1 files changed, 614 insertions, 81 deletions

diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index 1d2205b24800..95577c15ae56 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -40,6 +40,8 @@
 #include "psmouse.h"
 #include "hgpk.h"
 
+#define ILLEGAL_XY 999999
+
 static bool tpdebug;
 module_param(tpdebug, bool, 0644);
 MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
@@ -47,48 +49,150 @@ MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
 static int recalib_delta = 100;
 module_param(recalib_delta, int, 0644);
 MODULE_PARM_DESC(recalib_delta,
-        "packets containing a delta this large will cause a recalibration.");
+        "packets containing a delta this large will be discarded, and a "
+        "recalibration may be scheduled.");
 
-static int jumpy_delay = 1000;
+static int jumpy_delay = 20;
 module_param(jumpy_delay, int, 0644);
 MODULE_PARM_DESC(jumpy_delay,
         "delay (ms) before recal after jumpiness detected");
 
-static int spew_delay = 1000;
+static int spew_delay = 1;
 module_param(spew_delay, int, 0644);
 MODULE_PARM_DESC(spew_delay,
         "delay (ms) before recal after packet spew detected");
 
-static int recal_guard_time = 2000;
+static int recal_guard_time;
 module_param(recal_guard_time, int, 0644);
 MODULE_PARM_DESC(recal_guard_time,
         "interval (ms) during which recal will be restarted if packet received");
 
-static int post_interrupt_delay = 1000;
+static int post_interrupt_delay = 40;
 module_param(post_interrupt_delay, int, 0644);
 MODULE_PARM_DESC(post_interrupt_delay,
         "delay (ms) before recal after recal interrupt detected");
 
+static bool autorecal = true;
+module_param(autorecal, bool, 0644);
+MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");
+
+static char hgpk_mode_name[16];
+module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
+MODULE_PARM_DESC(hgpk_mode,
+        "default hgpk mode: mouse, glidesensor or pentablet");
+
+static int hgpk_default_mode = HGPK_MODE_MOUSE;
+
+static const char * const hgpk_mode_names[] = {
+        [HGPK_MODE_MOUSE] = "Mouse",
+        [HGPK_MODE_GLIDESENSOR] = "GlideSensor",
+        [HGPK_MODE_PENTABLET] = "PenTablet",
+};
+
+static int hgpk_mode_from_name(const char *buf, int len)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(hgpk_mode_names); i++) {
+                const char *name = hgpk_mode_names[i];
+                if (strlen(name) == len && !strncasecmp(name, buf, len))
+                        return i;
+        }
+
+        return HGPK_MODE_INVALID;
+}
+
+/*
+ * see if new value is within 20% of half of old value
+ */
+static int approx_half(int curr, int prev)
+{
+        int belowhalf, abovehalf;
+
+        if (curr < 5 || prev < 5)
+                return 0;
+
+        belowhalf = (prev * 8) / 20;
+        abovehalf = (prev * 12) / 20;
+
+        return belowhalf < curr && curr <= abovehalf;
+}
+
 /*
- * When the touchpad gets ultra-sensitive, one can keep their finger 1/2"
- * above the pad and still have it send packets.  This causes a jump cursor
- * when one places their finger on the pad.  We can probably detect the
- * jump as we see a large deltas (>= 100px).  In mouse mode, I've been
- * unable to even come close to 100px deltas during normal usage, so I think
- * this threshold is safe.  If a large delta occurs, trigger a recalibration.
+ * Throw out oddly large delta packets, and any that immediately follow whose
+ * values are each approximately half of the previous.  It seems that the ALPS
+ * firmware emits errant packets, and they get averaged out slowly.
  */
-static void hgpk_jumpy_hack(struct psmouse *psmouse, int x, int y)
+static int hgpk_discard_decay_hack(struct psmouse *psmouse, int x, int y)
 {
         struct hgpk_data *priv = psmouse->private;
+        int avx, avy;
+        bool do_recal = false;
+
+        avx = abs(x);
+        avy = abs(y);
+
+        /* discard if too big, or half that but > 4 times the prev delta */
+        if (avx > recalib_delta ||
+                (avx > recalib_delta / 2 && ((avx / 4) > priv->xlast))) {
+                hgpk_err(psmouse, "detected %dpx jump in x\n", x);
+                priv->xbigj = avx;
+        } else if (approx_half(avx, priv->xbigj)) {
+                hgpk_err(psmouse, "detected secondary %dpx jump in x\n", x);
+                priv->xbigj = avx;
+                priv->xsaw_secondary++;
+        } else {
+                if (priv->xbigj && priv->xsaw_secondary > 1)
+                        do_recal = true;
+                priv->xbigj = 0;
+                priv->xsaw_secondary = 0;
+        }
+
+        if (avy > recalib_delta ||
+                (avy > recalib_delta / 2 && ((avy / 4) > priv->ylast))) {
+                hgpk_err(psmouse, "detected %dpx jump in y\n", y);
+                priv->ybigj = avy;
+        } else if (approx_half(avy, priv->ybigj)) {
+                hgpk_err(psmouse, "detected secondary %dpx jump in y\n", y);
+                priv->ybigj = avy;
+                priv->ysaw_secondary++;
+        } else {
+                if (priv->ybigj && priv->ysaw_secondary > 1)
+                        do_recal = true;
+                priv->ybigj = 0;
+                priv->ysaw_secondary = 0;
+        }
 
