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Date:	Thu, 18 Aug 2011 10:57:57 +0800
From:	Daniel Kurtz <djkurtz@...omium.org>
To:	JJ Ding <jj_ding@....com.tw>
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Seth Forshee <seth.forshee@...onical.com>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Aaron Huang <aaron_huang@....com.tw>,
	Tom Lin <tom_lin@....com.tw>,
	Eric Piel <E.A.B.Piel@...elft.nl>,
	Chase Douglas <chase.douglas@...onical.com>,
	Henrik Rydberg <rydberg@...omail.se>,
	Alessandro Rubini <rubini@...l.unipv.it>
Subject: Re: [PATCH 6/6] Input: elantech - add v3 hardware support

On Thu, Aug 18, 2011 at 9:57 AM, JJ Ding <jj_ding@....com.tw> wrote:
> 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@....com.tw>
> ---
>  Documentation/input/elantech.txt |  104 ++++++++++++++++--
>  drivers/input/mouse/elantech.c   |  218 ++++++++++++++++++++++++++++++++++---
>  drivers/input/mouse/elantech.h   |   11 ++
>  3 files changed, 303 insertions(+), 30 deletions(-)
>
> diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
> index bce9941..ce578bd 100644
> --- a/Documentation/input/elantech.txt
> +++ b/Documentation/input/elantech.txt
> @@ -16,15 +16,22 @@ Contents
>
>  1. Introduction
>  2. Extra knobs
> - 3. Hardware version 1
> -    3.1 Registers
> -    3.2 Native relative mode 4 byte packet format
> -    3.3 Native absolute mode 4 byte packet format
> - 4. Hardware version 2
> + 3. Differentiating hardware versions
> + 4. Hardware version 1
>     4.1 Registers
> -    4.2 Native absolute mode 6 byte packet format
> -        4.2.1 One finger touch
> -        4.2.2 Two finger touch
> +    4.2 Native relative mode 4 byte packet format
> +    4.3 Native absolute mode 4 byte packet format
> + 5. Hardware version 2
> +    5.1 Registers
> +    5.2 Native absolute mode 6 byte packet format
> +        5.2.1 Parity checking and packet re-synchronization
> +        5.2.2 One/Three finger touch
> +        5.2.3 Two finger touch
> + 6. Hardware version 3
> +    6.1 Registers
> +    6.2 Native absolute mode 6 byte packet format
> +        6.2.1 One/Three finger touch
> +        6.2.2 Two finger touch
>
>
>
> @@ -375,7 +382,7 @@ For all the other ones, there are just a few constant bits:
>
>  In case an error is detected, all the packets are shifted by one (and packet[0] is discarded).
>
> -5.2.1 One/Three finger touch
> +5.2.2 One/Three finger touch
>       ~~~~~~~~~~~~~~~~
>
>  byte 0:
> @@ -384,7 +391,7 @@ byte 0:
>         n1  n0  w3  w2   .   .   R   L
>
>          L, R = 1 when Left, Right mouse button pressed
> -         n1..n0 = numbers of fingers on touchpad
> +         n1..n0 = number of fingers on touchpad
>
>  byte 1:
>
> @@ -432,7 +439,7 @@ byte 5:
>          y11..y0 = absolute y value (vertical)
>
>
> -4.2.2 Two finger touch
> +5.2.3 Two finger touch
>       ~~~~~~~~~~~~~~~~
>
>  Note that the two pairs of coordinates are not exactly the coordinates of the
> @@ -446,7 +453,7 @@ byte 0:
>         n1  n0  ay8 ax8  .   .   R   L
>
>          L, R = 1 when Left, Right mouse button pressed
> -         n1..n0 = numbers of fingers on touchpad
> +         n1..n0 = number of fingers on touchpad
>
>  byte 1:
>
> @@ -480,3 +487,76 @@ byte 5:
>         by7 by8 by5 by4 by3 by2 by1 by0
>
>          by8..by0 = upper-right finger absolute y value
> +
> +/////////////////////////////////////////////////////////////////////////////
> +
> +6. Hardware version 3
> +   ==================
> +
> +6.1 Registers
> +    ~~~~~~~~~
> +* reg_10
> +
> +   bit   7   6   5   4   3   2   1   0
> +         0   0   0   0   0   0   0   A
> +
> +         A: 1 = enable absolute tracking
> +
> +6.2 Native absolute mode 6 byte packet format
> +    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +1 and 3 finger touch shares the same 6-byte packet format, except that
> +3 finger touch only reports the position of the center of all three fingers.
