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[netbsd-mini2440.git] / sys / arch / macppc / dev / pbms.c

/* $Id: pbms.c,v 1.9 2009/11/05 05:37:30 dyoung Exp $ */

/*
 * Copyright (c) 2005, Johan Wallén
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 *   3. The name of the copyright holder may not be used to endorse or
 *      promote products derived from this software without specific
 *      prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * The pbms driver provides support for the trackpad on new (post
 * February 2005) Apple PowerBooks (and iBooks?) that are not standard
 * USB HID mice.
 */

/*
 * The protocol (that is, the interpretation of the data generated by
 * the trackpad) is taken from the Linux appletouch driver version
 * 0.08 by Johannes Berg, Stelian Pop and Frank Arnold.  The method
 * used to detect fingers on the trackpad is also taken from that
 * driver.
 */

/*
 * To add support for other devices using the same protocol, add an
 * entry to the pbms_devices table below.  See the comments for
 * pbms_devices and struct pbms_devs.
 */

/*
 * PROTOCOL:
 *
 * The driver transfers continuously 81 byte events.  The last byte is
 * 1 if the button is pressed, and is 0 otherwise. Of the remaining
 * bytes, 26 + 16 = 42 are sensors detecting pressure in the X or
 * horizontal, and Y or vertical directions, respectively.  On 12 and
 * 15 inch PowerBooks, only the 16 first sensors in the X-direction
 * are used. In the X-direction, the sensors correspond to byte
 * positions
 * 
 *   2, 7, 12, 17, 22, 27, 32, 37, 4, 9, 14, 19, 24, 29, 34, 39, 42,
 *   47, 52, 57, 62, 67, 72, 77, 44 and 49;
 * 
 * in the Y direction, the sensors correspond to byte positions
 *
 *   1, 6, 11, 16, 21, 26, 31, 36, 3, 8, 13, 18, 23, 28, 33 and 38.
 *
 * The change in the sensor values over time is more interesting than
 * their absolute values: if the pressure increases, we know that the
 * finger has just moved there.
 *
 * We keep track of the previous sample (of sensor values in the X and
 * Y directions) and the accumulated change for each sensor.  When we
 * receive a new sample, we add the difference of the new sensor value
 * and the old value to the accumulated change.  If the accumulator
 * becomes negative, we set it to zero.  The effect is that the
 * accumulator is large for sensors whose pressure has recently
 * increased.  If there is little change in pressure (or if the
 * pressure decreases), the accumulator drifts back to zero.
 *
 * Since there is some fluctuations, we ignore accumulator values
 * below a threshold.  The raw finger position is computed as a
 * weighted average of the other sensors (the weights are the
 * accumulated changes).
 *
 * For smoothing, we keep track of the previous raw finger position,
 * and the virtual position reported to wsmouse.  The new raw position
 * is computed as a weighted average of the old raw position and the
 * computed raw position.  Since this still generates some noise, we
 * compute a new virtual position as a weighted average of the previous
 * virtual position and the new raw position.  The weights are
 * controlled by the raw change and a noise parameter.  The position
 * is reported as a relative position.  
 */

/*
 * TODO:
 *
 * Add support for other drivers of the same type.
 *
 * Add support for tapping and two-finger scrolling?  The
 * implementation already detects two fingers, so this should be
 * relatively easy.
 *
 * Implement some of the mouse ioctls?
 *
 * Take care of the XXXs.
 *
 */

#include <sys/cdefs.h>

#include <sys/param.h>
#include <sys/device.h>
#include <sys/errno.h>

#include <sys/ioctl.h>
#include <sys/systm.h>
#include <sys/tty.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdevs.h>
#include <dev/usb/uhidev.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsmousevar.h>

/*
 * Magic numbers.
 */


/* The amount of data transfered by the USB device. */
#define PBMS_DATA_LEN 81

/* The maximum number of sensors. */
#define PBMS_X_SENSORS 26
#define PBMS_Y_SENSORS 16
#define PBMS_SENSORS (PBMS_X_SENSORS + PBMS_Y_SENSORS)