-        if (abs(x) > recalib_delta || abs(y) > recalib_delta) {
-                hgpk_err(psmouse, ">%dpx jump detected (%d,%d)\n",
-                                recalib_delta, x, y);
-                /* My car gets forty rods to the hogshead and that's the
-                 * way I likes it! */
+        priv->xlast = avx;
+        priv->ylast = avy;
+
+        if (do_recal && jumpy_delay) {
+                hgpk_err(psmouse, "scheduling recalibration\n");
                 psmouse_queue_work(psmouse, &priv->recalib_wq,
                                 msecs_to_jiffies(jumpy_delay));
         }
+
+        return priv->xbigj || priv->ybigj;
+}
+
+static void hgpk_reset_spew_detection(struct hgpk_data *priv)
+{
+        priv->spew_count = 0;
+        priv->dupe_count = 0;
+        priv->x_tally = 0;
+        priv->y_tally = 0;
+        priv->spew_flag = NO_SPEW;
+}
+
+static void hgpk_reset_hack_state(struct psmouse *psmouse)
+{
+        struct hgpk_data *priv = psmouse->private;
+
+        priv->abs_x = priv->abs_y = -1;
+        priv->xlast = priv->ylast = ILLEGAL_XY;
+        priv->xbigj = priv->ybigj = 0;
+        priv->xsaw_secondary = priv->ysaw_secondary = 0;
+        hgpk_reset_spew_detection(priv);
 }
 
 /*
@@ -116,20 +220,57 @@ static void hgpk_spewing_hack(struct psmouse *psmouse,
         if (l || r)
                 return;
 
+        /* don't track spew if the workaround feature has been turned off */
+        if (!spew_delay)
+                return;
+
+        if (abs(x) > 3 || abs(y) > 3) {
+                /* no spew, or spew ended */
+                hgpk_reset_spew_detection(priv);
+                return;
+        }
+
+        /* Keep a tally of the overall delta to the cursor position caused by
+         * the spew */
         priv->x_tally += x;
         priv->y_tally += y;
 
-        if (++priv->count > 100) {
+        switch (priv->spew_flag) {
+        case NO_SPEW:
+                /* we're not spewing, but this packet might be the start */
+                priv->spew_flag = MAYBE_SPEWING;
+
+                /* fall-through */
+
+        case MAYBE_SPEWING:
+                priv->spew_count++;
+
+                if (priv->spew_count < SPEW_WATCH_COUNT)
+                        break;
+
+                /* excessive spew detected, request recalibration */
+                priv->spew_flag = SPEW_DETECTED;
+
+                /* fall-through */
+
+        case SPEW_DETECTED:
+                /* only recalibrate when the overall delta to the cursor
+                 * is really small. if the spew is causing significant cursor
+                 * movement, it is probably a case of the user moving the
+                 * cursor very slowly across the screen. */
                 if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
-                        hgpk_dbg(psmouse, "packet spew detected (%d,%d)\n",
+                        hgpk_err(psmouse, "packet spew detected (%d,%d)\n",
                                  priv->x_tally, priv->y_tally);
+                        priv->spew_flag = RECALIBRATING;
                         psmouse_queue_work(psmouse, &priv->recalib_wq,
                                            msecs_to_jiffies(spew_delay));
                 }
-                /* reset every 100 packets */
-                priv->count = 0;
-                priv->x_tally = 0;
-                priv->y_tally = 0;
+
+                break;
+        case RECALIBRATING:
+                /* we already detected a spew and requested a recalibration,
+                 * just wait for the queue to kick into action. */
+                break;
         }
 }
 
