Input: elantech - add v3 hardware support

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

Signed-off-by: JJ Ding <jj_ding@emc.com.tw>
Acked-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 306 insertions, 31 deletions

diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
index bce9941ffa94..cee08eecda43 100644
--- a/Documentation/input/elantech.txt
+++ b/Documentation/input/elantech.txt
@@ -16,15 +16,22 @@ Contents
 
  1. Introduction
  2. Extra knobs
- 3. Hardware version 1
-    3.1 Registers
-    3.2 Native relative mode 4 byte packet format
-    3.3 Native absolute mode 4 byte packet format
- 4. Hardware version 2
+ 3. Differentiating hardware versions
+ 4. Hardware version 1
     4.1 Registers
-    4.2 Native absolute mode 6 byte packet format
-        4.2.1 One finger touch
-        4.2.2 Two finger touch
+    4.2 Native relative mode 4 byte packet format
+    4.3 Native absolute mode 4 byte packet format
+ 5. Hardware version 2
+    5.1 Registers
+    5.2 Native absolute mode 6 byte packet format
+        5.2.1 Parity checking and packet re-synchronization
+        5.2.2 One/Three finger touch
+        5.2.3 Two finger touch
+ 6. Hardware version 3
+    6.1 Registers
+    6.2 Native absolute mode 6 byte packet format
+        6.2.1 One/Three finger touch
+        6.2.2 Two finger touch
 
 
 
@@ -375,7 +382,7 @@ For all the other ones, there are just a few constant bits:
 
 In case an error is detected, all the packets are shifted by one (and packet[0] is discarded).
 
-5.2.1 One/Three finger touch
+5.2.2 One/Three finger touch
       ~~~~~~~~~~~~~~~~
 
 byte 0:
@@ -384,7 +391,7 @@ byte 0:
          n1  n0  w3  w2   .   .   R   L
 
          L, R = 1 when Left, Right mouse button pressed
-         n1..n0 = numbers of fingers on touchpad
+         n1..n0 = number of fingers on touchpad
 
 byte 1:
 
@@ -432,7 +439,7 @@ byte 5:
          y11..y0 = absolute y value (vertical)
 
 
-4.2.2 Two finger touch
+5.2.3 Two finger touch
       ~~~~~~~~~~~~~~~~
 
 Note that the two pairs of coordinates are not exactly the coordinates of the
@@ -446,7 +453,7 @@ byte 0:
         n1  n0  ay8 ax8  .   .   R   L
 
          L, R = 1 when Left, Right mouse button pressed
-         n1..n0 = numbers of fingers on touchpad
+         n1..n0 = number of fingers on touchpad
 
 byte 1:
 
