--- /dev/null
+/*
+ * BYD TouchPad PS/2 mouse driver
+ *
+ * Copyright (C) 2015 Chris Diamand <chris@diamand.org>
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/libps2.h>
+#include <linux/serio.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)
+
+/*
+ * The touchpad reports gestures in the last byte of each packet. It can take
+ * any of the following values:
+ */
+
+/* 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];
+
+ 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;
+
+ 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;
+}
+
+static psmouse_ret_t byd_process_byte(struct psmouse *psmouse)
+{
+ struct input_dev *dev = psmouse->dev;
+ u8 *pkt = psmouse->packet;
+
+ 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);
+ 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",
+ psmouse->packet[0], psmouse->packet[1],
+ psmouse->packet[2], psmouse->packet[3]);
+ return PSMOUSE_BAD_DATA;
+ }
+
+ 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)
+{
+ unsigned int i;
+
+ for (i = 0; i < len; ++i) {
+ if (ps2_command(&psmouse->ps2dev, NULL, seq[i]))
+ return -1;
+ }
+ 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;
+}
+
+/*
+ * 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)
+{
+ 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;
+ }
+
+ 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 0;
+}
+
+static int byd_reconnect(struct psmouse *psmouse)
+{
+ int retry = 0, error = 0;
+
+ psmouse_dbg(psmouse, "Reconnect\n");
+ do {
+ psmouse_reset(psmouse);
+ if (retry)
+ ssleep(1);
+ error = byd_detect(psmouse, 0);
+ } while (error && ++retry < 3);
+
+ if (error)
+ return error;
+
+ psmouse_dbg(psmouse, "Reconnected after %d attempts\n", retry);
+
+ error = byd_reset_touchpad(psmouse);
+ if (error) {
+ psmouse_err(psmouse, "Unable to initialize device\n");
+ return error;
+ }
+
+ return 0;
+}
+
+int byd_init(struct psmouse *psmouse)
+{
+ struct input_dev *dev = psmouse->dev;
+
+ if (psmouse_reset(psmouse))
+ return -EIO;
+
+ if (byd_reset_touchpad(psmouse))
+ return -EIO;
+
+ 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);
+
+ return 0;
+}