On Mon, Nov 12, 2018 at 06:50:27PM -0200, Martin Pieuchot wrote:
> On 09/11/18(Fri) 16:25, Ben Pye wrote:
> > On Thu, Nov 08, 2018 at 11:25:37PM -0600, joshua stein wrote:
> > > On Fri, 09 Nov 2018 at 03:30:07 +0000, b...@curlybracket.co.uk wrote:
> > > > Hi all,
> > > >
> > > > This patch adds a new touchpad driver, elan(4), which supports older non
> > > > PTP I2C Elantech touchpads. I have tested this on my HP Chromebook 13
> > > > and it appears to work well, multitouch is working as well as the three
> > > > physical mouse buttons. I do not know how well this will work on other
> > > > Elantech touchpads however; I believe there are a few devices that use
> > > > the same protocol though they may have different ACPI hids.
> > > >
> > > > This driver is similar to iatp(4) and is largely based upon it although
> > > > the actual protocol used by the touchpad is quite different.
> > > >
> > > > I have added a basic man page following iatp(4) as a guide. I wasn't
> > > > sure if I should add the copyright and OpenBSD headers and so for this
> > > > first patch I have omitted them.
> > > >
> > > > This together with my previous sdhc(4) patch results in a mostly working
> > > > OpenBSD install on the HP Chromebook 13, unfortunately apm(4) is still
> > > > problematic and the device gets stuck in sleep.
> > >
> > > Hi,
> > >
> > > Well done! The code looks mostly ok. There are a bunch of 8-space
> > > indentations instead of tabs that need to be fixed. You should
> > > include a comment header with your copyright and a license,
> > > preferably /usr/share/misc/license.template.
> >
> > I have updated both the man page and my code to include this as well as
> > fixing the identation and some trailing whitespace issues.
> >
> > > We have a habit of naming USB and i2c devices starting with 'u' and
> > > 'i', and since there is already a bunch of Elantech touchpad device
> > > support in pms(4), it would be best to rename this from 'elan' to
> > > something more narrow. Maybe ietp (since iatp is for i2c Atmel
> > > touchpads) or ielantp or something.
> >
> > I have renamed everything to ietp to mirror iatp(4).
> >
> > > As for the driver itself, is this implementing a specific protocol
> > > version for Elantech devices like the four in pms(4)? If this
> > > driver is limited to a specific protocol version or model, it would
> > > be beneficial to mention that in the driver code and man page.
> >
> > Unfortunately I can't find a specific list of devices using this
> > protocol however some searching indicates that there are certainly more
> > than just the "ELAN0000" device present on my laptop. I unfortunately do
> > not have any other hardware with an Elantech trackpad so I can't really
> > see if this will work on those devices though I believe it should.
> >
> > The updated patch is given below.
>
> Two questions below.
>
> > +int
> > +ietp_activate(struct device *self, int act)
> > +{
> > + struct ietp_softc *sc = (struct ietp_softc *)self;
> > +
> > + switch(act) {
> > + case DVACT_WAKEUP:
> > + sc->sc_busy = 1;
>
> What are you trying to serialize with this field? Can you describe the
> scenario that you're trying to avoid?
>
During init we reset and then write some configuration, I don't think
anything awful would happen if we didn't serialise this but we are more
likely to get reports we don't understand.
> > + ietp_init(sc);
> > + sc->sc_busy = 0;
> > + break;
> > + }
> > +
> > + config_activate_children(self, act);
> > +
> > + return 0;
> > +}
> > +
> > +
> > +void
> > +ietp_sleep(struct ietp_softc *sc, int ms)
> > +{
> > + int to = ms * hz / 1000;
>
> This function is never called, or it's me?
Not you, I based this driver on iatp(4) and the equivalent function is
needed there. I have removed it.
>
> > +
> > + if (cold)
> > + delay(ms * 1000);
> > + else {
> > + if (to <= 0)
> > + to = 1;
> > + tsleep(&sc, PWAIT, "ietp", to);
> > + }
> > +}
> > +
I have updated this change set to remove the unused ietp_sleep function.
I have also added ietp_sleep (apologies, same name) to put the device
into a sleep state before we suspend. I don't really have any way to
confirm that this state is lower power but the device certainly does
still work on resume.
The updated diff is below.
