSYS;
  }
+
  #endif /* CONFIG_MOUSE_PS2_BYD */

-#endif /* _BYD_H */
+#endif /* __BYD_H */
diff --git a/drivers/input/mouse/psmouse-base.c 
b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol 
psmouse_protocols[] = {
  #ifdef CONFIG_MOUSE_PS2_BYD
  	{
  		.type		= PSMOUSE_BYD,
-		.name		= "BydPS/2",
+		.name		= "BYDPS/2",
  		.alias		= "byd",
  		.detect		= byd_detect,
  		.init		= byd_init,


On 02/02/2016 05:46 PM, Richard Pospesel wrote:
> Hi Chris,
>
> Reporting absolute position allows the synaptics and libinput xorg
> drivers to treat the BYD touchpad as a touchpad, rather than a mouse.
> This allows edge scrolling, tap to click, natural scrolling and any
> other location based single touch gesture to work.
>
> I opted to completely disable the hardware multitouch gesture
> recognition (including two finger scroll) for a couple of reasons:
>
> 1.  time delta between gesture packets was very large resulting in a
> rather jerky scrolling experience, especially compared to touchpad with
> real multitouch reporting.
> 2.  Reporting absolute position and touch support enables the users to
> configure the touchpad in the touchpad settings section of gnome,
> cinnamon, etc because those applets configure synaptics and libinput.
> Otherwise xorg thinks it's just a mouse.
> 3.  Enabling multitouch gesture recognition results in the mouse cursor
> freezing up when the user uses two fingers, one to move the mouse cursor
> and another to click.  This is because movement packets stop getting
> sent while a gesture (such as pinch, rotate, etc) is being detected
> and/or reported.  Disabling all hardware gesture detection, including
> two finger scroll, provides the most fluid user experience.
>
> Regarding serio_pause_rx(), I was following a pattern similar to another
> touchpad driver in psmouse.  That whole callback mechanism is required
> to report the touch had ended, since the BYD hardware only sends packets
> when a touch is occurring.  Is there a better way?
>
> I'll try to rebase and post an updated patch tonight.
>
> best,
> Richard
>
> On Feb 2, 2016 4:41 PM, "Chris Diamand" <chris@diamand.org
> <mailto:chris@diamand.org>> wrote:
>  >
>  > Hi Richard,
>  >
>  > > This adds proper single-touch support for BYD touchpads to the
> psmouse input
>  > > driver.
>  >
>  > I posted a driver for the same touchpad a few weeks ago, which has
> been merged
>  > into linux-next. There's some stuff in this patch which is missing in
> my driver
>  > though, so we should definitely try and include that, and I'm very
> curious
>  > about the pseudo-absolute mode.
>  >
>  > > This patch is against commit
> b82dde0230439215b55e545880e90337ee16f51a (Merge tag
>  > > 'please-pull-copy_file_range' of
>  > > git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
> <http://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux> ) of Linus'
> kernel
>  > > branch.
>  >
>  > Can you rebase against
>  > 'git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
> <http://git.kernel.org/pub/scm/linux/kernel/git/dtor/input>'?
>  >
>  > > +/* BYD commands reverse engineered from windows driver */
>  > > +
>  > > +/*
>  > > + * swipe gesture from off-pad to on-pad
>  > > + *  0 : disable
>  > > + *  1 : enable
>  > > + */
>  > > +#define BYD_CMD_SET_OFFSCREEN_SWIPE             0xcc
>  > > +/*
>  > > + * tap and drag delay time
>  > > + *  0 : disable
>  > > + *  1 - 8 : least to most delay
>  > > + */
>  > > +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME         0xcf
>  > > +/*
>  > > + * physical buttons function mapping
>  > > + *  0 : enable
>  > > + *  4 : normal
>  > > + *  5 : left button custom command
>  > > + *  6 : right button custom command
>  > > + *  8 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_PHYSICAL_BUTTONS            0xd0
>  > > +/*
>  > > + * absolute mode (1 byte X/Y resolution)
>  > > + *  0 : disable
>  > > + *  2 : enable
>  > > + */
>  > > +#define BYD_CMD_SET_ABSOLUTE_MODE               0xd1
>  > > +/*
>  > > + * two finger scrolling
>  > > + *  1 : vertical
>  > > + *  2 : horizontal
>  > > + *  3 : vertical + horizontal
>  > > + *  4 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_TWO_FINGER_SCROLL           0xd2
>  > > +/*
>  > > + * handedness
>  > > + *  1 : right handed
>  > > + *  2 : left handed
>  > > + */
>  > > +#define BYD_CMD_SET_HANDEDNESS                  0xd3
>  > > +/*
>  > > + * tap to click
>  > > + *  1 : enable
>  > > + *  2 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_TAP                         0xd4
>  > > +/*
>  > > + * tap and drag
>  > > + *  1 : tap and hold to drag
>  > > + *  2 : tap and hold to drag + lock
>  > > + *  3 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_TAP_DRAG                    0xd5
>  > > +/*
>  > > + * touch sensitivity
>  > > + *  1 - 7 : least to most sensitive
>  > > + */
>  > > +#define BYD_CMD_SET_TOUCH_SENSITIVITY           0xd6
>  > > +/*
>  > > + * one finger scrolling
>  > > + *  1 : vertical
>  > > + *  2 : horizontal
>  > > + *  3 : vertical + horizontal
>  > > + *  4 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_ONE_FINGER_SCROLL           0xd7
>  > > +/*
>  > > + * one finger scrolling function
>  > > + *  1 : free scrolling
>  > > + *  2 : edge motion
>  > > + *  3 : free scrolling + edge motion
>  > > + *  4 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC      0xd8
>  > > +/*
>  > > + * sliding speed
>  > > + *  1 - 5 : slowest to fastest
>  > > + */
>  > > +#define BYD_CMD_SET_SLIDING_SPEED               0xda
>  > > +/*
>  > > + * edge motion
>  > > + *  1 : disable
>  > > + *  2 : enable when dragging
>  > > + *  3 : enable when dragging and pointing
>  > > + */
>  > > +#define BYD_CMD_SET_EDGE_MOTION                 0xdb
>  > > +/*
>  > > + * left edge region size
>  > > + *  0 - 7 : smallest to largest width
>  > > + */
>  > > +#define BYD_CMD_SET_LEFT_EDGE_REGION            0xdc
>  > > +/*
>  > > + * top edge region size
>  > > + *  0 - 9 : smallest to largest height
>  > > + */
>  > > +#define BYD_CMD_SET_TOP_EDGE_REGION             0xdd
>  > > +/*
>  > > + * disregard palm press as clicks
>  > > + *  1 - 6 : smallest to largest
>  > > + */
>  > > +#define BYD_CMD_SET_PALM_CHECK                  0xde
>  > > +/* right edge region size
>  > > + *  0 - 7 : smallest to largest width
>  > > + */
>  > > +#define BYD_CMD_SET_RIGHT_EDGE_REGION           0xdf
>  > > +/*
>  > > + * bottom edge region size
>  > > + *  0 - 9 : smallest to largest height
>  > > + */
>  > > +#define BYD_CMD_SET_BOTTOM_EDGE_REGION          0xe1
>  > > +/*
>  > > + * multitouch gestures
>  > > + *  1 : enable
>  > > + *  2 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_MULTITOUCH                  0xe3
>  > > +/*
>  > > + * edge motion speed
>  > > + *  0 : control with finger pressure
>  > > + *  1 - 9 : slowest to fastest
>  > > + */
>  > > +#define BYD_CMD_SET_EDGE_MOTION_SPEED           0xe4
>  > > +/*
>  > > + * two finger scolling function
>  > > + *  0 : free scrolling
>  > > + *  1 : free scrolling (with momentum)
>  > > + *  2 : edge motion
>  > > + *  3 : free scrolling (with momentum) + edge motion
>  > > + *  4 : disable
>  > > + */
>  > > +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC      0xe5
>  >
>  > These are definitely worth merging into the existing driver - I never
> got the
>  > time to figure out all of the different settings.
>  >
>  > > +
>  > > +struct byd_data {
>  > > + struct timer_list timer;
>  > > + int32_t abs_x;
>  > > + int32_t abs_y;
>  > > + uint32_t last_touch_time;
>  > > + uint32_t button_left      : 1;
>  > > + uint32_t button_right     : 1;
>  > > + uint32_t touch            : 1;
>  > > +};
>  > > +
>  >
>  > It looks like whatever email client you used has broken the
> formatting - when
>  > you resend, can you use something which will preserve whitespace
> properly? See
>  > 'Documentation/email-clients.txt'.
>  >
>  > > +static void byd_report_input(struct psmouse *psmouse)
>  > > +{
>  > > + struct byd_data *priv = (struct byd_data *)psmouse->private;
>  > > + struct input_dev *dev = psmouse->dev;
>  > > +
>  > > + input_report_abs(dev, ABS_X, priv->abs_x);
>  > > + input_report_abs(dev, ABS_Y, priv->abs_y);
>  > > + input_report_key(dev, BTN_LEFT, priv->button_left);
>  > > + input_report_key(dev, BTN_RIGHT, priv->button_right);
>  > > + input_report_key(dev, BTN_TOUCH, priv->touch);
>  > > + input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
>  > > +
>  > > + input_sync(dev);
>  > > +}
>  >
>  > Could you explain generally why you're reporting in absolute mode? What
>  > advantage does it have over using relative reporting and turning off the
>  > absolute packets in the touchpad init sequence?
>  >
>  > > +
>  > > +static void byd_clear_touch(unsigned long data)
>  > > +{
>  > > + struct psmouse *psmouse = (struct psmouse *)data;
>  > > + struct byd_data *priv = psmouse->private;
>  > > +
>  > > + serio_pause_rx(psmouse->ps2dev.serio);
>  > > +
>  > > + priv->touch = 0;
>  > > + /*
>  > > + * move cursor back to center of pad when we lose touch
>  > > + * this specifically improves user experiencce when moving
>  > > + * cursor with one finger, and pressing butoton with other
>  > > + */
>  > > + priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
>  > > + priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
>  > > +
>  > > + byd_report_input(psmouse);
>  >
>  > serio_pause_rx() takes a spinlock - might be worth checking that
>  > byd_report_input() doesn't do anything that might sleep.
>  >
>  > > + switch (packet[3]) {
>  > > + case BYD_PKT_ABSOLUTE:
>  > > + /* on first touch, use the absolute packet to determine our start
> location */
>  > > + if (priv->touch == 0) {
>  > > + priv->abs_x = packet[1] * (BYD_CONST_PAD_WIDTH / 256);
>  > > + priv->abs_y = (255 - packet[2]) * (BYD_CONST_PAD_HEIGHT / 256);
>  > > +
>  > > + /* needed to detect tap */
>  > > + if (now_msecs - priv->last_touch_time > 64) {
>  > > + priv->touch = 1;
>  > > + }
>  > > + }
>  > > + break;
>  > > + case BYD_PKT_RELATIVE:
>  > > + {
>  > > + int32_t rel_x, rel_y;
>  > > +
>  > > + /* same as regular PS/2 psmouse protocoal */
>  > > + rel_x = packet[1] ? (int) packet[1] - (int) ((packet[0] << 4) &
> 0x100) : 0;
>  > > + rel_y = packet[2] ? (int) ((packet[0] << 3) & 0x100) - (int)
> packet[2] : 0;
>  > > +
>  > > + /*
>  > > + * experiments show relative mouse packets come in increments of
>  > > + * 1 unit / 11 msecs (regardless of time delta between relative
> packets)
>  > > + */
>  > > + priv->abs_x += rel_x * 11;
>  > > + priv->abs_y += rel_y * 11;
>  > > +
>  > > + priv->touch = 1;
>  > > + }
>  >
>  > So can this not handle gestures/multitouch?
>  >
>  > Cheers!
>  > Chris
>

Re: [PATCH] psmouse: added BYD touchpad driver

[Chris Diamand]

Hi Richard,

> Reporting absolute position allows the synaptics and libinput xorg drivers
> to treat the BYD touchpad as a touchpad, rather than a mouse.  This allows
> edge scrolling, tap to click, natural scrolling and any other location
> based single touch gesture to work.
>
> I opted to completely disable the hardware multitouch gesture recognition
> (including two finger scroll) for a couple of reasons:
>
> 1.  time delta between gesture packets was very large resulting in a rather
> jerky scrolling experience, especially compared to touchpad with real
> multitouch reporting.
> 2.  Reporting absolute position and touch support enables the users to
> configure the touchpad in the touchpad settings section of gnome, cinnamon,
> etc because those applets configure synaptics and libinput.  Otherwise xorg
> thinks it's just a mouse.

This all sounds good - I look forward to trying your patch!

Also, how did you figure out how to enable the absolute packets? I couldn't
find anything like that with the Windows driver I was using.

> 3.  Enabling multitouch gesture recognition results in the mouse cursor
> freezing up when the user uses two fingers, one to move the mouse cursor
> and another to click.  This is because movement packets stop getting sent
> while a gesture (such as pinch, rotate, etc) is being detected and/or
> reported.

So with your patch, how will this gesture work, if it can only recognise one
finger at a time? I guess you'd have to enable the "double-tap then drag"
thing in synaptics and use that?

> Disabling all hardware gesture detection, including two finger
> scroll, provides the most fluid user experience.

Yep, I agree that if it works, good one-finger scrolling would be much better
than the touchpad's internal gesture recognition.

> Regarding serio_pause_rx(), I was following a pattern similar to another
> touchpad driver in psmouse.  That whole callback mechanism is required to
> report the touch had ended, since the BYD hardware only sends packets when
> a touch is occurring.  Is there a better way?

You're right, actually - I was worried that the input_report_* functions might
sleep, but I just had a proper look and they don't.

> I'll try to rebase and post an updated patch tonight.

Cheers!
Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Hi Chris,

See inline:

On 02/03/2016 12:58 AM, Chris Diamand wrote:
> Hi Richard,
>
>> Reporting absolute position allows the synaptics and libinput xorg drivers
>> to treat the BYD touchpad as a touchpad, rather than a mouse.  This allows
>> edge scrolling, tap to click, natural scrolling and any other location
>> based single touch gesture to work.
>>
>> I opted to completely disable the hardware multitouch gesture recognition
>> (including two finger scroll) for a couple of reasons:
>>
>> 1.  time delta between gesture packets was very large resulting in a rather
>> jerky scrolling experience, especially compared to touchpad with real
>> multitouch reporting.
>> 2.  Reporting absolute position and touch support enables the users to
>> configure the touchpad in the touchpad settings section of gnome, cinnamon,
>> etc because those applets configure synaptics and libinput.  Otherwise xorg
>> thinks it's just a mouse.
>
> This all sounds good - I look forward to trying your patch!
>
> Also, how did you figure out how to enable the absolute packets? I couldn't
> find anything like that with the Windows driver I was using.

The Windows driver provides a visualization of the regions for the 
hardware edge scrolling capability. When entering that screen, a 
particular command pair is sent, and the touchpad starts sending 
interleaved REL and ABS packets.  When leaving that screen, another 
particular command pair is sent, and the touchpad resumes the normal REL 
only stream.

>
>> 3.  Enabling multitouch gesture recognition results in the mouse cursor
>> freezing up when the user uses two fingers, one to move the mouse cursor
>> and another to click.  This is because movement packets stop getting sent
>> while a gesture (such as pinch, rotate, etc) is being detected and/or
>> reported.
>
> So with your patch, how will this gesture work, if it can only recognise one
> finger at a time? I guess you'd have to enable the "double-tap then drag"
> thing in synaptics and use that?

With multi-touch gestures disabled and two fingers on the pad, the 
touchpad sends ONLY a stream of REL packets, even when in absolute mode. 
  When this occurs I just anchor the start position at the middle of the 
pad.  Its not 100% accurate obviously, but in practice it works.

One side note, it's also possible for this driver to send ABS_X/Y 
packets with positions OUTSIDE the touchpad's supposed range due to the 
scheme where we anchor with a low-res ABS packet and update with hi-res 
REL packets.  I've talked about this potential issue with Peter Hutterer 
(from xorg input) and have been assured that this is fine and isn't 
taking advantage of an undefined behaviour in synaptics or libinput.

>
>> Disabling all hardware gesture detection, including two finger
>> scroll, provides the most fluid user experience.
>
> Yep, I agree that if it works, good one-finger scrolling would be much better
> than the touchpad's internal gesture recognition.
>
>> Regarding serio_pause_rx(), I was following a pattern similar to another
>> touchpad driver in psmouse.  That whole callback mechanism is required to
>> report the touch had ended, since the BYD hardware only sends packets when
>> a touch is occurring.  Is there a better way?
>
> You're right, actually - I was worried that the input_report_* functions might
> sleep, but I just had a proper look and they don't.
>
>> I'll try to rebase and post an updated patch tonight.
>
> Cheers!
> Chris
>

best,
-Richard

Re: [PATCH] psmouse: added BYD touchpad driver

[Chris Diamand]

> The Windows driver provides a visualization of the regions for the hardware
> edge scrolling capability. When entering that screen, a particular command
> pair is sent, and the touchpad starts sending interleaved REL and ABS
> packets.  When leaving that screen, another particular command pair is sent,
> and the touchpad resumes the normal REL only stream.

Good find! That's very crafty.

I've managed to apply your patch, and can confirm that it works - my initial
impressions (using it for 15 mins...) are that even 256x256 resolution absolute
mode + synaptics is much better than the touchpad's built-in gesture detection.

Let's work your patch into something which applies on top of the existing
driver, and get it merged.

Cheers!
Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Rebased patch against 98ee377144935857d8ad5d7d70cdab1da4ede32e:

---
diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..f213a08 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -2,93 +2,276 @@
   * BYD TouchPad PS/2 mouse driver
   *
   * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015 Richard Pospesel
+ * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015 Martin Wimpress
+ * Copyright (C) 2015 Jay Kuri
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as 
published by
   * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * md5:       0d5e4660b98fca9587a0df212fca3048
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
   */

  #include <linux/delay.h>
  #include <linux/input.h>
  #include <linux/libps2.h>
  #include <linux/serio.h>
+#include <linux/slab.h>

  #include "psmouse.h"
  #include "byd.h"

-#define PS2_Y_OVERFLOW	BIT_MASK(7)
-#define PS2_X_OVERFLOW	BIT_MASK(6)
-#define PS2_Y_SIGN	BIT_MASK(5)
-#define PS2_X_SIGN	BIT_MASK(4)
-#define PS2_ALWAYS_1	BIT_MASK(3)
-#define PS2_MIDDLE	BIT_MASK(2)
-#define PS2_RIGHT	BIT_MASK(1)
-#define PS2_LEFT	BIT_MASK(0)
+/* PS2 Bits */
+#define PS2_Y_OVERFLOW BIT_MASK(7)
+#define PS2_X_OVERFLOW BIT_MASK(6)
+#define PS2_Y_SIGN     BIT_MASK(5)
+#define PS2_X_SIGN     BIT_MASK(4)
+#define PS2_ALWAYS_1   BIT_MASK(3)
+#define PS2_MIDDLE     BIT_MASK(2)
+#define PS2_RIGHT      BIT_MASK(1)
+#define PS2_LEFT       BIT_MASK(0)

  /*
- * The touchpad reports gestures in the last byte of each packet. It 
can take
- * any of the following values:
+ * BYD pad constants
+ *
+ * True device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm.
+ * Absolute coordinate packets are in the range 0-255 for both X and Y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm.
   */
+#define BYD_CONST_PAD_WIDTH	     11264
+#define BYD_CONST_PAD_HEIGHT     6656
+#define BYD_CONST_PAD_RESOLUTION 111

-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP		0xCA
-#define BYD_SCROLLDOWN		0x36
-#define BYD_SCROLLLEFT		0xCB
-#define BYD_SCROLLRIGHT		0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN		0x2B
-#define BYD_2UP			0xD5
-#define BYD_2LEFT		0xD6
-#define BYD_2RIGHT		0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT		0xD8
-#define BYD_ZOOMIN		0x28
-/* Three-finger swipe. */
-#define BYD_3UP			0xD3
-#define BYD_3DOWN		0x2D
-#define BYD_3LEFT		0xD4
-#define BYD_3RIGHT		0x2C
-/* Four-finger swipe. */
-#define BYD_4UP			0xCD
-#define BYD_4DOWN		0x33
-
-int byd_detect(struct psmouse *psmouse, bool set_properties)
-{
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	unsigned char param[4];
+/* BYD commands reverse engineered from windows driver */

-	param[0] = 0x03;
-	param[1] = 0x00;
-	param[2] = 0x00;
-	param[3] = 0x00;
-
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
-		return -1;
+/*
+ * Swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
+/*
+ * Tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
+/*
+ * Physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
+/*
+ * Absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
+/*
+ * Two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
+/*
+ * Handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS             0x10d3
+/*
+ * Tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP                    0x10d4
+/*
+ * Tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG               0x10d5
+/*
+ * Touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
+/*
+ * One finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
+/*
+ * One finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
+/*
+ * Sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED          0x10da
+/*
+ * Edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION            0x10db
+/*
+ * Left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
+/*
+ * Top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
+/*
+ * Disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK             0x10de
+/*
+ * Right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
+/*
+ * Bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
+/*
+ * Multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH             0x10e3
+/*
+ * Edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
+/*
+ * Two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5

-	if (param[1] != 0x03 || param[2] != 0x64)
-		return -ENODEV;
+/*
+ * The touchpad generates a mixture of absolute and relative packets, 
indicated
+ * by the the last byte of each packet being set to one of the following:
+ */
+#define BYD_PACKET_ABSOLUTE	0xF8
+#define BYD_PACKET_RELATIVE	0x00

-	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+/*
+ * With multitouch gestures enabled, the following packets will be sent 
from
+ * the touchpad:
+ */
+#define BYD_PACKET_PINCH_IN                    0xd8
+#define BYD_PACKET_PINCH_OUT                   0x28
+#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
+#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
+#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
+#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
+#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
+#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
+#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
+#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
+#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
+#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
+#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
+#define BYD_PACKET_FOUR_FINGER_UP              0xcd
+#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
+#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
+#define BYD_PACKET_REGION_SCROLL_UP            0xca
+#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
+#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
+#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
+#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
+#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
+#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
+#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
+#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9
+
+struct byd_data {
+	struct timer_list timer;
+	s32 abs_x;
+	s32 abs_y;
+	u32 last_touch_time;
+	bool btn_left  : 1;
+	bool btn_right : 1;
+	bool touch     : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+	struct byd_data *priv = (struct byd_data *)psmouse->private;
+	struct input_dev *dev = psmouse->dev;

-	if (set_properties) {
-		psmouse->vendor = "BYD";
-		psmouse->name = "TouchPad";
-	}
+	input_report_abs(dev, ABS_X, priv->abs_x);
+	input_report_abs(dev, ABS_Y, priv->abs_y);
+	input_report_key(dev, BTN_LEFT, priv->btn_left);
+	input_report_key(dev, BTN_RIGHT, priv->btn_right);
+	input_report_key(dev, BTN_TOUCH, priv->touch);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+	input_sync(dev);
+}

-	return 0;
+static void byd_clear_touch(unsigned long data)
+{
+	struct psmouse *psmouse = (struct psmouse *) data;
+	struct byd_data *priv = psmouse->private;
+
+	serio_pause_rx(psmouse->ps2dev.serio);
+	priv->touch = false;
+	/*
+	 * Move cursor back to center of pad when we lose touch - this
+	 * specifically improves user experience when moving cursor with one
+	 * finger, and pressing a button with another.
+	 */
+	priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
+	priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
+	byd_report_input(psmouse);
+
+	serio_continue_rx(psmouse->ps2dev.serio);
  }

  static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
  {
-	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv = psmouse->private;
+	u32 now_msecs = jiffies_to_msecs(jiffies);
  	u8 *pkt = psmouse->packet;

  	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
@@ -102,53 +285,37 @@ static psmouse_ret_t byd_process_byte(struct 
psmouse *psmouse)

  	/* Otherwise, a full packet has been received */
  	switch (pkt[3]) {
-	case 0: {
+	case BYD_PACKET_ABSOLUTE:
+		/* Only use absolute packets for the start of movement. */
+		if (!priv->touch) {
+			priv->abs_x = pkt[1] * (BYD_CONST_PAD_WIDTH / 256);
+			priv->abs_y = (255 - pkt[2]) *
+				      (BYD_CONST_PAD_HEIGHT / 256);
+
+			/* needed to detect tap */
+			if (now_msecs - priv->last_touch_time > 64)
+				priv->touch = true;
+		}
+		break;
+	case BYD_PACKET_RELATIVE: {
  		/* Standard packet */
  		/* Sign-extend if a sign bit is set. */
-		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
-		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
-		int dx = signx | (int) pkt[1];
-		int dy = signy | (int) pkt[2];
-
-		input_report_rel(psmouse->dev, REL_X, dx);
-		input_report_rel(psmouse->dev, REL_Y, -dy);
-
-		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
-		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
-		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
+		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
+		s32 dx = signx | (int) pkt[1];
+		s32 dy = signy | (int) pkt[2];
+
+		/*
+		 * Experiments show relative mouse packets come in increments
+		 * of 1 unit / 11 milliseconds (regardless of time delta between
+		 * relative packets).
+		 */
+		priv->abs_x += dx * 11;
+		priv->abs_y -= dy * 11;
+
+		priv->touch = true;
  		break;
  	}
-
-	case BYD_SCROLLDOWN:
-	case BYD_2DOWN:
-		input_report_rel(dev, REL_WHEEL, -1);
-		break;
-
-	case BYD_SCROLLUP:
-	case BYD_2UP:
-		input_report_rel(dev, REL_WHEEL, 1);
-		break;
-
-	case BYD_SCROLLLEFT:
-	case BYD_2LEFT:
-		input_report_rel(dev, REL_HWHEEL, -1);
-		break;
-
-	case BYD_SCROLLRIGHT:
-	case BYD_2RIGHT:
-		input_report_rel(dev, REL_HWHEEL, 1);
-		break;
-
-	case BYD_ZOOMOUT:
-	case BYD_ZOOMIN:
-	case BYD_3UP:
-	case BYD_3DOWN:
-	case BYD_3LEFT:
-	case BYD_3RIGHT:
-	case BYD_4UP:
-	case BYD_4DOWN:
-		break;
-
  	default:
  		psmouse_warn(psmouse,
  			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
@@ -157,134 +324,76 @@ static psmouse_ret_t byd_process_byte(struct 
psmouse *psmouse)
  		return PSMOUSE_BAD_DATA;
  	}

-	input_sync(dev);
+	priv->btn_left = pkt[0] & PS2_LEFT;
+	priv->btn_right = pkt[0] & PS2_RIGHT;

-	return PSMOUSE_FULL_PACKET;
-}
+	byd_report_input(psmouse);

-/* Send a sequence of bytes, where each is ACKed before the next is 
sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, 
size_t len)
-{
-	unsigned int i;
-
-	for (i = 0; i < len; ++i) {
-		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
-			return -1;
+	/* Reset time since last touch. */
+	if (priv->touch) {
+		priv->last_touch_time = now_msecs;
+		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(64));
  	}
-	return 0;
-}
-
-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL		0x01
-#define SCROLL_NO_INERTIAL	0x02
-
-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH		0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY	0x02
-
-static int byd_enable(struct psmouse *psmouse)
-{
-	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
-	const u8 seq2[] = {
-		0xD3, 0x01,
-		0xD0, 0x00,
-		0xD0, 0x04,
-		/* Whether clicking is done by tapping or pressing. */
-		0xD4, CLICK_PRESS_ONLY,
-		0xD5, 0x01,
-		0xD7, 0x03,
-		/* Vertical and horizontal one-finger scroll zone inertia. */
-		0xD8, SCROLL_INERTIAL,
-		0xDA, 0x05,
-		0xDB, 0x02,
-		0xE4, 0x05,
-		0xD6, 0x01,
-		0xDE, 0x04,
-		0xE3, 0x01,
-		0xCF, 0x00,
-		0xD2, 0x03,
-		/* Vertical and horizontal two-finger scrolling inertia. */
-		0xE5, SCROLL_INERTIAL,
-		0xD9, 0x02,
-		0xD9, 0x07,
-		0xDC, 0x03,
-		0xDD, 0x03,
-		0xDF, 0x03,
-		0xE1, 0x03,
-		0xD1, 0x00,
-		0xCE, 0x00,
-		0xCC, 0x00,
-		0xE0, 0x00,
-		0xE2, 0x01
-	};
-	u8 param[4];
-
-	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
-		return -1;
-
-	/* Send a 0x01 command, which should return 4 bytes. */
-	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
-		return -1;