/* 
 * Parameters for supported devices.  For generality, these parameters
 * can be different for each device.  The meanings of the parameters
 * are as follows.
 *
 * desc:      A printable description used for dmesg output.
 *
 * noise:     Amount of noise in the computed position. This controls
 *            how large a change must be to get reported, and how 
 *            large enough changes are smoothed.  A good value can
 *            probably only be found experimentally, but something around
 *            16 seems suitable.
 *
 * product:   The product ID of the trackpad.
 *
 * 
 * threshold: Accumulated changes less than this are ignored.  A good 
 *            value could be determined experimentally, but 5 is a
 *            reasonable guess.
 *
 * vendor:    The vendor ID.  Currently USB_VENDOR_APPLE for all devices.
 *
 * x_factor:  Factor used in computations with X-coordinates.  If the
 *            x-resolution of the display is x, this should be 
 *            (x + 1) / (x_sensors - 1).  Other values work fine, but
 *            then the aspect ratio is not necessarily kept.
 *
 * x_sensors: The number of sensors in the X-direction.
 *
 * y_factor:  As x_factors, but for Y-coordinates.
 *
 * y_sensors: The number of sensors in the Y-direction.
 */

struct pbms_dev {
        const char *descr; /* Description of the driver (for dmesg). */
        int noise;         /* Amount of noise in the computed position. */
        int threshold;     /* Changes less than this are ignored. */
        int x_factor;      /* Factor used in computation with X-coordinates. */
        int x_sensors;     /* The number of X-sensors. */
        int y_factor;      /* Factor used in computation with Y-coordinates. */
        int y_sensors;     /* The number of Y-sensors. */
        uint16_t product;  /* Product ID. */
        uint16_t vendor;   /* The vendor ID. */
};

/* Devices supported by this driver. */
static struct pbms_dev pbms_devices[] =
{
#define POWERBOOK_TOUCHPAD(inches, prod, x_fact, x_sens, y_fact)              \
       {                                                                      \
                .descr = #inches " inch PowerBook Trackpad",                  \
                .vendor = USB_VENDOR_APPLE,                                   \
                .product = (prod),                                            \
                .noise = 16,                                                  \
                .threshold = 5,                                               \
                .x_factor = (x_fact),                                         \
                .x_sensors = (x_sens),                                        \
                .y_factor = (y_fact),                                         \
                .y_sensors = 16                                               \
       }
       /* 12 inch PowerBooks */
       POWERBOOK_TOUCHPAD(12, 0x030a, 69, 16, 52), /* XXX Not tested. */
       /* 15 inch PowerBooks */
       POWERBOOK_TOUCHPAD(15, 0x020e, 85, 16, 57), /* XXX Not tested. */
       POWERBOOK_TOUCHPAD(15, 0x020f, 85, 16, 57),
       POWERBOOK_TOUCHPAD(15, 0x0215, 90, 15, 107),
       /* 17 inch PowerBooks */
       POWERBOOK_TOUCHPAD(17, 0x020d, 71, 26, 68)  /* XXX Not tested. */
#undef POWERBOOK_TOUCHPAD
};

/* The number of supported devices. */
#define PBMS_NUM_DEVICES (sizeof(pbms_devices) / sizeof(pbms_devices[0]))


/*
 * Types and prototypes. 
 */


/* Device data. */
struct pbms_softc {
        struct uhidev sc_hdev;        /* USB parent (got the struct device). */
        int is_geyser2;
        int sc_datalen;
        int sc_acc[PBMS_SENSORS];     /* Accumulated sensor values. */
        unsigned char sc_prev[PBMS_SENSORS];   /* Previous sample. */
        unsigned char sc_sample[PBMS_SENSORS]; /* Current sample. */
        device_t sc_wsmousedev; /* WSMouse device. */
        int sc_noise;                 /* Amount of noise. */
        int sc_theshold;              /* Threshold value. */
        int sc_x;                     /* Virtual position in horizontal 
                                       * direction (wsmouse position). */
        int sc_x_factor;              /* X-coordinate factor. */
        int sc_x_raw;                 /* X-position of finger on trackpad. */
        int sc_x_sensors;             /* Number of X-sensors. */
        int sc_y;                     /* Virtual position in vertical direction
                                       * (wsmouse position). */
        int sc_y_factor;              /* Y-coordinate factor. */
        int sc_y_raw;                 /* Y-position of finger on trackpad. */
        int sc_y_sensors;             /* Number of Y-sensors. */
        uint32_t sc_buttons;          /* Button state. */
        uint32_t sc_status;           /* Status flags. */
#define PBMS_ENABLED 1                /* Is the device enabled? */
#define PBMS_DYING 2                  /* Is the device dying? */
#define PBMS_VALID 4                  /* Is the previous sample valid? */
};


/* Static function prototypes. */
static void pbms_intr(struct uhidev *, void *, unsigned int);
static int pbms_enable(void *);
static void pbms_disable(void *);
static int pbms_ioctl(void *, unsigned long, void *, int, struct lwp *);
static void reorder_sample(struct pbms_softc *, unsigned char *, unsigned char *);
static int compute_delta(struct pbms_softc *, int *, int *, int *, uint32_t *);
static int detect_pos(int *, int, int, int, int *, int *);
static int smooth_pos(int, int, int);