Thanks,
Ben
Index: sys/dev/i2c/ietp.c
===================================================================
RCS file: sys/dev/i2c/ietp.c
diff -N sys/dev/i2c/ietp.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ sys/dev/i2c/ietp.c 12 Nov 2018 21:32:04 -0000
@@ -0,0 +1,529 @@
+/*
+ * Elantech i2c touchpad driver
+ *
+ * Copyright (c) 2018 Ben Pye <b...@curlybracket.co.uk>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+#include <sys/stdint.h>
+
+#include <dev/i2c/i2cvar.h>
+
+#include <dev/wscons/wsconsio.h>
+#include <dev/wscons/wsmousevar.h>
+#include <dev/hid/hid.h>
+#include <dev/hid/hidmsvar.h>
+
+/* #define IETP_DEBUG */
+
+#ifdef IETP_DEBUG
+#define DPRINTF(x) printf x
+#else
+#define DPRINTF(x)
+#endif
+
+#define IETP_INPUT 0x0003
+#define IETP_MAX_X_AXIS 0x0106
+#define IETP_MAX_Y_AXIS 0x0107
+#define IETP_RESOLUTION 0x0108
+
+#define IETP_COMMAND 0x0005
+#define IETP_CONTROL 0x0300
+
+#define IETP_CMD_WAKEUP 0x0800
+#define IETP_CMD_SLEEP 0x0801
+#define IETP_CMD_RESET 0x0100
+
+#define IETP_CTRL_ABSOLUTE 0x0001
+#define IETP_CTRL_STANDARD 0x0000
+
+#define IETP_MAX_REPORT_LEN 34
+#define IETP_MAX_FINGERS 5
+
+#define IETP_REPORT_ABSOLUTE 0x5D
+
+#define IETP_REPORT_ID 2
+#define IETP_TOUCH_INFO 3
+#define IETP_FINGER_DATA 4
+
+#define IETP_TOUCH_LMB (1 << 0)
+#define IETP_TOUCH_RMB (1 << 1)
+#define IETP_TOUCH_MMB (1 << 2)
+
+#define IETP_FINGER_DATA_LEN 5
+#define IETP_FINGER_XY_HIGH 0
+#define IETP_FINGER_X_LOW 1
+#define IETP_FINGER_Y_LOW 2
+#define IETP_FINGER_WIDTH 3
+#define IETP_FINGER_PRESSURE 4
+
+struct ietp_softc {
+ struct device sc_dev;
+ i2c_tag_t sc_tag;
+
+ i2c_addr_t sc_addr;
+ void *sc_ih;
+
+ struct device *sc_wsmousedev;
+ char sc_hid[16];
+ int sc_enabled;
+ int sc_busy;
+ struct tsscale sc_tsscale;
+
+ uint16_t max_x;
+ uint16_t max_y;
+ uint8_t res_x;
+ uint8_t res_y;
+};
+
+int ietp_match(struct device *, void *, void *);
+void ietp_attach(struct device *, struct device *, void *);
+int ietp_detach(struct device *, int);
+int ietp_activate(struct device *, int);
+
+int ietp_ioctl(void *, u_long, caddr_t, int, struct proc *);
+int ietp_enable(void *);
+void ietp_disable(void *);
+
+int ietp_read_reg(struct ietp_softc *, uint16_t, size_t, void *);
+int ietp_write_reg(struct ietp_softc *, uint16_t, uint16_t);
+void ietp_proc_report(struct ietp_softc *);
+int ietp_init(struct ietp_softc *);
+int ietp_sleep(struct ietp_softc *);
+int ietp_reset(struct ietp_softc *);
+int ietp_intr(void *);
+
+const struct wsmouse_accessops ietp_accessops = {
+ ietp_enable,
+ ietp_ioctl,
+ ietp_disable,
+};
+
+struct cfattach ietp_ca = {
+ sizeof(struct ietp_softc),
+ ietp_match,
+ ietp_attach,
+ ietp_detach,
+ ietp_activate,
+};
+
+struct cfdriver ietp_cd = {
+ NULL, "ietp", DV_DULL
+};
+
+int
+ietp_match(struct device *parent, void *match, void *aux)
+{
+ struct i2c_attach_args *ia = aux;
+
+ if (strcmp(ia->ia_name, "ietp") == 0)
+ return 1;
+
+ return 0;
+}
+
+void
+ietp_attach(struct device *parent, struct device *self, void *aux)
+{
+ struct ietp_softc *sc = (struct ietp_softc *)self;