-	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
-		return -1;
-
-	return 0;
+	return PSMOUSE_FULL_PACKET;
  }

-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static int byd_reset_touchpad(struct psmouse *psmouse)
  {
  	struct ps2dev *ps2dev = &psmouse->ps2dev;
  	u8 param[4];
-	int i;
+	size_t i;
+
  	const struct {
  		u16 command;
  		u8 arg;
  	} seq[] = {
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_GETINFO, 0 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
+		/*
+		 * Intellimouse initialization sequence, to get 4-byte instead
+		 * of 3-byte packets.
+		 */
  		{ PSMOUSE_CMD_SETRATE, 0xC8 },
  		{ PSMOUSE_CMD_SETRATE, 0x64 },
  		{ PSMOUSE_CMD_SETRATE, 0x50 },
  		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_ENABLE, 0 }
+		{ PSMOUSE_CMD_ENABLE, 0 },
+		/*
+		 * BYD-specific initialization, which enables absolute mode and
+		 * (if desired), the touchpad's built-in gesture detection.
+		 */
+		{ 0x10E2, 0x00 },
+		{ 0x10E0, 0x02 },
+		/* The touchpad should reply with 4 seemingly-random bytes */
+		{ 0x14E0, 0x01 },
+		/* Pairs of parameters and values. */
+		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
+		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
+		{ BYD_CMD_SET_TAP, 0x02 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
+		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
+		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
+		/* Finalize initialization. */
+		{ 0x10E0, 0x00 },
+		{ 0x10E2, 0x01 },
  	};

-	memset(param, 0, sizeof(param));
  	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
+		memset(param, 0, sizeof(param));
  		param[0] = seq[i].arg;
  		if (ps2_command(ps2dev, param, seq[i].command))
-			return -1;
-	}
-
-	return 0;
-}
-
-static int byd_reset_touchpad(struct psmouse *psmouse)
-{
-	if (byd_send_intellimouse_sequence(psmouse))
-		return -EIO;
-
-	if (byd_enable(psmouse))
-		return -EIO;
+			return -EIO;

+	}
+	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
  	return 0;
  }

@@ -314,9 +423,50 @@ static int byd_reconnect(struct psmouse *psmouse)
  	return 0;
  }

+static void byd_disconnect(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+
+	if (priv) {
+		del_timer(&priv->timer);
+		kfree(psmouse->private);
+		psmouse->private = NULL;
+	}
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	if (param[1] != 0x03 || param[2] != 0x64)
+		return -ENODEV;
+
+	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+
+	if (set_properties) {
+		psmouse->vendor = "BYD";
+		psmouse->name = "TouchPad";
+	}
+
+	return 0;
+}
+
  int byd_init(struct psmouse *psmouse)
  {
  	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv;

  	if (psmouse_reset(psmouse))
  		return -EIO;
@@ -324,14 +474,39 @@ int byd_init(struct psmouse *psmouse)
  	if (byd_reset_touchpad(psmouse))
  		return -EIO;

+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(priv, 0, sizeof(*priv));
+	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
+
+	psmouse->private = priv;
+	psmouse->disconnect = byd_disconnect;
  	psmouse->reconnect = byd_reconnect;
  	psmouse->protocol_handler = byd_process_byte;
  	psmouse->pktsize = 4;
  	psmouse->resync_time = 0;

-	__set_bit(BTN_MIDDLE, dev->keybit);
-	__set_bit(REL_WHEEL, dev->relbit);
-	__set_bit(REL_HWHEEL, dev->relbit);
+	__set_bit(INPUT_PROP_POINTER, dev->propbit);
+	/* Touchpad */
+	__set_bit(BTN_TOUCH, dev->keybit);
+	__set_bit(BTN_TOOL_FINGER, dev->keybit);
+	/* Buttons */
+	__set_bit(BTN_LEFT, dev->keybit);
+	__set_bit(BTN_RIGHT, dev->keybit);
+	__clear_bit(BTN_MIDDLE, dev->keybit);
+
+	/* Absolute position */
+	__set_bit(EV_ABS, dev->evbit);
+	input_set_abs_params(dev, ABS_X, 0, BYD_CONST_PAD_WIDTH, 0, 0);
+	input_set_abs_params(dev, ABS_Y, 0, BYD_CONST_PAD_HEIGHT, 0, 0);
+	input_abs_set_res(dev, ABS_X, BYD_CONST_PAD_RESOLUTION);
+	input_abs_set_res(dev, ABS_Y, BYD_CONST_PAD_RESOLUTION);
+	/* No relative support */
+	__clear_bit(EV_REL, dev->evbit);
+	__clear_bit(REL_X, dev->relbit);
+	__clear_bit(REL_Y, dev->relbit);

  	return 0;
  }
diff --git a/drivers/input/mouse/psmouse-base.c 
b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol 
psmouse_protocols[] = {
  #ifdef CONFIG_MOUSE_PS2_BYD
  	{
  		.type		= PSMOUSE_BYD,
-		.name		= "BydPS/2",
+		.name		= "BYDPS/2",
  		.alias		= "byd",
  		.detect		= byd_detect,
  		.init		= byd_init,




On 02/03/2016 12:28 PM, Chris Diamand wrote:
>> The Windows driver provides a visualization of the regions for the hardware
>> edge scrolling capability. When entering that screen, a particular command
>> pair is sent, and the touchpad starts sending interleaved REL and ABS
>> packets.  When leaving that screen, another particular command pair is sent,
>> and the touchpad resumes the normal REL only stream.
>
> Good find! That's very crafty.
>
> I've managed to apply your patch, and can confirm that it works - my initial
> impressions (using it for 15 mins...) are that even 256x256 resolution absolute
> mode + synaptics is much better than the touchpad's built-in gesture detection.
>
> Let's work your patch into something which applies on top of the existing
> driver, and get it merged.
>
> Cheers!
> Chris
>

Re: [PATCH] psmouse: added BYD touchpad driver

[Chris Diamand]

Hi Richard,

Thanks for this.

> Rebased patch against 98ee377144935857d8ad5d7d70cdab1da4ede32e:

Can you include a proper commit message and Signed-off-by line?

> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
> index 9425e0f..f213a08 100644
> --- a/drivers/input/mouse/byd.c
> +++ b/drivers/input/mouse/byd.c
> @@ -2,93 +2,276 @@
>   * BYD TouchPad PS/2 mouse driver
>   *
>   * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
> + * Copyright (C) 2015 Richard Pospesel
> + * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
> + * Copyright (C) 2015 Martin Wimpress
> + * Copyright (C) 2015 Jay Kuri
>   *
>   * This program is free software; you can redistribute it and/or modify it
>   * under the terms of the GNU General Public License version 2 as published
> by
>   * the Free Software Foundation.

Your email client is still mangling the patch - use git send-email or
similar next time. Also try sending it to yourself and then applying
the patch to check it's worked.

> + *
> + * Protocol of BYD Touch Pad reverse-engineered from windows driver:
> + * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
> + * md5:       0d5e4660b98fca9587a0df212fca3048
> + * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
> + * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
>   */
> 
>  #include <linux/delay.h>
>  #include <linux/input.h>
>  #include <linux/libps2.h>
>  #include <linux/serio.h>
> +#include <linux/slab.h>
> 
>  #include "psmouse.h"
>  #include "byd.h"
> 
> -#define PS2_Y_OVERFLOW	BIT_MASK(7)
> -#define PS2_X_OVERFLOW	BIT_MASK(6)
> -#define PS2_Y_SIGN	BIT_MASK(5)
> -#define PS2_X_SIGN	BIT_MASK(4)
> -#define PS2_ALWAYS_1	BIT_MASK(3)
> -#define PS2_MIDDLE	BIT_MASK(2)
> -#define PS2_RIGHT	BIT_MASK(1)
> -#define PS2_LEFT	BIT_MASK(0)
> +/* PS2 Bits */
> +#define PS2_Y_OVERFLOW BIT_MASK(7)
> +#define PS2_X_OVERFLOW BIT_MASK(6)
> +#define PS2_Y_SIGN     BIT_MASK(5)
> +#define PS2_X_SIGN     BIT_MASK(4)
> +#define PS2_ALWAYS_1   BIT_MASK(3)
> +#define PS2_MIDDLE     BIT_MASK(2)
> +#define PS2_RIGHT      BIT_MASK(1)
> +#define PS2_LEFT       BIT_MASK(0)

The tabs between these were deliberate - no need to change them. Do
you have your tab width set to eight spaces? If you've got it set to
four then it'll look wrong.

> 
>  /*
> - * The touchpad reports gestures in the last byte of each packet. It can
> take
> - * any of the following values:

Another example of your email client wrapping lines incorrectly.

> + * BYD pad constants
> + *
> + * True device resolution is unknown, however experiments show the
> + * resolution is about 111 units/mm.
> + * Absolute coordinate packets are in the range 0-255 for both X and Y
> + * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
> + * the right ballpark given the touchpad's physical dimensions and estimate
> + * resolution per spec sheet, device active area dimensions are
> + * 101.6 x 60.1 mm.
>   */
> +#define BYD_CONST_PAD_WIDTH	     11264
> +#define BYD_CONST_PAD_HEIGHT     6656
> +#define BYD_CONST_PAD_RESOLUTION 111

Do these need to include "CONST"? It's pretty obvious that they're
constant from the capitalization.

> 
> -/* One-finger scrolling in one of the edge scroll zones. */
> -#define BYD_SCROLLUP		0xCA
> -#define BYD_SCROLLDOWN		0x36
> -#define BYD_SCROLLLEFT		0xCB
> -#define BYD_SCROLLRIGHT		0x35
> -/* Two-finger scrolling. */
> -#define BYD_2DOWN		0x2B
> -#define BYD_2UP			0xD5
> -#define BYD_2LEFT		0xD6
> -#define BYD_2RIGHT		0x2A
> -/* Pinching in or out. */
> -#define BYD_ZOOMOUT		0xD8
> -#define BYD_ZOOMIN		0x28
> -/* Three-finger swipe. */
> -#define BYD_3UP			0xD3
> -#define BYD_3DOWN		0x2D
> -#define BYD_3LEFT		0xD4
> -#define BYD_3RIGHT		0x2C
> -/* Four-finger swipe. */
> -#define BYD_4UP			0xCD
> -#define BYD_4DOWN		0x33
> -
> -int byd_detect(struct psmouse *psmouse, bool set_properties)
> -{
> -	struct ps2dev *ps2dev = &psmouse->ps2dev;
> -	unsigned char param[4];
> +/* BYD commands reverse engineered from windows driver */
> 
> -	param[0] = 0x03;
> -	param[1] = 0x00;
> -	param[2] = 0x00;
> -	param[3] = 0x00;
> -
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> -		return -1;

Did you need to move this function? No technical objections, but it
confuses the patch a bit.

> +/*
> + * Swipe gesture from off-pad to on-pad
> + *  0 : disable
> + *  1 : enable
> + */
> +#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
> +/*
> + * Tap and drag delay time
> + *  0 : disable
> + *  1 - 8 : least to most delay
> + */
> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
> +/*
> + * Physical buttons function mapping
> + *  0 : enable
> + *  4 : normal
> + *  5 : left button custom command
> + *  6 : right button custom command
> + *  8 : disable
> + */
> +#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
> +/*
> + * Absolute mode (1 byte X/Y resolution)
> + *  0 : disable
> + *  2 : enable
> + */
> +#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
> +/*
> + * Two finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
> +/*
> + * Handedness
> + *  1 : right handed
> + *  2 : left handed
> + */
> +#define BYD_CMD_SET_HANDEDNESS             0x10d3
> +/*
> + * Tap to click
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_TAP                    0x10d4
> +/*
> + * Tap and drag
> + *  1 : tap and hold to drag
> + *  2 : tap and hold to drag + lock
> + *  3 : disable
> + */
> +#define BYD_CMD_SET_TAP_DRAG               0x10d5
> +/*
> + * Touch sensitivity
> + *  1 - 7 : least to most sensitive
> + */
> +#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
> +/*
> + * One finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
> +/*
> + * One finger scrolling function
> + *  1 : free scrolling
> + *  2 : edge motion
> + *  3 : free scrolling + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
> +/*
> + * Sliding speed
> + *  1 - 5 : slowest to fastest
> + */
> +#define BYD_CMD_SET_SLIDING_SPEED          0x10da
> +/*
> + * Edge motion
> + *  1 : disable
> + *  2 : enable when dragging
> + *  3 : enable when dragging and pointing
> + */
> +#define BYD_CMD_SET_EDGE_MOTION            0x10db
> +/*
> + * Left edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
> +/*
> + * Top edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
> +/*
> + * Disregard palm press as clicks
> + *  1 - 6 : smallest to largest
> + */
> +#define BYD_CMD_SET_PALM_CHECK             0x10de
> +/*
> + * Right edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
> +/*
> + * Bottom edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
> +/*
> + * Multitouch gestures
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_MULTITOUCH             0x10e3
> +/*
> + * Edge motion speed
> + *  0 : control with finger pressure
> + *  1 - 9 : slowest to fastest
> + */
> +#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
> +/*
> + * Two finger scolling function
> + *  0 : free scrolling
> + *  1 : free scrolling (with momentum)
> + *  2 : edge motion
> + *  3 : free scrolling (with momentum) + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5
> 

Good effort figuring all the different settings by the way.

> -	if (param[1] != 0x03 || param[2] != 0x64)
> -		return -ENODEV;
> +/*
> + * The touchpad generates a mixture of absolute and relative packets,
> indicated
> + * by the the last byte of each packet being set to one of the following:
> + */
> +#define BYD_PACKET_ABSOLUTE	0xF8
> +#define BYD_PACKET_RELATIVE	0x00
> 
> -	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +/*
> + * With multitouch gestures enabled, the following packets will be sent
> from
> + * the touchpad:
> + */
> +#define BYD_PACKET_PINCH_IN                    0xd8
> +#define BYD_PACKET_PINCH_OUT                   0x28
> +#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
> +#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
> +#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
> +#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
> +#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
> +#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
> +#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
> +#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
> +#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
> +#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
> +#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
> +#define BYD_PACKET_FOUR_FINGER_UP              0xcd
> +#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
> +#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
> +#define BYD_PACKET_REGION_SCROLL_UP            0xca
> +#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
> +#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
> +#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
> +#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
> +#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
> +#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
> +#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
> +#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9

Can you merge this with the existing list of packet[3] values? Again,
just to keep the diff smaller/simpler.

> +
> +struct byd_data {
> +	struct timer_list timer;
> +	s32 abs_x;
> +	s32 abs_y;
> +	u32 last_touch_time;
> +	bool btn_left  : 1;
> +	bool btn_right : 1;
> +	bool touch     : 1;
> +};
> +
> +static void byd_report_input(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = (struct byd_data *)psmouse->private;

I've just noticed that none of the other drivers use a cast here, so
we can probably just do:

    struct byd_data *priv = psmouse->private;

> +	struct input_dev *dev = psmouse->dev;
> 
> -	if (set_properties) {
> -		psmouse->vendor = "BYD";
> -		psmouse->name = "TouchPad";
> -	}
> +	input_report_abs(dev, ABS_X, priv->abs_x);
> +	input_report_abs(dev, ABS_Y, priv->abs_y);
> +	input_report_key(dev, BTN_LEFT, priv->btn_left);
> +	input_report_key(dev, BTN_RIGHT, priv->btn_right);
> +	input_report_key(dev, BTN_TOUCH, priv->touch);
> +	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
> +	input_sync(dev);
> +}
> 
> -	return 0;
> +static void byd_clear_touch(unsigned long data)
> +{
> +	struct psmouse *psmouse = (struct psmouse *) data;

See previous comment.

> +	struct byd_data *priv = psmouse->private;
> +
> +	serio_pause_rx(psmouse->ps2dev.serio);
> +	priv->touch = false;
> +	/*
> +	 * Move cursor back to center of pad when we lose touch - this
> +	 * specifically improves user experience when moving cursor with one
> +	 * finger, and pressing a button with another.
> +	 */
> +	priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
> +	priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
> +	byd_report_input(psmouse);
> +
> +	serio_continue_rx(psmouse->ps2dev.serio);
>  }
> 
>  static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>  {
> -	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv = psmouse->private;
> +	u32 now_msecs = jiffies_to_msecs(jiffies);
>  	u8 *pkt = psmouse->packet;
> 
>  	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
> @@ -102,53 +285,37 @@ static psmouse_ret_t byd_process_byte(struct psmouse
> *psmouse)
> 
>  	/* Otherwise, a full packet has been received */
>  	switch (pkt[3]) {
> -	case 0: {
> +	case BYD_PACKET_ABSOLUTE:
> +		/* Only use absolute packets for the start of movement. */
> +		if (!priv->touch) {
> +			priv->abs_x = pkt[1] * (BYD_CONST_PAD_WIDTH / 256);
> +			priv->abs_y = (255 - pkt[2]) *
> +				      (BYD_CONST_PAD_HEIGHT / 256);
> +
> +			/* needed to detect tap */
> +			if (now_msecs - priv->last_touch_time > 64)
> +				priv->touch = true;
> +		}
> +		break;
> +	case BYD_PACKET_RELATIVE: {
>  		/* Standard packet */
>  		/* Sign-extend if a sign bit is set. */
> -		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> -		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> -		int dx = signx | (int) pkt[1];
> -		int dy = signy | (int) pkt[2];
> -
> -		input_report_rel(psmouse->dev, REL_X, dx);
> -		input_report_rel(psmouse->dev, REL_Y, -dy);
> -
> -		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
> -		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
> -		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
> +		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> +		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> +		s32 dx = signx | (int) pkt[1];
> +		s32 dy = signy | (int) pkt[2];

This bit (replacing int/unsigned int with u32/s32) doesn't actually
need to change, the logic doesn't depend on a particular type width.
(the draft patch I sent you had it as an experiment...).

> +
> +		/*
> +		 * Experiments show relative mouse packets come in increments
> +		 * of 1 unit / 11 milliseconds (regardless of time delta between
> +		 * relative packets).
> +		 */
> +		priv->abs_x += dx * 11;
> +		priv->abs_y -= dy * 11;

What do you mean by "1 unit / 11 ms"? Do you mean that relative
packets arrive every 11 ms? Except saying "regardless of time delta"
implies the opposite.

Also it might be worth putting replacing "11" with a #define.

> +
> +		priv->touch = true;
>  		break;
>  	}
> -
> -	case BYD_SCROLLDOWN:
> -	case BYD_2DOWN:
> -		input_report_rel(dev, REL_WHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLUP:
> -	case BYD_2UP:
> -		input_report_rel(dev, REL_WHEEL, 1);
> -		break;
> -
> -	case BYD_SCROLLLEFT:
> -	case BYD_2LEFT:
> -		input_report_rel(dev, REL_HWHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLRIGHT:
> -	case BYD_2RIGHT:
> -		input_report_rel(dev, REL_HWHEEL, 1);
> -		break;
> -
> -	case BYD_ZOOMOUT:
> -	case BYD_ZOOMIN:
> -	case BYD_3UP:
> -	case BYD_3DOWN:
> -	case BYD_3LEFT:
> -	case BYD_3RIGHT:
> -	case BYD_4UP:
> -	case BYD_4DOWN:
> -		break;
> -
>  	default:
>  		psmouse_warn(psmouse,
>  			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
> @@ -157,134 +324,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse
> *psmouse)
>  		return PSMOUSE_BAD_DATA;
>  	}
> 
> -	input_sync(dev);
> +	priv->btn_left = pkt[0] & PS2_LEFT;
> +	priv->btn_right = pkt[0] & PS2_RIGHT;
> 
> -	return PSMOUSE_FULL_PACKET;
> -}
> +	byd_report_input(psmouse);
> 
> -/* Send a sequence of bytes, where each is ACKed before the next is sent.
> */
> -static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t
> len)
> -{
> -	unsigned int i;
> -
> -	for (i = 0; i < len; ++i) {
> -		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
> -			return -1;
> +	/* Reset time since last touch. */
> +	if (priv->touch) {
> +		priv->last_touch_time = now_msecs;
> +		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(64));
>  	}
> -	return 0;
> -}
> -
> -/* Keep scrolling after fingers are removed. */
> -#define SCROLL_INERTIAL		0x01
> -#define SCROLL_NO_INERTIAL	0x02
> -
> -/* Clicking can be done by tapping or pressing. */
> -#define CLICK_BOTH		0x01
> -/* Clicking can only be done by pressing. */
> -#define CLICK_PRESS_ONLY	0x02
> -
> -static int byd_enable(struct psmouse *psmouse)
> -{
> -	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
> -	const u8 seq2[] = {
> -		0xD3, 0x01,
> -		0xD0, 0x00,
> -		0xD0, 0x04,
> -		/* Whether clicking is done by tapping or pressing. */
> -		0xD4, CLICK_PRESS_ONLY,
> -		0xD5, 0x01,
> -		0xD7, 0x03,
> -		/* Vertical and horizontal one-finger scroll zone inertia. */
> -		0xD8, SCROLL_INERTIAL,
> -		0xDA, 0x05,
> -		0xDB, 0x02,
> -		0xE4, 0x05,
> -		0xD6, 0x01,
> -		0xDE, 0x04,
> -		0xE3, 0x01,
> -		0xCF, 0x00,
> -		0xD2, 0x03,
> -		/* Vertical and horizontal two-finger scrolling inertia. */
> -		0xE5, SCROLL_INERTIAL,
> -		0xD9, 0x02,
> -		0xD9, 0x07,
> -		0xDC, 0x03,
> -		0xDD, 0x03,
> -		0xDF, 0x03,
> -		0xE1, 0x03,
> -		0xD1, 0x00,
> -		0xCE, 0x00,
> -		0xCC, 0x00,
> -		0xE0, 0x00,
> -		0xE2, 0x01
> -	};
> -	u8 param[4];
> -
> -	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
> -		return -1;
> -
> -	/* Send a 0x01 command, which should return 4 bytes. */
> -	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
> -		return -1;
> 
> -	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
> -		return -1;
> -
> -	return 0;
> +	return PSMOUSE_FULL_PACKET;
>  }
> 
> -/*
> - * Send the set of PS/2 commands required to make it identify as an
> - * intellimouse with 4-byte instead of 3-byte packets.
> - */
> -static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
> +static int byd_reset_touchpad(struct psmouse *psmouse)
>  {
>  	struct ps2dev *ps2dev = &psmouse->ps2dev;
>  	u8 param[4];
> -	int i;
> +	size_t i;
> +

Good point.

>  	const struct {
>  		u16 command;
>  		u8 arg;
>  	} seq[] = {
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_GETINFO, 0 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> +		/*
> +		 * Intellimouse initialization sequence, to get 4-byte instead
> +		 * of 3-byte packets.
> +		 */
>  		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>  		{ PSMOUSE_CMD_SETRATE, 0x64 },
>  		{ PSMOUSE_CMD_SETRATE, 0x50 },
>  		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0x50 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0x64 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> -		{ PSMOUSE_CMD_ENABLE, 0 }
> +		{ PSMOUSE_CMD_ENABLE, 0 },
> +		/*
> +		 * BYD-specific initialization, which enables absolute mode and
> +		 * (if desired), the touchpad's built-in gesture detection.
> +		 */
> +		{ 0x10E2, 0x00 },
> +		{ 0x10E0, 0x02 },
> +		/* The touchpad should reply with 4 seemingly-random bytes */
> +		{ 0x14E0, 0x01 },
> +		/* Pairs of parameters and values. */
> +		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
> +		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
> +		{ BYD_CMD_SET_TAP, 0x02 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
> +		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
> +		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
> +		/* Finalize initialization. */
> +		{ 0x10E0, 0x00 },
> +		{ 0x10E2, 0x01 },
>  	};
> 
> -	memset(param, 0, sizeof(param));
>  	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
> +		memset(param, 0, sizeof(param));
>  		param[0] = seq[i].arg;
>  		if (ps2_command(ps2dev, param, seq[i].command))
> -			return -1;
> -	}
> -
> -	return 0;
> -}
> -
> -static int byd_reset_touchpad(struct psmouse *psmouse)
> -{
> -	if (byd_send_intellimouse_sequence(psmouse))
> -		return -EIO;
> -
> -	if (byd_enable(psmouse))
> -		return -EIO;
> +			return -EIO;
> 
> +	}
> +	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
>  	return 0;
>  }
> 
> @@ -314,9 +423,50 @@ static int byd_reconnect(struct psmouse *psmouse)
>  	return 0;
>  }
> 
> +static void byd_disconnect(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = psmouse->private;
> +
> +	if (priv) {
> +		del_timer(&priv->timer);
> +		kfree(psmouse->private);
> +		psmouse->private = NULL;
> +	}
> +}
> +
> +int byd_detect(struct psmouse *psmouse, bool set_properties)
> +{
> +	struct ps2dev *ps2dev = &psmouse->ps2dev;
> +	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
> +
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> +		return -1;
> +
> +	if (param[1] != 0x03 || param[2] != 0x64)
> +		return -ENODEV;
> +
> +	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +
> +	if (set_properties) {
> +		psmouse->vendor = "BYD";
> +		psmouse->name = "TouchPad";
> +	}
> +
> +	return 0;
> +}
> +
>  int byd_init(struct psmouse *psmouse)
>  {
>  	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv;
> 
>  	if (psmouse_reset(psmouse))
>  		return -EIO;
> @@ -324,14 +474,39 @@ int byd_init(struct psmouse *psmouse)
>  	if (byd_reset_touchpad(psmouse))
>  		return -EIO;
> 
> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	memset(priv, 0, sizeof(*priv));
> +	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
> +
> +	psmouse->private = priv;
> +	psmouse->disconnect = byd_disconnect;
>  	psmouse->reconnect = byd_reconnect;
>  	psmouse->protocol_handler = byd_process_byte;
>  	psmouse->pktsize = 4;
>  	psmouse->resync_time = 0;
> 
> -	__set_bit(BTN_MIDDLE, dev->keybit);
> -	__set_bit(REL_WHEEL, dev->relbit);
> -	__set_bit(REL_HWHEEL, dev->relbit);
> +	__set_bit(INPUT_PROP_POINTER, dev->propbit);
> +	/* Touchpad */
> +	__set_bit(BTN_TOUCH, dev->keybit);
> +	__set_bit(BTN_TOOL_FINGER, dev->keybit);
> +	/* Buttons */
> +	__set_bit(BTN_LEFT, dev->keybit);
> +	__set_bit(BTN_RIGHT, dev->keybit);
> +	__clear_bit(BTN_MIDDLE, dev->keybit);
> +
> +	/* Absolute position */
> +	__set_bit(EV_ABS, dev->evbit);
> +	input_set_abs_params(dev, ABS_X, 0, BYD_CONST_PAD_WIDTH, 0, 0);
> +	input_set_abs_params(dev, ABS_Y, 0, BYD_CONST_PAD_HEIGHT, 0, 0);
> +	input_abs_set_res(dev, ABS_X, BYD_CONST_PAD_RESOLUTION);
> +	input_abs_set_res(dev, ABS_Y, BYD_CONST_PAD_RESOLUTION);
> +	/* No relative support */
> +	__clear_bit(EV_REL, dev->evbit);
> +	__clear_bit(REL_X, dev->relbit);
> +	__clear_bit(REL_Y, dev->relbit);
> 
>  	return 0;
>  }
> diff --git a/drivers/input/mouse/psmouse-base.c
> b/drivers/input/mouse/psmouse-base.c
> index 39d1bec..5784e20 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[]
> = {
>  #ifdef CONFIG_MOUSE_PS2_BYD
>  	{
>  		.type		= PSMOUSE_BYD,
> -		.name		= "BydPS/2",
> +		.name		= "BYDPS/2",
>  		.alias		= "byd",
>  		.detect		= byd_detect,
>  		.init		= byd_init,

Cheers!
Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Hy Chris, I'll send updated patch in a follow-up once I've verified thunderbird hasn't messed up the formatting yet again (seems like there are 3 separate settings I have to set, argh).