@@ -480,3 +487,89 @@ byte 5:
         by7 by8 by5 by4 by3 by2 by1 by0
 
          by8..by0 = upper-right finger absolute y value
+
+/////////////////////////////////////////////////////////////////////////////
+
+6. Hardware version 3
+   ==================
+
+6.1 Registers
+    ~~~~~~~~~
+* reg_10
+
+   bit   7   6   5   4   3   2   1   0
+         0   0   0   0   0   0   0   A
+
+         A: 1 = enable absolute tracking
+
+6.2 Native absolute mode 6 byte packet format
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+1 and 3 finger touch shares the same 6-byte packet format, except that
+3 finger touch only reports the position of the center of all three fingers.
+
+Firmware would send 12 bytes of data for 2 finger touch.
+
+Note on debounce:
+In case the box has unstable power supply or other electricity issues, or
+when number of finger changes, F/W would send "debounce packet" to inform
+driver that the hardware is in debounce status.
+The debouce packet has the following signature:
+    byte 0: 0xc4
+    byte 1: 0xff
+    byte 2: 0xff
+    byte 3: 0x02
+    byte 4: 0xff
+    byte 5: 0xff
+When we encounter this kind of packet, we just ignore it.
+
+6.2.1 One/Three finger touch
+      ~~~~~~~~~~~~~~~~~~~~~~
+
+byte 0:
+
+   bit   7   6   5   4   3   2   1   0
+        n1  n0  w3  w2   0   1   R   L
+
+        L, R = 1 when Left, Right mouse button pressed
+        n1..n0 = number of fingers on touchpad
+
+byte 1:
+
+   bit   7   6   5   4   3   2   1   0
+        p7  p6  p5  p4 x11 x10  x9  x8
+
+byte 2:
+
+   bit   7   6   5   4   3   2   1   0
+        x7  x6  x5  x4  x3  x2  x1  x0
+
+        x11..x0 = absolute x value (horizontal)
+
+byte 3:
+
+   bit   7   6   5   4   3   2   1   0
+         0   0  w1  w0   0   0   1   0
+
+         w3..w0 = width of the finger touch
+
+byte 4:
+
+   bit   7   6   5   4   3   2   1   0
+        p3  p1  p2  p0  y11 y10 y9  y8
+
+        p7..p0 = pressure
+
+byte 5:
+
+   bit   7   6   5   4   3   2   1   0
+        y7  y6  y5  y4  y3  y2  y1  y0
+
+        y11..y0 = absolute y value (vertical)
+
+6.2.2 Two finger touch
+      ~~~~~~~~~~~~~~~~
+
+The packet format is exactly the same for two finger touch, except the hardware
+sends two 6 byte packets. The first packet contains data for the first finger,
+the second packet has data for the second finger. So for two finger touch a
+total of 12 bytes are sent.
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 1ab1c14449d7..9cfc70ae83fd 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -108,6 +108,16 @@ static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
                         rc = -1;
                 }
                 break;
+
+        case 3:
+                if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+                    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                    elantech_ps2_command(psmouse, NULL, reg) ||
+                    elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
+                        rc = -1;
+                }
+                break;
         }
 
         if (rc)
@@ -154,6 +164,18 @@ static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
                         rc = -1;
                 }
                 break;
+
+        case 3:
+                if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                    elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
+                    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                    elantech_ps2_command(psmouse, NULL, reg) ||
+                    elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
+                    elantech_ps2_command(psmouse, NULL, val) ||
+                    elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
+                        rc = -1;
+                }
+                break;
         }
 
         if (rc)
@@ -350,6 +372,84 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
         input_sync(dev);
 }
 
+/*
+ * Interpret complete data packets and report absolute mode input events for
+ * hardware version 3. (12 byte packets for two fingers)
+ */
+static void elantech_report_absolute_v3(struct psmouse *psmouse,
+                                        int packet_type)
+{
+        struct input_dev *dev = psmouse->dev;
+        struct elantech_data *etd = psmouse->private;
+        unsigned char *packet = psmouse->packet;
+        unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
+        unsigned int width = 0, pres = 0;
+
+        /* byte 0: n1  n0   .   .   .   .   R   L */
+        fingers = (packet[0] & 0xc0) >> 6;
+
+        switch (fingers) {
+        case 3:
+        case 1:
+                /*
+                 * byte 1:  .   .   .   .  x11 x10 x9  x8
+                 * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
+                 */
+                x1 = ((packet[1] & 0x0f) << 8) | packet[2];
+                /*
+                 * byte 4:  .   .   .   .  y11 y10 y9  y8
+                 * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
+                 */
+                y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
+                break;
+
+        case 2:
+                if (packet_type == PACKET_V3_HEAD) {
+                        /*
+                         * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
+                         * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
+                         */
+                        etd->prev_x = ((packet[1] & 0x0f) << 8) | packet[2];
+                        /*
+                         * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
+                         * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
+                         */