@@ -143,25 +284,168 @@ static void hgpk_spewing_hack(struct psmouse *psmouse,
  * swr/swl are the left/right buttons.
  * x-neg/y-neg are the x and y delta negative bits
  * x-over/y-over are the x and y overflow bits
+ *
+ * ---
+ *
+ * HGPK Advanced Mode - single-mode format
+ *
+ * byte 0(PT):  1    1    0    0    1    1     1     1
+ * byte 0(GS):  1    1    1    1    1    1     1     1
+ * byte 1:      0   x6   x5   x4   x3   x2    x1    x0
+ * byte 2(PT):  0    0   x9   x8   x7    ? pt-dsw    0
+ * byte 2(GS):  0  x10   x9   x8   x7    ? gs-dsw pt-dsw
+ * byte 3:      0   y9   y8   y7    1    0   swr   swl
+ * byte 4:      0   y6   y5   y4   y3   y2    y1    y0
+ * byte 5:      0   z6   z5   z4   z3   z2    z1    z0
+ *
+ * ?'s are not defined in the protocol spec, may vary between models.
+ *
+ * swr/swl are the left/right buttons.
+ *
+ * pt-dsw/gs-dsw indicate that the pt/gs sensor is detecting a
+ * pen/finger
  */
-static int hgpk_validate_byte(unsigned char *packet)
+static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
 {
-        return (packet[0] & 0x0C) != 0x08;
+        struct hgpk_data *priv = psmouse->private;
+        int pktcnt = psmouse->pktcnt;
+        bool valid;
+
+        switch (priv->mode) {
+        case HGPK_MODE_MOUSE:
+                valid = (packet[0] & 0x0C) == 0x08;
+                break;
+
+        case HGPK_MODE_GLIDESENSOR:
+                valid = pktcnt == 1 ?
+                        packet[0] == HGPK_GS : !(packet[pktcnt - 1] & 0x80);
+                break;
+
+        case HGPK_MODE_PENTABLET:
+                valid = pktcnt == 1 ?
+                        packet[0] == HGPK_PT : !(packet[pktcnt - 1] & 0x80);
+                break;
+
+        default:
+                valid = false;
+                break;
+        }
+
+        if (!valid)
+                hgpk_dbg(psmouse,
+                         "bad data, mode %d (%d) %02x %02x %02x %02x %02x %02x\n",
+                         priv->mode, pktcnt,
+                         psmouse->packet[0], psmouse->packet[1],
+                         psmouse->packet[2], psmouse->packet[3],
+                         psmouse->packet[4], psmouse->packet[5]);
+
+        return valid;
 }
 
-static void hgpk_process_packet(struct psmouse *psmouse)
+static void hgpk_process_advanced_packet(struct psmouse *psmouse)
 {
-        struct input_dev *dev = psmouse->dev;
+        struct hgpk_data *priv = psmouse->private;
+        struct input_dev *idev = psmouse->dev;
         unsigned char *packet = psmouse->packet;
-        int x, y, left, right;
+        int down = !!(packet[2] & 2);
+        int left = !!(packet[3] & 1);
+        int right = !!(packet[3] & 2);
+        int x = packet[1] | ((packet[2] & 0x78) << 4);
+        int y = packet[4] | ((packet[3] & 0x70) << 3);
+
+        if (priv->mode == HGPK_MODE_GLIDESENSOR) {
+                int pt_down = !!(packet[2] & 1);
+                int finger_down = !!(packet[2] & 2);
+                int z = packet[5];
+
+                input_report_abs(idev, ABS_PRESSURE, z);
+                if (tpdebug)
+                        hgpk_dbg(psmouse, "pd=%d fd=%d z=%d",
+                                 pt_down, finger_down, z);
+        } else {
+                /*
+                 * PenTablet mode does not report pressure, so we don't
+                 * report it here
+                 */
+                if (tpdebug)
+                        hgpk_dbg(psmouse, "pd=%d ", down);
+        }
+
+        if (tpdebug)
+                hgpk_dbg(psmouse, "l=%d r=%d x=%d y=%d\n", left, right, x, y);
+
+        input_report_key(idev, BTN_TOUCH, down);
+        input_report_key(idev, BTN_LEFT, left);
+        input_report_key(idev, BTN_RIGHT, right);
+
+        /*
+         * If this packet says that the finger was removed, reset our position
+         * tracking so that we don't erroneously detect a jump on next press.
+         */
+        if (!down) {
+                hgpk_reset_hack_state(psmouse);
+                goto done;
+        }
+
+        /*
+         * Weed out duplicate packets (we get quite a few, and they mess up
+         * our jump detection)
+         */
+        if (x == priv->abs_x && y == priv->abs_y) {
+                if (++priv->dupe_count > SPEW_WATCH_COUNT) {
+                        if (tpdebug)
+                                hgpk_dbg(psmouse, "hard spew detected\n");
+                        priv->spew_flag = RECALIBRATING;
+                        psmouse_queue_work(psmouse, &priv->recalib_wq,
+                                           msecs_to_jiffies(spew_delay));
+                }
+                goto done;
+        }
 