On 02/05/2016 10:55 AM, Chris Diamand wrote:
> Hi Richard,
>
> Thanks for this.
>
>> Rebased patch against 98ee377144935857d8ad5d7d70cdab1da4ede32e:
>
> Can you include a proper commit message and Signed-off-by line?
>
>> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
>> index 9425e0f..f213a08 100644
>> --- a/drivers/input/mouse/byd.c
>> +++ b/drivers/input/mouse/byd.c
>> @@ -2,93 +2,276 @@
>>    * BYD TouchPad PS/2 mouse driver
>>    *
>>    * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
>> + * Copyright (C) 2015 Richard Pospesel
>> + * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
>> + * Copyright (C) 2015 Martin Wimpress
>> + * Copyright (C) 2015 Jay Kuri
>>    *
>>    * This program is free software; you can redistribute it and/or modify it
>>    * under the terms of the GNU General Public License version 2 as published
>> by
>>    * the Free Software Foundation.
>
> Your email client is still mangling the patch - use git send-email or
> similar next time. Also try sending it to yourself and then applying
> the patch to check it's worked.
>
>> + *
>> + * Protocol of BYD Touch Pad reverse-engineered from windows driver:
>> + * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
>> + * md5:       0d5e4660b98fca9587a0df212fca3048
>> + * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
>> + * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
>>    */
>>
>>   #include <linux/delay.h>
>>   #include <linux/input.h>
>>   #include <linux/libps2.h>
>>   #include <linux/serio.h>
>> +#include <linux/slab.h>
>>
>>   #include "psmouse.h"
>>   #include "byd.h"
>>
>> -#define PS2_Y_OVERFLOW	BIT_MASK(7)
>> -#define PS2_X_OVERFLOW	BIT_MASK(6)
>> -#define PS2_Y_SIGN	BIT_MASK(5)
>> -#define PS2_X_SIGN	BIT_MASK(4)
>> -#define PS2_ALWAYS_1	BIT_MASK(3)
>> -#define PS2_MIDDLE	BIT_MASK(2)
>> -#define PS2_RIGHT	BIT_MASK(1)
>> -#define PS2_LEFT	BIT_MASK(0)
>> +/* PS2 Bits */
>> +#define PS2_Y_OVERFLOW BIT_MASK(7)
>> +#define PS2_X_OVERFLOW BIT_MASK(6)
>> +#define PS2_Y_SIGN     BIT_MASK(5)
>> +#define PS2_X_SIGN     BIT_MASK(4)
>> +#define PS2_ALWAYS_1   BIT_MASK(3)
>> +#define PS2_MIDDLE     BIT_MASK(2)
>> +#define PS2_RIGHT      BIT_MASK(1)
>> +#define PS2_LEFT       BIT_MASK(0)
>
> The tabs between these were deliberate - no need to change them. Do
> you have your tab width set to eight spaces? If you've got it set to
> four then it'll look wrong.
>

I am using the proper 8 spaces/tab width.  However, I've always used the guideline of 'tabs for indentation, spaces for formatting.'  The kernel coding style doesn't seem to cover this but I can revert these bits for the sake of a smaller diff.

>>
>>   /*
>> - * The touchpad reports gestures in the last byte of each packet. It can
>> take
>> - * any of the following values:
>
> Another example of your email client wrapping lines incorrectly.
>
>> + * BYD pad constants
>> + *
>> + * True device resolution is unknown, however experiments show the
>> + * resolution is about 111 units/mm.
>> + * Absolute coordinate packets are in the range 0-255 for both X and Y
>> + * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
>> + * the right ballpark given the touchpad's physical dimensions and estimate
>> + * resolution per spec sheet, device active area dimensions are
>> + * 101.6 x 60.1 mm.
>>    */
>> +#define BYD_CONST_PAD_WIDTH	     11264
>> +#define BYD_CONST_PAD_HEIGHT     6656
>> +#define BYD_CONST_PAD_RESOLUTION 111
>
> Do these need to include "CONST"? It's pretty obvious that they're
> constant from the capitalization.

True enough, will fix.

>
>>
>> -/* One-finger scrolling in one of the edge scroll zones. */
>> -#define BYD_SCROLLUP		0xCA
>> -#define BYD_SCROLLDOWN		0x36
>> -#define BYD_SCROLLLEFT		0xCB
>> -#define BYD_SCROLLRIGHT		0x35
>> -/* Two-finger scrolling. */
>> -#define BYD_2DOWN		0x2B
>> -#define BYD_2UP			0xD5
>> -#define BYD_2LEFT		0xD6
>> -#define BYD_2RIGHT		0x2A
>> -/* Pinching in or out. */
>> -#define BYD_ZOOMOUT		0xD8
>> -#define BYD_ZOOMIN		0x28
>> -/* Three-finger swipe. */
>> -#define BYD_3UP			0xD3
>> -#define BYD_3DOWN		0x2D
>> -#define BYD_3LEFT		0xD4
>> -#define BYD_3RIGHT		0x2C
>> -/* Four-finger swipe. */
>> -#define BYD_4UP			0xCD
>> -#define BYD_4DOWN		0x33
>> -
>> -int byd_detect(struct psmouse *psmouse, bool set_properties)
>> -{
>> -	struct ps2dev *ps2dev = &psmouse->ps2dev;
>> -	unsigned char param[4];
>> +/* BYD commands reverse engineered from windows driver */
>>
>> -	param[0] = 0x03;
>> -	param[1] = 0x00;
>> -	param[2] = 0x00;
>> -	param[3] = 0x00;
>> -
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
>> -		return -1;
>
> Did you need to move this function? No technical objections, but it
> confuses the patch a bit.

True, but I opted to keep the externally accessible (vs the static ones) together for the sake of organization.

>
>> +/*
>> + * Swipe gesture from off-pad to on-pad
>> + *  0 : disable
>> + *  1 : enable
>> + */
>> +#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
>> +/*
>> + * Tap and drag delay time
>> + *  0 : disable
>> + *  1 - 8 : least to most delay
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
>> +/*
>> + * Physical buttons function mapping
>> + *  0 : enable
>> + *  4 : normal
>> + *  5 : left button custom command
>> + *  6 : right button custom command
>> + *  8 : disable
>> + */
>> +#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
>> +/*
>> + * Absolute mode (1 byte X/Y resolution)
>> + *  0 : disable
>> + *  2 : enable
>> + */
>> +#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
>> +/*
>> + * Two finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
>> +/*
>> + * Handedness
>> + *  1 : right handed
>> + *  2 : left handed
>> + */
>> +#define BYD_CMD_SET_HANDEDNESS             0x10d3
>> +/*
>> + * Tap to click
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_TAP                    0x10d4
>> +/*
>> + * Tap and drag
>> + *  1 : tap and hold to drag
>> + *  2 : tap and hold to drag + lock
>> + *  3 : disable
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG               0x10d5
>> +/*
>> + * Touch sensitivity
>> + *  1 - 7 : least to most sensitive
>> + */
>> +#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
>> +/*
>> + * One finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
>> +/*
>> + * One finger scrolling function
>> + *  1 : free scrolling
>> + *  2 : edge motion
>> + *  3 : free scrolling + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
>> +/*
>> + * Sliding speed
>> + *  1 - 5 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_SLIDING_SPEED          0x10da
>> +/*
>> + * Edge motion
>> + *  1 : disable
>> + *  2 : enable when dragging
>> + *  3 : enable when dragging and pointing
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION            0x10db
>> +/*
>> + * Left edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
>> +/*
>> + * Top edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
>> +/*
>> + * Disregard palm press as clicks
>> + *  1 - 6 : smallest to largest
>> + */
>> +#define BYD_CMD_SET_PALM_CHECK             0x10de
>> +/*
>> + * Right edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
>> +/*
>> + * Bottom edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
>> +/*
>> + * Multitouch gestures
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_MULTITOUCH             0x10e3
>> +/*
>> + * Edge motion speed
>> + *  0 : control with finger pressure
>> + *  1 - 9 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
>> +/*
>> + * Two finger scolling function
>> + *  0 : free scrolling
>> + *  1 : free scrolling (with momentum)
>> + *  2 : edge motion
>> + *  3 : free scrolling (with momentum) + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5
>>
>
> Good effort figuring all the different settings by the way.
>
>> -	if (param[1] != 0x03 || param[2] != 0x64)
>> -		return -ENODEV;
>> +/*
>> + * The touchpad generates a mixture of absolute and relative packets,
>> indicated
>> + * by the the last byte of each packet being set to one of the following:
>> + */
>> +#define BYD_PACKET_ABSOLUTE	0xF8
>> +#define BYD_PACKET_RELATIVE	0x00
>>
>> -	psmouse_dbg(psmouse, "BYD touchpad detected\n");
>> +/*
>> + * With multitouch gestures enabled, the following packets will be sent
>> from
>> + * the touchpad:
>> + */
>> +#define BYD_PACKET_PINCH_IN                    0xd8
>> +#define BYD_PACKET_PINCH_OUT                   0x28
>> +#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
>> +#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
>> +#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
>> +#define BYD_PACKET_FOUR_FINGER_UP              0xcd
>> +#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
>> +#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
>> +#define BYD_PACKET_REGION_SCROLL_UP            0xca
>> +#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
>> +#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
>> +#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
>> +#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9
>
> Can you merge this with the existing list of packet[3] values? Again,
> just to keep the diff smaller/simpler.

Yeah, this secondary list appars direclty below the existing ABS and REL constants.

>
>> +
>> +struct byd_data {
>> +	struct timer_list timer;
>> +	s32 abs_x;
>> +	s32 abs_y;
>> +	u32 last_touch_time;
>> +	bool btn_left  : 1;
>> +	bool btn_right : 1;
>> +	bool touch     : 1;
>> +};
>> +
>> +static void byd_report_input(struct psmouse *psmouse)
>> +{
>> +	struct byd_data *priv = (struct byd_data *)psmouse->private;
>
> I've just noticed that none of the other drivers use a cast here, so
> we can probably just do:

Sorry, too used to C++

>
>      struct byd_data *priv = psmouse->private;
>
>> +	struct input_dev *dev = psmouse->dev;
>>
>> -	if (set_properties) {
>> -		psmouse->vendor = "BYD";
>> -		psmouse->name = "TouchPad";
>> -	}
>> +	input_report_abs(dev, ABS_X, priv->abs_x);
>> +	input_report_abs(dev, ABS_Y, priv->abs_y);
>> +	input_report_key(dev, BTN_LEFT, priv->btn_left);
>> +	input_report_key(dev, BTN_RIGHT, priv->btn_right);
>> +	input_report_key(dev, BTN_TOUCH, priv->touch);
>> +	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
>> +	input_sync(dev);
>> +}
>>
>> -	return 0;
>> +static void byd_clear_touch(unsigned long data)
>> +{
>> +	struct psmouse *psmouse = (struct psmouse *) data;
>
> See previous comment.

I'm pretty sure you have to cast unsigned long however (will check).

>
>> +	struct byd_data *priv = psmouse->private;
>> +
>> +	serio_pause_rx(psmouse->ps2dev.serio);
>> +	priv->touch = false;
>> +	/*
>> +	 * Move cursor back to center of pad when we lose touch - this
>> +	 * specifically improves user experience when moving cursor with one
>> +	 * finger, and pressing a button with another.
>> +	 */
>> +	priv->abs_x = BYD_CONST_PAD_WIDTH / 2;
>> +	priv->abs_y = BYD_CONST_PAD_HEIGHT / 2;
>> +	byd_report_input(psmouse);
>> +
>> +	serio_continue_rx(psmouse->ps2dev.serio);
>>   }
>>
>>   static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>>   {
>> -	struct input_dev *dev = psmouse->dev;
>> +	struct byd_data *priv = psmouse->private;
>> +	u32 now_msecs = jiffies_to_msecs(jiffies);
>>   	u8 *pkt = psmouse->packet;
>>
>>   	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
>> @@ -102,53 +285,37 @@ static psmouse_ret_t byd_process_byte(struct psmouse
>> *psmouse)
>>
>>   	/* Otherwise, a full packet has been received */
>>   	switch (pkt[3]) {
>> -	case 0: {
>> +	case BYD_PACKET_ABSOLUTE:
>> +		/* Only use absolute packets for the start of movement. */
>> +		if (!priv->touch) {
>> +			priv->abs_x = pkt[1] * (BYD_CONST_PAD_WIDTH / 256);
>> +			priv->abs_y = (255 - pkt[2]) *
>> +				      (BYD_CONST_PAD_HEIGHT / 256);
>> +
>> +			/* needed to detect tap */
>> +			if (now_msecs - priv->last_touch_time > 64)
>> +				priv->touch = true;
>> +		}
>> +		break;
>> +	case BYD_PACKET_RELATIVE: {
>>   		/* Standard packet */
>>   		/* Sign-extend if a sign bit is set. */
>> -		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
>> -		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
>> -		int dx = signx | (int) pkt[1];
>> -		int dy = signy | (int) pkt[2];
>> -
>> -		input_report_rel(psmouse->dev, REL_X, dx);
>> -		input_report_rel(psmouse->dev, REL_Y, -dy);
>> -
>> -		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
>> -		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
>> -		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
>> +		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
>> +		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
>> +		s32 dx = signx | (int) pkt[1];
>> +		s32 dy = signy | (int) pkt[2];
>
> This bit (replacing int/unsigned int with u32/s32) doesn't actually
> need to change, the logic doesn't depend on a particular type width.
> (the draft patch I sent you had it as an experiment...).

True, but I think it's best to be consistent with the module in terms of which types of integer types we use.

>
>> +
>> +		/*
>> +		 * Experiments show relative mouse packets come in increments
>> +		 * of 1 unit / 11 milliseconds (regardless of time delta between
>> +		 * relative packets).
>> +		 */
>> +		priv->abs_x += dx * 11;
>> +		priv->abs_y -= dy * 11;
>
> What do you mean by "1 unit / 11 ms"? Do you mean that relative
> packets arrive every 11 ms? Except saying "regardless of time delta"
> implies the opposite.

Yeah I can explain.  The mouse sends relative packets with velocity information.  Velocity is distance traveled over a certain time delta.  My experiments have indicated that the time delta of one of these measurements is always (roughly) 11 milliseconds.  What I mean by 'regardless of the time delta' is that we don't always receive velocity packets every 11 millseconds, sometimes the delay is much longer.  All a relative packet tells us is that a finger moved X units over the 11 milliseconds prior to receiving the relative packet.

>
> Also it might be worth putting replacing "11" with a #define.

Agreed on this, will alsy replace the magic 64 ms timers with defines as well.

>
>> +
>> +		priv->touch = true;
>>   		break;
>>   	}
>> -
>> -	case BYD_SCROLLDOWN:
>> -	case BYD_2DOWN:
>> -		input_report_rel(dev, REL_WHEEL, -1);
>> -		break;
>> -
>> -	case BYD_SCROLLUP:
>> -	case BYD_2UP:
>> -		input_report_rel(dev, REL_WHEEL, 1);
>> -		break;
>> -
>> -	case BYD_SCROLLLEFT:
>> -	case BYD_2LEFT:
>> -		input_report_rel(dev, REL_HWHEEL, -1);
>> -		break;
>> -
>> -	case BYD_SCROLLRIGHT:
>> -	case BYD_2RIGHT:
>> -		input_report_rel(dev, REL_HWHEEL, 1);
>> -		break;
>> -
>> -	case BYD_ZOOMOUT:
>> -	case BYD_ZOOMIN:
>> -	case BYD_3UP:
>> -	case BYD_3DOWN:
>> -	case BYD_3LEFT:
>> -	case BYD_3RIGHT:
>> -	case BYD_4UP:
>> -	case BYD_4DOWN:
>> -		break;
>> -
>>   	default:
>>   		psmouse_warn(psmouse,
>>   			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
>> @@ -157,134 +324,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse
>> *psmouse)
>>   		return PSMOUSE_BAD_DATA;
>>   	}
>>
>> -	input_sync(dev);
>> +	priv->btn_left = pkt[0] & PS2_LEFT;
>> +	priv->btn_right = pkt[0] & PS2_RIGHT;
>>
>> -	return PSMOUSE_FULL_PACKET;
>> -}
>> +	byd_report_input(psmouse);
>>
>> -/* Send a sequence of bytes, where each is ACKed before the next is sent.
>> */
>> -static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t
>> len)
>> -{
>> -	unsigned int i;
>> -
>> -	for (i = 0; i < len; ++i) {
>> -		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
>> -			return -1;
>> +	/* Reset time since last touch. */
>> +	if (priv->touch) {
>> +		priv->last_touch_time = now_msecs;
>> +		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(64));
>>   	}
>> -	return 0;
>> -}
>> -
>> -/* Keep scrolling after fingers are removed. */
>> -#define SCROLL_INERTIAL		0x01
>> -#define SCROLL_NO_INERTIAL	0x02
>> -
>> -/* Clicking can be done by tapping or pressing. */
>> -#define CLICK_BOTH		0x01
>> -/* Clicking can only be done by pressing. */
>> -#define CLICK_PRESS_ONLY	0x02
>> -
>> -static int byd_enable(struct psmouse *psmouse)
>> -{
>> -	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
>> -	const u8 seq2[] = {
>> -		0xD3, 0x01,
>> -		0xD0, 0x00,
>> -		0xD0, 0x04,
>> -		/* Whether clicking is done by tapping or pressing. */
>> -		0xD4, CLICK_PRESS_ONLY,
>> -		0xD5, 0x01,
>> -		0xD7, 0x03,
>> -		/* Vertical and horizontal one-finger scroll zone inertia. */
>> -		0xD8, SCROLL_INERTIAL,
>> -		0xDA, 0x05,
>> -		0xDB, 0x02,
>> -		0xE4, 0x05,
>> -		0xD6, 0x01,
>> -		0xDE, 0x04,
>> -		0xE3, 0x01,
>> -		0xCF, 0x00,
>> -		0xD2, 0x03,
>> -		/* Vertical and horizontal two-finger scrolling inertia. */
>> -		0xE5, SCROLL_INERTIAL,
>> -		0xD9, 0x02,
>> -		0xD9, 0x07,
>> -		0xDC, 0x03,
>> -		0xDD, 0x03,
>> -		0xDF, 0x03,
>> -		0xE1, 0x03,
>> -		0xD1, 0x00,
>> -		0xCE, 0x00,
>> -		0xCC, 0x00,
>> -		0xE0, 0x00,
>> -		0xE2, 0x01
>> -	};
>> -	u8 param[4];
>> -
>> -	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
>> -		return -1;
>> -
>> -	/* Send a 0x01 command, which should return 4 bytes. */
>> -	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
>> -		return -1;
>>
>> -	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
>> -		return -1;
>> -
>> -	return 0;
>> +	return PSMOUSE_FULL_PACKET;
>>   }
>>
>> -/*
>> - * Send the set of PS/2 commands required to make it identify as an
>> - * intellimouse with 4-byte instead of 3-byte packets.
>> - */
>> -static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
>> +static int byd_reset_touchpad(struct psmouse *psmouse)
>>   {
>>   	struct ps2dev *ps2dev = &psmouse->ps2dev;
>>   	u8 param[4];
>> -	int i;
>> +	size_t i;
>> +
>
> Good point.
>
>>   	const struct {
>>   		u16 command;
>>   		u8 arg;
>>   	} seq[] = {
>> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
>> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
>> -		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_GETINFO, 0 },
>> -		{ PSMOUSE_CMD_SETRES, 0x03 },
>> +		/*
>> +		 * Intellimouse initialization sequence, to get 4-byte instead
>> +		 * of 3-byte packets.
>> +		 */
>>   		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>>   		{ PSMOUSE_CMD_SETRATE, 0x64 },
>>   		{ PSMOUSE_CMD_SETRATE, 0x50 },
>>   		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>> -		{ PSMOUSE_CMD_SETRATE, 0x50 },
>> -		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETRATE, 0x64 },
>> -		{ PSMOUSE_CMD_SETRES, 0x03 },
>> -		{ PSMOUSE_CMD_ENABLE, 0 }
>> +		{ PSMOUSE_CMD_ENABLE, 0 },
>> +		/*
>> +		 * BYD-specific initialization, which enables absolute mode and
>> +		 * (if desired), the touchpad's built-in gesture detection.
>> +		 */
>> +		{ 0x10E2, 0x00 },
>> +		{ 0x10E0, 0x02 },
>> +		/* The touchpad should reply with 4 seemingly-random bytes */
>> +		{ 0x14E0, 0x01 },
>> +		/* Pairs of parameters and values. */
>> +		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
>> +		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
>> +		{ BYD_CMD_SET_TAP, 0x02 },
>> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
>> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
>> +		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
>> +		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
>> +		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
>> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
>> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
>> +		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
>> +		/* Finalize initialization. */
>> +		{ 0x10E0, 0x00 },
>> +		{ 0x10E2, 0x01 },
>>   	};
>>
>> -	memset(param, 0, sizeof(param));
>>   	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
>> +		memset(param, 0, sizeof(param));
>>   		param[0] = seq[i].arg;
>>   		if (ps2_command(ps2dev, param, seq[i].command))
>> -			return -1;
>> -	}
>> -
>> -	return 0;
>> -}
>> -
>> -static int byd_reset_touchpad(struct psmouse *psmouse)
>> -{
>> -	if (byd_send_intellimouse_sequence(psmouse))
>> -		return -EIO;
>> -
>> -	if (byd_enable(psmouse))
>> -		return -EIO;
>> +			return -EIO;
>>
>> +	}
>> +	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
>>   	return 0;
>>   }
>>
>> @@ -314,9 +423,50 @@ static int byd_reconnect(struct psmouse *psmouse)
>>   	return 0;
>>   }
>>
>> +static void byd_disconnect(struct psmouse *psmouse)
>> +{
>> +	struct byd_data *priv = psmouse->private;
>> +
>> +	if (priv) {
>> +		del_timer(&priv->timer);
>> +		kfree(psmouse->private);
>> +		psmouse->private = NULL;
>> +	}
>> +}
>> +
>> +int byd_detect(struct psmouse *psmouse, bool set_properties)
>> +{
>> +	struct ps2dev *ps2dev = &psmouse->ps2dev;
>> +	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
>> +
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
>> +		return -1;
>> +
>> +	if (param[1] != 0x03 || param[2] != 0x64)
>> +		return -ENODEV;
>> +
>> +	psmouse_dbg(psmouse, "BYD touchpad detected\n");
>> +
>> +	if (set_properties) {
>> +		psmouse->vendor = "BYD";
>> +		psmouse->name = "TouchPad";
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   int byd_init(struct psmouse *psmouse)
>>   {
>>   	struct input_dev *dev = psmouse->dev;
>> +	struct byd_data *priv;
>>
>>   	if (psmouse_reset(psmouse))
>>   		return -EIO;
>> @@ -324,14 +474,39 @@ int byd_init(struct psmouse *psmouse)
>>   	if (byd_reset_touchpad(psmouse))
>>   		return -EIO;
>>
>> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	memset(priv, 0, sizeof(*priv));
>> +	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
>> +
>> +	psmouse->private = priv;
>> +	psmouse->disconnect = byd_disconnect;
>>   	psmouse->reconnect = byd_reconnect;
>>   	psmouse->protocol_handler = byd_process_byte;
>>   	psmouse->pktsize = 4;
>>   	psmouse->resync_time = 0;
>>
>> -	__set_bit(BTN_MIDDLE, dev->keybit);
>> -	__set_bit(REL_WHEEL, dev->relbit);
>> -	__set_bit(REL_HWHEEL, dev->relbit);
>> +	__set_bit(INPUT_PROP_POINTER, dev->propbit);
>> +	/* Touchpad */
>> +	__set_bit(BTN_TOUCH, dev->keybit);
>> +	__set_bit(BTN_TOOL_FINGER, dev->keybit);
>> +	/* Buttons */
>> +	__set_bit(BTN_LEFT, dev->keybit);
>> +	__set_bit(BTN_RIGHT, dev->keybit);
>> +	__clear_bit(BTN_MIDDLE, dev->keybit);
>> +
>> +	/* Absolute position */
>> +	__set_bit(EV_ABS, dev->evbit);
>> +	input_set_abs_params(dev, ABS_X, 0, BYD_CONST_PAD_WIDTH, 0, 0);
>> +	input_set_abs_params(dev, ABS_Y, 0, BYD_CONST_PAD_HEIGHT, 0, 0);
>> +	input_abs_set_res(dev, ABS_X, BYD_CONST_PAD_RESOLUTION);
>> +	input_abs_set_res(dev, ABS_Y, BYD_CONST_PAD_RESOLUTION);
>> +	/* No relative support */
>> +	__clear_bit(EV_REL, dev->evbit);
>> +	__clear_bit(REL_X, dev->relbit);
>> +	__clear_bit(REL_Y, dev->relbit);
>>
>>   	return 0;
>>   }
>> diff --git a/drivers/input/mouse/psmouse-base.c
>> b/drivers/input/mouse/psmouse-base.c
>> index 39d1bec..5784e20 100644
>> --- a/drivers/input/mouse/psmouse-base.c
>> +++ b/drivers/input/mouse/psmouse-base.c
>> @@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[]
>> = {
>>   #ifdef CONFIG_MOUSE_PS2_BYD
>>   	{
>>   		.type		= PSMOUSE_BYD,
>> -		.name		= "BydPS/2",
>> +		.name		= "BYDPS/2",
>>   		.alias		= "byd",
>>   		.detect		= byd_detect,
>>   		.init		= byd_init,
>
> Cheers!
> Chris
>

best,
-Richard

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Updated BYD driver to report absolute coordinates and single-touch events.   init and gesture packet documentation.  Confirmed working with both synaptics and libinput xorg touchpad drivers.  Patched against 98ee377144935857d8ad5d7d70cdab1da4ede32e on git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
---
diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..2900a3d 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -2,20 +2,32 @@
  * BYD TouchPad PS/2 mouse driver
  *
  * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015 Richard Pospesel
+ * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015 Martin Wimpress
+ * Copyright (C) 2015 Jay Kuri
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * md5:       0d5e4660b98fca9587a0df212fca3048
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
  */
 
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/libps2.h>
 #include <linux/serio.h>
+#include <linux/slab.h>
 
 #include "psmouse.h"
 #include "byd.h"
 
+/* PS2 Bits */
 #define PS2_Y_OVERFLOW	BIT_MASK(7)
 #define PS2_X_OVERFLOW	BIT_MASK(6)
 #define PS2_Y_SIGN	BIT_MASK(5)
@@ -26,69 +38,246 @@
 #define PS2_LEFT	BIT_MASK(0)
 
 /*
- * The touchpad reports gestures in the last byte of each packet. It can take
- * any of the following values:
+ * BYD pad constants
  */
 
-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP		0xCA
-#define BYD_SCROLLDOWN		0x36
-#define BYD_SCROLLLEFT		0xCB
-#define BYD_SCROLLRIGHT		0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN		0x2B
-#define BYD_2UP			0xD5
-#define BYD_2LEFT		0xD6
-#define BYD_2RIGHT		0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT		0xD8
-#define BYD_ZOOMIN		0x28
-/* Three-finger swipe. */
-#define BYD_3UP			0xD3
-#define BYD_3DOWN		0x2D
-#define BYD_3LEFT		0xD4
-#define BYD_3RIGHT		0x2C
-/* Four-finger swipe. */
-#define BYD_4UP			0xCD
-#define BYD_4DOWN		0x33
+/*
+ * True device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm.
+ * Absolute coordinate packets are in the range 0-255 for both X and Y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm.
+ */
+#define BYD_PAD_WIDTH	    11264
+#define BYD_PAD_HEIGHT      6656
+#define BYD_PAD_RESOLUTION  111
 
-int byd_detect(struct psmouse *psmouse, bool set_properties)
-{
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	unsigned char param[4];
+/*
+ * Given the above dimensions, relative packets velocity is in multiples of
+ * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
+ */
+#define BYD_DT              11
+/* Time in milliseconds used to timeout various touch events */
+#define BYD_TOUCH_TIMEOUT   64
 
-	param[0] = 0x03;
-	param[1] = 0x00;
-	param[2] = 0x00;
-	param[3] = 0x00;
+/* BYD commands reverse engineered from windows driver */
 
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
-		return -1;
-
-	if (param[1] != 0x03 || param[2] != 0x64)
-		return -ENODEV;
+/*
+ * Swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
+/*
+ * Tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
+/*
+ * Physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
+/*
+ * Absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
+/*
+ * Two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
+/*
+ * Handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS             0x10d3
+/*
+ * Tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP                    0x10d4
+/*
+ * Tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG               0x10d5
+/*
+ * Touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
+/*
+ * One finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
+/*
+ * One finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
+/*
+ * Sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED          0x10da
+/*
+ * Edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION            0x10db
+/*
+ * Left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
+/*
+ * Top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
+/*
+ * Disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK             0x10de
+/*
+ * Right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
+/*
+ * Bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
+/*
+ * Multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH             0x10e3
+/*
+ * Edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
+/*
+ * Two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5
 