+                        etd->prev_y = etd->y_max -
+                                (((packet[4] & 0x0f) << 8) | packet[5]);
+                        /*
+                         * wait for next packet
+                         */
+                        return;
+                }
+
+                /* packet_type == PACKET_V3_TAIL */
+                x1 = etd->prev_x;
+                y1 = etd->prev_y;
+                x2 = ((packet[1] & 0x0f) << 8) | packet[2];
+                y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
+                break;
+        }
+
+        pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
+        width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
+
+        input_report_key(dev, BTN_TOUCH, fingers != 0);
+        if (fingers != 0) {
+                input_report_abs(dev, ABS_X, x1);
+                input_report_abs(dev, ABS_Y, y1);
+        }
+        elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
+        input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
+        input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
+        input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
+        input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
+        input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
+        input_report_abs(dev, ABS_PRESSURE, pres);
+        input_report_abs(dev, ABS_TOOL_WIDTH, width);
+
+        input_sync(dev);
+}
+
 static int elantech_packet_check_v1(struct psmouse *psmouse)
 {
         struct elantech_data *etd = psmouse->private;
@@ -403,11 +503,37 @@ static int elantech_packet_check_v2(struct psmouse *psmouse)
 }
 
 /*
+ * We check the constant bits to determine what packet type we get,
+ * so packet checking is mandatory for v3 hardware.
+ */
+static int elantech_packet_check_v3(struct psmouse *psmouse)
+{
+        const u8 debounce_packet[] = { 0xc4, 0xff, 0xff, 0x02, 0xff, 0xff };
+        unsigned char *packet = psmouse->packet;
+
+        /*
+         * check debounce first, it has the same signature in byte 0
+         * and byte 3 as PACKET_V3_HEAD.
+         */
+        if (!memcmp(packet, debounce_packet, sizeof(debounce_packet)))
+                return PACKET_DEBOUNCE;
+
+        if ((packet[0] & 0x0c) == 0x04 && (packet[3] & 0xcf) == 0x02)
+                return PACKET_V3_HEAD;
+
+        if ((packet[0] & 0x0c) == 0x0c && (packet[3] & 0xce) == 0x0c)
+                return PACKET_V3_TAIL;
+
+        return PACKET_UNKNOWN;
+}
+
+/*
  * Process byte stream from mouse and handle complete packets
  */
 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 {
         struct elantech_data *etd = psmouse->private;
+        int packet_type;
 
         if (psmouse->pktcnt < psmouse->pktsize)
                 return PSMOUSE_GOOD_DATA;
@@ -429,6 +555,18 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 
                 elantech_report_absolute_v2(psmouse);
                 break;
+
+        case 3:
+                packet_type = elantech_packet_check_v3(psmouse);
+                /* ignore debounce */
+                if (packet_type == PACKET_DEBOUNCE)
+                        return PSMOUSE_FULL_PACKET;
+
+                if (packet_type == PACKET_UNKNOWN)
+                        return PSMOUSE_BAD_DATA;
+
+                elantech_report_absolute_v3(psmouse, packet_type);
+                break;
         }
 
         return PSMOUSE_FULL_PACKET;
@@ -463,8 +601,15 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
                     elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
                     elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
                         rc = -1;
-                        break;
                 }
+                break;
+
+        case 3:
+                etd->reg_10 = 0x0b;
+                if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
+                        rc = -1;
+
+                break;
         }
 
         if (rc == 0) {
@@ -498,11 +643,12 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
         return rc;
 }
 
-static void elantech_set_range(struct psmouse *psmouse,
-                               unsigned int *x_min, unsigned int *y_min,
-                               unsigned int *x_max, unsigned int *y_max)
+static int elantech_set_range(struct psmouse *psmouse,
+                              unsigned int *x_min, unsigned int *y_min,
+                              unsigned int *x_max, unsigned int *y_max)
 {
         struct elantech_data *etd = psmouse->private;
+        unsigned char param[3];
         int i;
 
         switch (etd->hw_version) {
@@ -530,19 +676,30 @@ static void elantech_set_range(struct psmouse *psmouse,
                         *y_max = (etd->capabilities[2] - i) * 64;
                 }
                 break;
+
+        case 3:
+                if (synaptics_send_cmd(psmouse, ETP_FW_ID_QUERY, param))
+                        return -1;
+
+                *x_max = (0x0f & param[0]) << 8 | param[1];
+                *y_max = (0xf0 & param[0]) << 4 | param[2];
+                break;
         }
+
+        return 0;
 }
 
 /*
  * Set the appropriate event bits for the input subsystem
  */
-static void elantech_set_input_params(struct psmouse *psmouse)
+static int elantech_set_input_params(struct psmouse *psmouse)
 {
         struct input_dev *dev = psmouse->dev;
         struct elantech_data *etd = psmouse->private;
         unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0;
 
-        elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max);
+        if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max))
+                return -1;
 
         __set_bit(EV_KEY, dev->evbit);
         __set_bit(EV_ABS, dev->evbit);