-        left = packet[0] & 1;
-        right = (packet[0] >> 1) & 1;
+        /* not a duplicate, continue with position reporting */
+        priv->dupe_count = 0;
+
+        /* Don't apply hacks in PT mode, it seems reliable */
+        if (priv->mode != HGPK_MODE_PENTABLET && priv->abs_x != -1) {
+                int x_diff = priv->abs_x - x;
+                int y_diff = priv->abs_y - y;
+                if (hgpk_discard_decay_hack(psmouse, x_diff, y_diff)) {
+                        if (tpdebug)
+                                hgpk_dbg(psmouse, "discarding\n");
+                        goto done;
+                }
+                hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
+        }
 
-        x = packet[1] - ((packet[0] << 4) & 0x100);
-        y = ((packet[0] << 3) & 0x100) - packet[2];
+        input_report_abs(idev, ABS_X, x);
+        input_report_abs(idev, ABS_Y, y);
+        priv->abs_x = x;
+        priv->abs_y = y;
+
+done:
+        input_sync(idev);
+}
+
+static void hgpk_process_simple_packet(struct psmouse *psmouse)
+{
+        struct input_dev *dev = psmouse->dev;
+        unsigned char *packet = psmouse->packet;
+        int left = packet[0] & 1;
+        int right = (packet[0] >> 1) & 1;
+        int x = packet[1] - ((packet[0] << 4) & 0x100);
+        int y = ((packet[0] << 3) & 0x100) - packet[2];
+
+        if (packet[0] & 0xc0)
+                hgpk_dbg(psmouse,
+                         "overflow -- 0x%02x 0x%02x 0x%02x\n",
+                         packet[0], packet[1], packet[2]);
+
+        if (hgpk_discard_decay_hack(psmouse, x, y)) {
+                if (tpdebug)
+                        hgpk_dbg(psmouse, "discarding\n");
+                return;
+        }
 
-        hgpk_jumpy_hack(psmouse, x, y);
         hgpk_spewing_hack(psmouse, left, right, x, y);
 
         if (tpdebug)
@@ -180,15 +464,14 @@ static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
 {
         struct hgpk_data *priv = psmouse->private;
 
-        if (hgpk_validate_byte(psmouse->packet)) {
-                hgpk_dbg(psmouse, "%s: (%d) %02x %02x %02x\n",
-                                __func__, psmouse->pktcnt, psmouse->packet[0],
-                                psmouse->packet[1], psmouse->packet[2]);
+        if (!hgpk_is_byte_valid(psmouse, psmouse->packet))
                 return PSMOUSE_BAD_DATA;
-        }
 
         if (psmouse->pktcnt >= psmouse->pktsize) {
-                hgpk_process_packet(psmouse);
+                if (priv->mode == HGPK_MODE_MOUSE)
+                        hgpk_process_simple_packet(psmouse);
+                else
+                        hgpk_process_advanced_packet(psmouse);
                 return PSMOUSE_FULL_PACKET;
         }
 
@@ -210,33 +493,176 @@ static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
         return PSMOUSE_GOOD_DATA;
 }
 