> +
> +Firmware would send 12 bytes of data for 2 finger touch.
> +
> +6.2.1 One/Three finger touch
> +      ~~~~~~~~~~~~~~~~~~~~~~
> +
> +byte 0:
> +
> +   bit   7   6   5   4   3   2   1   0
> +        n1  n0  w3  w2   0   1   R   L
> +
> +        L, R = 1 when Left, Right mouse button pressed
> +        n1..n0 = number of fingers on touchpad
> +
> +byte 1:
> +
> +   bit   7   6   5   4   3   2   1   0
> +        p7  p6  p5  p4 x11 x10  x9  x8
> +
> +byte 2:
> +
> +   bit   7   6   5   4   3   2   1   0
> +        x7  x6  x5  x4  x3  x2  x1  x0
> +
> +        x11..x0 = absolute x value (horizontal)
> +
> +byte 3:
> +
> +   bit   7   6   5   4   3   2   1   0
> +         0   0  w1  w0   0   0   1   0
> +
> +         w3..w0 = width of the finger touch
> +
> +byte 4:
> +
> +   bit   7   6   5   4   3   2   1   0
> +        p3  p1  p2  p0  y11 y10 y9  y8
> +
> +        p7..p0 = pressure
> +
> +byte 5:
> +
> +   bit   7   6   5   4   3   2   1   0
> +        y7  y6  y5  y4  y3  y2  y1  y0
> +
> +        y11..y0 = absolute y value (vertical)
> +
> +6.2.2 Two finger touch
> +      ~~~~~~~~~~~~~~~~
> +
> +The packet format is exactly the same for two finger touch, except the hardware
> +sends two 6 byte packets. The first packet contains data for the first finger,
> +the second packet has data for the second finger. So for two finger touch a
> +total of 12 bytes are sent.
> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> index ddd40eb..e13a719 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -108,6 +108,16 @@ static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
>                        rc = -1;
>                }
>                break;
> +
> +       case 3:
> +               if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
> +                   elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
> +                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
> +                   elantech_ps2_command(psmouse, NULL, reg) ||
> +                   elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
> +                       rc = -1;
> +               }
> +               break;
>        }
>
>        if (rc)
> @@ -154,6 +164,18 @@ static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
>                        rc = -1;
>                }
>                break;
> +
> +       case 3:
> +               if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
> +                   elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READWRITE) ||
> +                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
> +                   elantech_ps2_command(psmouse, NULL, reg) ||
> +                   elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
> +                   elantech_ps2_command(psmouse, NULL, val) ||
> +                   elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
> +                       rc = -1;
> +               }
> +               break;
>        }
>
>        if (rc)
> @@ -352,6 +374,94 @@ static void elantech_report_absolute_v2(struct psmouse *psmouse)
>        input_sync(dev);
>  }
>
> +/*
> + * firmware tells us there's noise.
> + */
> +static inline int debounce(unsigned int x, unsigned int y)
> +{
> +       return (x == 0xfff) && (y == 0xfff);

Perhaps you could document this behavior in the elantech.txt.

