/*
* Copyright (c) 2005, Johan Wall�n
* 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.
*
* On 12 inch iBooks only the 9 first sensors in Y-direction are used.
* 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.
*
*/
/* The amount of data transferred 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. */
};
/* 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 */
int is_geyser2;
int sc_datalen; /* Size of a data packet */
int sc_bufusage; /* Number of bytes in sc_databuf */
int sc_acc[PBMS_SENSORS]; /* Accumulated sensor values. */
unsigned char sc_prev[PBMS_SENSORS]; /* Previous sample. */
unsigned char sc_sample[PBMS_SENSORS]; /* Current sample. */
uint8_t sc_databuf[PBMS_DATA_LEN]; /* Buffer for a data packet */
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);
/* 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 (uha->uiaa->uiaa_proto == UIPROTO_MOUSE &&
((udd = usbd_get_device_descriptor(uha->uiaa->uiaa_device))
!= 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;
}
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;
uint8_t *data;
int dx, dy, dz, i, s;
uint32_t buttons;
/*
* We may have to construct the full data packet over two or three
* sequential interrupts, as the device only sends us chunks of
* 32 or 64 bytes of data.
* This also requires some synchronization, to make sure we place
* the first protocol-byte at the first byte in the bufffer.
*/
if (sc->is_geyser2) {
/* XXX Need to check this. */
} else {
/* the last chunk is always 17 bytes */
if (len == 17 && sc->sc_bufusage + len != sc->sc_datalen) {
sc->sc_bufusage = 0; /* discard bad packet */
return;
}
}
memcpy(sc->sc_databuf + sc->sc_bufusage, ibuf, len);
sc->sc_bufusage += len;
if (sc->sc_bufusage != sc->sc_datalen)
return; /* wait until packet is complete */
/* process the now complete protocol and clear the buffer */
data = sc->sc_databuf;
sc->sc_bufusage = 0;
#if 0
for (i = 0; i < sc->sc_datalen; i++)
printf(" %02x", 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;
/*
* 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.
*/
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;
/* 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;
}
}