+static int hgpk_select_mode(struct psmouse *psmouse)
+{
+        struct ps2dev *ps2dev = &psmouse->ps2dev;
+        struct hgpk_data *priv = psmouse->private;
+        int i;
+        int cmd;
+
+        /*
+         * 4 disables to enable advanced mode
+         * then 3 0xf2 bytes as the preamble for GS/PT selection
+         */
+        const int advanced_init[] = {
+                PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
+                PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
+                0xf2, 0xf2, 0xf2,
+        };
+
+        switch (priv->mode) {
+        case HGPK_MODE_MOUSE:
+                psmouse->pktsize = 3;
+                break;
+
+        case HGPK_MODE_GLIDESENSOR:
+        case HGPK_MODE_PENTABLET:
+                psmouse->pktsize = 6;
+
+                /* Switch to 'Advanced mode.', four disables in a row. */
+                for (i = 0; i < ARRAY_SIZE(advanced_init); i++)
+                        if (ps2_command(ps2dev, NULL, advanced_init[i]))
+                                return -EIO;
+
+                /* select between GlideSensor (mouse) or PenTablet */
+                cmd = priv->mode == HGPK_MODE_GLIDESENSOR ?
+                        PSMOUSE_CMD_SETSCALE11 : PSMOUSE_CMD_SETSCALE21;
+
+                if (ps2_command(ps2dev, NULL, cmd))
+                        return -EIO;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static void hgpk_setup_input_device(struct input_dev *input,
+                                    struct input_dev *old_input,
+                                    enum hgpk_mode mode)
+{
+        if (old_input) {
+                input->name = old_input->name;
+                input->phys = old_input->phys;
+                input->id = old_input->id;
+                input->dev.parent = old_input->dev.parent;
+        }
+
+        memset(input->evbit, 0, sizeof(input->evbit));
+        memset(input->relbit, 0, sizeof(input->relbit));
+        memset(input->keybit, 0, sizeof(input->keybit));
+
+        /* All modes report left and right buttons */
+        __set_bit(EV_KEY, input->evbit);
+        __set_bit(BTN_LEFT, input->keybit);
+        __set_bit(BTN_RIGHT, input->keybit);
+
+        switch (mode) {
+        case HGPK_MODE_MOUSE:
+                __set_bit(EV_REL, input->evbit);
+                __set_bit(REL_X, input->relbit);
+                __set_bit(REL_Y, input->relbit);
+                break;
+
+        case HGPK_MODE_GLIDESENSOR:
+                __set_bit(BTN_TOUCH, input->keybit);
+                __set_bit(BTN_TOOL_FINGER, input->keybit);
+
+                __set_bit(EV_ABS, input->evbit);
+
+                /* GlideSensor has pressure sensor, PenTablet does not */
+                input_set_abs_params(input, ABS_PRESSURE, 0, 15, 0, 0);
+
+                /* From device specs */
+                input_set_abs_params(input, ABS_X, 0, 399, 0, 0);
+                input_set_abs_params(input, ABS_Y, 0, 290, 0, 0);
+
+                /* Calculated by hand based on usable size (52mm x 38mm) */
+                input_abs_set_res(input, ABS_X, 8);
+                input_abs_set_res(input, ABS_Y, 8);
+                break;
+
+        case HGPK_MODE_PENTABLET:
+                __set_bit(BTN_TOUCH, input->keybit);
+                __set_bit(BTN_TOOL_FINGER, input->keybit);
+
+                __set_bit(EV_ABS, input->evbit);
+
+                /* From device specs */
+                input_set_abs_params(input, ABS_X, 0, 999, 0, 0);
+                input_set_abs_params(input, ABS_Y, 5, 239, 0, 0);
+
+                /* Calculated by hand based on usable size (156mm x 38mm) */
+                input_abs_set_res(input, ABS_X, 6);
+                input_abs_set_res(input, ABS_Y, 8);
+                break;
+
+        default:
+                BUG();
+        }
+}
+
+static int hgpk_reset_device(struct psmouse *psmouse, bool recalibrate)
+{
+        int err;
+
+        psmouse_reset(psmouse);
+
+        if (recalibrate) {
+                struct ps2dev *ps2dev = &psmouse->ps2dev;
+
+                /* send the recalibrate request */
+                if (ps2_command(ps2dev, NULL, 0xf5) ||
+                    ps2_command(ps2dev, NULL, 0xf5) ||
+                    ps2_command(ps2dev, NULL, 0xe6) ||
+                    ps2_command(ps2dev, NULL, 0xf5)) {
+                        return -1;
+                }
+
+                /* according to ALPS, 150mS is required for recalibration */
+                msleep(150);
+        }
+
+        err = hgpk_select_mode(psmouse);
+        if (err) {
+                hgpk_err(psmouse, "failed to select mode\n");
+                return err;
+        }
+
+        hgpk_reset_hack_state(psmouse);
+
+        return 0;
+}
+
 static int hgpk_force_recalibrate(struct psmouse *psmouse)
 {
         struct ps2dev *ps2dev = &psmouse->ps2dev;
         struct hgpk_data *priv = psmouse->private;
+        int err;
 