/* Access methods for wsmouse. */
const struct wsmouse_accessops pbms_accessops = {
        pbms_enable,
        pbms_ioctl,
        pbms_disable,
};

/* This take cares also of the basic device registration. */
int pbms_match(device_t, cfdata_t, void *);
void pbms_attach(device_t, device_t, void *);
int pbms_detach(device_t, int);
void pbms_childdet(device_t, device_t);
int pbms_activate(device_t, enum devact);
extern struct cfdriver pbms_cd;
CFATTACH_DECL2_NEW(pbms, sizeof(struct pbms_softc), pbms_match, pbms_attach,
    pbms_detach, pbms_activate, NULL, pbms_childdet);

/*
 * Basic driver. 
 */


/* Try to match the device at some uhidev. */

int 
pbms_match(device_t parent, cfdata_t match, void *aux)
{
        struct uhidev_attach_arg *uha = aux;
        usb_device_descriptor_t *udd;
        int i;
        uint16_t vendor, product;

        /* 
         * We just check if the vendor and product IDs have the magic numbers
         * we expect. 
         */
        if ((udd = usbd_get_device_descriptor(uha->parent->sc_udev)) != NULL) {
                vendor = UGETW(udd->idVendor);
                product = UGETW(udd->idProduct);
                for (i = 0; i < PBMS_NUM_DEVICES; i++) {
                        if (vendor == pbms_devices[i].vendor &&
                            product == pbms_devices[i].product)
                                return UMATCH_IFACECLASS;
                }
        }
        return UMATCH_NONE;
}


/* Attach the device. */

void
pbms_attach(device_t parent, device_t self, void *aux)
{
        struct wsmousedev_attach_args a;
        struct uhidev_attach_arg *uha = aux;
        struct pbms_dev *pd;
        struct pbms_softc *sc = device_private(self);
        usb_device_descriptor_t *udd;
        int i;
        uint16_t vendor, product;

        sc->sc_hdev.sc_intr = pbms_intr;
        sc->sc_hdev.sc_parent = uha->parent;
        sc->sc_hdev.sc_report_id = uha->reportid;

        sc->is_geyser2 = 0;
        sc->sc_datalen = PBMS_DATA_LEN;

        /* Fill in device-specific parameters. */
        if ((udd = usbd_get_device_descriptor(uha->parent->sc_udev)) != NULL) {
                product = UGETW(udd->idProduct);
                vendor = UGETW(udd->idVendor);
                for (i = 0; i < PBMS_NUM_DEVICES; i++) {
                        pd = &pbms_devices[i];
                        if (product == pd->product && vendor == pd->vendor) {
                                printf(": %s\n", pd->descr);
                                sc->sc_noise = pd->noise;
                                sc->sc_theshold = pd->threshold;
                                sc->sc_x_factor = pd->x_factor;
                                sc->sc_x_sensors = pd->x_sensors;
                                sc->sc_y_factor = pd->y_factor;
                                sc->sc_y_sensors = pd->y_sensors;
                                if (product == 0x0215) {
                                        sc->is_geyser2 = 1;
                                        sc->sc_datalen = 64;
                                        sc->sc_y_sensors = 9;
                                }
                                break;
                        }
                }
        }
        KASSERT(0 <= sc->sc_x_sensors && sc->sc_x_sensors <= PBMS_X_SENSORS);
        KASSERT(0 <= sc->sc_y_sensors && sc->sc_y_sensors <= PBMS_Y_SENSORS);

        sc->sc_status = 0;

        a.accessops = &pbms_accessops;
        a.accesscookie = sc;

        sc->sc_wsmousedev = config_found(self, &a, wsmousedevprint);

        USB_ATTACH_SUCCESS_RETURN;
}


/* Detach the device. */

void
pbms_childdet(device_t self, device_t child)
{
        struct pbms_softc *sc = device_private(self);

        if (sc->sc_wsmousedev == child)
                sc->sc_wsmousedev = NULL;
}

int
pbms_detach(device_t self, int flags)
{
        /* XXX This could not possibly be sufficient! */
        return config_detach_children(self, flags);
}


/* Activate the device. */

int
pbms_activate(device_t self, enum devact act)
{
        struct pbms_softc *sc = device_private(self);

        if (act != DVACT_DEACTIVATE)
                return EOPNOTSUPP;

        sc->sc_status |= PBMS_DYING;
        return 0;
}


/* Enable the device. */

static int
pbms_enable(void *v)
{
        struct pbms_softc *sc = v;

