Input: sentelic - enabling absolute coordinates output for newer hardware

- Hooking multi-finger coordinates output with kernel multitouch library;
- Enabling absolute coordinates output for Cx+ hardware. The older hardware
  performs much better in relative mode; thus relative mode related code
  are preserved.

Part of the code is based on the work done by Oskari Saarenmaa <os@ohmu.fi>,
which was used to support the clickpad found on ASUS UX21/31 Ultrabook.
On the other hand, the FSP found on UX21/31 doesn't have hardware capability
register other than PnP ID, which means that we'll have to figure out an
alternative approach to identify such pad correctly; otherwise, blindly
adding INPUT_PROP_BUTTONPAD property may compatability issues amongst
existing FSPs.

Signed-off-by: Tai-hwa Liang <avatar@sentelic.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 132 insertions, 4 deletions

diff --git a/drivers/input/mouse/sentelic.c b/drivers/input/mouse/sentelic.c
index 62fa69825671..5ea5c689d262 100644
--- a/drivers/input/mouse/sentelic.c
+++ b/drivers/input/mouse/sentelic.c
@@ -2,7 +2,7 @@
  * Finger Sensing Pad PS/2 mouse driver.
  *
  * Copyright (C) 2005-2007 Asia Vital Components Co., Ltd.
- * Copyright (C) 2005-2011 Tai-hwa Liang, Sentelic Corporation.
+ * Copyright (C) 2005-2012 Tai-hwa Liang, Sentelic Corporation.
  *
  *   This program is free software; you can redistribute it and/or
  *   modify it under the terms of the GNU General Public License
@@ -21,6 +21,7 @@
 
 #include <linux/module.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
 #include <linux/ctype.h>
 #include <linux/libps2.h>
 #include <linux/serio.h>
@@ -643,12 +644,24 @@ static void fsp_packet_debug(unsigned char packet[])
 }
 #endif
 
+static void fsp_set_slot(struct input_dev *dev, int slot, bool active,
+                         unsigned int x, unsigned int y)
+{
+        input_mt_slot(dev, slot);
+        input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
+        if (active) {
+                input_report_abs(dev, ABS_MT_POSITION_X, x);
+                input_report_abs(dev, ABS_MT_POSITION_Y, y);
+        }
+}
+
 static psmouse_ret_t fsp_process_byte(struct psmouse *psmouse)
 {
         struct input_dev *dev = psmouse->dev;
         struct fsp_data *ad = psmouse->private;
         unsigned char *packet = psmouse->packet;
         unsigned char button_status = 0, lscroll = 0, rscroll = 0;
+        unsigned short abs_x, abs_y, fgrs = 0;
         int rel_x, rel_y;
 
         if (psmouse->pktcnt < 4)
@@ -660,8 +673,66 @@ static psmouse_ret_t fsp_process_byte(struct psmouse *psmouse)
 
         switch (psmouse->packet[0] >> FSP_PKT_TYPE_SHIFT) {
         case FSP_PKT_TYPE_ABS:
-                psmouse_warn(psmouse,
-                             "Unexpected absolute mode packet, ignored.\n");
+                abs_x = (packet[1] << 2) | ((packet[3] >> 2) & 0x03);
+                abs_y = (packet[2] << 2) | (packet[3] & 0x03);
+
+                if (packet[0] & FSP_PB0_MFMC) {
+                        /*
+                         * MFMC packet: assume that there are two fingers on
+                         * pad
+                         */
+                        fgrs = 2;
+
+                        /* MFMC packet */
+                        if (packet[0] & FSP_PB0_MFMC_FGR2) {
+                                /* 2nd finger */
+                                if (ad->last_mt_fgr == 2) {
+                                        /*
+                                         * workaround for buggy firmware
+                                         * which doesn't clear MFMC bit if
+                                         * the 1st finger is up
+                                         */
+                                        fgrs = 1;
+                                        fsp_set_slot(dev, 0, false, 0, 0);
+                                }
+                                ad->last_mt_fgr = 2;
+
+                                fsp_set_slot(dev, 1, fgrs == 2, abs_x, abs_y);
+                        } else {
+                                /* 1st finger */
+                                if (ad->last_mt_fgr == 1) {
+                                        /*
+                                         * workaround for buggy firmware
+                                         * which doesn't clear MFMC bit if
+                                         * the 2nd finger is up
+                                         */
+                                        fgrs = 1;
+                                        fsp_set_slot(dev, 1, false, 0, 0);
+                                }
+                                ad->last_mt_fgr = 1;
+                                fsp_set_slot(dev, 0, fgrs != 0, abs_x, abs_y);
+                        }
+                } else {
+                        /* SFAC packet */
+
+                        /* no multi-finger information */
+                        ad->last_mt_fgr = 0;
+
+                        if (abs_x != 0 && abs_y != 0)
+                                fgrs = 1;
+
+                        fsp_set_slot(dev, 0, fgrs > 0, abs_x, abs_y);
+                        fsp_set_slot(dev, 1, false, 0, 0);
+                }
+                if (fgrs > 0) {
+                        input_report_abs(dev, ABS_X, abs_x);
+                        input_report_abs(dev, ABS_Y, abs_y);
+                }
+                input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
+                input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
+                input_report_key(dev, BTN_TOUCH, fgrs);
+                input_report_key(dev, BTN_TOOL_FINGER, fgrs == 1);
+                input_report_key(dev, BTN_TOOL_DOUBLETAP, fgrs == 2);
                 break;
 
