From 4dc772d274abdedcccbcebab42d4bf0016ec2e80 Mon Sep 17 00:00:00 2001 From: Daniel Kurtz Date: Tue, 23 Aug 2011 23:02:40 -0700 Subject: [PATCH] Input: synaptics - process finger (<=3) transitions Synaptics image sensor touchpads track 5 fingers, but only report 2. This patch attempts to deal with some idiosyncrasies of these touchpads: * When there are 3 or more fingers, only two are reported. * The touchpad tracks the 5 fingers in slot[0] through slot[4]. * It always reports the lowest and highest valid slots in SGM and AGM packets, respectively. * The number of fingers is only reported in the SGM packet. However, the number of fingers can change either before or after an AGM packet. * Thus, if an SGM reports a different number of fingers than the last SGM, it is impossible to tell whether the intervening AGM corresponds to the old number of fingers or the new number of fingers. * For example, when going from 2->3 fingers, it is not possible to tell whether tell AGM contains slot[1] (old 2nd finger) or slot[2] (new 3rd finger). * When fingers are added one at at time, from 1->2->3, it is possible to track which slots are contained in the SGM and AGM packets: 1 finger: SGM = slot[0], no AGM 2 fingers: SGM = slot[0], AGM = slot[1] 3 fingers: SGM = slot[0], AGM = slot[2] * It is also possible to track which slot is contained in the SGM when 1 of 2 fingers is removed. This is because the touchpad sends a special (0,0,0) AGM packet whenever all fingers are removed except slot[0]: Last AGM == (0,0,0): SGM contains slot[1] Else: SGM contains slot[0] * However, once there are 3 fingers, if exactly 1 finger is removed, it is impossible to tell which 2 slots are contained in SGM and AGM. The (SGM,AGM) could be (0,1), (0,2), or (1,2). There is no way to know. * Similarly, if two fingers are simultaneously removed (3->1), then it is only possible to know if SGM still contains slot[0]. * Since it is not possible to reliably track which slot is being reported, we invalidate the tracking_id every time the number of fingers changes until this ambiguity is resolved when: a) All fingers are removed. b) 4 or 5 fingers are touched, generates an AGM-CONTACT packet. c) All fingers are removed except slot[0]. In this special case, the ambiguity is resolved since by the (0,0,0) AGM packet. Behavior of the driver: When 2 or more fingers are present on the touchpad, the kernel reports up to two MT-B slots containing the position data for two of the fingers reported by the touchpad. If the identity of a finger cannot be tracked when the number-of-fingers changes, the corresponding MT-B slot will be invalidated (track_id set to -1), and a new track_id will be assigned in a subsequent input event report. The driver always reports the total number of fingers using one of the EV_KEY/BTN_TOOL_*TAP events. This could differ from the number of valid MT-B slots for two reasons: a) There are more than 2 fingers on the pad. b) During ambiguous number-of-fingers transitions, the correct track_id for one or both of the slots cannot be determined, so the slots are invalidated. Thus, this is a hybrid singletouch/MT-B scheme. Userspace can detect this behavior by noting that the driver supports more EV_KEY/BTN_TOOL_*TAP events than its maximum EV_ABS/ABS_MT_SLOT. Signed-off-by: Daniel Kurtz Acked-by: Chase Douglas Acked-by: Henrik Rydberg Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/synaptics.c | 290 ++++++++++++++++++++++++++++++-- drivers/input/mouse/synaptics.h | 4 + 2 files changed, 278 insertions(+), 16 deletions(-) diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index a7af8565e2de..aec9cf7124f8 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -453,6 +453,9 @@ static void synaptics_parse_agm(const unsigned char buf[], default: break; } + + /* Record that at least one AGM has been received since last SGM */ + priv->agm_pending = true; } static int synaptics_parse_hw_state(const unsigned char buf[], @@ -606,26 +609,53 @@ static void synaptics_report_slot(struct input_dev *dev, int slot, } static void synaptics_report_mt_data(struct psmouse *psmouse, - int count, + struct synaptics_mt_state *mt_state, const struct synaptics_hw_state *sgm) { struct input_dev *dev = psmouse->dev; struct synaptics_data *priv = psmouse->private; struct synaptics_hw_state *agm = &priv->agm; + struct synaptics_mt_state *old = &priv->mt_state; - switch (count) { + switch (mt_state->count) { case 0: synaptics_report_slot(dev, 0, NULL); synaptics_report_slot(dev, 1, NULL); break; case 1: - synaptics_report_slot(dev, 0, sgm); - synaptics_report_slot(dev, 1, NULL); + if (mt_state->sgm == -1) { + synaptics_report_slot(dev, 