        /* Check that we are not detaching or already enabled. */
        if (sc->sc_status & PBMS_DYING)
                return EIO;
        if (sc->sc_status & PBMS_ENABLED)
                return EBUSY;

        sc->sc_status |= PBMS_ENABLED;
        sc->sc_status &= ~PBMS_VALID;
        sc->sc_buttons = 0;
        memset(sc->sc_sample, 0, sizeof(sc->sc_sample));

        return uhidev_open(&sc->sc_hdev);
}


/* Disable the device. */

static void
pbms_disable(void *v)
{
        struct pbms_softc *sc = v;

        if (!(sc->sc_status & PBMS_ENABLED))
                return;

        sc->sc_status &= ~PBMS_ENABLED;
        uhidev_close(&sc->sc_hdev);
}


/* XXX ioctl not implemented. */

static int
pbms_ioctl(void *v, unsigned long cmd, void *data, int flag, struct lwp *p)
{
        return EPASSTHROUGH;
}


/*
 * Interrupts & pointer movement. 
 */


/* Handle interrupts. */

void
pbms_intr(struct uhidev *addr, void *ibuf, unsigned int len)
{
        struct pbms_softc *sc = (struct pbms_softc *)addr;
        unsigned char *data;
        int dx, dy, dz, i, s;
        uint32_t buttons;

        /* Ignore incomplete data packets. */
        if (len != sc->sc_datalen)
                return;
        data = ibuf;

#if 0
        printf("(");
        for (i = 0; i < len; i++)
                printf(" %d", data[i]);
        printf(" )\n");
#endif

        /* The last byte is 1 if the button is pressed and 0 otherwise. */
        buttons = !!data[sc->sc_datalen - 1];

        /* Everything below assumes that the sample is reordered. */
        reorder_sample(sc, sc->sc_sample, data);

        /* Is this the first sample? */
        if (!(sc->sc_status & PBMS_VALID)) {
                sc->sc_status |= PBMS_VALID;
                sc->sc_x = sc->sc_y = -1;
                sc->sc_x_raw = sc->sc_y_raw = -1;
                memcpy(sc->sc_prev, sc->sc_sample, sizeof(sc->sc_prev));
                memset(sc->sc_acc, 0, sizeof(sc->sc_acc));
                return;
        }
        /* Accumulate the sensor change while keeping it nonnegative. */
        for (i = 0; i < PBMS_SENSORS; i++) {
                sc->sc_acc[i] +=
                        (signed char) (sc->sc_sample[i] - sc->sc_prev[i]);
                if (sc->sc_acc[i] < 0)
                        sc->sc_acc[i] = 0;
        }
        memcpy(sc->sc_prev, sc->sc_sample, sizeof(sc->sc_prev));

        /* Compute change. */
        dx = dy = dz = 0;
        if (!compute_delta(sc, &dx, &dy, &dz, &buttons))
                return;

        /* Report to wsmouse. */
        if ((dx != 0 || dy != 0 || dz != 0 || buttons != sc->sc_buttons) &&
            sc->sc_wsmousedev != NULL) {
                s = spltty();
                wsmouse_input(sc->sc_wsmousedev, buttons, dx, -dy, dz, 0,
                    WSMOUSE_INPUT_DELTA);
                splx(s);
        }
        sc->sc_buttons = buttons;
}


/* 
 * Reorder the sensor values so that all the X-sensors are before the
 * Y-sensors in the natural order. Note that this might have to be
 * rewritten if PBMS_X_SENSORS or PBMS_Y_SENSORS change. 
 */

static void 
reorder_sample(struct pbms_softc *sc, unsigned char *to, unsigned char *from)
{
        int i;

        if (sc->is_geyser2) {
                int j;

                memset(to, 0, PBMS_SENSORS);
                for (i = 0, j = 19; i < 20; i += 2, j += 3) {
                        to[i] = from[j];
                        to[i + 1] = from[j + 1];
                }
                for (i = 0, j = 1; i < 9; i += 2, j += 3) {
                        to[PBMS_X_SENSORS + i] = from[j];
                        to[PBMS_X_SENSORS + i + 1] = from[j + 1];
                }
        } else {
                for (i = 0; i < 8; i++) {
                        /* X-sensors. */
                        to[i] = from[5 * i + 2];
                        to[i + 8] = from[5 * i + 4];
                        to[i + 16] = from[5 * i + 42];
        #if 0
                        /* 
                         * XXX This seems to introduce random ventical jumps, so
                         * we ignore these sensors until we figure out their meaning.
                         */
                        if (i < 2)
                                to[i + 24] = from[5 * i + 44];
        #endif /* 0 */
                        /* Y-sensors. */
                        to[i + 26] = from[5 * i + 1];
                        to[i + 34] = from[5 * i + 3];
                }
        }
}