-	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+/*
+ * The touchpad generates a mixture of absolute and relative packets, indicated
+ * by the the last byte of each packet being set to one of the following:
+ */
+#define BYD_PACKET_ABSOLUTE                    0xF8
+#define BYD_PACKET_RELATIVE                    0x00
+/* Multitouch gesture packets */
+#define BYD_PACKET_PINCH_IN                    0xd8
+#define BYD_PACKET_PINCH_OUT                   0x28
+#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
+#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
+#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
+#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
+#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
+#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
+#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
+#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
+#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
+#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
+#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
+#define BYD_PACKET_FOUR_FINGER_UP              0xcd
+#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
+#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
+#define BYD_PACKET_REGION_SCROLL_UP            0xca
+#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
+#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
+#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
+#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
+#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
+#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
+#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
+#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9
+
+struct byd_data {
+	struct timer_list timer;
+	s32 abs_x;
+	s32 abs_y;
+	u32 last_touch_time;
+	bool btn_left  : 1;
+	bool btn_right : 1;
+	bool touch     : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+	struct input_dev *dev = psmouse->dev;
 
-	if (set_properties) {
-		psmouse->vendor = "BYD";
-		psmouse->name = "TouchPad";
-	}
+	input_report_abs(dev, ABS_X, priv->abs_x);
+	input_report_abs(dev, ABS_Y, priv->abs_y);
+	input_report_key(dev, BTN_LEFT, priv->btn_left);
+	input_report_key(dev, BTN_RIGHT, priv->btn_right);
+	input_report_key(dev, BTN_TOUCH, priv->touch);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+	input_sync(dev);
+}
 
-	return 0;
+static void byd_clear_touch(unsigned long data)
+{
+	struct psmouse *psmouse = (struct psmouse*)data;
+	struct byd_data *priv = psmouse->private;
+
+	serio_pause_rx(psmouse->ps2dev.serio);
+	priv->touch = false;
+	/*
+	 * Move cursor back to center of pad when we lose touch - this
+	 * specifically improves user experience when moving cursor with one
+	 * finger, and pressing a button with another.
+	 */
+	priv->abs_x = BYD_PAD_WIDTH / 2;
+	priv->abs_y = BYD_PAD_HEIGHT / 2;
+	byd_report_input(psmouse);
+
+	serio_continue_rx(psmouse->ps2dev.serio);
 }
 
 static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 {
-	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv = psmouse->private;
+	u32 now_msecs = jiffies_to_msecs(jiffies);
 	u8 *pkt = psmouse->packet;
 
 	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
@@ -102,53 +291,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 
 	/* Otherwise, a full packet has been received */
 	switch (pkt[3]) {
-	case 0: {
+	case BYD_PACKET_ABSOLUTE:
+		/* Only use absolute packets for the start of movement. */
+		if (!priv->touch) {
+			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
+			priv->abs_y = (255 - pkt[2]) *
+				      (BYD_PAD_HEIGHT / 256);
+
+			/* needed to detect tap */
+			if (now_msecs - priv->last_touch_time > BYD_TOUCH_TIMEOUT)
+				priv->touch = true;
+		}
+		break;
+	case BYD_PACKET_RELATIVE: {
 		/* Standard packet */
 		/* Sign-extend if a sign bit is set. */
-		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
-		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
-		int dx = signx | (int) pkt[1];
-		int dy = signy | (int) pkt[2];
+		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
+		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
+		s32 dx = signx | (int) pkt[1];
+		s32 dy = signy | (int) pkt[2];
 
-		input_report_rel(psmouse->dev, REL_X, dx);
-		input_report_rel(psmouse->dev, REL_Y, -dy);
+		/* Update position based on velocity */
+		priv->abs_x += dx * BYD_DT;
+		priv->abs_y -= dy * BYD_DT;
 
-		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
-		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
-		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+		priv->touch = true;
 		break;
 	}
-
-	case BYD_SCROLLDOWN:
-	case BYD_2DOWN:
-		input_report_rel(dev, REL_WHEEL, -1);
-		break;
-
-	case BYD_SCROLLUP:
-	case BYD_2UP:
-		input_report_rel(dev, REL_WHEEL, 1);
-		break;
-
-	case BYD_SCROLLLEFT:
-	case BYD_2LEFT:
-		input_report_rel(dev, REL_HWHEEL, -1);
-		break;
-
-	case BYD_SCROLLRIGHT:
-	case BYD_2RIGHT:
-		input_report_rel(dev, REL_HWHEEL, 1);
-		break;
-
-	case BYD_ZOOMOUT:
-	case BYD_ZOOMIN:
-	case BYD_3UP:
-	case BYD_3DOWN:
-	case BYD_3LEFT:
-	case BYD_3RIGHT:
-	case BYD_4UP:
-	case BYD_4DOWN:
-		break;
-
 	default:
 		psmouse_warn(psmouse,
 			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
@@ -157,134 +326,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 		return PSMOUSE_BAD_DATA;
 	}
 
-	input_sync(dev);
+	priv->btn_left = pkt[0] & PS2_LEFT;
+	priv->btn_right = pkt[0] & PS2_RIGHT;
 
-	return PSMOUSE_FULL_PACKET;
-}
-
-/* Send a sequence of bytes, where each is ACKed before the next is sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
-{
-	unsigned int i;
+	byd_report_input(psmouse);
 
-	for (i = 0; i < len; ++i) {
-		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
-			return -1;
+	/* Reset time since last touch. */
+	if (priv->touch) {
+		priv->last_touch_time = now_msecs;
+		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(BYD_TOUCH_TIMEOUT));
 	}
-	return 0;
-}
-
-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL		0x01
-#define SCROLL_NO_INERTIAL	0x02
-
-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH		0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY	0x02
-
-static int byd_enable(struct psmouse *psmouse)
-{
-	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
-	const u8 seq2[] = {
-		0xD3, 0x01,
-		0xD0, 0x00,
-		0xD0, 0x04,
-		/* Whether clicking is done by tapping or pressing. */
-		0xD4, CLICK_PRESS_ONLY,
-		0xD5, 0x01,
-		0xD7, 0x03,
-		/* Vertical and horizontal one-finger scroll zone inertia. */
-		0xD8, SCROLL_INERTIAL,
-		0xDA, 0x05,
-		0xDB, 0x02,
-		0xE4, 0x05,
-		0xD6, 0x01,
-		0xDE, 0x04,
-		0xE3, 0x01,
-		0xCF, 0x00,
-		0xD2, 0x03,
-		/* Vertical and horizontal two-finger scrolling inertia. */
-		0xE5, SCROLL_INERTIAL,
-		0xD9, 0x02,
-		0xD9, 0x07,
-		0xDC, 0x03,
-		0xDD, 0x03,
-		0xDF, 0x03,
-		0xE1, 0x03,
-		0xD1, 0x00,
-		0xCE, 0x00,
-		0xCC, 0x00,
-		0xE0, 0x00,
-		0xE2, 0x01
-	};
-	u8 param[4];
-
-	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
-		return -1;
 
-	/* Send a 0x01 command, which should return 4 bytes. */
-	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
-		return -1;
-
-	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
-		return -1;
-
-	return 0;
+	return PSMOUSE_FULL_PACKET;
 }
 
-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static int byd_reset_touchpad(struct psmouse *psmouse)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	u8 param[4];
-	int i;
+	size_t i;
+
 	const struct {
 		u16 command;
 		u8 arg;
 	} seq[] = {
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_GETINFO, 0 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
+		/*
+		 * Intellimouse initialization sequence, to get 4-byte instead
+		 * of 3-byte packets.
+		 */
 		{ PSMOUSE_CMD_SETRATE, 0xC8 },
 		{ PSMOUSE_CMD_SETRATE, 0x64 },
 		{ PSMOUSE_CMD_SETRATE, 0x50 },
 		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_ENABLE, 0 }
+		{ PSMOUSE_CMD_ENABLE, 0 },
+		/*
+		 * BYD-specific initialization, which enables absolute mode and
+		 * (if desired), the touchpad's built-in gesture detection.
+		 */
+		{ 0x10E2, 0x00 },
+		{ 0x10E0, 0x02 },
+		/* The touchpad should reply with 4 seemingly-random bytes */
+		{ 0x14E0, 0x01 },
+		/* Pairs of parameters and values. */
+		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
+		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
+		{ BYD_CMD_SET_TAP, 0x02 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
+		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
+		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
+		/* Finalize initialization. */
+		{ 0x10E0, 0x00 },
+		{ 0x10E2, 0x01 },
 	};
 
-	memset(param, 0, sizeof(param));
 	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
+		memset(param, 0, sizeof(param));
 		param[0] = seq[i].arg;
 		if (ps2_command(ps2dev, param, seq[i].command))
-			return -1;
-	}
-
-	return 0;
-}
-
-static int byd_reset_touchpad(struct psmouse *psmouse)
-{
-	if (byd_send_intellimouse_sequence(psmouse))
-		return -EIO;
-
-	if (byd_enable(psmouse))
-		return -EIO;
+			return -EIO;
 
+	}
+	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
 	return 0;
 }
 
@@ -314,9 +425,50 @@ static int byd_reconnect(struct psmouse *psmouse)
 	return 0;
 }
 
+static void byd_disconnect(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+
+	if (priv) {
+		del_timer(&priv->timer);
+		kfree(psmouse->private);
+		psmouse->private = NULL;
+	}
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	if (param[1] != 0x03 || param[2] != 0x64)
+		return -ENODEV;
+
+	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+
+	if (set_properties) {
+		psmouse->vendor = "BYD";
+		psmouse->name = "TouchPad";
+	}
+
+	return 0;
+}
+
 int byd_init(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv;
 
 	if (psmouse_reset(psmouse))
 		return -EIO;
@@ -324,14 +476,39 @@ int byd_init(struct psmouse *psmouse)
 	if (byd_reset_touchpad(psmouse))
 		return -EIO;
 
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(priv, 0, sizeof(*priv));
+	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
+
+	psmouse->private = priv;
+	psmouse->disconnect = byd_disconnect;
 	psmouse->reconnect = byd_reconnect;
 	psmouse->protocol_handler = byd_process_byte;
 	psmouse->pktsize = 4;
 	psmouse->resync_time = 0;
 
-	__set_bit(BTN_MIDDLE, dev->keybit);
-	__set_bit(REL_WHEEL, dev->relbit);
-	__set_bit(REL_HWHEEL, dev->relbit);
+	__set_bit(INPUT_PROP_POINTER, dev->propbit);
+	/* Touchpad */
+	__set_bit(BTN_TOUCH, dev->keybit);
+	__set_bit(BTN_TOOL_FINGER, dev->keybit);
+	/* Buttons */
+	__set_bit(BTN_LEFT, dev->keybit);
+	__set_bit(BTN_RIGHT, dev->keybit);
+	__clear_bit(BTN_MIDDLE, dev->keybit);
+
+	/* Absolute position */
+	__set_bit(EV_ABS, dev->evbit);
+	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
+	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
+	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
+	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
+	/* No relative support */
+	__clear_bit(EV_REL, dev->evbit);
+	__clear_bit(REL_X, dev->relbit);
+	__clear_bit(REL_Y, dev->relbit);
 
 	return 0;
 }
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 #ifdef CONFIG_MOUSE_PS2_BYD
 	{
 		.type		= PSMOUSE_BYD,
-		.name		= "BydPS/2",
+		.name		= "BYDPS/2",
 		.alias		= "byd",
 		.detect		= byd_detect,
 		.init		= byd_init,

Re: [PATCH] psmouse: added BYD touchpad driver

[Chris Diamand]

Hi Richard,

The patch applies! So your email client is working at last :)

Looks good, just some style issues to fix now.

> Updated BYD driver to report absolute coordinates and single-touch events.   init and gesture packet documentation.  Confirmed working with both synaptics and libinput xorg touchpad drivers.  Patched against 98ee377144935857d8ad5d7d70cdab1da4ede32e on git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.
> 
> Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
> ---o

I think the commit message needs to follow some style guidelines as
well. Something like:

Input: byd - report absolute coordinates
            <blank line>
More details...

Also can you use `git format-patch' to create your patches? That'll
include your name and email so people can commit the patch directly
with `git am'.

> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
> index 9425e0f..2900a3d 100644
> --- a/drivers/input/mouse/byd.c
> +++ b/drivers/input/mouse/byd.c
> @@ -2,20 +2,32 @@
>   * BYD TouchPad PS/2 mouse driver
>   *
>   * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
> + * Copyright (C) 2015 Richard Pospesel
> + * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
> + * Copyright (C) 2015 Martin Wimpress
> + * Copyright (C) 2015 Jay Kuri
>   *
>   * This program is free software; you can redistribute it and/or modify it
>   * under the terms of the GNU General Public License version 2 as published by
>   * the Free Software Foundation.
> + *
> + * Protocol of BYD Touch Pad reverse-engineered from windows driver:
> + * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
> + * md5:       0d5e4660b98fca9587a0df212fca3048
> + * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
> + * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
>   */
>  
>  #include <linux/delay.h>
>  #include <linux/input.h>
>  #include <linux/libps2.h>
>  #include <linux/serio.h>
> +#include <linux/slab.h>
>  
>  #include "psmouse.h"
>  #include "byd.h"
>  
> +/* PS2 Bits */
>  #define PS2_Y_OVERFLOW	BIT_MASK(7)
>  #define PS2_X_OVERFLOW	BIT_MASK(6)
>  #define PS2_Y_SIGN	BIT_MASK(5)
> @@ -26,69 +38,246 @@
>  #define PS2_LEFT	BIT_MASK(0)
>  
>  /*
> - * The touchpad reports gestures in the last byte of each packet. It can take
> - * any of the following values:
> + * BYD pad constants
>   */
>  
> -/* One-finger scrolling in one of the edge scroll zones. */
> -#define BYD_SCROLLUP		0xCA
> -#define BYD_SCROLLDOWN		0x36
> -#define BYD_SCROLLLEFT		0xCB
> -#define BYD_SCROLLRIGHT		0x35
> -/* Two-finger scrolling. */
> -#define BYD_2DOWN		0x2B
> -#define BYD_2UP			0xD5
> -#define BYD_2LEFT		0xD6
> -#define BYD_2RIGHT		0x2A
> -/* Pinching in or out. */
> -#define BYD_ZOOMOUT		0xD8
> -#define BYD_ZOOMIN		0x28
> -/* Three-finger swipe. */
> -#define BYD_3UP			0xD3
> -#define BYD_3DOWN		0x2D
> -#define BYD_3LEFT		0xD4
> -#define BYD_3RIGHT		0x2C
> -/* Four-finger swipe. */
> -#define BYD_4UP			0xCD
> -#define BYD_4DOWN		0x33
> +/*
> + * True device resolution is unknown, however experiments show the
> + * resolution is about 111 units/mm.
> + * Absolute coordinate packets are in the range 0-255 for both X and Y
> + * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
> + * the right ballpark given the touchpad's physical dimensions and estimate
> + * resolution per spec sheet, device active area dimensions are
> + * 101.6 x 60.1 mm.
> + */
> +#define BYD_PAD_WIDTH	    11264
> +#define BYD_PAD_HEIGHT      6656
> +#define BYD_PAD_RESOLUTION  111
>  
> -int byd_detect(struct psmouse *psmouse, bool set_properties)
> -{
> -	struct ps2dev *ps2dev = &psmouse->ps2dev;
> -	unsigned char param[4];
> +/*
> + * Given the above dimensions, relative packets velocity is in multiples of
> + * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
> + */
> +#define BYD_DT              11
> +/* Time in milliseconds used to timeout various touch events */
> +#define BYD_TOUCH_TIMEOUT   64
>  
> -	param[0] = 0x03;
> -	param[1] = 0x00;
> -	param[2] = 0x00;
> -	param[3] = 0x00;
> +/* BYD commands reverse engineered from windows driver */
>  
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> -		return -1;
> -
> -	if (param[1] != 0x03 || param[2] != 0x64)
> -		return -ENODEV;
> +/*
> + * Swipe gesture from off-pad to on-pad
> + *  0 : disable
> + *  1 : enable
> + */
> +#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
> +/*
> + * Tap and drag delay time
> + *  0 : disable
> + *  1 - 8 : least to most delay
> + */
> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
> +/*
> + * Physical buttons function mapping
> + *  0 : enable
> + *  4 : normal
> + *  5 : left button custom command
> + *  6 : right button custom command
> + *  8 : disable
> + */
> +#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
> +/*
> + * Absolute mode (1 byte X/Y resolution)
> + *  0 : disable
> + *  2 : enable
> + */
> +#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
> +/*
> + * Two finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
> +/*
> + * Handedness
> + *  1 : right handed
> + *  2 : left handed
> + */
> +#define BYD_CMD_SET_HANDEDNESS             0x10d3
> +/*
> + * Tap to click
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_TAP                    0x10d4
> +/*
> + * Tap and drag
> + *  1 : tap and hold to drag
> + *  2 : tap and hold to drag + lock
> + *  3 : disable
> + */
> +#define BYD_CMD_SET_TAP_DRAG               0x10d5
> +/*
> + * Touch sensitivity
> + *  1 - 7 : least to most sensitive
> + */
> +#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
> +/*
> + * One finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
> +/*
> + * One finger scrolling function
> + *  1 : free scrolling
> + *  2 : edge motion
> + *  3 : free scrolling + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
> +/*
> + * Sliding speed
> + *  1 - 5 : slowest to fastest
> + */
> +#define BYD_CMD_SET_SLIDING_SPEED          0x10da
> +/*
> + * Edge motion
> + *  1 : disable
> + *  2 : enable when dragging
> + *  3 : enable when dragging and pointing
> + */
> +#define BYD_CMD_SET_EDGE_MOTION            0x10db
> +/*
> + * Left edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
> +/*
> + * Top edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
> +/*
> + * Disregard palm press as clicks
> + *  1 - 6 : smallest to largest
> + */
> +#define BYD_CMD_SET_PALM_CHECK             0x10de
> +/*
> + * Right edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
> +/*
> + * Bottom edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
> +/*
> + * Multitouch gestures
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_MULTITOUCH             0x10e3
> +/*
> + * Edge motion speed
> + *  0 : control with finger pressure
> + *  1 - 9 : slowest to fastest
> + */
> +#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
> +/*
> + * Two finger scolling function
> + *  0 : free scrolling
> + *  1 : free scrolling (with momentum)
> + *  2 : edge motion
> + *  3 : free scrolling (with momentum) + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5
>  
> -	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +/*
> + * The touchpad generates a mixture of absolute and relative packets, indicated
> + * by the the last byte of each packet being set to one of the following:
> + */
> +#define BYD_PACKET_ABSOLUTE                    0xF8
> +#define BYD_PACKET_RELATIVE                    0x00
> +/* Multitouch gesture packets */
> +#define BYD_PACKET_PINCH_IN                    0xd8
> +#define BYD_PACKET_PINCH_OUT                   0x28
> +#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
> +#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
> +#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
> +#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
> +#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
> +#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
> +#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
> +#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
> +#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
> +#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
> +#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
> +#define BYD_PACKET_FOUR_FINGER_UP              0xcd
> +#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
> +#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
> +#define BYD_PACKET_REGION_SCROLL_UP            0xca
> +#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
> +#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
> +#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
> +#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
> +#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
> +#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
> +#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
> +#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9

Hmm. There aren't aligned to a multiple of 8. Can they be?

Also, re. using tabs or spaces for these - I personally have no
particular preference, and I looked around other drivers and couldn't
find any particular pattern. But: when Dmitry applied my patch, he
changed my spaces to tabs. So we should probably go with that :)

> +
> +struct byd_data {
> +	struct timer_list timer;
> +	s32 abs_x;
> +	s32 abs_y;
> +	u32 last_touch_time;
> +	bool btn_left  : 1;
> +	bool btn_right : 1;
> +	bool touch     : 1;
> +};
> +
> +static void byd_report_input(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = psmouse->private;
> +	struct input_dev *dev = psmouse->dev;
>  
> -	if (set_properties) {
> -		psmouse->vendor = "BYD";
> -		psmouse->name = "TouchPad";
> -	}
> +	input_report_abs(dev, ABS_X, priv->abs_x);
> +	input_report_abs(dev, ABS_Y, priv->abs_y);
> +	input_report_key(dev, BTN_LEFT, priv->btn_left);
> +	input_report_key(dev, BTN_RIGHT, priv->btn_right);
> +	input_report_key(dev, BTN_TOUCH, priv->touch);
> +	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
> +	input_sync(dev);
> +}
>  
> -	return 0;
> +static void byd_clear_touch(unsigned long data)
> +{
> +	struct psmouse *psmouse = (struct psmouse*)data;

According to checkpatch.pl, needs a space between `psmouse' and `*':

    (struct psmouse *)

FYI - there's a script, `scripts/checkpatch.pl', which checks for
style violations - if you run it on your patch it'll pick up stuff
like this.

> +	struct byd_data *priv = psmouse->private;
> +
> +	serio_pause_rx(psmouse->ps2dev.serio);
> +	priv->touch = false;
> +	/*
> +	 * Move cursor back to center of pad when we lose touch - this
> +	 * specifically improves user experience when moving cursor with one
> +	 * finger, and pressing a button with another.
> +	 */
> +	priv->abs_x = BYD_PAD_WIDTH / 2;
> +	priv->abs_y = BYD_PAD_HEIGHT / 2;
> +	byd_report_input(psmouse);
> +
> +	serio_continue_rx(psmouse->ps2dev.serio);
>  }
>  
>  static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>  {
> -	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv = psmouse->private;
> +	u32 now_msecs = jiffies_to_msecs(jiffies);
>  	u8 *pkt = psmouse->packet;
>  
>  	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
> @@ -102,53 +291,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>  
>  	/* Otherwise, a full packet has been received */
>  	switch (pkt[3]) {
> -	case 0: {
> +	case BYD_PACKET_ABSOLUTE:
> +		/* Only use absolute packets for the start of movement. */
> +		if (!priv->touch) {
> +			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
> +			priv->abs_y = (255 - pkt[2]) *
> +				      (BYD_PAD_HEIGHT / 256);
> +
> +			/* needed to detect tap */
> +			if (now_msecs - priv->last_touch_time > BYD_TOUCH_TIMEOUT)

Line too long (according to checkpatch).

> +				priv->touch = true;
> +		}
> +		break;
> +	case BYD_PACKET_RELATIVE: {
>  		/* Standard packet */
>  		/* Sign-extend if a sign bit is set. */
> -		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> -		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> -		int dx = signx | (int) pkt[1];
> -		int dy = signy | (int) pkt[2];
> +		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> +		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> +		s32 dx = signx | (int) pkt[1];
> +		s32 dy = signy | (int) pkt[2];
>  
> -		input_report_rel(psmouse->dev, REL_X, dx);
> -		input_report_rel(psmouse->dev, REL_Y, -dy);
> +		/* Update position based on velocity */
> +		priv->abs_x += dx * BYD_DT;
> +		priv->abs_y -= dy * BYD_DT;
>  
> -		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
> -		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
> -		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
> +		priv->touch = true;
>  		break;
>  	}
> -
> -	case BYD_SCROLLDOWN:
> -	case BYD_2DOWN:
> -		input_report_rel(dev, REL_WHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLUP:
> -	case BYD_2UP:
> -		input_report_rel(dev, REL_WHEEL, 1);
> -		break;
> -
> -	case BYD_SCROLLLEFT:
> -	case BYD_2LEFT:
> -		input_report_rel(dev, REL_HWHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLRIGHT:
> -	case BYD_2RIGHT:
> -		input_report_rel(dev, REL_HWHEEL, 1);
> -		break;
> -
> -	case BYD_ZOOMOUT:
> -	case BYD_ZOOMIN:
> -	case BYD_3UP:
> -	case BYD_3DOWN:
> -	case BYD_3LEFT:
> -	case BYD_3RIGHT:
> -	case BYD_4UP:
> -	case BYD_4DOWN:
> -		break;
> -
>  	default:
>  		psmouse_warn(psmouse,
>  			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
> @@ -157,134 +326,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>  		return PSMOUSE_BAD_DATA;
>  	}
>  
> -	input_sync(dev);
> +	priv->btn_left = pkt[0] & PS2_LEFT;
> +	priv->btn_right = pkt[0] & PS2_RIGHT;
>  
> -	return PSMOUSE_FULL_PACKET;
> -}
> -
> -/* Send a sequence of bytes, where each is ACKed before the next is sent. */
> -static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
> -{
> -	unsigned int i;
> +	byd_report_input(psmouse);
>  
> -	for (i = 0; i < len; ++i) {
> -		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
> -			return -1;
> +	/* Reset time since last touch. */
> +	if (priv->touch) {
> +		priv->last_touch_time = now_msecs;
> +		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(BYD_TOUCH_TIMEOUT));

Line too long (according to checkpatch).