0, NULL); + synaptics_report_slot(dev, 1, NULL); + } else if (mt_state->sgm == 0) { + synaptics_report_slot(dev, 0, sgm); + synaptics_report_slot(dev, 1, NULL); + } else { + synaptics_report_slot(dev, 0, NULL); + synaptics_report_slot(dev, 1, sgm); + } break; - case 2: - case 3: /* Fall-through case */ - synaptics_report_slot(dev, 0, sgm); - synaptics_report_slot(dev, 1, agm); + default: + /* + * If the finger slot contained in SGM is valid, and either + * hasn't changed, or is new, then report SGM in MTB slot 0. + * Otherwise, empty MTB slot 0. + */ + if (mt_state->sgm != -1 && + (mt_state->sgm == old->sgm || old->sgm == -1)) + synaptics_report_slot(dev, 0, sgm); + else + synaptics_report_slot(dev, 0, NULL); + + /* + * If the finger slot contained in AGM is valid, and either + * hasn't changed, or is new, then report AGM in MTB slot 1. + * Otherwise, empty MTB slot 1. + */ + if (mt_state->agm != -1 && + (mt_state->agm == old->agm || old->agm == -1)) + synaptics_report_slot(dev, 1, agm); + else + synaptics_report_slot(dev, 1, NULL); break; } @@ -633,29 +663,257 @@ static void synaptics_report_mt_data(struct psmouse *psmouse, input_mt_report_pointer_emulation(dev, false); /* Send the number of fingers reported by touchpad itself. */ - input_mt_report_finger_count(dev, count); + input_mt_report_finger_count(dev, mt_state->count); synaptics_report_buttons(psmouse, sgm); input_sync(dev); } +/* Handle case where mt_state->count = 0 */ +static void synaptics_image_sensor_0f(struct synaptics_data *priv, + struct synaptics_mt_state *mt_state) +{ + synaptics_mt_state_set(mt_state, 0, -1, -1); + priv->mt_state_lost = false; +} + +/* Handle case where mt_state->count = 1 */ +static void synaptics_image_sensor_1f(struct synaptics_data *priv, + struct synaptics_mt_state *mt_state) +{ + struct synaptics_hw_state *agm = &priv->agm; + struct synaptics_mt_state *old = &priv->mt_state; + + /* + * If the last AGM was (0,0,0), and there is only one finger left, + * then we absolutely know that SGM contains slot 0, and all other + * fingers have been removed. + */ + if (priv->agm_pending && agm->z == 0) { + synaptics_mt_state_set(mt_state, 1, 0, -1); + priv->mt_state_lost = false; + return; + } + + switch (old->count) { + case 0: + synaptics_mt_state_set(mt_state, 1, 0, -1); + break; + case 1: + /* + * If mt_state_lost, then the previous transition was 3->1, + * and SGM now contains either slot 0 or 1, but we don't know + * which. So, we just assume that the SGM now contains slot 1. + * + * If pending AGM and either: + * (a) the previous SGM slot contains slot 0, or + * (b) there was no SGM slot + * then, the SGM now contains slot 1 + * + * Case (a) happens with very rapid "drum roll" gestures, where + * slot 0 finger is lifted and a new slot 1 finger touches + * within one reporting interval. + * + * Case (b) happens if initially two or more fingers tap + * briefly, and all but one lift before the end of the first + * reporting interval. + * + * (In both these cases, slot 0 will becomes empty, so SGM + * contains slot 1 with the new finger) + * + * Else, if there was no previous SGM, it now contains slot 0. + * + * Otherwise, SGM still contains the same slot. + */ + if (priv->mt_state_lost || + (priv->agm_pending && old->sgm <= 0)) + synaptics_mt_state_set(mt_state, 1, 1, -1); + else if (old->sgm == -1) + synaptics_mt_state_set(mt_state, 1, 0, -1); + break; + case 2: + /* + * If mt_state_lost, we don't know which finger SGM contains. + * + * So, report 1 finger, but with both slots empty. + * We will use slot 1 on subsequent 1->1 + */ + if (priv->mt_state_lost) { + synaptics_mt_state_set(mt_state, 1, -1, -1); + break; + } + /* + * Since the last AGM was NOT (0,0,0), it was the finger in + * slot 0 that has been removed. + * So, SGM now contains previous AGM's slot, and AGM is now + * empty. + */ + synaptics_mt_state_set(mt_state, 1, old->agm, -1); + break; + case 3: + /* + * Since last AGM was not (0,0,0), we don't know which finger + * is left. + * + * So, report 1 finger, but with both slots empty. + * We will use slot 1 on subsequent 1->1 + */ + synaptics_mt_state_set(mt_state, 1, -1, -1); + priv->mt_state_lost = true; + break; + } +} + +/* Handle case where mt_state->count = 2 */ +static void synaptics_image_sensor_2f(struct synaptics_data *priv, + struct synaptics_mt_state *mt_state) +{ + struct synaptics_mt_state *old = &priv->mt_state; + + switch (old->count) { + case 0: + synaptics_mt_state_set(mt_state, 2, 0, 1); + break; + case 1: + /* + * If previous SGM contained slot 1 or higher, SGM now contains + * slot 0 (the newly touching finger) and AGM contains SGM's + * previous