> +}
> +
> +/*
> + * Interpret complete data packets and report absolute mode input events for
> + * hardware version 3. (12 byte packets for two fingers)
> + */
> +static void elantech_report_absolute_v3(struct psmouse *psmouse,
> +                                       int packet_type)
> +{
> +       struct input_dev *dev = psmouse->dev;
> +       struct elantech_data *etd = psmouse->private;
> +       unsigned char *packet = psmouse->packet;
> +       unsigned int fingers = 0, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
> +       unsigned int width = 0, pres = 0;
> +
> +       /* byte 0: n1  n0   .   .   .   .   R   L */
> +       fingers = (packet[0] & 0xc0) >> 6;
> +
> +       switch (fingers) {
> +       case 3:
> +       case 1:
> +               /*
> +                * byte 1:  .   .   .   .  x11 x10 x9  x8
> +                * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
> +                */
> +               x1 = ((packet[1] & 0x0f) << 8) | packet[2];
> +               /*
> +                * byte 4:  .   .   .   .  y11 y10 y9  y8
> +                * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
> +                */
> +               y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
> +
> +               if (fingers == 3 && debounce(x1, y1))
> +                       return;
> +
> +               break;
> +
> +       case 2:
> +               if (packet_type == PACKET_V3_HEAD) {
> +                       /*
> +                        * byte 1:   .    .    .    .  ax11 ax10 ax9  ax8
> +                        * byte 2: ax7  ax6  ax5  ax4  ax3  ax2  ax1  ax0
> +                        */
> +                       etd->prev_x = ((packet[1] & 0x0f) << 8) | packet[2];
> +                       /*
> +                        * byte 4:   .    .    .    .  ay11 ay10 ay9  ay8
> +                        * byte 5: ay7  ay6  ay5  ay4  ay3  ay2  ay1  ay0
> +                        */
> +                       etd->prev_y = etd->y_max -
> +                               (((packet[4] & 0x0f) << 8) | packet[5]);
> +                       /*
> +                        * wait for next packet
> +                        */
> +                       return;
> +               }
> +
> +               /* packet_type == PACKET_V3_TAIL */
> +               x1 = etd->prev_x;
> +               y1 = etd->prev_y;
> +               x2 = ((packet[1] & 0x0f) << 8) | packet[2];
> +               y2 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
> +               break;
> +       }
> +
> +       pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
> +       width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
> +
> +       input_report_key(dev, BTN_TOUCH, fingers != 0);
> +       input_report_abs(dev, ABS_X, x1);
> +       input_report_abs(dev, ABS_Y, y1);
> +       elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
> +       input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
> +       input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
> +       input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
> +       input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
> +       input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
> +       input_report_abs(dev, ABS_PRESSURE, pres);
> +       input_report_abs(dev, ABS_TOOL_WIDTH, width);
> +
> +       input_sync(dev);
> +}
> +
>  static int elantech_check_parity_v1(struct psmouse *psmouse)
>  {
>        struct elantech_data *etd = psmouse->private;
> @@ -396,11 +506,31 @@ static int packet_simple_check_v2(struct psmouse *psmouse)
>  }
>
>  /*
> + * We check the constant bits to determine what packet type we get,
> + * so packet checking is mandatory for v3 hardware.