>  	}
> -	return 0;
> -}
> -
> -/* Keep scrolling after fingers are removed. */
> -#define SCROLL_INERTIAL		0x01
> -#define SCROLL_NO_INERTIAL	0x02
> -
> -/* Clicking can be done by tapping or pressing. */
> -#define CLICK_BOTH		0x01
> -/* Clicking can only be done by pressing. */
> -#define CLICK_PRESS_ONLY	0x02
> -
> -static int byd_enable(struct psmouse *psmouse)
> -{
> -	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
> -	const u8 seq2[] = {
> -		0xD3, 0x01,
> -		0xD0, 0x00,
> -		0xD0, 0x04,
> -		/* Whether clicking is done by tapping or pressing. */
> -		0xD4, CLICK_PRESS_ONLY,
> -		0xD5, 0x01,
> -		0xD7, 0x03,
> -		/* Vertical and horizontal one-finger scroll zone inertia. */
> -		0xD8, SCROLL_INERTIAL,
> -		0xDA, 0x05,
> -		0xDB, 0x02,
> -		0xE4, 0x05,
> -		0xD6, 0x01,
> -		0xDE, 0x04,
> -		0xE3, 0x01,
> -		0xCF, 0x00,
> -		0xD2, 0x03,
> -		/* Vertical and horizontal two-finger scrolling inertia. */
> -		0xE5, SCROLL_INERTIAL,
> -		0xD9, 0x02,
> -		0xD9, 0x07,
> -		0xDC, 0x03,
> -		0xDD, 0x03,
> -		0xDF, 0x03,
> -		0xE1, 0x03,
> -		0xD1, 0x00,
> -		0xCE, 0x00,
> -		0xCC, 0x00,
> -		0xE0, 0x00,
> -		0xE2, 0x01
> -	};
> -	u8 param[4];
> -
> -	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
> -		return -1;
>  
> -	/* Send a 0x01 command, which should return 4 bytes. */
> -	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
> -		return -1;
> -
> -	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
> -		return -1;
> -
> -	return 0;
> +	return PSMOUSE_FULL_PACKET;
>  }
>  
> -/*
> - * Send the set of PS/2 commands required to make it identify as an
> - * intellimouse with 4-byte instead of 3-byte packets.
> - */
> -static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
> +static int byd_reset_touchpad(struct psmouse *psmouse)
>  {
>  	struct ps2dev *ps2dev = &psmouse->ps2dev;
>  	u8 param[4];
> -	int i;
> +	size_t i;
> +
>  	const struct {
>  		u16 command;
>  		u8 arg;
>  	} seq[] = {
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_GETINFO, 0 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> +		/*
> +		 * Intellimouse initialization sequence, to get 4-byte instead
> +		 * of 3-byte packets.
> +		 */
>  		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>  		{ PSMOUSE_CMD_SETRATE, 0x64 },
>  		{ PSMOUSE_CMD_SETRATE, 0x50 },
>  		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0x50 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0x64 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> -		{ PSMOUSE_CMD_ENABLE, 0 }
> +		{ PSMOUSE_CMD_ENABLE, 0 },
> +		/*
> +		 * BYD-specific initialization, which enables absolute mode and
> +		 * (if desired), the touchpad's built-in gesture detection.
> +		 */
> +		{ 0x10E2, 0x00 },
> +		{ 0x10E0, 0x02 },
> +		/* The touchpad should reply with 4 seemingly-random bytes */
> +		{ 0x14E0, 0x01 },
> +		/* Pairs of parameters and values. */
> +		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
> +		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
> +		{ BYD_CMD_SET_TAP, 0x02 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
> +		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
> +		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
> +		/* Finalize initialization. */
> +		{ 0x10E0, 0x00 },
> +		{ 0x10E2, 0x01 },
>  	};
>  
> -	memset(param, 0, sizeof(param));
>  	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
> +		memset(param, 0, sizeof(param));
>  		param[0] = seq[i].arg;
>  		if (ps2_command(ps2dev, param, seq[i].command))
> -			return -1;
> -	}
> -
> -	return 0;
> -}
> -
> -static int byd_reset_touchpad(struct psmouse *psmouse)
> -{
> -	if (byd_send_intellimouse_sequence(psmouse))
> -		return -EIO;
> -
> -	if (byd_enable(psmouse))
> -		return -EIO;
> +			return -EIO;
>  
> +	}
> +	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
>  	return 0;
>  }
>  
> @@ -314,9 +425,50 @@ static int byd_reconnect(struct psmouse *psmouse)
>  	return 0;
>  }
>  
> +static void byd_disconnect(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = psmouse->private;
> +
> +	if (priv) {
> +		del_timer(&priv->timer);
> +		kfree(psmouse->private);
> +		psmouse->private = NULL;
> +	}
> +}
> +
> +int byd_detect(struct psmouse *psmouse, bool set_properties)
> +{
> +	struct ps2dev *ps2dev = &psmouse->ps2dev;
> +	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
> +
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> +		return -1;
> +
> +	if (param[1] != 0x03 || param[2] != 0x64)
> +		return -ENODEV;
> +
> +	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +
> +	if (set_properties) {
> +		psmouse->vendor = "BYD";
> +		psmouse->name = "TouchPad";
> +	}
> +
> +	return 0;
> +}
> +
>  int byd_init(struct psmouse *psmouse)
>  {
>  	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv;
>  
>  	if (psmouse_reset(psmouse))
>  		return -EIO;
> @@ -324,14 +476,39 @@ int byd_init(struct psmouse *psmouse)
>  	if (byd_reset_touchpad(psmouse))
>  		return -EIO;
>  
> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	memset(priv, 0, sizeof(*priv));
> +	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
> +
> +	psmouse->private = priv;
> +	psmouse->disconnect = byd_disconnect;
>  	psmouse->reconnect = byd_reconnect;
>  	psmouse->protocol_handler = byd_process_byte;
>  	psmouse->pktsize = 4;
>  	psmouse->resync_time = 0;
>  
> -	__set_bit(BTN_MIDDLE, dev->keybit);
> -	__set_bit(REL_WHEEL, dev->relbit);
> -	__set_bit(REL_HWHEEL, dev->relbit);
> +	__set_bit(INPUT_PROP_POINTER, dev->propbit);
> +	/* Touchpad */
> +	__set_bit(BTN_TOUCH, dev->keybit);
> +	__set_bit(BTN_TOOL_FINGER, dev->keybit);
> +	/* Buttons */
> +	__set_bit(BTN_LEFT, dev->keybit);
> +	__set_bit(BTN_RIGHT, dev->keybit);
> +	__clear_bit(BTN_MIDDLE, dev->keybit);
> +
> +	/* Absolute position */
> +	__set_bit(EV_ABS, dev->evbit);
> +	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
> +	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
> +	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
> +	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
> +	/* No relative support */
> +	__clear_bit(EV_REL, dev->evbit);
> +	__clear_bit(REL_X, dev->relbit);
> +	__clear_bit(REL_Y, dev->relbit);
>  
>  	return 0;
>  }
> diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
> index 39d1bec..5784e20 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
>  #ifdef CONFIG_MOUSE_PS2_BYD
>  	{
>  		.type		= PSMOUSE_BYD,
> -		.name		= "BydPS/2",
> +		.name		= "BYDPS/2",
>  		.alias		= "byd",
>  		.detect		= byd_detect,
>  		.init		= byd_init,

Cheers,
Chris

Re: [PATCH] psmouse: added BYD touchpad driver

[Richard Pospesel]

Ok I think this about covers it.  The line length issues remain, but the script
repors them as warnings so I'm not to worried about it.  Patch follows:
---
Input: BYD: Added proper touch support

Implemented absolute position and touch reporting.  Now BYD touchpads will use 
the synaptics/libinput xorg touchpad drivers.  Added documenatation for all 
known gesture packets and initialization commands.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
---
>From c0d0ece9ace3939691831eb20c2a5f01343781f1 Mon Sep 17 00:00:00 2001
From: pospeselr <pospeselr@gmail.com>
Date: Wed, 10 Feb 2016 18:24:00 -0800
Subject: [PATCH] byd changes

---
 drivers/input/mouse/byd.c          | 577 ++++++++++++++++++++++++-------------
 drivers/input/mouse/psmouse-base.c |   2 +-
 2 files changed, 378 insertions(+), 201 deletions(-)

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..4c388ed 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -2,20 +2,32 @@
  * BYD TouchPad PS/2 mouse driver
  *
  * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015 Richard Pospesel <pospeselr@gmail.com>
+ * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015 Martin Wimpress
+ * Copyright (C) 2015 Jay Kuri
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * md5:       0d5e4660b98fca9587a0df212fca3048
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
  */
 
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/libps2.h>
 #include <linux/serio.h>
+#include <linux/slab.h>
 
 #include "psmouse.h"
 #include "byd.h"
 
+/* PS2 Bits */
 #define PS2_Y_OVERFLOW	BIT_MASK(7)
 #define PS2_X_OVERFLOW	BIT_MASK(6)
 #define PS2_Y_SIGN	BIT_MASK(5)
@@ -26,69 +38,246 @@
 #define PS2_LEFT	BIT_MASK(0)
 
 /*
- * The touchpad reports gestures in the last byte of each packet. It can take
- * any of the following values:
+ * BYD pad constants
  */
 
-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP		0xCA
-#define BYD_SCROLLDOWN		0x36
-#define BYD_SCROLLLEFT		0xCB
-#define BYD_SCROLLRIGHT		0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN		0x2B
-#define BYD_2UP			0xD5
-#define BYD_2LEFT		0xD6
-#define BYD_2RIGHT		0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT		0xD8
-#define BYD_ZOOMIN		0x28
-/* Three-finger swipe. */
-#define BYD_3UP			0xD3
-#define BYD_3DOWN		0x2D
-#define BYD_3LEFT		0xD4
-#define BYD_3RIGHT		0x2C
-/* Four-finger swipe. */
-#define BYD_4UP			0xCD
-#define BYD_4DOWN		0x33
+/*
+ * True device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm.
+ * Absolute coordinate packets are in the range 0-255 for both X and Y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm.
+ */
+#define BYD_PAD_WIDTH		11264
+#define BYD_PAD_HEIGHT		6656
+#define BYD_PAD_RESOLUTION	111
 
-int byd_detect(struct psmouse *psmouse, bool set_properties)
-{
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	unsigned char param[4];
+/*
+ * Given the above dimensions, relative packets velocity is in multiples of
+ * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
+ */
+#define BYD_DT			11
+/* Time in milliseconds used to timeout various touch events */
+#define BYD_TOUCH_TIMEOUT	64
 
-	param[0] = 0x03;
-	param[1] = 0x00;
-	param[2] = 0x00;
-	param[3] = 0x00;
+/* BYD commands reverse engineered from windows driver */
 
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
-		return -1;
-
-	if (param[1] != 0x03 || param[2] != 0x64)
-		return -ENODEV;
+/*
+ * Swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE		0x10cc
+/*
+ * Tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME		0x10cf
+/*
+ * Physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS		0x10d0
+/*
+ * Absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE		0x10d1
+/*
+ * Two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL		0x10d2
+/*
+ * Handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS			0x10d3
+/*
+ * Tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP				0x10d4
+/*
+ * Tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG			0x10d5
+/*
+ * Touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY		0x10d6
+/*
+ * One finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL		0x10d7
+/*
+ * One finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC	0x10d8
+/*
+ * Sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED		0x10da
+/*
+ * Edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION			0x10db
+/*
+ * Left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION		0x10dc
+/*
+ * Top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION		0x10dd
+/*
+ * Disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK			0x10de
+/*
+ * Right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION		0x10df
+/*
+ * Bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION		0x10e1
+/*
+ * Multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH			0x10e3
+/*
+ * Edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED		0x10e4
+/*
+ * Two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC	0x10e5
 
-	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+/*
+ * The touchpad generates a mixture of absolute and relative packets, indicated
+ * by the the last byte of each packet being set to one of the following:
+ */
+#define BYD_PACKET_ABSOLUTE			0xf8
+#define BYD_PACKET_RELATIVE			0x00
+/* Multitouch gesture packets */
+#define BYD_PACKET_PINCH_IN			0xd8
+#define BYD_PACKET_PINCH_OUT			0x28
+#define BYD_PACKET_ROTATE_CLOCKWISE		0x29
+#define BYD_PACKET_ROTATE_ANTICLOCKWISE		0xd7
+#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT	0x2a
+#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN	0x2b
+#define BYD_PACKET_TWO_FINGER_SCROLL_UP		0xd5
+#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT	0xd6
+#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT	0x2c
+#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN	0x2d
+#define BYD_PACKET_THREE_FINGER_SWIPE_UP	0xd3
+#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT	0xd4
+#define BYD_PACKET_FOUR_FINGER_DOWN		0x33
+#define BYD_PACKET_FOUR_FINGER_UP		0xcd
+#define BYD_PACKET_REGION_SCROLL_RIGHT		0x35
+#define BYD_PACKET_REGION_SCROLL_DOWN		0x36
+#define BYD_PACKET_REGION_SCROLL_UP		0xca
+#define BYD_PACKET_REGION_SCROLL_LEFT		0xcb
+#define BYD_PACKET_RIGHT_CORNER_CLICK		0xd2
+#define BYD_PACKET_LEFT_CORNER_CLICK		0x2e
+#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK	0x2f
+#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT		0x37
+#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN		0x30
+#define BYD_PACKET_ONTO_PAD_SWIPE_UP		0xd0
+#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT		0xc9
+
+struct byd_data {
+	struct timer_list timer;
+	s32 abs_x;
+	s32 abs_y;
+	u32 last_touch_time;
+	bool btn_left  : 1;
+	bool btn_right : 1;
+	bool touch     : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+	struct input_dev *dev = psmouse->dev;
 
-	if (set_properties) {
-		psmouse->vendor = "BYD";
-		psmouse->name = "TouchPad";
-	}
+	input_report_abs(dev, ABS_X, priv->abs_x);
+	input_report_abs(dev, ABS_Y, priv->abs_y);
+	input_report_key(dev, BTN_LEFT, priv->btn_left);
+	input_report_key(dev, BTN_RIGHT, priv->btn_right);
+	input_report_key(dev, BTN_TOUCH, priv->touch);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+	input_sync(dev);
+}
 
-	return 0;
+static void byd_clear_touch(unsigned long data)
+{
+	struct psmouse *psmouse = (struct psmouse *)data;
+	struct byd_data *priv = psmouse->private;
+
+	serio_pause_rx(psmouse->ps2dev.serio);
+	priv->touch = false;
+	/*
+	 * Move cursor back to center of pad when we lose touch - this
+	 * specifically improves user experience when moving cursor with one
+	 * finger, and pressing a button with another.
+	 */
+	priv->abs_x = BYD_PAD_WIDTH / 2;
+	priv->abs_y = BYD_PAD_HEIGHT / 2;
+	byd_report_input(psmouse);
+
+	serio_continue_rx(psmouse->ps2dev.serio);
 }
 
 static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 {
-	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv = psmouse->private;
+	u32 now_msecs = jiffies_to_msecs(jiffies);
 	u8 *pkt = psmouse->packet;
 
 	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
@@ -102,53 +291,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 
 	/* Otherwise, a full packet has been received */
 	switch (pkt[3]) {
-	case 0: {
+	case BYD_PACKET_ABSOLUTE:
+		/* Only use absolute packets for the start of movement. */
+		if (!priv->touch) {
+			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
+			priv->abs_y = (255 - pkt[2]) *
+				      (BYD_PAD_HEIGHT / 256);
+
+			/* needed to detect tap */
+			if (now_msecs - priv->last_touch_time > BYD_TOUCH_TIMEOUT)
+				priv->touch = true;
+		}
+		break;
+	case BYD_PACKET_RELATIVE: {
 		/* Standard packet */
 		/* Sign-extend if a sign bit is set. */
-		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
-		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
-		int dx = signx | (int) pkt[1];
-		int dy = signy | (int) pkt[2];
+		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
+		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
+		s32 dx = signx | (int) pkt[1];
+		s32 dy = signy | (int) pkt[2];
 
-		input_report_rel(psmouse->dev, REL_X, dx);
-		input_report_rel(psmouse->dev, REL_Y, -dy);
+		/* Update position based on velocity */
+		priv->abs_x += dx * BYD_DT;
+		priv->abs_y -= dy * BYD_DT;
 
-		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
-		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
-		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+		priv->touch = true;
 		break;
 	}
-
-	case BYD_SCROLLDOWN:
-	case BYD_2DOWN:
-		input_report_rel(dev, REL_WHEEL, -1);
-		break;
-
-	case BYD_SCROLLUP:
-	case BYD_2UP:
-		input_report_rel(dev, REL_WHEEL, 1);
-		break;
-
-	case BYD_SCROLLLEFT:
-	case BYD_2LEFT:
-		input_report_rel(dev, REL_HWHEEL, -1);
-		break;
-
-	case BYD_SCROLLRIGHT:
-	case BYD_2RIGHT:
-		input_report_rel(dev, REL_HWHEEL, 1);
-		break;
-
-	case BYD_ZOOMOUT:
-	case BYD_ZOOMIN:
-	case BYD_3UP:
-	case BYD_3DOWN:
-	case BYD_3LEFT:
-	case BYD_3RIGHT:
-	case BYD_4UP:
-	case BYD_4DOWN:
-		break;
-
 	default:
 		psmouse_warn(psmouse,
 			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
@@ -157,134 +326,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 		return PSMOUSE_BAD_DATA;
 	}
 
-	input_sync(dev);
+	priv->btn_left = pkt[0] & PS2_LEFT;
+	priv->btn_right = pkt[0] & PS2_RIGHT;
 
-	return PSMOUSE_FULL_PACKET;
-}
-
-/* Send a sequence of bytes, where each is ACKed before the next is sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
-{
-	unsigned int i;
+	byd_report_input(psmouse);
 
-	for (i = 0; i < len; ++i) {
-		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
-			return -1;
+	/* Reset time since last touch. */
+	if (priv->touch) {
+		priv->last_touch_time = now_msecs;
+		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(BYD_TOUCH_TIMEOUT));
 	}
-	return 0;
-}
-
-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL		0x01
-#define SCROLL_NO_INERTIAL	0x02
-
-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH		0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY	0x02
-
-static int byd_enable(struct psmouse *psmouse)
-{
-	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
-	const u8 seq2[] = {
-		0xD3, 0x01,
-		0xD0, 0x00,
-		0xD0, 0x04,
-		/* Whether clicking is done by tapping or pressing. */
-		0xD4, CLICK_PRESS_ONLY,
-		0xD5, 0x01,
-		0xD7, 0x03,
-		/* Vertical and horizontal one-finger scroll zone inertia. */
-		0xD8, SCROLL_INERTIAL,
-		0xDA, 0x05,
-		0xDB, 0x02,
-		0xE4, 0x05,
-		0xD6, 0x01,
-		0xDE, 0x04,
-		0xE3, 0x01,
-		0xCF, 0x00,
-		0xD2, 0x03,
-		/* Vertical and horizontal two-finger scrolling inertia. */
-		0xE5, SCROLL_INERTIAL,
-		0xD9, 0x02,
-		0xD9, 0x07,
-		0xDC, 0x03,
-		0xDD, 0x03,
-		0xDF, 0x03,
-		0xE1, 0x03,
-		0xD1, 0x00,
-		0xCE, 0x00,
-		0xCC, 0x00,
-		0xE0, 0x00,
-		0xE2, 0x01
-	};
-	u8 param[4];
-
-	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
-		return -1;
 
-	/* Send a 0x01 command, which should return 4 bytes. */
-	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
-		return -1;
-
-	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
-		return -1;
-
-	return 0;
+	return PSMOUSE_FULL_PACKET;
 }
 
-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static int byd_reset_touchpad(struct psmouse *psmouse)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	u8 param[4];
-	int i;
+	size_t i;
+
 	const struct {
 		u16 command;
 		u8 arg;
 	} seq[] = {
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_GETINFO, 0 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
+		/*
+		 * Intellimouse initialization sequence, to get 4-byte instead
+		 * of 3-byte packets.
+		 */
 		{ PSMOUSE_CMD_SETRATE, 0xC8 },
 		{ PSMOUSE_CMD_SETRATE, 0x64 },
 		{ PSMOUSE_CMD_SETRATE, 0x50 },
 		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_ENABLE, 0 }
+		{ PSMOUSE_CMD_ENABLE, 0 },
+		/*
+		 * BYD-specific initialization, which enables absolute mode and
+		 * (if desired), the touchpad's built-in gesture detection.
+		 */
+		{ 0x10E2, 0x00 },
+		{ 0x10E0, 0x02 },
+		/* The touchpad should reply with 4 seemingly-random bytes */
+		{ 0x14E0, 0x01 },
+		/* Pairs of parameters and values. */
+		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
+		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
+		{ BYD_CMD_SET_TAP, 0x02 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
+		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
+		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
+		/* Finalize initialization. */
+		{ 0x10E0, 0x00 },
+		{ 0x10E2, 0x01 },
 	};
 
-	memset(param, 0, sizeof(param));
 	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
+		memset(param, 0, sizeof(param));
 		param[0] = seq[i].arg;
 		if (ps2_command(ps2dev, param, seq[i].command))
-			return -1;
-	}
-
-	return 0;
-}
-
-static int byd_reset_touchpad(struct psmouse *psmouse)
-{
-	if (byd_send_intellimouse_sequence(psmouse))
-		return -EIO;
-
-	if (byd_enable(psmouse))
-		return -EIO;
+			return -EIO;
 
+	}
+	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
 	return 0;
 }
 
@@ -314,9 +425,50 @@ static int byd_reconnect(struct psmouse *psmouse)
 	return 0;
 }
 
+static void byd_disconnect(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+
+	if (priv) {
+		del_timer(&priv->timer);
+		kfree(psmouse->private);
+		psmouse->private = NULL;
+	}
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	if (param[1] != 0x03 || param[2] != 0x64)
+		return -ENODEV;
+
+	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+
+	if (set_properties) {
+		psmouse->vendor = "BYD";
+		psmouse->name = "TouchPad";
+	}
+
+	return 0;
+}
+
 int byd_init(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv;
 
 	if (psmouse_reset(psmouse))
 		return -EIO;
@@ -324,14 +476,39 @@ int byd_init(struct psmouse *psmouse)
 	if (byd_reset_touchpad(psmouse))
 		return -EIO;
 
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(priv, 0, sizeof(*priv));
+	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
+
+	psmouse->private = priv;
+	psmouse->disconnect = byd_disconnect;
 	psmouse->reconnect = byd_reconnect;
 	psmouse->protocol_handler = byd_process_byte;
 	psmouse->pktsize = 4;
 	psmouse->resync_time = 0;
 
-	__set_bit(BTN_MIDDLE, dev->keybit);
-	__set_bit(REL_WHEEL, dev->relbit);
-	__set_bit(REL_HWHEEL, dev->relbit);
+	__set_bit(INPUT_PROP_POINTER, dev->propbit);
+	/* Touchpad */
+	__set_bit(BTN_TOUCH, dev->keybit);
+	__set_bit(BTN_TOOL_FINGER, dev->keybit);
+	/* Buttons */
+	__set_bit(BTN_LEFT, dev->keybit);
+	__set_bit(BTN_RIGHT, dev->keybit);
+	__clear_bit(BTN_MIDDLE, dev->keybit);
+
+	/* Absolute position */
+	__set_bit(EV_ABS, dev->evbit);
+	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
+	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
+	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
+	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
+	/* No relative support */
+	__clear_bit(EV_REL, dev->evbit);
+	__clear_bit(REL_X, dev->relbit);
+	__clear_bit(REL_Y, dev->relbit);
 
 	return 0;
 }
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 #ifdef CONFIG_MOUSE_PS2_BYD
 	{
 		.type		= PSMOUSE_BYD,
-		.name		= "BydPS/2",
+		.name		= "BYDPS/2",
 		.alias		= "byd",
 		.detect		= byd_detect,
 		.init		= byd_init,
-- 
2.6.4




