Re: [PATCH] psmouse: Add some support for the FocalTech PS/2 protocol extensions.

[Mathias Gottschlag <mgottschlag@gmail.com>]

Am 25.10.2014 um 14:01 schrieb Mathias Gottschlag:
> Most of the protocol for these touchpads has been reverse engineered. This
> commit adds a basic multitouch-capable driver.
>
> A lot of the protocol is still unknown. Especially, we don't know how to
> identify the device yet apart from the PNP ID. The code currently compares
> known good values with all data from the touchpad which could be
usable for
> identification, so by design even minor variations will cause the driver
> to fail to detect the device and fall back to compatibility mode.
>
> The previous workaround for these devices has been left in place in case
> the driver is not compiled into the kernel or in case some other device
> with the same PNP ID is not recognized by the driver yet still has the
same
> problems with the device probing code.
> ---
>
> Hi,
>
> this patch is related to the following bugs:
> https://bugzilla.redhat.com/show_bug.cgi?id=1110011
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1372609
>
> It has been tested on the Asus UX303LN, UX303LA and K750L laptops. The
> latter is affected by bug 1110011 above and used to require additional
> flags before the touchpad would work. This behaviour should have been
> fixed by the previous FocalTech patch, but is still present after this
> patch. I have not yet gotten any feedback yet, but my theory is that the
> original patch failed to fix the kernel on that device. I have to admit
> though that I haven't 100% understood that patch.
Update: I failed to include one of the related patches when testing.
Everything should be fine.

Regards,
Mathias
>
>
> When reviewing, keep in mind that this is my first linux patch. I am
> using the code for quite some time now without issues, but I might have
> overlooked quite some problems.
>
> Regards,
> Mathias
>
>  drivers/input/mouse/Kconfig        |  10 ++
>  drivers/input/mouse/focaltech.c    | 326
> ++++++++++++++++++++++++++++++++++++-
>  drivers/input/mouse/focaltech.h    |  61 +++++++
>  drivers/input/mouse/psmouse-base.c |  15 ++
>  drivers/input/mouse/psmouse.h      |   1 +
>  5 files changed, 406 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
> index 366fc7a..db973e5 100644
> --- a/drivers/input/mouse/Kconfig
> +++ b/drivers/input/mouse/Kconfig
> @@ -146,6 +146,16 @@ config MOUSE_PS2_OLPC
>         If unsure, say N.
>  +config MOUSE_PS2_FOCALTECH
> +    bool "FocalTech PS/2 mouse protocol extension" if EXPERT
> +    default y
> +    depends on MOUSE_PS2
> +    help
> +      Say Y here if you have a FocalTech PS/2 TouchPad connected to
> +      your system.
> +
> +      If unsure, say Y.
> +
>  config MOUSE_SERIAL
>      tristate "Serial mouse"
>      select SERIO
> diff --git a/drivers/input/mouse/focaltech.c
> b/drivers/input/mouse/focaltech.c
> index f4d657e..ada97cc 100644
> --- a/drivers/input/mouse/focaltech.c
> +++ b/drivers/input/mouse/focaltech.c
> @@ -2,6 +2,7 @@
>   * Focaltech TouchPad PS/2 mouse driver
>   *
>   * Copyright (c) 2014 Red Hat Inc.
> + * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License as published by
> @@ -13,15 +14,14 @@
>   * Hans de Goede <hdegoede@redhat.com>
>   */
>  -/*
> - * The Focaltech PS/2 touchpad protocol is unknown. This drivers
deals with
> - * detection only, to avoid further detection attempts confusing the
> touchpad
> - * this way it at least works in PS/2 mouse compatibility mode.
> - */
>   #include <linux/device.h>
>  #include <linux/libps2.h>
> +#include <linux/input/mt.h>
> +#include <linux/serio.h>
> +#include <linux/slab.h>
>  #include "psmouse.h"
> +#include "focaltech.h"
>   static const char * const focaltech_pnp_ids[] = {
>      "FLT0101",
> @@ -30,7 +30,14 @@ static const char * const focaltech_pnp_ids[] = {
>      NULL
>  };
>  -int focaltech_detect(struct psmouse *psmouse, bool set_properties)
> +/*
> + * Even if the kernel is built without support for Focaltech PS/2
> touchpads (or
> + * when the real driver fails to recognize the device), we still have
> to detect
> + * them in order to avoid further detection attempts confusing the
> touchpad.