         /* C-series touchpads added the recalibrate command */
         if (psmouse->model < HGPK_MODEL_C)
                 return 0;
 
+        if (!autorecal) {
+                hgpk_dbg(psmouse, "recalibrations disabled, ignoring\n");
+                return 0;
+        }
+
+        hgpk_dbg(psmouse, "recalibrating touchpad..\n");
+
         /* we don't want to race with the irq handler, nor with resyncs */
         psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
 
         /* start by resetting the device */
-        psmouse_reset(psmouse);
-
-        /* send the recalibrate request */
-        if (ps2_command(ps2dev, NULL, 0xf5) ||
-            ps2_command(ps2dev, NULL, 0xf5) ||
-            ps2_command(ps2dev, NULL, 0xe6) ||
-            ps2_command(ps2dev, NULL, 0xf5)) {
-                return -1;
-        }
-
-        /* according to ALPS, 150mS is required for recalibration */
-        msleep(150);
+        err = hgpk_reset_device(psmouse, true);
+        if (err)
+                return err;
 
-        /* XXX: If a finger is down during this delay, recalibration will
+        /*
+         * XXX: If a finger is down during this delay, recalibration will
          * detect capacitance incorrectly.  This is a hardware bug, and
          * we don't have a good way to deal with it.  The 2s window stuff
          * (below) is our best option for now.
@@ -247,25 +673,35 @@ static int hgpk_force_recalibrate(struct psmouse *psmouse)
 
         psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
 
-        /* After we recalibrate, we shouldn't get any packets for 2s.  If
-         * we do, it's likely that someone's finger was on the touchpad.
-         * If someone's finger *was* on the touchpad, it's probably
-         * miscalibrated.  So, we should schedule another recalibration
+        if (tpdebug)
+                hgpk_dbg(psmouse, "touchpad reactivated\n");
+
+        /*
+         * If we get packets right away after recalibrating, it's likely
+         * that a finger was on the touchpad.  If so, it's probably
+         * miscalibrated, so we optionally schedule another.
          */
-        priv->recalib_window = jiffies +  msecs_to_jiffies(recal_guard_time);
+        if (recal_guard_time)
+                priv->recalib_window = jiffies +
+                        msecs_to_jiffies(recal_guard_time);
 
         return 0;
 }
 
 /*
- * This kills power to the touchpad; according to ALPS, current consumption
- * goes down to 50uA after running this.  To turn power back on, we drive
- * MS-DAT low.
+ * This puts the touchpad in a power saving mode; according to ALPS, current
+ * consumption goes down to 50uA after running this.  To turn power back on,
+ * we drive MS-DAT low.  Measuring with a 1mA resolution ammeter says that
+ * the current on the SUS_3.3V rail drops from 3mA or 4mA to 0 when we do this.
+ *
+ * We have no formal spec that details this operation -- the low-power
+ * sequence came from a long-lost email trail.
  */
-static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
+static int hgpk_toggle_powersave(struct psmouse *psmouse, int enable)
 {
         struct ps2dev *ps2dev = &psmouse->ps2dev;
         int timeo;
+        int err;
 
         /* Added on D-series touchpads */
         if (psmouse->model < HGPK_MODEL_D)
@@ -279,24 +715,27 @@ static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
                  * the controller.  Once we get an ACK back from it, it
                  * means we can continue with the touchpad re-init.  ALPS
                  * tells us that 1s should be long enough, so set that as
-                 * the upper bound.
+                 * the upper bound. (in practice, it takes about 3 loops.)
                  */
                 for (timeo = 20; timeo > 0; timeo--) {
                         if (!ps2_sendbyte(&psmouse->ps2dev,
                                         PSMOUSE_CMD_DISABLE, 20))
                                 break;
-                        msleep(50);
+                        msleep(25);
                 }
 