On 02/09/2016 03:36 PM, Chris Diamand wrote:
> Hi Richard,
> 
> The patch applies! So your email client is working at last :)
> 
> Looks good, just some style issues to fix now.
> 
>> Updated BYD driver to report absolute coordinates and single-touch events.   
>>
>> Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
>> ---o
> 
> I think the commit message needs to follow some style guidelines as
> well. Something like:
> 
> Input: byd - report absolute coordinates
>             <blank line>
> More details...
> 
> Also can you use `git format-patch' to create your patches? That'll
> include your name and email so people can commit the patch directly
> with `git am'.
> 
>> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
>> index 9425e0f..2900a3d 100644
>> --- a/drivers/input/mouse/byd.c
>> +++ b/drivers/input/mouse/byd.c
>> @@ -2,20 +2,32 @@
>>   * BYD TouchPad PS/2 mouse driver
>>   *
>>   * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
>> + * Copyright (C) 2015 Richard Pospesel
>> + * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
>> + * Copyright (C) 2015 Martin Wimpress
>> + * Copyright (C) 2015 Jay Kuri
>>   *
>>   * This program is free software; you can redistribute it and/or modify it
>>   * under the terms of the GNU General Public License version 2 as published by
>>   * the Free Software Foundation.
>> + *
>> + * Protocol of BYD Touch Pad reverse-engineered from windows driver:
>> + * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
>> + * md5:       0d5e4660b98fca9587a0df212fca3048
>> + * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
>> + * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
>>   */
>>  
>>  #include <linux/delay.h>
>>  #include <linux/input.h>
>>  #include <linux/libps2.h>
>>  #include <linux/serio.h>
>> +#include <linux/slab.h>
>>  
>>  #include "psmouse.h"
>>  #include "byd.h"
>>  
>> +/* PS2 Bits */
>>  #define PS2_Y_OVERFLOW	BIT_MASK(7)
>>  #define PS2_X_OVERFLOW	BIT_MASK(6)
>>  #define PS2_Y_SIGN	BIT_MASK(5)
>> @@ -26,69 +38,246 @@
>>  #define PS2_LEFT	BIT_MASK(0)
>>  
>>  /*
>> - * The touchpad reports gestures in the last byte of each packet. It can take
>> - * any of the following values:
>> + * BYD pad constants
>>   */
>>  
>> -/* One-finger scrolling in one of the edge scroll zones. */
>> -#define BYD_SCROLLUP		0xCA
>> -#define BYD_SCROLLDOWN		0x36
>> -#define BYD_SCROLLLEFT		0xCB
>> -#define BYD_SCROLLRIGHT		0x35
>> -/* Two-finger scrolling. */
>> -#define BYD_2DOWN		0x2B
>> -#define BYD_2UP			0xD5
>> -#define BYD_2LEFT		0xD6
>> -#define BYD_2RIGHT		0x2A
>> -/* Pinching in or out. */
>> -#define BYD_ZOOMOUT		0xD8
>> -#define BYD_ZOOMIN		0x28
>> -/* Three-finger swipe. */
>> -#define BYD_3UP			0xD3
>> -#define BYD_3DOWN		0x2D
>> -#define BYD_3LEFT		0xD4
>> -#define BYD_3RIGHT		0x2C
>> -/* Four-finger swipe. */
>> -#define BYD_4UP			0xCD
>> -#define BYD_4DOWN		0x33
>> +/*
>> + * True device resolution is unknown, however experiments show the
>> + * resolution is about 111 units/mm.
>> + * Absolute coordinate packets are in the range 0-255 for both X and Y
>> + * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
>> + * the right ballpark given the touchpad's physical dimensions and estimate
>> + * resolution per spec sheet, device active area dimensions are
>> + * 101.6 x 60.1 mm.
>> + */
>> +#define BYD_PAD_WIDTH	    11264
>> +#define BYD_PAD_HEIGHT      6656
>> +#define BYD_PAD_RESOLUTION  111
>>  
>> -int byd_detect(struct psmouse *psmouse, bool set_properties)
>> -{
>> -	struct ps2dev *ps2dev = &psmouse->ps2dev;
>> -	unsigned char param[4];
>> +/*
>> + * Given the above dimensions, relative packets velocity is in multiples of
>> + * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
>> + */
>> +#define BYD_DT              11
>> +/* Time in milliseconds used to timeout various touch events */
>> +#define BYD_TOUCH_TIMEOUT   64
>>  
>> -	param[0] = 0x03;
>> -	param[1] = 0x00;
>> -	param[2] = 0x00;
>> -	param[3] = 0x00;
>> +/* BYD commands reverse engineered from windows driver */
>>  
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> -		return -1;
>> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
>> -		return -1;
>> -
>> -	if (param[1] != 0x03 || param[2] != 0x64)
>> -		return -ENODEV;
>> +/*
>> + * Swipe gesture from off-pad to on-pad
>> + *  0 : disable
>> + *  1 : enable
>> + */
>> +#define BYD_CMD_SET_OFFSCREEN_SWIPE        0x10cc
>> +/*
>> + * Tap and drag delay time
>> + *  0 : disable
>> + *  1 - 8 : least to most delay
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME    0x10cf
>> +/*
>> + * Physical buttons function mapping
>> + *  0 : enable
>> + *  4 : normal
>> + *  5 : left button custom command
>> + *  6 : right button custom command
>> + *  8 : disable
>> + */
>> +#define BYD_CMD_SET_PHYSICAL_BUTTONS       0x10d0
>> +/*
>> + * Absolute mode (1 byte X/Y resolution)
>> + *  0 : disable
>> + *  2 : enable
>> + */
>> +#define BYD_CMD_SET_ABSOLUTE_MODE          0x10d1
>> +/*
>> + * Two finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL      0x10d2
>> +/*
>> + * Handedness
>> + *  1 : right handed
>> + *  2 : left handed
>> + */
>> +#define BYD_CMD_SET_HANDEDNESS             0x10d3
>> +/*
>> + * Tap to click
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_TAP                    0x10d4
>> +/*
>> + * Tap and drag
>> + *  1 : tap and hold to drag
>> + *  2 : tap and hold to drag + lock
>> + *  3 : disable
>> + */
>> +#define BYD_CMD_SET_TAP_DRAG               0x10d5
>> +/*
>> + * Touch sensitivity
>> + *  1 - 7 : least to most sensitive
>> + */
>> +#define BYD_CMD_SET_TOUCH_SENSITIVITY      0x10d6
>> +/*
>> + * One finger scrolling
>> + *  1 : vertical
>> + *  2 : horizontal
>> + *  3 : vertical + horizontal
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL      0x10d7
>> +/*
>> + * One finger scrolling function
>> + *  1 : free scrolling
>> + *  2 : edge motion
>> + *  3 : free scrolling + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
>> +/*
>> + * Sliding speed
>> + *  1 - 5 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_SLIDING_SPEED          0x10da
>> +/*
>> + * Edge motion
>> + *  1 : disable
>> + *  2 : enable when dragging
>> + *  3 : enable when dragging and pointing
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION            0x10db
>> +/*
>> + * Left edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_LEFT_EDGE_REGION       0x10dc
>> +/*
>> + * Top edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_TOP_EDGE_REGION        0x10dd
>> +/*
>> + * Disregard palm press as clicks
>> + *  1 - 6 : smallest to largest
>> + */
>> +#define BYD_CMD_SET_PALM_CHECK             0x10de
>> +/*
>> + * Right edge region size
>> + *  0 - 7 : smallest to largest width
>> + */
>> +#define BYD_CMD_SET_RIGHT_EDGE_REGION      0x10df
>> +/*
>> + * Bottom edge region size
>> + *  0 - 9 : smallest to largest height
>> + */
>> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION     0x10e1
>> +/*
>> + * Multitouch gestures
>> + *  1 : enable
>> + *  2 : disable
>> + */
>> +#define BYD_CMD_SET_MULTITOUCH             0x10e3
>> +/*
>> + * Edge motion speed
>> + *  0 : control with finger pressure
>> + *  1 - 9 : slowest to fastest
>> + */
>> +#define BYD_CMD_SET_EDGE_MOTION_SPEED      0x10e4
>> +/*
>> + * Two finger scolling function
>> + *  0 : free scrolling
>> + *  1 : free scrolling (with momentum)
>> + *  2 : edge motion
>> + *  3 : free scrolling (with momentum) + edge motion
>> + *  4 : disable
>> + */
>> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5
>>  
>> -	psmouse_dbg(psmouse, "BYD touchpad detected\n");
>> +/*
>> + * The touchpad generates a mixture of absolute and relative packets, indicated
>> + * by the the last byte of each packet being set to one of the following:
>> + */
>> +#define BYD_PACKET_ABSOLUTE                    0xF8
>> +#define BYD_PACKET_RELATIVE                    0x00
>> +/* Multitouch gesture packets */
>> +#define BYD_PACKET_PINCH_IN                    0xd8
>> +#define BYD_PACKET_PINCH_OUT                   0x28
>> +#define BYD_PACKET_ROTATE_CLOCKWISE            0x29
>> +#define BYD_PACKET_ROTATE_ANTICLOCKWISE        0xd7
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT     0x2a
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN      0x2b
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_UP        0xd5
>> +#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT      0xd6
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT    0x2c
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN     0x2d
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_UP       0xd3
>> +#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT     0xd4
>> +#define BYD_PACKET_FOUR_FINGER_DOWN            0x33
>> +#define BYD_PACKET_FOUR_FINGER_UP              0xcd
>> +#define BYD_PACKET_REGION_SCROLL_RIGHT         0x35
>> +#define BYD_PACKET_REGION_SCROLL_DOWN          0x36
>> +#define BYD_PACKET_REGION_SCROLL_UP            0xca
>> +#define BYD_PACKET_REGION_SCROLL_LEFT          0xcb
>> +#define BYD_PACKET_RIGHT_CORNER_CLICK          0xd2
>> +#define BYD_PACKET_LEFT_CORNER_CLICK           0x2e
>> +#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT        0x37
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN         0x30
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_UP           0xd0
>> +#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT         0xc9
> 
> Hmm. There aren't aligned to a multiple of 8. Can they be?
> 
> Also, re. using tabs or spaces for these - I personally have no
> particular preference, and I looked around other drivers and couldn't
> find any particular pattern. But: when Dmitry applied my patch, he
> changed my spaces to tabs. So we should probably go with that :)
> 
>> +
>> +struct byd_data {
>> +	struct timer_list timer;
>> +	s32 abs_x;
>> +	s32 abs_y;
>> +	u32 last_touch_time;
>> +	bool btn_left  : 1;
>> +	bool btn_right : 1;
>> +	bool touch     : 1;
>> +};
>> +
>> +static void byd_report_input(struct psmouse *psmouse)
>> +{
>> +	struct byd_data *priv = psmouse->private;
>> +	struct input_dev *dev = psmouse->dev;
>>  
>> -	if (set_properties) {
>> -		psmouse->vendor = "BYD";
>> -		psmouse->name = "TouchPad";
>> -	}
>> +	input_report_abs(dev, ABS_X, priv->abs_x);
>> +	input_report_abs(dev, ABS_Y, priv->abs_y);
>> +	input_report_key(dev, BTN_LEFT, priv->btn_left);
>> +	input_report_key(dev, BTN_RIGHT, priv->btn_right);
>> +	input_report_key(dev, BTN_TOUCH, priv->touch);
>> +	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
>> +	input_sync(dev);
>> +}
>>  
>> -	return 0;
>> +static void byd_clear_touch(unsigned long data)
>> +{
>> +	struct psmouse *psmouse = (struct psmouse*)data;
> 
> According to checkpatch.pl, needs a space between `psmouse' and `*':
> 
>     (struct psmouse *)
> 
> FYI - there's a script, `scripts/checkpatch.pl', which checks for
> style violations - if you run it on your patch it'll pick up stuff
> like this.
> 
>> +	struct byd_data *priv = psmouse->private;
>> +
>> +	serio_pause_rx(psmouse->ps2dev.serio);
>> +	priv->touch = false;
>> +	/*
>> +	 * Move cursor back to center of pad when we lose touch - this
>> +	 * specifically improves user experience when moving cursor with one
>> +	 * finger, and pressing a button with another.
>> +	 */
>> +	priv->abs_x = BYD_PAD_WIDTH / 2;
>> +	priv->abs_y = BYD_PAD_HEIGHT / 2;
>> +	byd_report_input(psmouse);
>> +
>> +	serio_continue_rx(psmouse->ps2dev.serio);
>>  }
>>  
>>  static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>>  {
>> -	struct input_dev *dev = psmouse->dev;
>> +	struct byd_data *priv = psmouse->private;
>> +	u32 now_msecs = jiffies_to_msecs(jiffies);
>>  	u8 *pkt = psmouse->packet;
>>  
>>  	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
>> @@ -102,53 +291,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>>  
>>  	/* Otherwise, a full packet has been received */
>>  	switch (pkt[3]) {
>> -	case 0: {
>> +	case BYD_PACKET_ABSOLUTE:
>> +		/* Only use absolute packets for the start of movement. */
>> +		if (!priv->touch) {
>> +			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
>> +			priv->abs_y = (255 - pkt[2]) *
>> +				      (BYD_PAD_HEIGHT / 256);
>> +
>> +			/* needed to detect tap */
>> +			if (now_msecs - priv->last_touch_time > BYD_TOUCH_TIMEOUT)
> 
> Line too long (according to checkpatch).
> 
>> +				priv->touch = true;
>> +		}
>> +		break;
>> +	case BYD_PACKET_RELATIVE: {
>>  		/* Standard packet */
>>  		/* Sign-extend if a sign bit is set. */
>> -		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
>> -		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
>> -		int dx = signx | (int) pkt[1];
>> -		int dy = signy | (int) pkt[2];
>> +		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
>> +		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
>> +		s32 dx = signx | (int) pkt[1];
>> +		s32 dy = signy | (int) pkt[2];
>>  
>> -		input_report_rel(psmouse->dev, REL_X, dx);
>> -		input_report_rel(psmouse->dev, REL_Y, -dy);
>> +		/* Update position based on velocity */
>> +		priv->abs_x += dx * BYD_DT;
>> +		priv->abs_y -= dy * BYD_DT;
>>  
>> -		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
>> -		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
>> -		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
>> +		priv->touch = true;
>>  		break;
>>  	}
>> -
>> -	case BYD_SCROLLDOWN:
>> -	case BYD_2DOWN:
>> -		input_report_rel(dev, REL_WHEEL, -1);
>> -		break;
>> -
>> -	case BYD_SCROLLUP:
>> -	case BYD_2UP:
>> -		input_report_rel(dev, REL_WHEEL, 1);
>> -		break;
>> -
>> -	case BYD_SCROLLLEFT:
>> -	case BYD_2LEFT:
>> -		input_report_rel(dev, REL_HWHEEL, -1);
>> -		break;
>> -
>> -	case BYD_SCROLLRIGHT:
>> -	case BYD_2RIGHT:
>> -		input_report_rel(dev, REL_HWHEEL, 1);
>> -		break;
>> -
>> -	case BYD_ZOOMOUT:
>> -	case BYD_ZOOMIN:
>> -	case BYD_3UP:
>> -	case BYD_3DOWN:
>> -	case BYD_3LEFT:
>> -	case BYD_3RIGHT:
>> -	case BYD_4UP:
>> -	case BYD_4DOWN:
>> -		break;
>> -
>>  	default:
>>  		psmouse_warn(psmouse,
>>  			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
>> @@ -157,134 +326,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>>  		return PSMOUSE_BAD_DATA;
>>  	}
>>  
>> -	input_sync(dev);
>> +	priv->btn_left = pkt[0] & PS2_LEFT;
>> +	priv->btn_right = pkt[0] & PS2_RIGHT;
>>  
>> -	return PSMOUSE_FULL_PACKET;
>> -}
>> -
>> -/* Send a sequence of bytes, where each is ACKed before the next is sent. */
>> -static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
>> -{
>> -	unsigned int i;
>> +	byd_report_input(psmouse);
>>  
>> -	for (i = 0; i < len; ++i) {
>> -		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
>> -			return -1;
>> +	/* Reset time since last touch. */
>> +	if (priv->touch) {
>> +		priv->last_touch_time = now_msecs;
>> +		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(BYD_TOUCH_TIMEOUT));
> 
> Line too long (according to checkpatch).
> 
>>  	}
>> -	return 0;
>> -}
>> -
>> -/* Keep scrolling after fingers are removed. */
>> -#define SCROLL_INERTIAL		0x01
>> -#define SCROLL_NO_INERTIAL	0x02
>> -
>> -/* Clicking can be done by tapping or pressing. */
>> -#define CLICK_BOTH		0x01
>> -/* Clicking can only be done by pressing. */
>> -#define CLICK_PRESS_ONLY	0x02
>> -
>> -static int byd_enable(struct psmouse *psmouse)
>> -{
>> -	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
>> -	const u8 seq2[] = {
>> -		0xD3, 0x01,
>> -		0xD0, 0x00,
>> -		0xD0, 0x04,
>> -		/* Whether clicking is done by tapping or pressing. */
>> -		0xD4, CLICK_PRESS_ONLY,
>> -		0xD5, 0x01,
>> -		0xD7, 0x03,
>> -		/* Vertical and horizontal one-finger scroll zone inertia. */
>> -		0xD8, SCROLL_INERTIAL,
>> -		0xDA, 0x05,
>> -		0xDB, 0x02,
>> -		0xE4, 0x05,
>> -		0xD6, 0x01,
>> -		0xDE, 0x04,
>> -		0xE3, 0x01,
>> -		0xCF, 0x00,
>> -		0xD2, 0x03,
>> -		/* Vertical and horizontal two-finger scrolling inertia. */
>> -		0xE5, SCROLL_INERTIAL,
>> -		0xD9, 0x02,
>> -		0xD9, 0x07,
>> -		0xDC, 0x03,
>> -		0xDD, 0x03,
>> -		0xDF, 0x03,
>> -		0xE1, 0x03,
>> -		0xD1, 0x00,
>> -		0xCE, 0x00,
>> -		0xCC, 0x00,
>> -		0xE0, 0x00,
>> -		0xE2, 0x01
>> -	};
>> -	u8 param[4];
>> -
>> -	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
>> -		return -1;
>>  
>> -	/* Send a 0x01 command, which should return 4 bytes. */
>> -	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
>> -		return -1;
>> -
>> -	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
>> -		return -1;
>> -
>> -	return 0;
>> +	return PSMOUSE_FULL_PACKET;
>>  }
>>  
>> -/*
>> - * Send the set of PS/2 commands required to make it identify as an
>> - * intellimouse with 4-byte instead of 3-byte packets.
>> - */
>> -static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
>> +static int byd_reset_touchpad(struct psmouse *psmouse)
>>  {
>>  	struct ps2dev *ps2dev = &psmouse->ps2dev;
>>  	u8 param[4];
>> -	int i;
>> +	size_t i;
>> +
>>  	const struct {
>>  		u16 command;
>>  		u8 arg;
>>  	} seq[] = {
>> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
>> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
>> -		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
>> -		{ PSMOUSE_CMD_GETINFO, 0 },
>> -		{ PSMOUSE_CMD_SETRES, 0x03 },
>> +		/*
>> +		 * Intellimouse initialization sequence, to get 4-byte instead
>> +		 * of 3-byte packets.
>> +		 */
>>  		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>>  		{ PSMOUSE_CMD_SETRATE, 0x64 },
>>  		{ PSMOUSE_CMD_SETRATE, 0x50 },
>>  		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>> -		{ PSMOUSE_CMD_SETRATE, 0x50 },
>> -		{ PSMOUSE_CMD_GETID, 0 },
>> -		{ PSMOUSE_CMD_SETRATE, 0x64 },
>> -		{ PSMOUSE_CMD_SETRES, 0x03 },
>> -		{ PSMOUSE_CMD_ENABLE, 0 }
>> +		{ PSMOUSE_CMD_ENABLE, 0 },
>> +		/*
>> +		 * BYD-specific initialization, which enables absolute mode and
>> +		 * (if desired), the touchpad's built-in gesture detection.
>> +		 */
>> +		{ 0x10E2, 0x00 },
>> +		{ 0x10E0, 0x02 },
>> +		/* The touchpad should reply with 4 seemingly-random bytes */
>> +		{ 0x14E0, 0x01 },
>> +		/* Pairs of parameters and values. */
>> +		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
>> +		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
>> +		{ BYD_CMD_SET_TAP, 0x02 },
>> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
>> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
>> +		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
>> +		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
>> +		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
>> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
>> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
>> +		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
>> +		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
>> +		/* Finalize initialization. */
>> +		{ 0x10E0, 0x00 },
>> +		{ 0x10E2, 0x01 },
>>  	};
>>  
>> -	memset(param, 0, sizeof(param));
>>  	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
>> +		memset(param, 0, sizeof(param));
>>  		param[0] = seq[i].arg;
>>  		if (ps2_command(ps2dev, param, seq[i].command))
>> -			return -1;
>> -	}
>> -
>> -	return 0;
>> -}
>> -
>> -static int byd_reset_touchpad(struct psmouse *psmouse)
>> -{
>> -	if (byd_send_intellimouse_sequence(psmouse))
>> -		return -EIO;
>> -
>> -	if (byd_enable(psmouse))
>> -		return -EIO;
>> +			return -EIO;
>>  
>> +	}
>> +	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
>>  	return 0;
>>  }
>>  
>> @@ -314,9 +425,50 @@ static int byd_reconnect(struct psmouse *psmouse)
>>  	return 0;
>>  }
>>  
>> +static void byd_disconnect(struct psmouse *psmouse)
>> +{
>> +	struct byd_data *priv = psmouse->private;
>> +
>> +	if (priv) {
>> +		del_timer(&priv->timer);
>> +		kfree(psmouse->private);
>> +		psmouse->private = NULL;
>> +	}
>> +}
>> +
>> +int byd_detect(struct psmouse *psmouse, bool set_properties)
>> +{
>> +	struct ps2dev *ps2dev = &psmouse->ps2dev;
>> +	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
>> +
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
>> +		return -1;
>> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
>> +		return -1;
>> +
>> +	if (param[1] != 0x03 || param[2] != 0x64)
>> +		return -ENODEV;
>> +
>> +	psmouse_dbg(psmouse, "BYD touchpad detected\n");
>> +
>> +	if (set_properties) {
>> +		psmouse->vendor = "BYD";
>> +		psmouse->name = "TouchPad";
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  int byd_init(struct psmouse *psmouse)
>>  {
>>  	struct input_dev *dev = psmouse->dev;
>> +	struct byd_data *priv;
>>  
>>  	if (psmouse_reset(psmouse))
>>  		return -EIO;
>> @@ -324,14 +476,39 @@ int byd_init(struct psmouse *psmouse)
>>  	if (byd_reset_touchpad(psmouse))
>>  		return -EIO;
>>  
>> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	memset(priv, 0, sizeof(*priv));
>> +	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
>> +
>> +	psmouse->private = priv;
>> +	psmouse->disconnect = byd_disconnect;
>>  	psmouse->reconnect = byd_reconnect;
>>  	psmouse->protocol_handler = byd_process_byte;
>>  	psmouse->pktsize = 4;
>>  	psmouse->resync_time = 0;
>>  
>> -	__set_bit(BTN_MIDDLE, dev->keybit);
>> -	__set_bit(REL_WHEEL, dev->relbit);
>> -	__set_bit(REL_HWHEEL, dev->relbit);
>> +	__set_bit(INPUT_PROP_POINTER, dev->propbit);
>> +	/* Touchpad */
>> +	__set_bit(BTN_TOUCH, dev->keybit);
>> +	__set_bit(BTN_TOOL_FINGER, dev->keybit);
>> +	/* Buttons */
>> +	__set_bit(BTN_LEFT, dev->keybit);
>> +	__set_bit(BTN_RIGHT, dev->keybit);
>> +	__clear_bit(BTN_MIDDLE, dev->keybit);
>> +
>> +	/* Absolute position */
>> +	__set_bit(EV_ABS, dev->evbit);
>> +	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
>> +	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
>> +	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
>> +	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
>> +	/* No relative support */
>> +	__clear_bit(EV_REL, dev->evbit);
>> +	__clear_bit(REL_X, dev->relbit);
>> +	__clear_bit(REL_Y, dev->relbit);
>>  
>>  	return 0;
>>  }
>> diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
>> index 39d1bec..5784e20 100644
>> --- a/drivers/input/mouse/psmouse-base.c
>> +++ b/drivers/input/mouse/psmouse-base.c
>> @@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
>>  #ifdef CONFIG_MOUSE_PS2_BYD
>>  	{
>>  		.type		= PSMOUSE_BYD,
>> -		.name		= "BydPS/2",
>> +		.name		= "BYDPS/2",
>>  		.alias		= "byd",
>>  		.detect		= byd_detect,
>>  		.init		= byd_init,
> 
> Cheers,
> Chris
> 

[PATCH] psmouse: added absolute touch event support to BYD touchpad driver

[Richard Pospesel]

Fixed the line length issues per offline discussion with Chris.
---
Input: BYD: added absolute touch event support to BYD touchpad driver

Implemented absolute position and touch reporting. Now BYD touchpads will use
the synaptics/libinput xorg touchpad drivers. Added documentation for all
known gesture packets and initialization commands.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
---
 From c42408cd614ed6f0b3e695055f2caa82bddc8893 Mon Sep 17 00:00:00 2001
From: Richard Pospesel <pospeselr@gmail.com>
Date: Tue, 16 Feb 2016 20:37:42 -0800
Subject: [PATCH] psmouse: added absolute touch event support to BYD touchpad driver

---
drivers/input/mouse/byd.c | 578 ++++++++++++++++++++++++-------------
drivers/input/mouse/psmouse-base.c | 2 +-
2 files changed, 379 insertions(+), 201 deletions(-)

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..5b004b2c 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -2,20 +2,32 @@
* BYD TouchPad PS/2 mouse driver
*
* Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015 Richard Pospesel <pospeselr@gmail.com>
+ * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015 Martin Wimpress
+ * Copyright (C) 2015 Jay Kuri
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename: "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * md5: 0d5e4660b98fca9587a0df212fca3048
+ * sha1: 97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
*/

#include <linux/delay.h>
#include <linux/input.h>
#include <linux/libps2.h>
#include <linux/serio.h>
+#include <linux/slab.h>

#include "psmouse.h"
#include "byd.h"

+/* PS2 Bits */
#define PS2_Y_OVERFLOW BIT_MASK(7)
#define PS2_X_OVERFLOW BIT_MASK(6)
#define PS2_Y_SIGN BIT_MASK(5)
@@ -26,69 +38,247 @@
#define PS2_LEFT BIT_MASK(0)

/*
- * The touchpad reports gestures in the last byte of each packet. It can take
- * any of the following values:
+ * BYD pad constants
*/

-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP 0xCA
-#define BYD_SCROLLDOWN 0x36
-#define BYD_SCROLLLEFT 0xCB
-#define BYD_SCROLLRIGHT 0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN 0x2B
-#define BYD_2UP 0xD5
-#define BYD_2LEFT 0xD6
-#define BYD_2RIGHT 0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT 0xD8
-#define BYD_ZOOMIN 0x28
-/* Three-finger swipe. */
-#define BYD_3UP 0xD3
-#define BYD_3DOWN 0x2D
-#define BYD_3LEFT 0xD4
-#define BYD_3RIGHT 0x2C
-/* Four-finger swipe. */
-#define BYD_4UP 0xCD
-#define BYD_4DOWN 0x33
+/*
+ * True device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm.
+ * Absolute coordinate packets are in the range 0-255 for both X and Y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm.
+ */
+#define BYD_PAD_WIDTH 11264
+#define BYD_PAD_HEIGHT 6656
+#define BYD_PAD_RESOLUTION 111

-int byd_detect(struct psmouse *psmouse, bool set_properties)
-{
- struct ps2dev *ps2dev = &psmouse->ps2dev;
- unsigned char param[4];
+/*
+ * Given the above dimensions, relative packets velocity is in multiples of
+ * 1 unit / 11 milliseconds. We use this dt to estimate distance traveled
+ */
+#define BYD_DT 11
+/* Time in milliseconds used to timeout various touch events */
+#define BYD_TOUCH_TIMEOUT_MS 64
+#define BYD_TOUCH_TIMEOUT_JIFFIES msecs_to_jiffies(BYD_TOUCH_TIMEOUT_MS)

- param[0] = 0x03;
- param[1] = 0x00;
- param[2] = 0x00;
- param[3] = 0x00;
+/* BYD commands reverse engineered from windows driver */

- if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
- return -1;
- if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
- return -1;
- if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
- return -1;
- if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
- return -1;
- if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
- return -1;
-
- if (param[1] != 0x03 || param[2] != 0x64)
- return -ENODEV;
+/*
+ * Swipe gesture from off-pad to on-pad
+ * 0 : disable
+ * 1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE 0x10cc
+/*
+ * Tap and drag delay time
+ * 0 : disable
+ * 1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME 0x10cf
+/*
+ * Physical buttons function mapping
+ * 0 : enable
+ * 4 : normal
+ * 5 : left button custom command
+ * 6 : right button custom command
+ * 8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS 0x10d0
+/*
+ * Absolute mode (1 byte X/Y resolution)
+ * 0 : disable
+ * 2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE 0x10d1
+/*
+ * Two finger scrolling
+ * 1 : vertical
+ * 2 : horizontal
+ * 3 : vertical + horizontal
+ * 4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL 0x10d2
+/*
+ * Handedness
+ * 1 : right handed
+ * 2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS 0x10d3
+/*
+ * Tap to click
+ * 1 : enable
+ * 2 : disable
+ */
+#define BYD_CMD_SET_TAP 0x10d4
+/*
+ * Tap and drag
+ * 1 : tap and hold to drag
+ * 2 : tap and hold to drag + lock
+ * 3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG 0x10d5
+/*
+ * Touch sensitivity
+ * 1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY 0x10d6
+/*
+ * One finger scrolling
+ * 1 : vertical
+ * 2 : horizontal
+ * 3 : vertical + horizontal
+ * 4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL 0x10d7
+/*
+ * One finger scrolling function
+ * 1 : free scrolling
+ * 2 : edge motion
+ * 3 : free scrolling + edge motion
+ * 4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC 0x10d8
+/*
+ * Sliding speed
+ * 1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED 0x10da
+/*
+ * Edge motion
+ * 1 : disable
+ * 2 : enable when dragging
+ * 3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION 0x10db
+/*
+ * Left edge region size
+ * 0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION 0x10dc
+/*
+ * Top edge region size
+ * 0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION 0x10dd
+/*
+ * Disregard palm press as clicks
+ * 1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK 0x10de
+/*
+ * Right edge region size
+ * 0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION 0x10df
+/*
+ * Bottom edge region size
+ * 0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION 0x10e1
+/*
+ * Multitouch gestures
+ * 1 : enable
+ * 2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH 0x10e3
+/*
+ * Edge motion speed
+ * 0 : control with finger pressure
+ * 1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED 0x10e4
+/*
+ * Two finger scolling function
+ * 0 : free scrolling
+ * 1 : free scrolling (with momentum)
+ * 2 : edge motion
+ * 3 : free scrolling (with momentum) + edge motion
+ * 4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC 0x10e5

- psmouse_dbg(psmouse, "BYD touchpad detected\n");
+/*
+ * The touchpad generates a mixture of absolute and relative packets, indicated
+ * by the the last byte of each packet being set to one of the following:
+ */
+#define BYD_PACKET_ABSOLUTE 0xf8
+#define BYD_PACKET_RELATIVE 0x00
+/* Multitouch gesture packets */
+#define BYD_PACKET_PINCH_IN 0xd8
+#define BYD_PACKET_PINCH_OUT 0x28
+#define BYD_PACKET_ROTATE_CLOCKWISE 0x29
+#define BYD_PACKET_ROTATE_ANTICLOCKWISE 0xd7
+#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT 0x2a
+#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN 0x2b
+#define BYD_PACKET_TWO_FINGER_SCROLL_UP 0xd5
+#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT 0xd6
+#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT 0x2c
+#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN 0x2d
+#define BYD_PACKET_THREE_FINGER_SWIPE_UP 0xd3
+#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT 0xd4
+#define BYD_PACKET_FOUR_FINGER_DOWN 0x33
+#define BYD_PACKET_FOUR_FINGER_UP 0xcd
+#define BYD_PACKET_REGION_SCROLL_RIGHT 0x35
+#define BYD_PACKET_REGION_SCROLL_DOWN 0x36
+#define BYD_PACKET_REGION_SCROLL_UP 0xca
+#define BYD_PACKET_REGION_SCROLL_LEFT 0xcb
+#define BYD_PACKET_RIGHT_CORNER_CLICK 0xd2
+#define BYD_PACKET_LEFT_CORNER_CLICK 0x2e
+#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK 0x2f
+#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT 0x37
+#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN 0x30
+#define BYD_PACKET_ONTO_PAD_SWIPE_UP 0xd0
+#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT 0xc9
+
+struct byd_data {
+ struct timer_list timer;
+ s32 abs_x;
+ s32 abs_y;
+ u32 last_touch_time;
+ bool btn_left : 1;
+ bool btn_right : 1;
+ bool touch : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+ struct byd_data *priv = psmouse->private;
+ struct input_dev *dev = psmouse->dev;

- if (set_properties) {
- psmouse->vendor = "BYD";
- psmouse->name = "TouchPad";
- }
+ input_report_abs(dev, ABS_X, priv->abs_x);
+ input_report_abs(dev, ABS_Y, priv->abs_y);
+ input_report_key(dev, BTN_LEFT, priv->btn_left);
+ input_report_key(dev, BTN_RIGHT, priv->btn_right);
+ input_report_key(dev, BTN_TOUCH, priv->touch);
+ input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+ input_sync(dev);
+}

- return 0;
+static void byd_clear_touch(unsigned long data)
+{
+ struct psmouse *psmouse = (struct psmouse *)data;
+ struct byd_data *priv = psmouse->private;
+
+ serio_pause_rx(psmouse->ps2dev.serio);
+ priv->touch = false;
+ /*
+ * Move cursor back to center of pad when we lose touch - this
+ * specifically improves user experience when moving cursor with one
+ * finger, and pressing a button with another.
+ */
+ priv->abs_x = BYD_PAD_WIDTH / 2;
+ priv->abs_y = BYD_PAD_HEIGHT / 2
+; byd_report_input(psmouse);
+
+ serio_continue_rx(psmouse->ps2dev.serio);
}

static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
{
- struct input_dev *dev = psmouse->dev;
+ struct byd_data *priv = psmouse->private;
+ u32 now = jiffies_to_msecs(jiffies);
u8 *pkt = psmouse->packet;

if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
@@ -102,53 +292,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)

/* Otherwise, a full packet has been received */
switch (pkt[3]) {
- case 0: {
+ case BYD_PACKET_ABSOLUTE:
+ /* Only use absolute packets for the start of movement. */
+ if (!priv->touch) {
+ priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
+ priv->abs_y = (255 - pkt[2]) *
+ (BYD_PAD_HEIGHT / 256);
+
+ /* needed to detect tap */
+ if (now - priv->last_touch_time > BYD_TOUCH_TIMEOUT_MS)
+ priv->touch = true;
+ }
+ break;
+ case BYD_PACKET_RELATIVE: {
/* Standard packet */
/* Sign-extend if a sign bit is set. */
- unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
- unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
- int dx = signx | (int) pkt[1];
- int dy = signy | (int) pkt[2];
+ u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
+ u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
+ s32 dx = signx | (int) pkt[1];
+ s32 dy = signy | (int) pkt[2];

- input_report_rel(psmouse->dev, REL_X, dx);
- input_report_rel(psmouse->dev, REL_Y, -dy);
+ /* Update position based on velocity */
+ priv->abs_x += dx * BYD_DT;
+ priv->abs_y -= dy * BYD_DT;

- input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
- input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
- input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+ priv->touch = true;
break;
}
-
- case BYD_SCROLLDOWN:
- case BYD_2DOWN:
- input_report_rel(dev, REL_WHEEL, -1);
- break;
-
- case BYD_SCROLLUP:
- case BYD_2UP:
- input_report_rel(dev, REL_WHEEL, 1);
- break;
-
- case BYD_SCROLLLEFT:
- case BYD_2LEFT:
- input_report_rel(dev, REL_HWHEEL, -1);
- break;
-
- case BYD_SCROLLRIGHT:
- case BYD_2RIGHT:
- input_report_rel(dev, REL_HWHEEL, 1);
- break;
-
- case BYD_ZOOMOUT:
- case BYD_ZOOMIN:
- case BYD_3UP:
- case BYD_3DOWN:
- case BYD_3LEFT:
- case BYD_3RIGHT:
- case BYD_4UP:
- case BYD_4DOWN:
- break;
-
default:
psmouse_warn(psmouse,
"Unrecognized Z: pkt = %02x %02x %02x %02x\n",
@@ -157,134 +327,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
return PSMOUSE_BAD_DATA;
}