+ struct i2c_attach_args *ia = aux;
+ struct wsmousedev_attach_args wsmaa;
+
+ sc->sc_tag = ia->ia_tag;
+ sc->sc_addr = ia->ia_addr;
+
+ if (ia->ia_cookie != NULL)
+ memcpy(&sc->sc_hid, ia->ia_cookie, sizeof(sc->sc_hid));
+
+ if (!ietp_init(sc))
+ return;
+
+ if (ia->ia_intr) {
+ printf(" %s", iic_intr_string(sc->sc_tag, ia->ia_intr));
+
+ sc->sc_ih = iic_intr_establish(sc->sc_tag, ia->ia_intr,
+ IPL_TTY, ietp_intr, sc, sc->sc_dev.dv_xname);
+ if (sc->sc_ih == NULL) {
+ printf(", can't establish interrupt\n");
+ return;
+ }
+ }
+
+ printf(": Elantech Touchpad (%dx%d)\n", sc->max_x, sc->max_y);
+
+ wsmaa.accessops = &ietp_accessops;
+ wsmaa.accesscookie = sc;
+ sc->sc_wsmousedev = config_found(self, &wsmaa, wsmousedevprint);
+}
+
+int
+ietp_detach(struct device *self, int flags)
+{
+ struct ietp_softc *sc = (struct ietp_softc *)self;
+
+ if (sc->sc_ih != NULL) {
+ intr_disestablish(sc->sc_ih);
+ sc->sc_ih = NULL;
+ }
+
+ sc->sc_enabled = 0;
+
+ return 0;
+}
+
+int
+ietp_activate(struct device *self, int act)
+{
+ struct ietp_softc *sc = (struct ietp_softc *)self;
+
+ switch(act) {
+ case DVACT_QUIESCE:
+ ietp_sleep(sc);
+ break;
+ case DVACT_WAKEUP:
+ sc->sc_busy = 1;
+ ietp_init(sc);
+ sc->sc_busy = 0;
+ break;
+ }
+
+ config_activate_children(self, act);
+
+ return 0;
+}
+
+int
+ietp_configure(struct ietp_softc *sc)
+{
+ struct wsmousehw *hw;
+
+ hw = wsmouse_get_hw(sc->sc_wsmousedev);
+ hw->type = WSMOUSE_TYPE_ELANTECH;
+ hw->hw_type = WSMOUSEHW_CLICKPAD;
+ hw->x_min = sc->sc_tsscale.minx;
+ hw->x_max = sc->sc_tsscale.maxx;
+ hw->y_min = sc->sc_tsscale.miny;
+ hw->y_max = sc->sc_tsscale.maxy;
+ hw->h_res = sc->sc_tsscale.resx;
+ hw->v_res = sc->sc_tsscale.resy;
+ hw->mt_slots = IETP_MAX_FINGERS;
+
+ return (wsmouse_configure(sc->sc_wsmousedev, NULL, 0));
+}
+
+int
+ietp_enable(void *v)
+{
+ struct ietp_softc *sc = v;
+
+ if (sc->sc_busy && tsleep(&sc->sc_busy, PRIBIO, "ietp", hz) != 0) {
+ printf("%s: trying to enable but we're busy\n",
+ sc->sc_dev.dv_xname);
+ return 1;
+ }
+
+ sc->sc_busy = 1;
+
+ DPRINTF(("%s: enabling\n", sc->sc_dev.dv_xname));
+
+ if (ietp_configure(sc)) {
+ printf("%s: failed wsmouse_configure\n", sc->sc_dev.dv_xname);
+ return 1;
+ }
+
+ sc->sc_enabled = 1;
+ sc->sc_busy = 0;
+
+ return 0;
+}
+
+void
+ietp_disable(void *v)
+{
+ struct ietp_softc *sc = v;
+
+ DPRINTF(("%s: disabling\n", sc->sc_dev.dv_xname));
+
+ wsmouse_set_mode(sc->sc_wsmousedev, WSMOUSE_COMPAT);
+
+ sc->sc_enabled = 0;
+}
+
+int
+ietp_ioctl(void *v, u_long cmd, caddr_t data, int flag, struct proc *p)
+{
+ struct ietp_softc *sc = v;
+ struct wsmouse_calibcoords *wsmc = (struct wsmouse_calibcoords *)data;
+ int wsmode;
+
+ DPRINTF(("%s: %s: cmd %ld\n", sc->sc_dev.dv_xname, __func__, cmd));
+
+ switch (cmd) {
+ case WSMOUSEIO_SCALIBCOORDS:
+ sc->sc_tsscale.minx = wsmc->minx;
+ sc->sc_tsscale.maxx = wsmc->maxx;
+ sc->sc_tsscale.miny = wsmc->miny;
+ sc->sc_tsscale.maxy = wsmc->maxy;
+ sc->sc_tsscale.swapxy = wsmc->swapxy;
+ sc->sc_tsscale.resx = wsmc->resx;
+ sc->sc_tsscale.resy = wsmc->resy;
+ break;
+