> + * This way it at least works in PS/2 mouse compatibility mode.
> + */
> +
> +int focaltech_detect_fallback(struct psmouse *psmouse, bool
set_properties)
>  {
>      if (!psmouse_matches_pnp_id(psmouse, focaltech_pnp_ids))
>          return -ENODEV;
> @@ -43,10 +50,315 @@ int focaltech_detect(struct psmouse *psmouse, bool
> set_properties)
>      return 0;
>  }
>  -int focaltech_init(struct psmouse *psmouse)
> +int focaltech_init_fallback(struct psmouse *psmouse)
> +{
> +    ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
> +    psmouse_reset(psmouse);
> +
> +    return 0;
> +}
> +
> +#ifdef CONFIG_MOUSE_PS2_FOCALTECH
> +
> +static int focaltech_read_register(struct ps2dev *ps2dev, int reg,
> +        unsigned char *param)
> +{
> +    if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
> +        return -1;
> +    param[0] = 0;
> +    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;
> +    param[0] = reg;
> +    if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
> +        return -1;
> +    if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
> +        return -1;
> +    return 0;
> +}
> +
> +int focaltech_detect(struct psmouse *psmouse, bool set_properties)
> +{
> +    struct ps2dev *ps2dev = &psmouse->ps2dev;
> +    unsigned char param[3];
> +
> +    if (!psmouse_matches_pnp_id(psmouse, focaltech_pnp_ids))
> +        return -ENODEV;
> +
> +    /*
> +     * We don't know how to identify the device, so we just check the
> +     * content of all registers.
> +     */
> +    if (focaltech_read_register(ps2dev, 0, param))
> +        return -EIO;
> +    if (param[0] != 0x69 || param[1] != 0x80 || param[2] != 0x80)
> +        return -ENODEV;
> +    if (focaltech_read_register(ps2dev, 1, param))
> +        return -EIO;
> +    if (param[0] != 0x36 || param[1] != 0x53 || param[2] != 0x03)
> +        return -ENODEV;
> +    if (focaltech_read_register(ps2dev, 2, param))
> +        return -EIO;
> +    /* 0x13 and 0x0d might be the touchpad size? */
> +    if (param[0] != 0x00 || param[1] != 0x13 || param[2] != 0x0d)
> +        return -ENODEV;
> +    if (focaltech_read_register(ps2dev, 5, param))
> +        return -EIO;
> +    if (param[0] != 0x0b || param[1] != 0x03 || param[2] != 0x00)
> +        return -ENODEV;
> +    if (focaltech_read_register(ps2dev, 6, param))
> +        return -EIO;
> +    if (param[0] != 0x23 || param[1] != 0xbd || param[2] != 0xf8)
> +        return -ENODEV;
> +
> +    if (set_properties) {
> +        psmouse->vendor = "FocalTech";
> +        psmouse->name = "FocalTech Touchpad";
> +    }
> +
> +    return 0;
> +}
> +
> +static void focaltech_report_state(struct psmouse *psmouse)
> +{
> +    int i;
> +    struct focaltech_data *priv = psmouse->private;
> +    struct focaltech_hw_state *state = &priv->state;
> +    struct input_dev *dev = psmouse->dev;
> +    int finger_count = 0;
> +
> +    for (i = 0; i < FOC_MAX_FINGERS; i++) {
> +        struct focaltech_finger_state *finger = &state->fingers[i];
> +        int active = finger->active && finger->valid;
> +        input_mt_slot(dev, i);
> +        input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
> +        if (active) {
> +            finger_count++;
> +            input_report_abs(dev, ABS_MT_POSITION_X, finger->x);
> +            input_report_abs(dev, ABS_MT_POSITION_Y,
> +                    focaltech_invert_y(finger->y));
> +        }
> +    }
> +    input_mt_report_pointer_emulation(dev, false);
> +    input_mt_report_finger_count(dev, finger_count);
> +
> +    input_report_key(psmouse->dev, BTN_LEFT, state->pressed);
> +    input_sync(psmouse->dev);
> +}
> +
> +static void process_touch_packet(struct focaltech_hw_state *state,
> +        unsigned char *packet)
> +{
> +    int i;
> +    unsigned char fingers = packet[1];
> +
> +    state->pressed = (packet[0] >> 4) & 1;
> +    /* the second byte contains a bitmap of all fingers touching the
pad */
> +    for (i = 0; i < FOC_MAX_FINGERS; i++) {
> +        if ((fingers & 0x1) && !state->fingers[i].active) {
> +            /* we do not have a valid position for the finger yet */
> +            state->fingers[i].valid = 0;
> +        }
> +        state->fingers[i].active = fingers & 0x1;
> +        fingers >>= 1;
> +    }
> +}
> +
> +static void process_abs_packet(struct focaltech_hw_state *state,
> +        unsigned char *packet)
> +{
> +    unsigned int finger = (packet[1] >> 4) - 1;
> +
> +    state->pressed = (packet[0] >> 4) & 1;
> +    if (finger >= FOC_MAX_FINGERS)
> +        return;
> +    /*
> +     * packet[5] contains some kind of tool size in the most significant
> +     * nibble. 0xff is a special value (latching) that signals a large
> +     * contact area.