-                psmouse_reset(psmouse);
+                err = hgpk_reset_device(psmouse, false);
+                if (err) {
+                        hgpk_err(psmouse, "Failed to reset device!\n");
+                        return err;
+                }
 
                 /* should be all set, enable the touchpad */
                 ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE);
                 psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
-
+                hgpk_dbg(psmouse, "Touchpad powered up.\n");
         } else {
                 hgpk_dbg(psmouse, "Powering off touchpad.\n");
-                psmouse_set_state(psmouse, PSMOUSE_IGNORE);
 
                 if (ps2_command(ps2dev, NULL, 0xec) ||
                     ps2_command(ps2dev, NULL, 0xec) ||
@@ -304,6 +743,8 @@ static int hgpk_toggle_power(struct psmouse *psmouse, int enable)
                         return -1;
                 }
 
+                psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+
                 /* probably won't see an ACK, the touchpad will be off */
                 ps2_sendbyte(&psmouse->ps2dev, 0xec, 20);
         }
@@ -319,17 +760,20 @@ static int hgpk_poll(struct psmouse *psmouse)
 
 static int hgpk_reconnect(struct psmouse *psmouse)
 {
-        /* During suspend/resume the ps2 rails remain powered.  We don't want
+        struct hgpk_data *priv = psmouse->private;
+
+        /*
+         * During suspend/resume the ps2 rails remain powered.  We don't want
          * to do a reset because it's flush data out of buffers; however,
-         * earlier prototypes (B1) had some brokenness that required a reset. */
+         * earlier prototypes (B1) had some brokenness that required a reset.
+         */
         if (olpc_board_at_least(olpc_board(0xb2)))
                 if (psmouse->ps2dev.serio->dev.power.power_state.event !=
                                 PM_EVENT_ON)
                         return 0;
 
-        psmouse_reset(psmouse);
-
-        return 0;
+        priv->powered = 1;
+        return hgpk_reset_device(psmouse, false);
 }
 
 static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
@@ -355,7 +799,7 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
                  * hgpk_toggle_power will deal w/ state so
                  * we're not racing w/ irq
                  */
-                err = hgpk_toggle_power(psmouse, value);
+                err = hgpk_toggle_powersave(psmouse, value);
                 if (!err)
                         priv->powered = value;
         }
@@ -366,6 +810,65 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
 __PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
                       hgpk_show_powered, hgpk_set_powered, false);
 
+static ssize_t attr_show_mode(struct psmouse *psmouse, void *data, char *buf)
+{
+        struct hgpk_data *priv = psmouse->private;
+
+        return sprintf(buf, "%s\n", hgpk_mode_names[priv->mode]);
+}
+
+static ssize_t attr_set_mode(struct psmouse *psmouse, void *data,
+                             const char *buf, size_t len)
+{
+        struct hgpk_data *priv = psmouse->private;
+        enum hgpk_mode old_mode = priv->mode;
+        enum hgpk_mode new_mode = hgpk_mode_from_name(buf, len);
+        struct input_dev *old_dev = psmouse->dev;
+        struct input_dev *new_dev;
+        int err;
+
+        if (new_mode == HGPK_MODE_INVALID)
+                return -EINVAL;
+
+        if (old_mode == new_mode)
+                return len;
+
+        new_dev = input_allocate_device();
+        if (!new_dev)
+                return -ENOMEM;
+
+        psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+        /* Switch device into the new mode */
+        priv->mode = new_mode;
+        err = hgpk_reset_device(psmouse, false);
+        if (err)
+                goto err_try_restore;
+
+        hgpk_setup_input_device(new_dev, old_dev, new_mode);
+
+        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
+
+        err = input_register_device(new_dev);
+        if (err)
+                goto err_try_restore;
+
+        psmouse->dev = new_dev;
+        input_unregister_device(old_dev);
+
+        return len;
+
+err_try_restore:
+        input_free_device(new_dev);
+        priv->mode = old_mode;
+        hgpk_reset_device(psmouse, false);
+
+        return err;
+}
+
+PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
+                    attr_show_mode, attr_set_mode);
+
 static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
                 void *data, char *buf)
 {
@@ -401,6 +904,8 @@ static void hgpk_disconnect(struct psmouse *psmouse)
 