+ case WSMOUSEIO_GCALIBCOORDS:
+ wsmc->minx = sc->sc_tsscale.minx;
+ wsmc->maxx = sc->sc_tsscale.maxx;
+ wsmc->miny = sc->sc_tsscale.miny;
+ wsmc->maxy = sc->sc_tsscale.maxy;
+ wsmc->swapxy = sc->sc_tsscale.swapxy;
+ wsmc->resx = sc->sc_tsscale.resx;
+ wsmc->resy = sc->sc_tsscale.resy;
+ break;
+
+ case WSMOUSEIO_GTYPE: {
+ struct wsmousehw *hw = wsmouse_get_hw(sc->sc_wsmousedev);
+ *(u_int *)data = hw->type;
+ break;
+ }
+
+ case WSMOUSEIO_SETMODE:
+ wsmode = *(u_int *)data;
+ if (wsmode != WSMOUSE_COMPAT && wsmode != WSMOUSE_NATIVE) {
+ printf("%s: invalid mode %d\n", sc->sc_dev.dv_xname,
+ wsmode);
+ return EINVAL;
+ }
+ wsmouse_set_mode(sc->sc_wsmousedev, wsmode);
+ break;
+
+ default:
+ return -1;
+ }
+
+ return 0;
+}
+
+int
+ietp_reset(struct ietp_softc *sc)
+{
+ uint16_t buf;
+
+ if (ietp_write_reg(sc, IETP_COMMAND, IETP_CMD_RESET)) {
+ printf("%s: failed writing reset command\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ if (ietp_read_reg(sc, 0x0000, sizeof(buf), &buf)) {
+ printf("%s: failed reading reset ack\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ if (ietp_write_reg(sc, IETP_CONTROL, IETP_CTRL_ABSOLUTE)) {
+ printf("%s: failed setting absolute mode\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ if (ietp_write_reg(sc, IETP_COMMAND, IETP_CMD_WAKEUP)) {
+ printf("%s: failed writing wakeup command\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ return 1;
+}
+
+int
+ietp_sleep(struct ietp_softc *sc)
+{
+ if (ietp_write_reg(sc, IETP_COMMAND, IETP_CMD_SLEEP)) {
+ printf("%s: failed writing sleep command\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ return 1;
+}
+
+int
+ietp_init(struct ietp_softc *sc)
+{
+ uint16_t buf;
+
+ sc->sc_enabled = 0;
+
+ if (!ietp_reset(sc)) {
+ printf("%s: failed to reset\n", sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ if (ietp_read_reg(sc, IETP_MAX_X_AXIS, sizeof(buf), &buf)) {
+ printf("%s: failed reading max x\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ sc->max_x = le16toh(buf) & 0xFFF;
+
+ if (ietp_read_reg(sc, IETP_MAX_Y_AXIS, sizeof(buf), &buf)) {
+ printf("%s: failed reading max y\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ sc->max_y = le16toh(buf) & 0xFFF;
+
+ if (ietp_read_reg(sc, IETP_RESOLUTION, sizeof(buf), &buf)) {
+ printf("%s: failed reading resolution\n",
+ sc->sc_dev.dv_xname);
+ return 0;
+ }
+
+ sc->res_x = le16toh(buf) & 0xFF;
+ sc->res_y = (le16toh(buf) >> 8) & 0xFF;
+
+ /* Conversion from internal format to DPI */
+ sc->res_x = 790 + sc->res_x * 10;
+ sc->res_y = 790 + sc->res_y * 10;
+
+ sc->sc_tsscale.minx = 0;
+ sc->sc_tsscale.maxx = sc->max_x;
+ sc->sc_tsscale.miny = 0;
+ sc->sc_tsscale.maxy = sc->max_y;
+ sc->sc_tsscale.swapxy = 0;
+ sc->sc_tsscale.resx = sc->res_x;
+ sc->sc_tsscale.resy = sc->res_y;
+
+ return 1;
+}
+
+int
+ietp_read_reg(struct ietp_softc *sc, uint16_t reg, size_t len, void *val)
+{
+ uint8_t cmd[2] = { reg & 0xff, (reg >> 8) & 0xff };
+ int ret;
+
+ iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+
+ ret = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &cmd,