> +     */
> +    if (packet[5] == 0xff)
> +        return;
> +    state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
> +    state->fingers[finger].y = (packet[3] << 8) | packet[4];
> +    state->fingers[finger].valid = 1;
> +}
> +static void process_rel_packet(struct focaltech_hw_state *state,
> +        unsigned char *packet)
> +{
> +    int finger1 = ((packet[0] >> 4) & 0x7) - 1;
> +    int finger2 = ((packet[3] >> 4) & 0x7) - 1;
> +
> +    state->pressed = packet[0] >> 7;
> +    if (finger1 < FOC_MAX_FINGERS) {
> +        state->fingers[finger1].x += (char)packet[1];
> +        state->fingers[finger1].y += (char)packet[2];
> +    }
> +    /*
> +     * If there is an odd number of fingers, the last relative packet
only
> +     * contains one finger. In this case, the second finger index in the
> +     * packet is 0 (we subtract 1 in the lines above to create array
> +     * indices).
> +     */
> +    if (finger2 != -1 && finger2 < FOC_MAX_FINGERS) {
> +        state->fingers[finger2].x += (char)packet[4];
> +        state->fingers[finger2].y += (char)packet[5];
> +    }
> +}
> +
> +static void focaltech_process_packet(struct psmouse *psmouse)
> +{
> +    struct focaltech_data *priv = psmouse->private;
> +    unsigned char *packet = psmouse->packet;
> +
> +    switch (packet[0] & 0xf) {
> +    case FOC_TOUCH:
> +        process_touch_packet(&priv->state, packet);
> +        break;
> +    case FOC_ABS:
> +        process_abs_packet(&priv->state, packet);
> +        break;
> +    case FOC_REL:
> +        process_rel_packet(&priv->state, packet);
> +        break;
> +    default:
> +        psmouse_err(psmouse, "Unknown packet type: %02x", packet[0]);
> +        break;
> +    }
> +
> +    focaltech_report_state(psmouse);
> +}
> +
> +static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
>  {
> +    if (psmouse->pktcnt >= 6) { /* Full packet received */
> +        focaltech_process_packet(psmouse);
> +        return PSMOUSE_FULL_PACKET;
> +    }
> +    /*
> +     * we might want to do some validation of the data here, but we
do not
> +     * know the protocoll well enough
> +     */
> +    return PSMOUSE_GOOD_DATA;
> +}
> +
> +static void focaltech_reset(struct psmouse *psmouse)
> +{
> +    psmouse_info(psmouse, "focaltech_reset");
>      ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
>      psmouse_reset(psmouse);
> +}
> +
> +static int focaltech_switch_protocol(struct psmouse *psmouse)
> +{
> +    struct ps2dev *ps2dev = &psmouse->ps2dev;
> +    unsigned char param[3];
> +
> +    param[0] = 0;
> +    if (ps2_command(ps2dev, param, 0x10f8))
> +        return -EIO;
> +    if (ps2_command(ps2dev, param, 0x10f8))
> +        return -EIO;
> +    if (ps2_command(ps2dev, param, 0x10f8))
> +        return -EIO;
> +    param[0] = 1;
> +    if (ps2_command(ps2dev, param, 0x10f8))
> +        return -EIO;
> +    if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
> +        return -EIO;
> +
> +    if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
> +        return -EIO;
>       return 0;
>  }
> +
> +static void focaltech_disconnect(struct psmouse *psmouse)
> +{
> +    focaltech_reset(psmouse);
> +    kfree(psmouse->private);