slot. + * + * Otherwise, SGM still contains slot 0 and AGM now contains + * slot 1. + */ + if (old->sgm >= 1) + synaptics_mt_state_set(mt_state, 2, 0, old->sgm); + else + synaptics_mt_state_set(mt_state, 2, 0, 1); + break; + case 2: + /* + * If mt_state_lost, SGM now contains either finger 1 or 2, but + * we don't know which. + * So, we just assume that the SGM contains slot 0 and AGM 1. + */ + if (priv->mt_state_lost) + synaptics_mt_state_set(mt_state, 2, 0, 1); + /* + * Otherwise, use the same mt_state, since it either hasn't + * changed, or was updated by a recently received AGM-CONTACT + * packet. + */ + break; + case 3: + /* + * 3->2 transitions have two unsolvable problems: + * 1) no indication is given which finger was removed + * 2) no way to tell if agm packet was for finger 3 + * before 3->2, or finger 2 after 3->2. + * + * So, report 2 fingers, but empty all slots. + * We will guess slots [0,1] on subsequent 2->2. + */ + synaptics_mt_state_set(mt_state, 2, -1, -1); + priv->mt_state_lost = true; + break; + } +} + +/* Handle case where mt_state->count = 3 */ +static void synaptics_image_sensor_3f(struct synaptics_data *priv, + struct synaptics_mt_state *mt_state) +{ + struct synaptics_mt_state *old = &priv->mt_state; + + switch (old->count) { + case 0: + synaptics_mt_state_set(mt_state, 3, 0, 2); + break; + case 1: + /* + * If previous SGM contained slot 2 or higher, SGM now contains + * slot 0 (one of the newly touching fingers) and AGM contains + * SGM's previous slot. + * + * Otherwise, SGM now contains slot 0 and AGM contains slot 2. + */ + if (old->sgm >= 2) + synaptics_mt_state_set(mt_state, 3, 0, old->sgm); + else + synaptics_mt_state_set(mt_state, 3, 0, 2); + break; + case 2: + /* + * After some 3->1 and all 3->2 transitions, we lose track + * of which slot is reported by SGM and AGM. + * + * For 2->3 in this state, report 3 fingers, but empty all + * slots, and we will guess (0,2) on a subsequent 0->3. + * + * To userspace, the resulting transition will look like: + * 2:[0,1] -> 3:[-1,-1] -> 3:[0,2] + */ + if (priv->mt_state_lost) { + synaptics_mt_state_set(mt_state, 3, -1, -1); + break; + } + + /* + * If the (SGM,AGM) really previously contained slots (0, 1), + * then we cannot know what slot was just reported by the AGM, + * because the 2->3 transition can occur either before or after + * the AGM packet. Thus, this most recent AGM could contain + * either the same old slot 1 or the new slot 2. + * Subsequent AGMs will be reporting slot 2. + * + * To userspace, the resulting transition will look like: + * 2:[0,1] -> 3:[0,-1] -> 3:[0,2] + */ + synaptics_mt_state_set(mt_state, 3, 0, -1); + break; + case 3: + /* + * If, for whatever reason, the previous agm was invalid, + * Assume SGM now contains slot 0, AGM now contains slot 2. + */ + if (old->agm <= 2) + synaptics_mt_state_set(mt_state, 3, 0, 2); + /* + * mt_state either hasn't changed, or was updated by a recently + * received AGM-CONTACT packet. + */ + break; + } +} + static void synaptics_image_sensor_process(struct psmouse *psmouse, struct synaptics_hw_state *sgm) { - int count; + struct synaptics_data *priv = psmouse->private; + struct synaptics_hw_state *agm = &priv->agm; + struct synaptics_mt_state mt_state; + /* Initialize using current mt_state (as updated by last agm) */ + mt_state = agm->mt_state; + + /* + * Update mt_state using the new finger count and current mt_state. + */ if (sgm->z == 0) - count = 0; + synaptics_image_sensor_0f(priv, &mt_state); else if (sgm->w >= 4) - count = 1; + synaptics_image_sensor_1f(priv, &mt_state); else if (sgm->w == 0) - count = 2; - else - count = 3; + synaptics_image_sensor_2f(priv, &mt_state); + else if (sgm->w == 1) + synaptics_image_sensor_3f(priv, &mt_state); /* Send resulting input events to user space */ - synaptics_report_mt_data(psmouse, count, sgm); + synaptics_report_mt_data(psmouse, &mt_state, sgm); + + /* Store updated mt_state */ + priv->mt_state = agm->mt_state = mt_state; + priv->agm_pending = false; } /* diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h index 20f57dfebed1..622aea8dd7e0 100644 --- a/drivers/input/mouse/synaptics.h +++ b/drivers/input/mouse/synaptics.h @@ -161,11 +161,15 @@ struct synaptics_data { struct serio *pt_port; /* Pass-through serio port */ + struct synaptics_mt_state mt_state; /* Current mt finger state */ + bool mt_state_lost; /* mt_state may be incorrect */ + /* * Last received Advanced Gesture Mode (AGM) packet. An AGM packet * contains position data for a second contact, at half resolution. */ struct synaptics_hw_state agm; + bool agm_pending; /* new AGM packet received */ }; void synaptics_module_init(void); -- 2.20.1