         device_remove_file(&psmouse->ps2dev.serio->dev,
                            &psmouse_attr_powered.dattr);
+        device_remove_file(&psmouse->ps2dev.serio->dev,
+                           &psmouse_attr_hgpk_mode.dattr);
 
         if (psmouse->model >= HGPK_MODEL_C)
                 device_remove_file(&psmouse->ps2dev.serio->dev,
@@ -416,14 +921,13 @@ static void hgpk_recalib_work(struct work_struct *work)
         struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
         struct psmouse *psmouse = priv->psmouse;
 
-        hgpk_dbg(psmouse, "recalibrating touchpad..\n");
-
         if (hgpk_force_recalibrate(psmouse))
                 hgpk_err(psmouse, "recalibration failed!\n");
 }
 
 static int hgpk_register(struct psmouse *psmouse)
 {
+        struct hgpk_data *priv = psmouse->private;
         int err;
 
         /* register handlers */
@@ -431,13 +935,14 @@ static int hgpk_register(struct psmouse *psmouse)
         psmouse->poll = hgpk_poll;
         psmouse->disconnect = hgpk_disconnect;
         psmouse->reconnect = hgpk_reconnect;
-        psmouse->pktsize = 3;
 
         /* Disable the idle resync. */
         psmouse->resync_time = 0;
         /* Reset after a lot of bad bytes. */
         psmouse->resetafter = 1024;
 
+        hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);
+
         err = device_create_file(&psmouse->ps2dev.serio->dev,
                                  &psmouse_attr_powered.dattr);
         if (err) {
@@ -445,6 +950,13 @@ static int hgpk_register(struct psmouse *psmouse)
                 return err;
         }
 
+        err = device_create_file(&psmouse->ps2dev.serio->dev,
+                                 &psmouse_attr_hgpk_mode.dattr);
+        if (err) {
+                hgpk_err(psmouse, "Failed creating 'hgpk_mode' sysfs node\n");
+                goto err_remove_powered;
+        }
+
         /* C-series touchpads added the recalibrate command */
         if (psmouse->model >= HGPK_MODEL_C) {
                 err = device_create_file(&psmouse->ps2dev.serio->dev,
@@ -452,30 +964,40 @@ static int hgpk_register(struct psmouse *psmouse)
                 if (err) {
                         hgpk_err(psmouse,
                                 "Failed creating 'recalibrate' sysfs node\n");
-                        device_remove_file(&psmouse->ps2dev.serio->dev,
-                                        &psmouse_attr_powered.dattr);
-                        return err;
+                        goto err_remove_mode;
                 }
         }
 
         return 0;
+
+err_remove_mode:
+        device_remove_file(&psmouse->ps2dev.serio->dev,
+                           &psmouse_attr_hgpk_mode.dattr);
+err_remove_powered:
+        device_remove_file(&psmouse->ps2dev.serio->dev,
+                           &psmouse_attr_powered.dattr);
+        return err;
 }
 
 int hgpk_init(struct psmouse *psmouse)
 {
         struct hgpk_data *priv;
-        int err = -ENOMEM;
+        int err;
 
         priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
-        if (!priv)
+        if (!priv) {
+                err = -ENOMEM;
                 goto alloc_fail;
+        }
 
         psmouse->private = priv;
+
         priv->psmouse = psmouse;
         priv->powered = true;
+        priv->mode = hgpk_default_mode;
         INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
 
-        err = psmouse_reset(psmouse);
+        err = hgpk_reset_device(psmouse, false);
         if (err)
                 goto init_fail;
 
@@ -531,3 +1053,14 @@ int hgpk_detect(struct psmouse *psmouse, bool set_properties)
 
         return 0;
 }
+
+void hgpk_module_init(void)
+{
+        hgpk_default_mode = hgpk_mode_from_name(hgpk_mode_name,
+                                                strlen(hgpk_mode_name));
+        if (hgpk_default_mode == HGPK_MODE_INVALID) {
+                hgpk_default_mode = HGPK_MODE_MOUSE;
+                strlcpy(hgpk_mode_name, hgpk_mode_names[HGPK_MODE_MOUSE],
+                        sizeof(hgpk_mode_name));
+        }
+}