> + */
> +static int determine_packet_v3(struct psmouse *psmouse)
> +{
> +       unsigned char *packet = psmouse->packet;
> +
> +       if ((packet[0] & 0x0c) == 0x04 &&
> +           (packet[3] & 0xcf) == 0x02)
> +               return PACKET_V3_HEAD;
> +
> +       if ((packet[0] & 0x0c) == 0x0c &&
> +           (packet[3] & 0xce) == 0x0c)
> +               return PACKET_V3_TAIL;
> +
> +       return PACKET_UNKNOWN;
> +}
> +
> +/*
>  * Process byte stream from mouse and handle complete packets
>  */
>  static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
>  {
>        struct elantech_data *etd = psmouse->private;
> +       int packet_type;
>
>        if (psmouse->pktcnt < psmouse->pktsize)
>                return PSMOUSE_GOOD_DATA;
> @@ -422,6 +552,14 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
>
>                elantech_report_absolute_v2(psmouse);
>                break;
> +
> +       case 3:
> +               packet_type = determine_packet_v3(psmouse);
> +               if (packet_type == PACKET_UNKNOWN)
> +                       goto bad_packet;
> +
> +               elantech_report_absolute_v3(psmouse, packet_type);
> +               break;
>        }
>
>        return PSMOUSE_FULL_PACKET;
> @@ -459,10 +597,17 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
>                etd->reg_21 = 0x60;     /* 0x00 */
>                if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
>                    elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
> -                   elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
> +                   elantech_write_reg(psmouse, 0x21, etd->reg_21))
>                        rc = -1;
> -                       break;
> -               }
> +
> +               break;
> +
> +       case 3:
> +               etd->reg_10 = 0x0b;
> +               if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
> +                       rc = -1;
> +
> +               break;
>        }
>
>        if (rc == 0) {
> @@ -496,11 +641,12 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
>        return rc;
>  }
>
> -static void set_range(struct psmouse *psmouse, unsigned int *x_min,
> +static int set_range(struct psmouse *psmouse, unsigned int *x_min,
>                     unsigned int *y_min, unsigned int *x_max,
>                     unsigned int *y_max, unsigned int *y_2ft_max)
>  {
>        struct elantech_data *etd = psmouse->private;
> +       unsigned char param[3];
>        int i;
>
>        switch (etd->hw_version) {
> @@ -529,19 +675,30 @@ static void set_range(struct psmouse *psmouse, unsigned int *x_min,
>                *y_max = (etd->capabilities[2] - i) * 64;
>                *y_2ft_max = (*y_max - i) * 64 / 4;
>                break;
> +
> +       case 3:
> +               if (synaptics_send_cmd(psmouse, ETP_FW_ID_QUERY, param))
> +                       return -1;
> +
> +               *x_max = (0x0f & param[0]) << 8 | param[1];
> +               *y_max = (0xf0 & param[0]) << 4 | param[2];
> +               break;
>        }
> +
> +       return 0;
>  }
>
>  /*
>  * Set the appropriate event bits for the input subsystem
>  */
> -static void elantech_set_input_params(struct psmouse *psmouse)
> +static int elantech_set_input_params(struct psmouse *psmouse)
>  {
>        struct input_dev *dev = psmouse->dev;
>        struct elantech_data *etd = psmouse->private;
>        unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, y_2ft_max = 0;
>
> -       set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &y_2ft_max);
> +       if (set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &y_2ft_max))
> +               return -1;
>
>        __set_bit(EV_KEY, dev->evbit);
>        __set_bit(EV_ABS, dev->evbit);
> @@ -582,10 +739,26 @@ static void elantech_set_input_params(struct psmouse *psmouse)
>                input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
>                input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
>                break;
> +
> +       case 3:
> +               input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
> +               input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
> +               /* range of pressure and width is the same as v2 */
> +               input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
> +                                    ETP_PMAX_V2, 0, 0);
> +               input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
> +                                    ETP_WMAX_V2, 0, 0);
> +               __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
> +               input_mt_init_slots(dev, 2);
> +               input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
> +               input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
> +               break;
>        }
>
>        etd->y_max = y_max;
>        etd->y_2ft_max = y_2ft_max;
> +
> +       return 0;
>  }
>
>  struct elantech_attr_data {
> @@ -727,7 +900,8 @@ int elantech_detect(struct psmouse *psmouse, bool set_properties)
>         * Report this in case there are Elantech models that use a different
>         * set of magic numbers
>         */
> -       if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
> +       if (param[0] != 0x3c || param[1] != 0x03 ||
> +           (param[2] != 0xc8 && param[2] != 0x00)) {
>                pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
>                         param[0], param[1], param[2]);
>                return -1;
> @@ -793,16 +967,16 @@ static int elantech_reconnect(struct psmouse *psmouse)
>  /*
>  * determine hardware version and set some properties according to it.