- input_sync(dev);
+ priv->btn_left = pkt[0] & PS2_LEFT;
+ priv->btn_right = pkt[0] & PS2_RIGHT;

- return PSMOUSE_FULL_PACKET;
-}
-
-/* Send a sequence of bytes, where each is ACKed before the next is sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
-{
- unsigned int i;
+ byd_report_input(psmouse);

- for (i = 0; i < len; ++i) {
- if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
- return -1;
+ /* Reset time since last touch. */
+ if (priv->touch) {
+ priv->last_touch_time = now;
+ mod_timer(&priv->timer, jiffies + BYD_TOUCH_TIMEOUT_JIFFIES);
}
- return 0;
-}
-
-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL 0x01
-#define SCROLL_NO_INERTIAL 0x02
-
-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH 0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY 0x02
-
-static int byd_enable(struct psmouse *psmouse)
-{
- const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
- const u8 seq2[] = {
- 0xD3, 0x01,
- 0xD0, 0x00,
- 0xD0, 0x04,
- /* Whether clicking is done by tapping or pressing. */
- 0xD4, CLICK_PRESS_ONLY,
- 0xD5, 0x01,
- 0xD7, 0x03,
- /* Vertical and horizontal one-finger scroll zone inertia. */
- 0xD8, SCROLL_INERTIAL,
- 0xDA, 0x05,
- 0xDB, 0x02,
- 0xE4, 0x05,
- 0xD6, 0x01,
- 0xDE, 0x04,
- 0xE3, 0x01,
- 0xCF, 0x00,
- 0xD2, 0x03,
- /* Vertical and horizontal two-finger scrolling inertia. */
- 0xE5, SCROLL_INERTIAL,
- 0xD9, 0x02,
- 0xD9, 0x07,
- 0xDC, 0x03,
- 0xDD, 0x03,
- 0xDF, 0x03,
- 0xE1, 0x03,
- 0xD1, 0x00,
- 0xCE, 0x00,
- 0xCC, 0x00,
- 0xE0, 0x00,
- 0xE2, 0x01
- };
- u8 param[4];
-
- if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
- return -1;

- /* Send a 0x01 command, which should return 4 bytes. */
- if (ps2_command(&psmouse->ps2dev, param, 0x0401))
- return -1;
-
- if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
- return -1;
-
- return 0;
+ return PSMOUSE_FULL_PACKET;
}

-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static int byd_reset_touchpad(struct psmouse *psmouse)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
u8 param[4];
- int i;
+ size_t i;
+
const struct {
u16 command;
u8 arg;
} seq[] = {
- { PSMOUSE_CMD_RESET_BAT, 0 },
- { PSMOUSE_CMD_RESET_BAT, 0 },
- { PSMOUSE_CMD_GETID, 0 },
- { PSMOUSE_CMD_SETSCALE11, 0 },
- { PSMOUSE_CMD_SETSCALE11, 0 },
- { PSMOUSE_CMD_SETSCALE11, 0 },
- { PSMOUSE_CMD_GETINFO, 0 },
- { PSMOUSE_CMD_SETRES, 0x03 },
+ /*
+ * Intellimouse initialization sequence, to get 4-byte instead
+ * of 3-byte packets.
+ */
{ PSMOUSE_CMD_SETRATE, 0xC8 },
{ PSMOUSE_CMD_SETRATE, 0x64 },
{ PSMOUSE_CMD_SETRATE, 0x50 },
{ PSMOUSE_CMD_GETID, 0 },
- { PSMOUSE_CMD_SETRATE, 0xC8 },
- { PSMOUSE_CMD_SETRATE, 0xC8 },
- { PSMOUSE_CMD_SETRATE, 0x50 },
- { PSMOUSE_CMD_GETID, 0 },
- { PSMOUSE_CMD_SETRATE, 0x64 },
- { PSMOUSE_CMD_SETRES, 0x03 },
- { PSMOUSE_CMD_ENABLE, 0 }
+ { PSMOUSE_CMD_ENABLE, 0 },
+ /*
+ * BYD-specific initialization, which enables absolute mode and
+ * (if desired), the touchpad's built-in gesture detection.
+ */
+ { 0x10E2, 0x00 },
+ { 0x10E0, 0x02 },
+ /* The touchpad should reply with 4 seemingly-random bytes */
+ { 0x14E0, 0x01 },
+ /* Pairs of parameters and values. */
+ { BYD_CMD_SET_HANDEDNESS, 0x01 },
+ { BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
+ { BYD_CMD_SET_TAP, 0x02 },
+ { BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
+ { BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
+ { BYD_CMD_SET_EDGE_MOTION, 0x01 },
+ { BYD_CMD_SET_PALM_CHECK, 0x00 },
+ { BYD_CMD_SET_MULTITOUCH, 0x02 },
+ { BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
+ { BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
+ { BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
+ { BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
+ { BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
+ { BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
+ { BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
+ /* Finalize initialization. */
+ { 0x10E0, 0x00 },
+ { 0x10E2, 0x01 },
};

- memset(param, 0, sizeof(param));
for (i = 0; i < ARRAY_SIZE(seq); ++i) {
+ memset(param, 0, sizeof(param));
param[0] = seq[i].arg;
if (ps2_command(ps2dev, param, seq[i].command))
- return -1;
- }
-
- return 0;
-}
-
-static int byd_reset_touchpad(struct psmouse *psmouse)
-{
- if (byd_send_intellimouse_sequence(psmouse))
- return -EIO;
-
- if (byd_enable(psmouse))
- return -EIO;
+ return -EIO;

+ }
+ psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
return 0;
}

@@ -314,9 +426,50 @@ static int byd_reconnect(struct psmouse *psmouse)
return 0;
}

+static void byd_disconnect(struct psmouse *psmouse)
+{
+ struct byd_data *priv = psmouse->private;
+
+ if (priv) {
+ del_timer(&priv->timer);
+ kfree(psmouse->private);
+ psmouse->private = NULL;
+ }
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+ struct ps2dev *ps2dev = &psmouse->ps2dev;
+ u8 param[4] = {0x03, 0x00, 0x00, 0x00};
+
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+ return -1;
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+ return -1;
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+ return -1;
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+ return -1;
+ if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+ return -1;
+
+ if (param[1] != 0x03 || param[2] != 0x64)
+ return -ENODEV;
+
+ psmouse_dbg(psmouse, "BYD touchpad detected\n");
+
+ if (set_properties) {
+ psmouse->vendor = "BYD";
+ psmouse->name = "TouchPad";
+ }
+
+ return 0;
+}
+
int byd_init(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
+ struct byd_data *priv;

if (psmouse_reset(psmouse))
return -EIO;
@@ -324,14 +477,39 @@ int byd_init(struct psmouse *psmouse)
if (byd_reset_touchpad(psmouse))
return -EIO;

+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ memset(priv, 0, sizeof(*priv));
+ setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
+
+ psmouse->private = priv;
+ psmouse->disconnect = byd_disconnect;
psmouse->reconnect = byd_reconnect;
psmouse->protocol_handler = byd_process_byte;
psmouse->pktsize = 4;
psmouse->resync_time = 0;

- __set_bit(BTN_MIDDLE, dev->keybit);
- __set_bit(REL_WHEEL, dev->relbit);
- __set_bit(REL_HWHEEL, dev->relbit);
+ __set_bit(INPUT_PROP_POINTER, dev->propbit);
+ /* Touchpad */
+ __set_bit(BTN_TOUCH, dev->keybit);
+ __set_bit(BTN_TOOL_FINGER, dev->keybit);
+ /* Buttons */
+ __set_bit(BTN_LEFT, dev->keybit);
+ __set_bit(BTN_RIGHT, dev->keybit);
+ __clear_bit(BTN_MIDDLE, dev->keybit);
+
+ /* Absolute position */
+ __set_bit(EV_ABS, dev->evbit);
+ input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
+ input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
+ input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
+ input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
+ /* No relative support */
+ __clear_bit(EV_REL, dev->evbit);
+ __clear_bit(REL_X, dev->relbit);
+ __clear_bit(REL_Y, dev->relbit);

return 0;
}
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
#ifdef CONFIG_MOUSE_PS2_BYD
{
.type = PSMOUSE_BYD,
- .name = "BydPS/2",
+ .name = "BYDPS/2",
.alias = "byd",
.detect = byd_detect,
.init = byd_init,
-- 
2.7.0



On 02/10/2016 06:58 PM, Richard Pospesel wrote:
> Ok I think this about covers it.  The line length issues remain, but the script
> repors them as warnings so I'm not to worried about it.  Patch follows:
> ---
> Input: BYD: Added proper touch support
>
> Implemented absolute position and touch reporting.  Now BYD touchpads will use
> the synaptics/libinput xorg touchpad drivers.  Added documenatation for all
> known gesture packets and initialization commands.
>
> Signed-off-by: Richard Pospesel <pospeselr@gmail.com>
> ---
>  From c0d0ece9ace3939691831eb20c2a5f01343781f1 Mon Sep 17 00:00:00 2001
> From: pospeselr <pospeselr@gmail.com>
> Date: Wed, 10 Feb 2016 18:24:00 -0800
> Subject: [PATCH] byd changes
>
> ---
>   drivers/input/mouse/byd.c          | 577 ++++++++++++++++++++++++-------------
>   drivers/input/mouse/psmouse-base.c |   2 +-
>   2 files changed, 378 insertions(+), 201 deletions(-)
>
> diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
> index 9425e0f..4c388ed 100644
> --- a/drivers/input/mouse/byd.c
> +++ b/drivers/input/mouse/byd.c
> @@ -2,20 +2,32 @@
>    * BYD TouchPad PS/2 mouse driver
>    *
>    * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
> + * Copyright (C) 2015 Richard Pospesel <pospeselr@gmail.com>
> + * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
> + * Copyright (C) 2015 Martin Wimpress
> + * Copyright (C) 2015 Jay Kuri
>    *
>    * This program is free software; you can redistribute it and/or modify it
>    * under the terms of the GNU General Public License version 2 as published by
>    * the Free Software Foundation.
> + *
> + * Protocol of BYD Touch Pad reverse-engineered from windows driver:
> + * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
> + * md5:       0d5e4660b98fca9587a0df212fca3048
> + * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
> + * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
>    */
>
>   #include <linux/delay.h>
>   #include <linux/input.h>
>   #include <linux/libps2.h>
>   #include <linux/serio.h>
> +#include <linux/slab.h>
>
>   #include "psmouse.h"
>   #include "byd.h"
>
> +/* PS2 Bits */
>   #define PS2_Y_OVERFLOW	BIT_MASK(7)
>   #define PS2_X_OVERFLOW	BIT_MASK(6)
>   #define PS2_Y_SIGN	BIT_MASK(5)
> @@ -26,69 +38,246 @@
>   #define PS2_LEFT	BIT_MASK(0)
>
>   /*
> - * The touchpad reports gestures in the last byte of each packet. It can take
> - * any of the following values:
> + * BYD pad constants
>    */
>
> -/* One-finger scrolling in one of the edge scroll zones. */
> -#define BYD_SCROLLUP		0xCA
> -#define BYD_SCROLLDOWN		0x36
> -#define BYD_SCROLLLEFT		0xCB
> -#define BYD_SCROLLRIGHT		0x35
> -/* Two-finger scrolling. */
> -#define BYD_2DOWN		0x2B
> -#define BYD_2UP			0xD5
> -#define BYD_2LEFT		0xD6
> -#define BYD_2RIGHT		0x2A
> -/* Pinching in or out. */
> -#define BYD_ZOOMOUT		0xD8
> -#define BYD_ZOOMIN		0x28
> -/* Three-finger swipe. */
> -#define BYD_3UP			0xD3
> -#define BYD_3DOWN		0x2D
> -#define BYD_3LEFT		0xD4
> -#define BYD_3RIGHT		0x2C
> -/* Four-finger swipe. */
> -#define BYD_4UP			0xCD
> -#define BYD_4DOWN		0x33
> +/*
> + * True device resolution is unknown, however experiments show the
> + * resolution is about 111 units/mm.
> + * Absolute coordinate packets are in the range 0-255 for both X and Y
> + * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
> + * the right ballpark given the touchpad's physical dimensions and estimate
> + * resolution per spec sheet, device active area dimensions are
> + * 101.6 x 60.1 mm.
> + */
> +#define BYD_PAD_WIDTH		11264
> +#define BYD_PAD_HEIGHT		6656
> +#define BYD_PAD_RESOLUTION	111
>
> -int byd_detect(struct psmouse *psmouse, bool set_properties)
> -{
> -	struct ps2dev *ps2dev = &psmouse->ps2dev;
> -	unsigned char param[4];
> +/*
> + * Given the above dimensions, relative packets velocity is in multiples of
> + * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
> + */
> +#define BYD_DT			11
> +/* Time in milliseconds used to timeout various touch events */
> +#define BYD_TOUCH_TIMEOUT	64
>
> -	param[0] = 0x03;
> -	param[1] = 0x00;
> -	param[2] = 0x00;
> -	param[3] = 0x00;
> +/* BYD commands reverse engineered from windows driver */
>
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> -		return -1;
> -	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> -		return -1;
> -
> -	if (param[1] != 0x03 || param[2] != 0x64)
> -		return -ENODEV;
> +/*
> + * Swipe gesture from off-pad to on-pad
> + *  0 : disable
> + *  1 : enable
> + */
> +#define BYD_CMD_SET_OFFSCREEN_SWIPE		0x10cc
> +/*
> + * Tap and drag delay time
> + *  0 : disable
> + *  1 - 8 : least to most delay
> + */
> +#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME		0x10cf
> +/*
> + * Physical buttons function mapping
> + *  0 : enable
> + *  4 : normal
> + *  5 : left button custom command
> + *  6 : right button custom command
> + *  8 : disable
> + */
> +#define BYD_CMD_SET_PHYSICAL_BUTTONS		0x10d0
> +/*
> + * Absolute mode (1 byte X/Y resolution)
> + *  0 : disable
> + *  2 : enable
> + */
> +#define BYD_CMD_SET_ABSOLUTE_MODE		0x10d1
> +/*
> + * Two finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL		0x10d2
> +/*
> + * Handedness
> + *  1 : right handed
> + *  2 : left handed
> + */
> +#define BYD_CMD_SET_HANDEDNESS			0x10d3
> +/*
> + * Tap to click
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_TAP				0x10d4
> +/*
> + * Tap and drag
> + *  1 : tap and hold to drag
> + *  2 : tap and hold to drag + lock
> + *  3 : disable
> + */
> +#define BYD_CMD_SET_TAP_DRAG			0x10d5
> +/*
> + * Touch sensitivity
> + *  1 - 7 : least to most sensitive
> + */
> +#define BYD_CMD_SET_TOUCH_SENSITIVITY		0x10d6
> +/*
> + * One finger scrolling
> + *  1 : vertical
> + *  2 : horizontal
> + *  3 : vertical + horizontal
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL		0x10d7
> +/*
> + * One finger scrolling function
> + *  1 : free scrolling
> + *  2 : edge motion
> + *  3 : free scrolling + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC	0x10d8
> +/*
> + * Sliding speed
> + *  1 - 5 : slowest to fastest
> + */
> +#define BYD_CMD_SET_SLIDING_SPEED		0x10da
> +/*
> + * Edge motion
> + *  1 : disable
> + *  2 : enable when dragging
> + *  3 : enable when dragging and pointing
> + */
> +#define BYD_CMD_SET_EDGE_MOTION			0x10db
> +/*
> + * Left edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_LEFT_EDGE_REGION		0x10dc
> +/*
> + * Top edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_TOP_EDGE_REGION		0x10dd
> +/*
> + * Disregard palm press as clicks
> + *  1 - 6 : smallest to largest
> + */
> +#define BYD_CMD_SET_PALM_CHECK			0x10de
> +/*
> + * Right edge region size
> + *  0 - 7 : smallest to largest width
> + */
> +#define BYD_CMD_SET_RIGHT_EDGE_REGION		0x10df
> +/*
> + * Bottom edge region size
> + *  0 - 9 : smallest to largest height
> + */
> +#define BYD_CMD_SET_BOTTOM_EDGE_REGION		0x10e1
> +/*
> + * Multitouch gestures
> + *  1 : enable
> + *  2 : disable
> + */
> +#define BYD_CMD_SET_MULTITOUCH			0x10e3
> +/*
> + * Edge motion speed
> + *  0 : control with finger pressure
> + *  1 - 9 : slowest to fastest
> + */
> +#define BYD_CMD_SET_EDGE_MOTION_SPEED		0x10e4
> +/*
> + * Two finger scolling function
> + *  0 : free scrolling
> + *  1 : free scrolling (with momentum)
> + *  2 : edge motion
> + *  3 : free scrolling (with momentum) + edge motion
> + *  4 : disable
> + */
> +#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC	0x10e5
>
> -	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +/*
> + * The touchpad generates a mixture of absolute and relative packets, indicated
> + * by the the last byte of each packet being set to one of the following:
> + */
> +#define BYD_PACKET_ABSOLUTE			0xf8
> +#define BYD_PACKET_RELATIVE			0x00
> +/* Multitouch gesture packets */
> +#define BYD_PACKET_PINCH_IN			0xd8
> +#define BYD_PACKET_PINCH_OUT			0x28
> +#define BYD_PACKET_ROTATE_CLOCKWISE		0x29
> +#define BYD_PACKET_ROTATE_ANTICLOCKWISE		0xd7
> +#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT	0x2a
> +#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN	0x2b
> +#define BYD_PACKET_TWO_FINGER_SCROLL_UP		0xd5
> +#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT	0xd6
> +#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT	0x2c
> +#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN	0x2d
> +#define BYD_PACKET_THREE_FINGER_SWIPE_UP	0xd3
> +#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT	0xd4
> +#define BYD_PACKET_FOUR_FINGER_DOWN		0x33
> +#define BYD_PACKET_FOUR_FINGER_UP		0xcd
> +#define BYD_PACKET_REGION_SCROLL_RIGHT		0x35
> +#define BYD_PACKET_REGION_SCROLL_DOWN		0x36
> +#define BYD_PACKET_REGION_SCROLL_UP		0xca
> +#define BYD_PACKET_REGION_SCROLL_LEFT		0xcb
> +#define BYD_PACKET_RIGHT_CORNER_CLICK		0xd2
> +#define BYD_PACKET_LEFT_CORNER_CLICK		0x2e
> +#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK	0x2f
> +#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT		0x37
> +#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN		0x30
> +#define BYD_PACKET_ONTO_PAD_SWIPE_UP		0xd0
> +#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT		0xc9
> +
> +struct byd_data {
> +	struct timer_list timer;
> +	s32 abs_x;
> +	s32 abs_y;
> +	u32 last_touch_time;
> +	bool btn_left  : 1;
> +	bool btn_right : 1;
> +	bool touch     : 1;
> +};
> +
> +static void byd_report_input(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = psmouse->private;
> +	struct input_dev *dev = psmouse->dev;
>
> -	if (set_properties) {
> -		psmouse->vendor = "BYD";
> -		psmouse->name = "TouchPad";
> -	}
> +	input_report_abs(dev, ABS_X, priv->abs_x);
> +	input_report_abs(dev, ABS_Y, priv->abs_y);
> +	input_report_key(dev, BTN_LEFT, priv->btn_left);
> +	input_report_key(dev, BTN_RIGHT, priv->btn_right);
> +	input_report_key(dev, BTN_TOUCH, priv->touch);
> +	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
> +	input_sync(dev);
> +}
>
> -	return 0;
> +static void byd_clear_touch(unsigned long data)
> +{
> +	struct psmouse *psmouse = (struct psmouse *)data;
> +	struct byd_data *priv = psmouse->private;
> +
> +	serio_pause_rx(psmouse->ps2dev.serio);
> +	priv->touch = false;
> +	/*
> +	 * Move cursor back to center of pad when we lose touch - this
> +	 * specifically improves user experience when moving cursor with one
> +	 * finger, and pressing a button with another.
> +	 */
> +	priv->abs_x = BYD_PAD_WIDTH / 2;
> +	priv->abs_y = BYD_PAD_HEIGHT / 2;
> +	byd_report_input(psmouse);
> +
> +	serio_continue_rx(psmouse->ps2dev.serio);
>   }
>
>   static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>   {
> -	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv = psmouse->private;
> +	u32 now_msecs = jiffies_to_msecs(jiffies);
>   	u8 *pkt = psmouse->packet;
>
>   	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
> @@ -102,53 +291,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>
>   	/* Otherwise, a full packet has been received */
>   	switch (pkt[3]) {
> -	case 0: {
> +	case BYD_PACKET_ABSOLUTE:
> +		/* Only use absolute packets for the start of movement. */
> +		if (!priv->touch) {
> +			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
> +			priv->abs_y = (255 - pkt[2]) *
> +				      (BYD_PAD_HEIGHT / 256);
> +
> +			/* needed to detect tap */
> +			if (now_msecs - priv->last_touch_time > BYD_TOUCH_TIMEOUT)
> +				priv->touch = true;
> +		}
> +		break;
> +	case BYD_PACKET_RELATIVE: {
>   		/* Standard packet */
>   		/* Sign-extend if a sign bit is set. */
> -		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> -		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> -		int dx = signx | (int) pkt[1];
> -		int dy = signy | (int) pkt[2];
> +		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
> +		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
> +		s32 dx = signx | (int) pkt[1];
> +		s32 dy = signy | (int) pkt[2];
>
> -		input_report_rel(psmouse->dev, REL_X, dx);
> -		input_report_rel(psmouse->dev, REL_Y, -dy);
> +		/* Update position based on velocity */
> +		priv->abs_x += dx * BYD_DT;
> +		priv->abs_y -= dy * BYD_DT;
>
> -		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
> -		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
> -		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
> +		priv->touch = true;
>   		break;
>   	}
> -
> -	case BYD_SCROLLDOWN:
> -	case BYD_2DOWN:
> -		input_report_rel(dev, REL_WHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLUP:
> -	case BYD_2UP:
> -		input_report_rel(dev, REL_WHEEL, 1);
> -		break;
> -
> -	case BYD_SCROLLLEFT:
> -	case BYD_2LEFT:
> -		input_report_rel(dev, REL_HWHEEL, -1);
> -		break;
> -
> -	case BYD_SCROLLRIGHT:
> -	case BYD_2RIGHT:
> -		input_report_rel(dev, REL_HWHEEL, 1);
> -		break;
> -
> -	case BYD_ZOOMOUT:
> -	case BYD_ZOOMIN:
> -	case BYD_3UP:
> -	case BYD_3DOWN:
> -	case BYD_3LEFT:
> -	case BYD_3RIGHT:
> -	case BYD_4UP:
> -	case BYD_4DOWN:
> -		break;
> -
>   	default:
>   		psmouse_warn(psmouse,
>   			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
> @@ -157,134 +326,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
>   		return PSMOUSE_BAD_DATA;
>   	}
>
> -	input_sync(dev);
> +	priv->btn_left = pkt[0] & PS2_LEFT;
> +	priv->btn_right = pkt[0] & PS2_RIGHT;
>
> -	return PSMOUSE_FULL_PACKET;
> -}
> -
> -/* Send a sequence of bytes, where each is ACKed before the next is sent. */
> -static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
> -{
> -	unsigned int i;
> +	byd_report_input(psmouse);
>
> -	for (i = 0; i < len; ++i) {
> -		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
> -			return -1;
> +	/* Reset time since last touch. */
> +	if (priv->touch) {
> +		priv->last_touch_time = now_msecs;
> +		mod_timer(&priv->timer, jiffies + msecs_to_jiffies(BYD_TOUCH_TIMEOUT));
>   	}
> -	return 0;
> -}
> -
> -/* Keep scrolling after fingers are removed. */
> -#define SCROLL_INERTIAL		0x01
> -#define SCROLL_NO_INERTIAL	0x02
> -
> -/* Clicking can be done by tapping or pressing. */
> -#define CLICK_BOTH		0x01
> -/* Clicking can only be done by pressing. */
> -#define CLICK_PRESS_ONLY	0x02
> -
> -static int byd_enable(struct psmouse *psmouse)
> -{
> -	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
> -	const u8 seq2[] = {
> -		0xD3, 0x01,
> -		0xD0, 0x00,
> -		0xD0, 0x04,
> -		/* Whether clicking is done by tapping or pressing. */
> -		0xD4, CLICK_PRESS_ONLY,
> -		0xD5, 0x01,
> -		0xD7, 0x03,
> -		/* Vertical and horizontal one-finger scroll zone inertia. */
> -		0xD8, SCROLL_INERTIAL,
> -		0xDA, 0x05,
> -		0xDB, 0x02,
> -		0xE4, 0x05,
> -		0xD6, 0x01,
> -		0xDE, 0x04,
> -		0xE3, 0x01,
> -		0xCF, 0x00,
> -		0xD2, 0x03,
> -		/* Vertical and horizontal two-finger scrolling inertia. */
> -		0xE5, SCROLL_INERTIAL,
> -		0xD9, 0x02,
> -		0xD9, 0x07,
> -		0xDC, 0x03,
> -		0xDD, 0x03,
> -		0xDF, 0x03,
> -		0xE1, 0x03,
> -		0xD1, 0x00,
> -		0xCE, 0x00,
> -		0xCC, 0x00,
> -		0xE0, 0x00,
> -		0xE2, 0x01
> -	};
> -	u8 param[4];
> -
> -	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
> -		return -1;
>
> -	/* Send a 0x01 command, which should return 4 bytes. */
> -	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
> -		return -1;
> -
> -	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
> -		return -1;
> -
> -	return 0;
> +	return PSMOUSE_FULL_PACKET;
>   }
>
> -/*
> - * Send the set of PS/2 commands required to make it identify as an
> - * intellimouse with 4-byte instead of 3-byte packets.
> - */
> -static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
> +static int byd_reset_touchpad(struct psmouse *psmouse)
>   {
>   	struct ps2dev *ps2dev = &psmouse->ps2dev;
>   	u8 param[4];
> -	int i;
> +	size_t i;
> +
>   	const struct {
>   		u16 command;
>   		u8 arg;
>   	} seq[] = {
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_RESET_BAT, 0 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_SETSCALE11, 0 },
> -		{ PSMOUSE_CMD_GETINFO, 0 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> +		/*
> +		 * Intellimouse initialization sequence, to get 4-byte instead
> +		 * of 3-byte packets.
> +		 */
>   		{ PSMOUSE_CMD_SETRATE, 0xC8 },
>   		{ PSMOUSE_CMD_SETRATE, 0x64 },
>   		{ PSMOUSE_CMD_SETRATE, 0x50 },
>   		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0xC8 },
> -		{ PSMOUSE_CMD_SETRATE, 0x50 },
> -		{ PSMOUSE_CMD_GETID, 0 },
> -		{ PSMOUSE_CMD_SETRATE, 0x64 },
> -		{ PSMOUSE_CMD_SETRES, 0x03 },
> -		{ PSMOUSE_CMD_ENABLE, 0 }
> +		{ PSMOUSE_CMD_ENABLE, 0 },
> +		/*
> +		 * BYD-specific initialization, which enables absolute mode and
> +		 * (if desired), the touchpad's built-in gesture detection.
> +		 */
> +		{ 0x10E2, 0x00 },
> +		{ 0x10E0, 0x02 },
> +		/* The touchpad should reply with 4 seemingly-random bytes */
> +		{ 0x14E0, 0x01 },
> +		/* Pairs of parameters and values. */
> +		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
> +		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
> +		{ BYD_CMD_SET_TAP, 0x02 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
> +		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
> +		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
> +		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
> +		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
> +		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
> +		/* Finalize initialization. */
> +		{ 0x10E0, 0x00 },
> +		{ 0x10E2, 0x01 },
>   	};
>
> -	memset(param, 0, sizeof(param));
>   	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
> +		memset(param, 0, sizeof(param));
>   		param[0] = seq[i].arg;
>   		if (ps2_command(ps2dev, param, seq[i].command))
> -			return -1;
> -	}
> -
> -	return 0;
> -}
> -
> -static int byd_reset_touchpad(struct psmouse *psmouse)
> -{
> -	if (byd_send_intellimouse_sequence(psmouse))
> -		return -EIO;
> -
> -	if (byd_enable(psmouse))
> -		return -EIO;
> +			return -EIO;
>
> +	}
> +	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
>   	return 0;
>   }
>
> @@ -314,9 +425,50 @@ static int byd_reconnect(struct psmouse *psmouse)
>   	return 0;
>   }
>
> +static void byd_disconnect(struct psmouse *psmouse)
> +{
> +	struct byd_data *priv = psmouse->private;
> +
> +	if (priv) {
> +		del_timer(&priv->timer);
> +		kfree(psmouse->private);
> +		psmouse->private = NULL;
> +	}
> +}
> +
> +int byd_detect(struct psmouse *psmouse, bool set_properties)
> +{
> +	struct ps2dev *ps2dev = &psmouse->ps2dev;
> +	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
> +
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +		return -1;
> +	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> +		return -1;
> +
> +	if (param[1] != 0x03 || param[2] != 0x64)
> +		return -ENODEV;
> +
> +	psmouse_dbg(psmouse, "BYD touchpad detected\n");
> +
> +	if (set_properties) {
> +		psmouse->vendor = "BYD";
> +		psmouse->name = "TouchPad";
> +	}
> +
> +	return 0;
> +}
> +
>   int byd_init(struct psmouse *psmouse)
>   {
>   	struct input_dev *dev = psmouse->dev;
> +	struct byd_data *priv;
>
>   	if (psmouse_reset(psmouse))
>   		return -EIO;
> @@ -324,14 +476,39 @@ int byd_init(struct psmouse *psmouse)
>   	if (byd_reset_touchpad(psmouse))
>   		return -EIO;
>
> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	memset(priv, 0, sizeof(*priv));
> +	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
> +
> +	psmouse->private = priv;
> +	psmouse->disconnect = byd_disconnect;
>   	psmouse->reconnect = byd_reconnect;
>   	psmouse->protocol_handler = byd_process_byte;
>   	psmouse->pktsize = 4;
>   	psmouse->resync_time = 0;
>
> -	__set_bit(BTN_MIDDLE, dev->keybit);
> -	__set_bit(REL_WHEEL, dev->relbit);
> -	__set_bit(REL_HWHEEL, dev->relbit);
> +	__set_bit(INPUT_PROP_POINTER, dev->propbit);
> +	/* Touchpad */
> +	__set_bit(BTN_TOUCH, dev->keybit);
> +	__set_bit(BTN_TOOL_FINGER, dev->keybit);
> +	/* Buttons */
> +	__set_bit(BTN_LEFT, dev->keybit);
> +	__set_bit(BTN_RIGHT, dev->keybit);
> +	__clear_bit(BTN_MIDDLE, dev->keybit);
> +
> +	/* Absolute position */
> +	__set_bit(EV_ABS, dev->evbit);
> +	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
> +	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
> +	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
> +	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
> +	/* No relative support */
> +	__clear_bit(EV_REL, dev->evbit);
> +	__clear_bit(REL_X, dev->relbit);
> +	__clear_bit(REL_Y, dev->relbit);
>
>   	return 0;
>   }
> diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
> index 39d1bec..5784e20 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
>   #ifdef CONFIG_MOUSE_PS2_BYD
>   	{
>   		.type		= PSMOUSE_BYD,
> -		.name		= "BydPS/2",
> +		.name		= "BYDPS/2",
>   		.alias		= "byd",
>   		.detect		= byd_detect,
>   		.init		= byd_init,
>

(unknown),

[Richard Pospesel]

Fixed the line length issues per offline discussion with Chris.
---
Input: BYD: added absolute touch event support to BYD touchpad driver

Implemented absolute position and touch reporting. Now BYD touchpads will use
the synaptics/libinput xorg touchpad drivers. Added documentation for all
known gesture packets and initialization commands.