         case FSP_PKT_TYPE_NORMAL_OPC:
@@ -785,6 +856,17 @@ static int fsp_activate_protocol(struct psmouse *psmouse)
                 /* Enable on-pad vertical and horizontal scrolling */
                 fsp_onpad_vscr(psmouse, true);
                 fsp_onpad_hscr(psmouse, true);
+        } else {
+                /* Enable absolute coordinates output for Cx/Dx hardware */
+                if (fsp_reg_write(psmouse, FSP_REG_SWC1,
+                                  FSP_BIT_SWC1_EN_ABS_1F |
+                                  FSP_BIT_SWC1_EN_ABS_2F |
+                                  FSP_BIT_SWC1_EN_FUP_OUT |
+                                  FSP_BIT_SWC1_EN_ABS_CON)) {
+                        psmouse_err(psmouse,
+                                    "Unable to enable absolute coordinates output.\n");
+                        return -EIO;
+                }
         }
 
         return 0;
@@ -801,6 +883,32 @@ static int fsp_set_input_params(struct psmouse *psmouse)
                 __set_bit(BTN_FORWARD, dev->keybit);
                 __set_bit(REL_WHEEL, dev->relbit);
                 __set_bit(REL_HWHEEL, dev->relbit);
+        } else {
+                /*
+                 * Hardware prior to Cx performs much better in relative mode;
+                 * hence, only enable absolute coordinates output as well as
+                 * multi-touch output for the newer hardware.
+                 *
+                 * Maximum coordinates can be computed as:
+                 *
+                 *      number of scanlines * 64 - 57
+                 *
+                 * where number of X/Y scanline lines are 16/12.
+                 */
+                int abs_x = 967, abs_y = 711;
+
+                __set_bit(EV_ABS, dev->evbit);
+                __clear_bit(EV_REL, dev->evbit);
+                __set_bit(BTN_TOUCH, dev->keybit);
+                __set_bit(BTN_TOOL_FINGER, dev->keybit);
+                __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
+                __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
+
+                input_set_abs_params(dev, ABS_X, 0, abs_x, 0, 0);
+                input_set_abs_params(dev, ABS_Y, 0, abs_y, 0, 0);
+                input_mt_init_slots(dev, 2);
+                input_set_abs_params(dev, ABS_MT_POSITION_X, 0, abs_x, 0, 0);
+                input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, abs_y, 0, 0);
         }
 
         return 0;
diff --git a/drivers/input/mouse/sentelic.h b/drivers/input/mouse/sentelic.h
index 23bd25e539ba..334de19e5ddb 100644
--- a/drivers/input/mouse/sentelic.h
+++ b/drivers/input/mouse/sentelic.h
@@ -2,7 +2,7 @@
  * Finger Sensing Pad PS/2 mouse driver.
  *
  * Copyright (C) 2005-2007 Asia Vital Components Co., Ltd.
- * Copyright (C) 2005-2011 Tai-hwa Liang, Sentelic Corporation.
+ * Copyright (C) 2005-2012 Tai-hwa Liang, Sentelic Corporation.
  *
  *   This program is free software; you can redistribute it and/or
  *   modify it under the terms of the GNU General Public License
@@ -55,6 +55,16 @@
 #define FSP_BIT_FIX_HSCR        BIT(5)
 #define FSP_BIT_DRAG_LOCK       BIT(6)
 
+#define FSP_REG_SWC1            (0x90)
+#define FSP_BIT_SWC1_EN_ABS_1F  BIT(0)
+#define FSP_BIT_SWC1_EN_GID     BIT(1)
+#define FSP_BIT_SWC1_EN_ABS_2F  BIT(2)
+#define FSP_BIT_SWC1_EN_FUP_OUT BIT(3)
+#define FSP_BIT_SWC1_EN_ABS_CON BIT(4)
+#define FSP_BIT_SWC1_GST_GRP0   BIT(5)
+#define FSP_BIT_SWC1_GST_GRP1   BIT(6)
+#define FSP_BIT_SWC1_BX_COMPAT  BIT(7)
+
 /* Finger-sensing Pad packet formating related definitions */
 
 /* absolute packet type */
@@ -64,6 +74,15 @@
 #define FSP_PKT_TYPE_NORMAL_OPC (0x03)
 #define FSP_PKT_TYPE_SHIFT      (6)
 
+/* bit definitions for the first byte of report packet */
+#define FSP_PB0_LBTN            BIT(0)
+#define FSP_PB0_RBTN            BIT(1)
+#define FSP_PB0_MBTN            BIT(2)
+#define FSP_PB0_MFMC_FGR2       FSP_PB0_MBTN
+#define FSP_PB0_MUST_SET        BIT(3)
+#define FSP_PB0_PHY_BTN         BIT(4)
+#define FSP_PB0_MFMC            BIT(5)
+
 /* hardware revisions */
 #define FSP_VER_STL3888_A4      (0xC1)
 #define FSP_VER_STL3888_B0      (0xD0)
@@ -89,6 +108,7 @@ struct fsp_data {
 
         unsigned char   last_reg;       /* Last register we requested read from */
         unsigned char   last_val;
+        unsigned int    last_mt_fgr;    /* Last seen finger(multitouch) */
 };
 
 #ifdef CONFIG_MOUSE_PS2_SENTELIC