>  */
> -static void elantech_set_properties(struct elantech_data *etd)
> +static int elantech_set_properties(struct elantech_data *etd)
>  {
> -       /*
> -        * Assume every version greater than 0x020030 is new EeePC style
> -        * hardware with 6 byte packets, except 0x020600
> -        */
>        if (etd->fw_version < 0x020030 || etd->fw_version == 0x020600)
>                etd->hw_version = 1;
> -       else
> +       else if (etd->fw_version < 0x150600)
>                etd->hw_version = 2;
> +       else if ((etd->fw_version & 0x0f0000) >> 16 == 5)
> +               etd->hw_version = 3;
> +       else
> +               return -1;
>
>        /*
>         * Turn on packet checking by default.
> @@ -817,13 +991,15 @@ static void elantech_set_properties(struct elantech_data *etd)
>        etd->jumpy_cursor =
>                (etd->fw_version == 0x020022 || etd->fw_version == 0x020600);
>
> -       if (etd->hw_version == 2) {
> +       if (etd->hw_version > 1) {
>                /* For now show extra debug information */
>                etd->debug = 1;
>
>                if (etd->fw_version >= 0x020800)
>                        etd->reports_pressure = true;
>        }
> +
> +       return 0;
>  }
>
>  /*
> @@ -850,9 +1026,12 @@ int elantech_init(struct psmouse *psmouse)
>                pr_err("failed to query firmware version.\n");
>                goto init_fail;
>        }
> -
>        etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
> -       elantech_set_properties(etd);
> +
> +       if (elantech_set_properties(etd)) {
> +               pr_err("unknown hardware version, aborting...\n");
> +               goto init_fail;
> +       }
>        pr_info("assuming hardware version %d "
>                "(with firmware version 0x%02x%02x%02x)\n",
>                etd->hw_version, param[0], param[1], param[2]);
> @@ -871,7 +1050,10 @@ int elantech_init(struct psmouse *psmouse)
>                goto init_fail;
>        }
>
> -       elantech_set_input_params(psmouse);
> +       if (elantech_set_input_params(psmouse)) {
> +               pr_err("failed to query touchpad range.\n");
> +               goto init_fail;
> +       }
>
>        error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
>                                   &elantech_attr_group);
> @@ -883,7 +1065,7 @@ int elantech_init(struct psmouse *psmouse)
>        psmouse->protocol_handler = elantech_process_byte;
>        psmouse->disconnect = elantech_disconnect;
>        psmouse->reconnect = elantech_reconnect;
> -       psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
> +       psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
>
>        return 0;
>
> diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
> index 4b7447e..4f01fc6 100644
> --- a/drivers/input/mouse/elantech.h
> +++ b/drivers/input/mouse/elantech.h
> @@ -16,6 +16,7 @@
>  /*
>  * Command values for Synaptics style queries
>  */
> +#define ETP_FW_ID_QUERY                        0x00

One tab too many?

>  #define ETP_FW_VERSION_QUERY           0x01
>  #define ETP_CAPABILITIES_QUERY         0x02
>
> @@ -24,6 +25,7 @@
>  */
>  #define ETP_REGISTER_READ              0x10
>  #define ETP_REGISTER_WRITE             0x11
> +#define ETP_REGISTER_READWRITE         0x00
>
>  /*
>  * Hardware version 2 custom PS/2 command value
> @@ -93,6 +95,13 @@
>  #define ETP_2FT_YMIN                   (  0 + ETP_2FT_FUZZ)
>  #define ETP_2FT_YMAX                   (192 - ETP_2FT_FUZZ)
>
> +/*
> + * v3 hardware has 2 kinds of packet types.
> + */
> +#define PACKET_UNKNOWN                 0x01
> +#define PACKET_V3_HEAD                 0x02
> +#define PACKET_V3_TAIL                 0x03
> +
>  struct elantech_data {
>        unsigned char reg_10;
>        unsigned char reg_11;
> @@ -113,6 +122,8 @@ struct elantech_data {
>        unsigned int single_finger_reports;
>        unsigned int y_max;
>        unsigned int y_2ft_max;
> +       unsigned int prev_x;
> +       unsigned int prev_y;
>        unsigned char parity[256];
>  };
>
> --
> 1.7.4.1
>
>
--
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