> +    psmouse->private = NULL;
> +}
> +
> +static int focaltech_reconnect(struct psmouse *psmouse)
> +{
> +    focaltech_reset(psmouse);
> +    if (focaltech_switch_protocol(psmouse)) {
> +        psmouse_err(psmouse,
> +                "Unable to initialize the device.");
> +        return -1;
> +    }
> +    return 0;
> +}
> +
> +static void set_input_params(struct psmouse *psmouse)
> +{
> +    struct input_dev *dev = psmouse->dev;
> +
> +    __set_bit(EV_KEY, dev->evbit);
> +    __set_bit(EV_ABS, dev->evbit);
> +    input_set_abs_params(dev, ABS_X, 0, FOC_MAX_X, 0, 0);
> +    input_set_abs_params(dev, ABS_Y, 0, FOC_MAX_Y, 0, 0);
> +    input_mt_init_slots(dev, 5, INPUT_MT_POINTER);
> +    input_set_abs_params(dev, ABS_MT_POSITION_X, 0, FOC_MAX_X, 0, 0);
> +    input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, FOC_MAX_Y, 0, 0);
> +    __set_bit(BTN_TOUCH, dev->keybit);
> +    __set_bit(BTN_TOOL_FINGER, dev->keybit);
> +    __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
> +    __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
> +    __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
> +    __set_bit(BTN_TOOL_QUINTTAP, dev->keybit);
> +    __clear_bit(EV_REL, dev->evbit);
> +    __clear_bit(REL_X, dev->relbit);
> +    __clear_bit(REL_Y, dev->relbit);
> +    __set_bit(BTN_LEFT, dev->keybit);
> +    __clear_bit(BTN_RIGHT, dev->keybit);
> +    __clear_bit(BTN_MIDDLE, dev->keybit);
> +    __set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
> +}
> +
> +int focaltech_init(struct psmouse *psmouse)
> +{
> +    struct focaltech_data *priv;
> +
> +    focaltech_reset(psmouse);
> +    if (focaltech_switch_protocol(psmouse)) {
> +        focaltech_reset(psmouse);
> +        psmouse_info(psmouse,
> +                 "Unable to initialize the device.");
> +        return -ENOSYS;
> +    }
> +
> +    psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
> GFP_KERNEL);
> +    if (!priv)
> +        return -ENOMEM;
> +
> +    set_input_params(psmouse);
> +
> +    psmouse->protocol_handler = focaltech_process_byte;
> +    psmouse->pktsize = 6;
> +    psmouse->disconnect = focaltech_disconnect;
> +    psmouse->reconnect = focaltech_reconnect;
> +    psmouse->cleanup = focaltech_reset;
> +    /* resync is not supported yet */
> +    psmouse->resync_time = 0;
> +
> +    return 0;
> +}
> +
> +#else /* CONFIG_MOUSE_PS2_FOCALTECH */
> +
> +int focaltech_detect(struct psmouse *psmouse, bool set_properties)
> +{
> +    return -ENOSYS;
> +}
> +
> +int focaltech_init(struct psmouse *psmouse)
> +{
> +    return -ENOSYS;
> +}
> +
> +#endif /* CONFIG_MOUSE_PS2_FOCALTECH */
> diff --git a/drivers/input/mouse/focaltech.h
> b/drivers/input/mouse/focaltech.h
> index 498650c..3c553b2 100644
> --- a/drivers/input/mouse/focaltech.h
> +++ b/drivers/input/mouse/focaltech.h
> @@ -2,6 +2,7 @@
>   * Focaltech TouchPad PS/2 mouse driver
>   *
>   * Copyright (c) 2014 Red Hat Inc.
> + * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License as published by
> @@ -16,7 +17,67 @@
>  #ifndef _FOCALTECH_H
>  #define _FOCALTECH_H
>  +/*
> + * Packet types - the numbers are not consecutive, so we might be missing
> + * something here.