/*
 * Compute the change in x, y and z direction, update the button state
 * (to simulate more than one button, scrolling etc.), and update the
 * history. Note that dx, dy, dz and buttons are modified only if
 * corresponding pressure is detected and should thus be initialised
 * before the call.  Return 0 on error.
 */

/* XXX Could we report something useful in dz? */

static int
compute_delta(struct pbms_softc *sc, int *dx, int *dy, int *dz, 
              uint32_t * buttons)
{
        int x_det, y_det, x_raw, y_raw, x_fingers, y_fingers, fingers, x, y;

        x_det = detect_pos(sc->sc_acc, sc->sc_x_sensors, sc->sc_theshold,
                           sc->sc_x_factor, &x_raw, &x_fingers);
        y_det = detect_pos(sc->sc_acc + PBMS_X_SENSORS, sc->sc_y_sensors,
                           sc->sc_theshold, sc->sc_y_factor,
                           &y_raw, &y_fingers);
        fingers = max(x_fingers, y_fingers);

        /* Check the number of fingers and if we have detected a position. */
        if (fingers > 1) {
                /* More than one finger detected, resetting. */
                memset(sc->sc_acc, 0, sizeof(sc->sc_acc));
                sc->sc_x_raw = sc->sc_y_raw = sc->sc_x = sc->sc_y = -1;
                return 0;
        } else if (x_det == 0 && y_det == 0) {
                /* No position detected, resetting. */
                memset(sc->sc_acc, 0, sizeof(sc->sc_acc));
                sc->sc_x_raw = sc->sc_y_raw = sc->sc_x = sc->sc_y = -1;
        } else if (x_det > 0 && y_det > 0) {
                /* Smooth position. */
                if (sc->sc_x_raw >= 0) {
                        sc->sc_x_raw = (3 * sc->sc_x_raw + x_raw) / 4;
                        sc->sc_y_raw = (3 * sc->sc_y_raw + y_raw) / 4;
                        /* 
                         * Compute virtual position and change if we already
                         * have a decent position. 
                         */
                        if (sc->sc_x >= 0) {
                                x = smooth_pos(sc->sc_x, sc->sc_x_raw,
                                               sc->sc_noise);
                                y = smooth_pos(sc->sc_y, sc->sc_y_raw,
                                               sc->sc_noise);
                                *dx = x - sc->sc_x;
                                *dy = y - sc->sc_y;
                                sc->sc_x = x;
                                sc->sc_y = y;
                        } else {
                                /* Initialise virtual position. */
                                sc->sc_x = sc->sc_x_raw;
                                sc->sc_y = sc->sc_y_raw;
                        }
                } else {
                        /* Initialise raw position. */
                        sc->sc_x_raw = x_raw;
                        sc->sc_y_raw = y_raw;
                }
        }
        return 1;
}


/*
 * Compute the new smoothed position from the previous smoothed position
 * and the raw position.
 */

static int
smooth_pos(int pos_old, int pos_raw, int noise)
{
        int ad, delta;

        delta = pos_raw - pos_old;
        ad = abs(delta);

        /* Too small changes are ignored. */
        if (ad < noise / 2)
                delta = 0;
        /* A bit larger changes are smoothed. */
        else if (ad < noise)
                delta /= 4;
        else if (ad < 2 * noise)
                delta /= 2;

        return pos_old + delta;
}


/*
 * Detect the position of the finger.  Returns the total pressure.
 * The position is returned in pos_ret and the number of fingers
 * is returned in fingers_ret.  The position returned in pos_ret
 * is in [0, (n_sensors - 1) * factor - 1].
 */

static int
detect_pos(int *sensors, int n_sensors, int threshold, int fact,
           int *pos_ret, int *fingers_ret)
{
        int i, w, s;

        /*
         * Compute the number of fingers, total pressure, and weighted
         * position of the fingers. 
         */
        *fingers_ret = 0;
        w = s = 0;
        for (i = 0; i < n_sensors; i++) {
                if (sensors[i] >= threshold) {
                        if (i == 0 || sensors[i - 1] < threshold)
                                *fingers_ret += 1;
                        s += sensors[i];
                        w += sensors[i] * i;
                }
        }

        if (s > 0)
                *pos_ret = w * fact / s;

        return s;
}