Signed-off-by: Richard Pospesel <pospeselr@gmail.com>

[PATCH] psmouse: added absolute touch event support to BYD touchpad driver

[Richard Pospesel]

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 9425e0f..5b004b2c 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -2,20 +2,32 @@
  * BYD TouchPad PS/2 mouse driver
  *
  * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ * Copyright (C) 2015 Richard Pospesel <pospeselr@gmail.com>
+ * Copyright (C) 2015 Tai Chi Minh Ralph Eastwood
+ * Copyright (C) 2015 Martin Wimpress
+ * Copyright (C) 2015 Jay Kuri
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
+ *
+ * Protocol of BYD Touch Pad reverse-engineered from windows driver:
+ * filename:  "byd touchpad driver - win7, 8, 8.1 - 2.4.1.102.zip"
+ * md5:       0d5e4660b98fca9587a0df212fca3048
+ * sha1:      97a0eca8edc482bf9d08ab9509084a514dad4c4b
+ * datasheet: http://bydit.com/userfiles/file/BTP10463-XXX.pdf
  */
 
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/libps2.h>
 #include <linux/serio.h>
+#include <linux/slab.h>
 
 #include "psmouse.h"
 #include "byd.h"
 
+/* PS2 Bits */
 #define PS2_Y_OVERFLOW	BIT_MASK(7)
 #define PS2_X_OVERFLOW	BIT_MASK(6)
 #define PS2_Y_SIGN	BIT_MASK(5)
@@ -26,69 +38,247 @@
 #define PS2_LEFT	BIT_MASK(0)
 
 /*
- * The touchpad reports gestures in the last byte of each packet. It can take
- * any of the following values:
+ * BYD pad constants
  */
 
-/* One-finger scrolling in one of the edge scroll zones. */
-#define BYD_SCROLLUP		0xCA
-#define BYD_SCROLLDOWN		0x36
-#define BYD_SCROLLLEFT		0xCB
-#define BYD_SCROLLRIGHT		0x35
-/* Two-finger scrolling. */
-#define BYD_2DOWN		0x2B
-#define BYD_2UP			0xD5
-#define BYD_2LEFT		0xD6
-#define BYD_2RIGHT		0x2A
-/* Pinching in or out. */
-#define BYD_ZOOMOUT		0xD8
-#define BYD_ZOOMIN		0x28
-/* Three-finger swipe. */
-#define BYD_3UP			0xD3
-#define BYD_3DOWN		0x2D
-#define BYD_3LEFT		0xD4
-#define BYD_3RIGHT		0x2C
-/* Four-finger swipe. */
-#define BYD_4UP			0xCD
-#define BYD_4DOWN		0x33
+/*
+ * True device resolution is unknown, however experiments show the
+ * resolution is about 111 units/mm.
+ * Absolute coordinate packets are in the range 0-255 for both X and Y
+ * we pick ABS_X/ABS_Y dimensions which are multiples of 256 and in
+ * the right ballpark given the touchpad's physical dimensions and estimate
+ * resolution per spec sheet, device active area dimensions are
+ * 101.6 x 60.1 mm.
+ */
+#define BYD_PAD_WIDTH		11264
+#define BYD_PAD_HEIGHT		6656
+#define BYD_PAD_RESOLUTION	111
 
-int byd_detect(struct psmouse *psmouse, bool set_properties)
-{
-	struct ps2dev *ps2dev = &psmouse->ps2dev;
-	unsigned char param[4];
+/*
+ * Given the above dimensions, relative packets velocity is in multiples of
+ * 1 unit / 11 milliseconds.  We use this dt to estimate distance traveled
+ */
+#define BYD_DT				11
+/* Time in milliseconds used to timeout various touch events */
+#define BYD_TOUCH_TIMEOUT_MS		64
+#define BYD_TOUCH_TIMEOUT_JIFFIES	msecs_to_jiffies(BYD_TOUCH_TIMEOUT_MS)
 
-	param[0] = 0x03;
-	param[1] = 0x00;
-	param[2] = 0x00;
-	param[3] = 0x00;
+/* BYD commands reverse engineered from windows driver */
 
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
-		return -1;
-	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
-		return -1;
-
-	if (param[1] != 0x03 || param[2] != 0x64)
-		return -ENODEV;
+/*
+ * Swipe gesture from off-pad to on-pad
+ *  0 : disable
+ *  1 : enable
+ */
+#define BYD_CMD_SET_OFFSCREEN_SWIPE		0x10cc
+/*
+ * Tap and drag delay time
+ *  0 : disable
+ *  1 - 8 : least to most delay
+ */
+#define BYD_CMD_SET_TAP_DRAG_DELAY_TIME		0x10cf
+/*
+ * Physical buttons function mapping
+ *  0 : enable
+ *  4 : normal
+ *  5 : left button custom command
+ *  6 : right button custom command
+ *  8 : disable
+ */
+#define BYD_CMD_SET_PHYSICAL_BUTTONS		0x10d0
+/*
+ * Absolute mode (1 byte X/Y resolution)
+ *  0 : disable
+ *  2 : enable
+ */
+#define BYD_CMD_SET_ABSOLUTE_MODE		0x10d1
+/*
+ * Two finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL		0x10d2
+/*
+ * Handedness
+ *  1 : right handed
+ *  2 : left handed
+ */
+#define BYD_CMD_SET_HANDEDNESS			0x10d3
+/*
+ * Tap to click
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_TAP				0x10d4
+/*
+ * Tap and drag
+ *  1 : tap and hold to drag
+ *  2 : tap and hold to drag + lock
+ *  3 : disable
+ */
+#define BYD_CMD_SET_TAP_DRAG			0x10d5
+/*
+ * Touch sensitivity
+ *  1 - 7 : least to most sensitive
+ */
+#define BYD_CMD_SET_TOUCH_SENSITIVITY		0x10d6
+/*
+ * One finger scrolling
+ *  1 : vertical
+ *  2 : horizontal
+ *  3 : vertical + horizontal
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL		0x10d7
+/*
+ * One finger scrolling function
+ *  1 : free scrolling
+ *  2 : edge motion
+ *  3 : free scrolling + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC	0x10d8
+/*
+ * Sliding speed
+ *  1 - 5 : slowest to fastest
+ */
+#define BYD_CMD_SET_SLIDING_SPEED		0x10da
+/*
+ * Edge motion
+ *  1 : disable
+ *  2 : enable when dragging
+ *  3 : enable when dragging and pointing
+ */
+#define BYD_CMD_SET_EDGE_MOTION			0x10db
+/*
+ * Left edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_LEFT_EDGE_REGION		0x10dc
+/*
+ * Top edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_TOP_EDGE_REGION		0x10dd
+/*
+ * Disregard palm press as clicks
+ *  1 - 6 : smallest to largest
+ */
+#define BYD_CMD_SET_PALM_CHECK			0x10de
+/*
+ * Right edge region size
+ *  0 - 7 : smallest to largest width
+ */
+#define BYD_CMD_SET_RIGHT_EDGE_REGION		0x10df
+/*
+ * Bottom edge region size
+ *  0 - 9 : smallest to largest height
+ */
+#define BYD_CMD_SET_BOTTOM_EDGE_REGION		0x10e1
+/*
+ * Multitouch gestures
+ *  1 : enable
+ *  2 : disable
+ */
+#define BYD_CMD_SET_MULTITOUCH			0x10e3
+/*
+ * Edge motion speed
+ *  0 : control with finger pressure
+ *  1 - 9 : slowest to fastest
+ */
+#define BYD_CMD_SET_EDGE_MOTION_SPEED		0x10e4
+/*
+ * Two finger scolling function
+ *  0 : free scrolling
+ *  1 : free scrolling (with momentum)
+ *  2 : edge motion
+ *  3 : free scrolling (with momentum) + edge motion
+ *  4 : disable
+ */
+#define BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC	0x10e5
 
-	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+/*
+ * The touchpad generates a mixture of absolute and relative packets, indicated
+ * by the the last byte of each packet being set to one of the following:
+ */
+#define BYD_PACKET_ABSOLUTE			0xf8
+#define BYD_PACKET_RELATIVE			0x00
+/* Multitouch gesture packets */
+#define BYD_PACKET_PINCH_IN			0xd8
+#define BYD_PACKET_PINCH_OUT			0x28
+#define BYD_PACKET_ROTATE_CLOCKWISE		0x29
+#define BYD_PACKET_ROTATE_ANTICLOCKWISE		0xd7
+#define BYD_PACKET_TWO_FINGER_SCROLL_RIGHT	0x2a
+#define BYD_PACKET_TWO_FINGER_SCROLL_DOWN	0x2b
+#define BYD_PACKET_TWO_FINGER_SCROLL_UP		0xd5
+#define BYD_PACKET_TWO_FINGER_SCROLL_LEFT	0xd6
+#define BYD_PACKET_THREE_FINGER_SWIPE_RIGHT	0x2c
+#define BYD_PACKET_THREE_FINGER_SWIPE_DOWN	0x2d
+#define BYD_PACKET_THREE_FINGER_SWIPE_UP	0xd3
+#define BYD_PACKET_THREE_FINGER_SWIPE_LEFT	0xd4
+#define BYD_PACKET_FOUR_FINGER_DOWN		0x33
+#define BYD_PACKET_FOUR_FINGER_UP		0xcd
+#define BYD_PACKET_REGION_SCROLL_RIGHT		0x35
+#define BYD_PACKET_REGION_SCROLL_DOWN		0x36
+#define BYD_PACKET_REGION_SCROLL_UP		0xca
+#define BYD_PACKET_REGION_SCROLL_LEFT		0xcb
+#define BYD_PACKET_RIGHT_CORNER_CLICK		0xd2
+#define BYD_PACKET_LEFT_CORNER_CLICK		0x2e
+#define BYD_PACKET_LEFT_AND_RIGHT_CORNER_CLICK	0x2f
+#define BYD_PACKET_ONTO_PAD_SWIPE_RIGHT		0x37
+#define BYD_PACKET_ONTO_PAD_SWIPE_DOWN		0x30
+#define BYD_PACKET_ONTO_PAD_SWIPE_UP		0xd0
+#define BYD_PACKET_ONTO_PAD_SWIPE_LEFT		0xc9
+
+struct byd_data {
+	struct timer_list timer;
+	s32 abs_x;
+	s32 abs_y;
+	u32 last_touch_time;
+	bool btn_left  : 1;
+	bool btn_right : 1;
+	bool touch     : 1;
+};
+
+static void byd_report_input(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+	struct input_dev *dev = psmouse->dev;
 
-	if (set_properties) {
-		psmouse->vendor = "BYD";
-		psmouse->name = "TouchPad";
-	}
+	input_report_abs(dev, ABS_X, priv->abs_x);
+	input_report_abs(dev, ABS_Y, priv->abs_y);
+	input_report_key(dev, BTN_LEFT, priv->btn_left);
+	input_report_key(dev, BTN_RIGHT, priv->btn_right);
+	input_report_key(dev, BTN_TOUCH, priv->touch);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->touch);
+	input_sync(dev);
+}
 
-	return 0;
+static void byd_clear_touch(unsigned long data)
+{
+	struct psmouse *psmouse = (struct psmouse *)data;
+	struct byd_data *priv = psmouse->private;
+
+	serio_pause_rx(psmouse->ps2dev.serio);
+	priv->touch = false;
+	/*
+	 * Move cursor back to center of pad when we lose touch - this
+	 * specifically improves user experience when moving cursor with one
+	 * finger, and pressing a button with another.
+	 */
+	priv->abs_x = BYD_PAD_WIDTH / 2;
+	priv->abs_y = BYD_PAD_HEIGHT / 2
+;	byd_report_input(psmouse);
+
+	serio_continue_rx(psmouse->ps2dev.serio);
 }
 
 static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 {
-	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv = psmouse->private;
+	u32 now = jiffies_to_msecs(jiffies);
 	u8 *pkt = psmouse->packet;
 
 	if (psmouse->pktcnt > 0 && !(pkt[0] & PS2_ALWAYS_1)) {
@@ -102,53 +292,33 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 
 	/* Otherwise, a full packet has been received */
 	switch (pkt[3]) {
-	case 0: {
+	case BYD_PACKET_ABSOLUTE:
+		/* Only use absolute packets for the start of movement. */
+		if (!priv->touch) {
+			priv->abs_x = pkt[1] * (BYD_PAD_WIDTH / 256);
+			priv->abs_y = (255 - pkt[2]) *
+				      (BYD_PAD_HEIGHT / 256);
+
+			/* needed to detect tap */
+			if (now - priv->last_touch_time > BYD_TOUCH_TIMEOUT_MS)
+				priv->touch = true;
+		}
+		break;
+	case BYD_PACKET_RELATIVE: {
 		/* Standard packet */
 		/* Sign-extend if a sign bit is set. */
-		unsigned int signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
-		unsigned int signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
-		int dx = signx | (int) pkt[1];
-		int dy = signy | (int) pkt[2];
+		u32 signx = pkt[0] & PS2_X_SIGN ? ~0xFF : 0;
+		u32 signy = pkt[0] & PS2_Y_SIGN ? ~0xFF : 0;
+		s32 dx = signx | (int) pkt[1];
+		s32 dy = signy | (int) pkt[2];
 
-		input_report_rel(psmouse->dev, REL_X, dx);
-		input_report_rel(psmouse->dev, REL_Y, -dy);
+		/* Update position based on velocity */
+		priv->abs_x += dx * BYD_DT;
+		priv->abs_y -= dy * BYD_DT;
 
-		input_report_key(psmouse->dev, BTN_LEFT, pkt[0] & PS2_LEFT);
-		input_report_key(psmouse->dev, BTN_RIGHT, pkt[0] & PS2_RIGHT);
-		input_report_key(psmouse->dev, BTN_MIDDLE, pkt[0] & PS2_MIDDLE);
+		priv->touch = true;
 		break;
 	}
-
-	case BYD_SCROLLDOWN:
-	case BYD_2DOWN:
-		input_report_rel(dev, REL_WHEEL, -1);
-		break;
-
-	case BYD_SCROLLUP:
-	case BYD_2UP:
-		input_report_rel(dev, REL_WHEEL, 1);
-		break;
-
-	case BYD_SCROLLLEFT:
-	case BYD_2LEFT:
-		input_report_rel(dev, REL_HWHEEL, -1);
-		break;
-
-	case BYD_SCROLLRIGHT:
-	case BYD_2RIGHT:
-		input_report_rel(dev, REL_HWHEEL, 1);
-		break;
-
-	case BYD_ZOOMOUT:
-	case BYD_ZOOMIN:
-	case BYD_3UP:
-	case BYD_3DOWN:
-	case BYD_3LEFT:
-	case BYD_3RIGHT:
-	case BYD_4UP:
-	case BYD_4DOWN:
-		break;
-
 	default:
 		psmouse_warn(psmouse,
 			     "Unrecognized Z: pkt = %02x %02x %02x %02x\n",
@@ -157,134 +327,76 @@ static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
 		return PSMOUSE_BAD_DATA;
 	}
 
-	input_sync(dev);
+	priv->btn_left = pkt[0] & PS2_LEFT;
+	priv->btn_right = pkt[0] & PS2_RIGHT;
 
-	return PSMOUSE_FULL_PACKET;
-}
-
-/* Send a sequence of bytes, where each is ACKed before the next is sent. */
-static int byd_send_sequence(struct psmouse *psmouse, const u8 *seq, size_t len)
-{
-	unsigned int i;
+	byd_report_input(psmouse);
 
-	for (i = 0; i < len; ++i) {
-		if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
-			return -1;
+	/* Reset time since last touch. */
+	if (priv->touch) {
+		priv->last_touch_time = now;
+		mod_timer(&priv->timer, jiffies + BYD_TOUCH_TIMEOUT_JIFFIES);
 	}
-	return 0;
-}
-
-/* Keep scrolling after fingers are removed. */
-#define SCROLL_INERTIAL		0x01
-#define SCROLL_NO_INERTIAL	0x02
-
-/* Clicking can be done by tapping or pressing. */
-#define CLICK_BOTH		0x01
-/* Clicking can only be done by pressing. */
-#define CLICK_PRESS_ONLY	0x02
-
-static int byd_enable(struct psmouse *psmouse)
-{
-	const u8 seq1[] = { 0xE2, 0x00, 0xE0, 0x02, 0xE0 };
-	const u8 seq2[] = {
-		0xD3, 0x01,
-		0xD0, 0x00,
-		0xD0, 0x04,
-		/* Whether clicking is done by tapping or pressing. */
-		0xD4, CLICK_PRESS_ONLY,
-		0xD5, 0x01,
-		0xD7, 0x03,
-		/* Vertical and horizontal one-finger scroll zone inertia. */
-		0xD8, SCROLL_INERTIAL,
-		0xDA, 0x05,
-		0xDB, 0x02,
-		0xE4, 0x05,
-		0xD6, 0x01,
-		0xDE, 0x04,
-		0xE3, 0x01,
-		0xCF, 0x00,
-		0xD2, 0x03,
-		/* Vertical and horizontal two-finger scrolling inertia. */
-		0xE5, SCROLL_INERTIAL,
-		0xD9, 0x02,
-		0xD9, 0x07,
-		0xDC, 0x03,
-		0xDD, 0x03,
-		0xDF, 0x03,
-		0xE1, 0x03,
-		0xD1, 0x00,
-		0xCE, 0x00,
-		0xCC, 0x00,
-		0xE0, 0x00,
-		0xE2, 0x01
-	};
-	u8 param[4];
-
-	if (byd_send_sequence(psmouse, seq1, ARRAY_SIZE(seq1)))
-		return -1;
 
-	/* Send a 0x01 command, which should return 4 bytes. */
-	if (ps2_command(&psmouse->ps2dev, param, 0x0401))
-		return -1;
-
-	if (byd_send_sequence(psmouse, seq2, ARRAY_SIZE(seq2)))
-		return -1;
-
-	return 0;
+	return PSMOUSE_FULL_PACKET;
 }
 
-/*
- * Send the set of PS/2 commands required to make it identify as an
- * intellimouse with 4-byte instead of 3-byte packets.
- */
-static int byd_send_intellimouse_sequence(struct psmouse *psmouse)
+static int byd_reset_touchpad(struct psmouse *psmouse)
 {
 	struct ps2dev *ps2dev = &psmouse->ps2dev;
 	u8 param[4];
-	int i;
+	size_t i;
+
 	const struct {
 		u16 command;
 		u8 arg;
 	} seq[] = {
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_RESET_BAT, 0 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_SETSCALE11, 0 },
-		{ PSMOUSE_CMD_GETINFO, 0 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
+		/*
+		 * Intellimouse initialization sequence, to get 4-byte instead
+		 * of 3-byte packets.
+		 */
 		{ PSMOUSE_CMD_SETRATE, 0xC8 },
 		{ PSMOUSE_CMD_SETRATE, 0x64 },
 		{ PSMOUSE_CMD_SETRATE, 0x50 },
 		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0xC8 },
-		{ PSMOUSE_CMD_SETRATE, 0x50 },
-		{ PSMOUSE_CMD_GETID, 0 },
-		{ PSMOUSE_CMD_SETRATE, 0x64 },
-		{ PSMOUSE_CMD_SETRES, 0x03 },
-		{ PSMOUSE_CMD_ENABLE, 0 }
+		{ PSMOUSE_CMD_ENABLE, 0 },
+		/*
+		 * BYD-specific initialization, which enables absolute mode and
+		 * (if desired), the touchpad's built-in gesture detection.
+		 */
+		{ 0x10E2, 0x00 },
+		{ 0x10E0, 0x02 },
+		/* The touchpad should reply with 4 seemingly-random bytes */
+		{ 0x14E0, 0x01 },
+		/* Pairs of parameters and values. */
+		{ BYD_CMD_SET_HANDEDNESS, 0x01 },
+		{ BYD_CMD_SET_PHYSICAL_BUTTONS, 0x04 },
+		{ BYD_CMD_SET_TAP, 0x02 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_ONE_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_EDGE_MOTION, 0x01 },
+		{ BYD_CMD_SET_PALM_CHECK, 0x00 },
+		{ BYD_CMD_SET_MULTITOUCH, 0x02 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL, 0x04 },
+		{ BYD_CMD_SET_TWO_FINGER_SCROLL_FUNC, 0x04 },
+		{ BYD_CMD_SET_LEFT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_TOP_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_RIGHT_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_BOTTOM_EDGE_REGION, 0x00 },
+		{ BYD_CMD_SET_ABSOLUTE_MODE, 0x02 },
+		/* Finalize initialization. */
+		{ 0x10E0, 0x00 },
+		{ 0x10E2, 0x01 },
 	};
 
-	memset(param, 0, sizeof(param));
 	for (i = 0; i < ARRAY_SIZE(seq); ++i) {
+		memset(param, 0, sizeof(param));
 		param[0] = seq[i].arg;
 		if (ps2_command(ps2dev, param, seq[i].command))
-			return -1;
-	}
-
-	return 0;
-}
-
-static int byd_reset_touchpad(struct psmouse *psmouse)
-{
-	if (byd_send_intellimouse_sequence(psmouse))
-		return -EIO;
-
-	if (byd_enable(psmouse))
-		return -EIO;
+			return -EIO;
 
+	}
+	psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
 	return 0;
 }
 
@@ -314,9 +426,50 @@ static int byd_reconnect(struct psmouse *psmouse)
 	return 0;
 }
 
+static void byd_disconnect(struct psmouse *psmouse)
+{
+	struct byd_data *priv = psmouse->private;
+
+	if (priv) {
+		del_timer(&priv->timer);
+		kfree(psmouse->private);
+		psmouse->private = NULL;
+	}
+}
+
+int byd_detect(struct psmouse *psmouse, bool set_properties)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	u8 param[4] = {0x03, 0x00, 0x00, 0x00};
+
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
+		return -1;
+	if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
+		return -1;
+
+	if (param[1] != 0x03 || param[2] != 0x64)
+		return -ENODEV;
+
+	psmouse_dbg(psmouse, "BYD touchpad detected\n");
+
+	if (set_properties) {
+		psmouse->vendor = "BYD";
+		psmouse->name = "TouchPad";
+	}
+
+	return 0;
+}
+
 int byd_init(struct psmouse *psmouse)
 {
 	struct input_dev *dev = psmouse->dev;
+	struct byd_data *priv;
 
 	if (psmouse_reset(psmouse))
 		return -EIO;
@@ -324,14 +477,39 @@ int byd_init(struct psmouse *psmouse)
 	if (byd_reset_touchpad(psmouse))
 		return -EIO;
 
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	memset(priv, 0, sizeof(*priv));
+	setup_timer(&priv->timer, byd_clear_touch, (unsigned long) psmouse);
+
+	psmouse->private = priv;
+	psmouse->disconnect = byd_disconnect;
 	psmouse->reconnect = byd_reconnect;
 	psmouse->protocol_handler = byd_process_byte;
 	psmouse->pktsize = 4;
 	psmouse->resync_time = 0;
 
-	__set_bit(BTN_MIDDLE, dev->keybit);
-	__set_bit(REL_WHEEL, dev->relbit);
-	__set_bit(REL_HWHEEL, dev->relbit);
+	__set_bit(INPUT_PROP_POINTER, dev->propbit);
+	/* Touchpad */
+	__set_bit(BTN_TOUCH, dev->keybit);
+	__set_bit(BTN_TOOL_FINGER, dev->keybit);
+	/* Buttons */
+	__set_bit(BTN_LEFT, dev->keybit);
+	__set_bit(BTN_RIGHT, dev->keybit);
+	__clear_bit(BTN_MIDDLE, dev->keybit);
+
+	/* Absolute position */
+	__set_bit(EV_ABS, dev->evbit);
+	input_set_abs_params(dev, ABS_X, 0, BYD_PAD_WIDTH, 0, 0);
+	input_set_abs_params(dev, ABS_Y, 0, BYD_PAD_HEIGHT, 0, 0);
+	input_abs_set_res(dev, ABS_X, BYD_PAD_RESOLUTION);
+	input_abs_set_res(dev, ABS_Y, BYD_PAD_RESOLUTION);
+	/* No relative support */
+	__clear_bit(EV_REL, dev->evbit);
+	__clear_bit(REL_X, dev->relbit);
+	__clear_bit(REL_Y, dev->relbit);
 
 	return 0;
 }
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 39d1bec..5784e20 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -846,7 +846,7 @@ static const struct psmouse_protocol psmouse_protocols[] = {
 #ifdef CONFIG_MOUSE_PS2_BYD
 	{
 		.type		= PSMOUSE_BYD,
-		.name		= "BydPS/2",
+		.name		= "BYDPS/2",
 		.alias		= "byd",
 		.detect		= byd_detect,
 		.init		= byd_init,
-- 
2.7.0