@@ -570,6 +727,9 @@ static void elantech_set_input_params(struct psmouse *psmouse)
 
         case 2:
                 __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
+                __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
+                /* fall through */
+        case 3:
                 input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
                 input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
                 if (etd->reports_pressure) {
@@ -578,7 +738,6 @@ static void elantech_set_input_params(struct psmouse *psmouse)
                         input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
                                              ETP_WMAX_V2, 0, 0);
                 }
-                __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
                 input_mt_init_slots(dev, 2);
                 input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
                 input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
@@ -586,6 +745,8 @@ static void elantech_set_input_params(struct psmouse *psmouse)
         }
 
         etd->y_max = y_max;
+
+        return 0;
 }
 
 struct elantech_attr_data {
@@ -727,7 +888,8 @@ int elantech_detect(struct psmouse *psmouse, bool set_properties)
          * Report this in case there are Elantech models that use a different
          * set of magic numbers
          */
-        if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
+        if (param[0] != 0x3c || param[1] != 0x03 ||
+            (param[2] != 0xc8 && param[2] != 0x00)) {
                 pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
                          param[0], param[1], param[2]);
                 return -1;
@@ -793,16 +955,16 @@ static int elantech_reconnect(struct psmouse *psmouse)
 /*
  * determine hardware version and set some properties according to it.
  */
-static void elantech_set_properties(struct elantech_data *etd)
+static int elantech_set_properties(struct elantech_data *etd)
 {
-        /*
-         * Assume every version greater than 0x020030 is new EeePC style
-         * hardware with 6 byte packets, except 0x020600
-         */
         if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
                 etd->hw_version = 1;
-        else
+        else if (etd->fw_version < 0x150600)
                 etd->hw_version = 2;
+        else if ((etd->fw_version & 0x0f0000) >> 16 == 5)
+                etd->hw_version = 3;
+        else
+                return -1;
 
         /*
          * Turn on packet checking by default.
@@ -817,13 +979,15 @@ static void elantech_set_properties(struct elantech_data *etd)
         etd->jumpy_cursor =
                 (etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
 
-        if (etd->hw_version == 2) {
+        if (etd->hw_version > 1) {
                 /* For now show extra debug information */
                 etd->debug = 1;
 
                 if (etd->fw_version >= 0x020800)
                         etd->reports_pressure = true;
         }
+
+        return 0;
 }
 
 /*
@@ -850,9 +1014,12 @@ int elantech_init(struct psmouse *psmouse)
                 pr_err("failed to query firmware version.\n");
                 goto init_fail;
         }
-
         etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
-        elantech_set_properties(etd);
+
+        if (elantech_set_properties(etd)) {
+                pr_err("unknown hardware version, aborting...\n");
+                goto init_fail;
+        }
         pr_info("assuming hardware version %d "
                 "(with firmware version 0x%02x%02x%02x)\n",
                 etd->hw_version, param[0], param[1], param[2]);
@@ -871,7 +1038,10 @@ int elantech_init(struct psmouse *psmouse)
                 goto init_fail;
         }
 
-        elantech_set_input_params(psmouse);
+        if (elantech_set_input_params(psmouse)) {
+                pr_err("failed to query touchpad range.\n");
+                goto init_fail;
+        }
 
         error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
                                    &elantech_attr_group);
@@ -883,7 +1053,7 @@ int elantech_init(struct psmouse *psmouse)
         psmouse->protocol_handler = elantech_process_byte;
         psmouse->disconnect = elantech_disconnect;
         psmouse->reconnect = elantech_reconnect;
-        psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
+        psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
 
         return 0;
 
diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index d9e614409f92..236c33cdc708 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -16,6 +16,7 @@
 /*
  * Command values for Synaptics style queries
  */
+#define ETP_FW_ID_QUERY                 0x00
 #define ETP_FW_VERSION_QUERY            0x01
 #define ETP_CAPABILITIES_QUERY          0x02
 
@@ -24,6 +25,7 @@
  */
 #define ETP_REGISTER_READ               0x10
 #define ETP_REGISTER_WRITE              0x11
+#define ETP_REGISTER_READWRITE          0x00
 
 /*
  * Hardware version 2 custom PS/2 command value
@@ -79,6 +81,14 @@
 #define ETP_WMIN_V2                     0
 #define ETP_WMAX_V2                     15
 
+/*
+ * v3 hardware has 2 kinds of packet types.
+ */
+#define PACKET_UNKNOWN                  0x01
+#define PACKET_DEBOUNCE                 0x02
+#define PACKET_V3_HEAD                  0x03
+#define PACKET_V3_TAIL                  0x04
+
 struct elantech_data {
         unsigned char reg_10;
         unsigned char reg_11;
@@ -98,6 +108,8 @@ struct elantech_data {
         unsigned int fw_version;
         unsigned int single_finger_reports;
         unsigned int y_max;
+        unsigned int prev_x;
+        unsigned int prev_y;
         unsigned char parity[256];
 };