> + */
> +#define FOC_TOUCH 0x3 /* bitmap of active fingers */
> +#define FOC_ABS 0x6 /* absolute position of one finger */
> +#define FOC_REL 0x9 /* relative position of 1-2 fingers */
> +
> +#define FOC_MAX_FINGERS 5
> +
> +#define FOC_MAX_X 2431
> +#define FOC_MAX_Y 1663
> +
> +static inline int focaltech_invert_y(int y)
> +{
> +    return FOC_MAX_Y - y;
> +}
> +
> +/*
> + * Current state of a single finger on the touchpad.
> + */
> +struct focaltech_finger_state {
> +    /* the touchpad has generated a touch event for the finger */
> +    bool active;
> +    /*
> +     * The touchpad has sent position data for the finger. Touch event
> +     * packages reset this flag for new fingers, and there is a time
> +     * between the first touch event and the following absolute position
> +     * packet for the finger where the touchpad has declared the
finger to
> +     * be valid, but we do not have any valid position yet.
> +     */
> +    bool valid;
> +    /* absolute position (from the bottom left corner) of the finger */
> +    unsigned int x;
> +    unsigned int y;
> +};
> +
> +/*
> + * Description of the current state of the touchpad hardware.
> + */
> +struct focaltech_hw_state {
> +    /*
> +     * The touchpad tracks the positions of the fingers for us, the array
> +     * indices correspond to the finger indices returned in the report
> +     * packages.
> +     */
> +    struct focaltech_finger_state fingers[FOC_MAX_FINGERS];
> +    /*
> +     * True if the clickpad has been pressed.
> +     */
> +    bool pressed;
> +};
> +
> +struct focaltech_data {
> +    struct focaltech_hw_state state;
> +};
> +
>  int focaltech_detect(struct psmouse *psmouse, bool set_properties);
>  int focaltech_init(struct psmouse *psmouse);
>  +int focaltech_detect_fallback(struct psmouse *psmouse, bool
> set_properties);
> +int focaltech_init_fallback(struct psmouse *psmouse);
> +
>  #endif
> diff --git a/drivers/input/mouse/psmouse-base.c
> b/drivers/input/mouse/psmouse-base.c
> index 26994f6..2e2b98d 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -726,6 +726,12 @@ static int psmouse_extensions(struct psmouse
*psmouse,
>  /* Always check for focaltech, this is safe as it uses pnp-id matching */
>      if (psmouse_do_detect(focaltech_detect, psmouse, set_properties)
== 0) {
>          if (!set_properties || focaltech_init(psmouse) == 0) {
> +            return PSMOUSE_FOCALTECH;
> +        }
> +    }
> +    if (psmouse_do_detect(focaltech_detect_fallback,
> +                  psmouse, set_properties) == 0) {
> +        if (!set_properties || focaltech_init_fallback(psmouse) == 0) {
>              /*
>               * Not supported yet, use bare protocol.
>               * Note that we need to also restrict
> @@ -1063,6 +1069,15 @@ static const struct psmouse_protocol
> psmouse_protocols[] = {
>          .alias        = "cortps",
>          .detect        = cortron_detect,
>      },
> +#ifdef CONFIG_MOUSE_PS2_FOCALTECH
> +    {
> +        .type        = PSMOUSE_FOCALTECH,
> +        .name        = "FocalTechPS/2",
> +        .alias        = "focaltech",
> +        .detect        = focaltech_detect,
> +        .init        = focaltech_init,
> +    },
> +#endif
>      {
>          .type        = PSMOUSE_AUTO,
>          .name        = "auto",
> diff --git a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
> index f4cf664..c2ff137 100644
> --- a/drivers/input/mouse/psmouse.h
> +++ b/drivers/input/mouse/psmouse.h
> @@ -96,6 +96,7 @@ enum psmouse_type {
>      PSMOUSE_FSP,
>      PSMOUSE_SYNAPTICS_RELATIVE,
>      PSMOUSE_CYPRESS,
> +    PSMOUSE_FOCALTECH,
>      PSMOUSE_AUTO        /* This one should always be last */
>  };
>  -- 1.9.1
>