+ sizeof(cmd), val, len, I2C_F_POLL);
+
+ iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+ return ret;
+}
+
+int
+ietp_write_reg(struct ietp_softc *sc, uint16_t reg, uint16_t val)
+{
+ uint8_t cmd[4] = { reg & 0xff, (reg >> 8) & 0xff,
+ val & 0xff, (val >> 8) & 0xff };
+ int ret;
+
+ iic_acquire_bus(sc->sc_tag, 0);
+
+ ret = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, &cmd,
+ sizeof(cmd), NULL, 0, I2C_F_POLL);
+
+ iic_release_bus(sc->sc_tag, 0);
+
+ return ret;
+}
+
+void
+ietp_proc_report(struct ietp_softc *sc)
+{
+ uint8_t report[IETP_MAX_REPORT_LEN];
+ uint8_t *finger_data;
+ uint8_t report_id;
+ uint16_t len;
+ int i, s, x, y, valid_contact, pressure;
+ u_int buttons;
+
+ if (ietp_read_reg(sc, 0x00, sizeof(report), report)) {
+ printf("%s: failed reading report\n",
+ sc->sc_dev.dv_xname);
+ return;
+ }
+
+ report_id = report[IETP_REPORT_ID];
+ len = le16toh(report[0] | (report[1] << 8));
+
+ /* we seem to get 0 length reports sometimes, ignore them */
+ if (report_id != IETP_REPORT_ABSOLUTE ||
+ len < IETP_MAX_REPORT_LEN) {
+ return;
+ }
+
+ finger_data = &report[IETP_FINGER_DATA];
+
+ for (i = 0; i < IETP_MAX_FINGERS; i++) {
+ valid_contact = report[IETP_TOUCH_INFO] & (1 << (i + 3));
+
+ x = 0;
+ y = 0;
+ pressure = 0;
+
+ if (valid_contact) {
+ x = (finger_data[IETP_FINGER_XY_HIGH] & 0xF0) << 4;
+ y = (finger_data[IETP_FINGER_XY_HIGH] & 0x0F) << 8;
+
+ x |= finger_data[IETP_FINGER_X_LOW];
+ y |= finger_data[IETP_FINGER_Y_LOW];
+
+ pressure = finger_data[IETP_FINGER_PRESSURE];
+ }
+
+ wsmouse_mtstate(sc->sc_wsmousedev, i, x, y, pressure);
+ finger_data += IETP_FINGER_DATA_LEN;
+ }
+
+ buttons = 0;
+ if (report[IETP_TOUCH_INFO] & IETP_TOUCH_LMB)
+ buttons |= (1 << 0);
+ if (report[IETP_TOUCH_INFO] & IETP_TOUCH_MMB)
+ buttons |= (1 << 1);
+ if (report[IETP_TOUCH_INFO] & IETP_TOUCH_RMB)
+ buttons |= (1 << 2);
+
+ s = spltty();
+
+ wsmouse_buttons(sc->sc_wsmousedev, buttons);
+ wsmouse_input_sync(sc->sc_wsmousedev);
+
+ splx(s);
+}
+
+int
+ietp_intr(void *arg)
+{
+ struct ietp_softc *sc = arg;
+
+ if (sc->sc_busy)
+ return 1;
+
+ sc->sc_busy = 1;
+
+ ietp_proc_report(sc);
+
+ sc->sc_busy = 0;
+ wakeup(&sc->sc_busy);
+
+ return 1;
+}
Index: share/man/man4/ietp.4
===================================================================
RCS file: share/man/man4/ietp.4
diff -N share/man/man4/ietp.4
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ share/man/man4/ietp.4 12 Nov 2018 21:32:04 -0000
@@ -0,0 +1,39 @@
+.\" Copyright (c) 2018 Ben Pye <b...@curlybracket.co.uk>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: November 09 2018 $
+.Dt IETP 4
+.Os
+.Sh NAME
+.Nm ietp
+.Nd Elantech touchpad
+.Sh SYNOPSIS
+.Cd "ietp* at iic?"
+.Cd "wsmouse* at ietp? mux 0"
+.Sh DESCRIPTION
+The
+.Nm
+driver provides support for Elantech touchpad devices connected over
+Inter-Integrated Circuit (I2C) buses.
+Access to these devices is through the
+.Xr wscons 4
+driver.
+.Sh SEE ALSO
+.Xr iic 4 ,
+.Xr wsmouse 4
+.Sh AUTHORS
+The
+.Nm
+driver was written by
+.An Ben Pye Aq Mt b...@curlybracket.co.uk .
