--- /dev/null
+/*
+ * HID driver for multitouch panels
+ *
+ * Copyright (c) 2010-2011 Stephane Chatty <chatty@enac.fr>
+ * Copyright (c) 2010-2011 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2010-2011 Ecole Nationale de l'Aviation Civile, France
+ *
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/input/mt.h>
+#include "usbhid/usbhid.h"
+
+
+MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
+MODULE_DESCRIPTION("HID multitouch panels");
+MODULE_LICENSE("GPL");
+
+#include "hid-ids.h"
+
+/* quirks to control the device */
+#define MT_QUIRK_NOT_SEEN_MEANS_UP (1 << 0)
+#define MT_QUIRK_SLOT_IS_CONTACTID (1 << 1)
+
+struct mt_slot {
+ __s32 x, y, p, w, h;
+ __s32 contactid; /* the device ContactID assigned to this slot */
+ bool touch_state; /* is the touch valid? */
+ bool seen_in_this_frame;/* has this slot been updated */
+};
+
+struct mt_device {
+ struct mt_slot curdata; /* placeholder of incoming data */
+ struct mt_class *mtclass; /* our mt device class */
+ unsigned last_field_index; /* last field index of the report */
+ unsigned last_slot_field; /* the last field of a slot */
+ __s8 inputmode; /* InputMode HID feature, -1 if non-existent */
+ __u8 num_received; /* how many contacts we received */
+ __u8 num_expected; /* expected last contact index */
+ bool curvalid; /* is the current contact valid? */
+ struct mt_slot slots[0]; /* first slot */
+};
+
+struct mt_class {
+ __s32 quirks;
+ __s32 sn_move; /* Signal/noise ratio for move events */
+ __s32 sn_pressure; /* Signal/noise ratio for pressure events */
+ __u8 maxcontacts;
+};
+
+/* classes of device behavior */
+#define MT_CLS_DEFAULT 0
+#define MT_CLS_DUAL1 1
+
+/*
+ * these device-dependent functions determine what slot corresponds
+ * to a valid contact that was just read.
+ */
+
+static int slot_is_contactid(struct mt_device *td)
+{
+ return td->curdata.contactid;
+}
+
+static int find_slot_from_contactid(struct mt_device *td)
+{
+ int i;
+ for (i = 0; i < td->mtclass->maxcontacts; ++i) {
+ if (td->slots[i].contactid == td->curdata.contactid &&
+ td->slots[i].touch_state)
+ return i;
+ }
+ for (i = 0; i < td->mtclass->maxcontacts; ++i) {
+ if (!td->slots[i].seen_in_this_frame &&
+ !td->slots[i].touch_state)
+ return i;
+ }
+ return -1;
+ /* should not occurs. If this happens that means
+ * that the device sent more touches that it says
+ * in the report descriptor. It is ignored then. */
+}
+
+struct mt_class mt_classes[] = {
+ { 0, 0, 0, 10 }, /* MT_CLS_DEFAULT */
+ { MT_QUIRK_SLOT_IS_CONTACTID, 0, 0, 2 }, /* MT_CLS_DUAL1 */
+};
+
+static void mt_feature_mapping(struct hid_device *hdev, struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage)
+{
+ if (usage->hid == HID_DG_INPUTMODE) {
+ struct mt_device *td = hid_get_drvdata(hdev);
+ td->inputmode = field->report->id;
+ }
+}
+
+static void set_abs(struct input_dev *input, unsigned int code,
+ struct hid_field *field, int snratio)
+{
+ int fmin = field->logical_minimum;
+ int fmax = field->logical_maximum;
+ int fuzz = snratio ? (fmax - fmin) / snratio : 0;
+ input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
+}
+
+static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ struct mt_device *td = hid_get_drvdata(hdev);
+ struct mt_class *cls = td->mtclass;
+ switch (usage->hid & HID_USAGE_PAGE) {
+
+ case HID_UP_GENDESK:
+ switch (usage->hid) {
+ case HID_GD_X:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_POSITION_X);
+ set_abs(hi->input, ABS_MT_POSITION_X, field,
+ cls->sn_move);
+ /* touchscreen emulation */
+ set_abs(hi->input, ABS_X, field, cls->sn_move);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_GD_Y:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_POSITION_Y);
+ set_abs(hi->input, ABS_MT_POSITION_Y, field,
+ cls->sn_move);
+ /* touchscreen emulation */
+ set_abs(hi->input, ABS_Y, field, cls->sn_move);
+ td->last_slot_field = usage->hid;
+ return 1;
+ }
+ return 0;
+
+ case HID_UP_DIGITIZER:
+ switch (usage->hid) {
+ case HID_DG_INRANGE:
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_CONFIDENCE:
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_TIPSWITCH:
+ hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
+ input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_CONTACTID:
+ input_mt_init_slots(hi->input,
+ td->mtclass->maxcontacts);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_WIDTH:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_TOUCH_MAJOR);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_HEIGHT:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_TOUCH_MINOR);
+ field->logical_maximum = 1;
+ field->logical_minimum = 1;
+ set_abs(hi->input, ABS_MT_ORIENTATION, field, 0);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_TIPPRESSURE:
+ hid_map_usage(hi, usage, bit, max,
+ EV_ABS, ABS_MT_PRESSURE);
+ set_abs(hi->input, ABS_MT_PRESSURE, field,
+ cls->sn_pressure);
+ /* touchscreen emulation */
+ set_abs(hi->input, ABS_PRESSURE, field,
+ cls->sn_pressure);
+ td->last_slot_field = usage->hid;
+ return 1;
+ case HID_DG_CONTACTCOUNT:
+ td->last_field_index = field->report->maxfield - 1;
+ return 1;
+ case HID_DG_CONTACTMAX:
+ /* we don't set td->last_slot_field as contactcount and
+ * contact max are global to the report */
+ return -1;
+ }
+ /* let hid-input decide for the others */
+ return 0;
+
+ case 0xff000000:
+ /* we do not want to map these: no input-oriented meaning */
+ return -1;
+ }
+
+ return 0;
+}
+
+static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
+ struct hid_field *field, struct hid_usage *usage,
+ unsigned long **bit, int *max)
+{
+ if (usage->type == EV_KEY || usage->type == EV_ABS)
+ set_bit(usage->type, hi->input->evbit);
+
+ return -1;
+}
+
+static int mt_compute_slot(struct mt_device *td)
+{
+ struct mt_class *cls = td->mtclass;
+
+ if (cls->quirks & MT_QUIRK_SLOT_IS_CONTACTID)
+ return slot_is_contactid(td);
+
+ return find_slot_from_contactid(td);
+}
+
+/*
+ * this function is called when a whole contact has been processed,
+ * so that it can assign it to a slot and store the data there
+ */
+static void mt_complete_slot(struct mt_device *td)
+{
+ if (td->curvalid) {
+ struct mt_slot *slot;
+ int slotnum = mt_compute_slot(td);
+
+ if (slotnum >= 0 && slotnum < td->mtclass->maxcontacts) {
+ slot = td->slots + slotnum;
+
+ memcpy(slot, &(td->curdata), sizeof(struct mt_slot));
+ slot->seen_in_this_frame = true;
+ }
+ }
+ td->num_received++;
+}
+
+
+/*
+ * this function is called when a whole packet has been received and processed,
+ * so that it can decide what to send to the input layer.
+ */
+static void mt_emit_event(struct mt_device *td, struct input_dev *input)
+{
+ int i;
+
+ for (i = 0; i < td->mtclass->maxcontacts; ++i) {
+ struct mt_slot *s = &(td->slots[i]);
+ if ((td->mtclass->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
+ !s->seen_in_this_frame) {
+ /*
+ * this slot does not contain useful data,
+ * notify its closure
+ */
+ s->touch_state = false;
+ }
+
+ input_mt_slot(input, i);
+ input_mt_report_slot_state(input, MT_TOOL_FINGER,
+ s->touch_state);
+ input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
+ input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
+ input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
+ input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
+ input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
+ s->seen_in_this_frame = false;
+
+ }
+
+ input_mt_report_pointer_emulation(input, true);
+ input_sync(input);
+ td->num_received = 0;
+}
+
+
+
+static int mt_event(struct hid_device *hid, struct hid_field *field,
+ struct hid_usage *usage, __s32 value)
+{
+ struct mt_device *td = hid_get_drvdata(hid);
+
+ if (hid->claimed & HID_CLAIMED_INPUT) {
+ switch (usage->hid) {
+ case HID_DG_INRANGE:
+ break;
+ case HID_DG_TIPSWITCH:
+ td->curvalid = value;
+ td->curdata.touch_state = value;
+ break;
+ case HID_DG_CONFIDENCE:
+ break;
+ case HID_DG_CONTACTID:
+ td->curdata.contactid = value;
+ break;
+ case HID_DG_TIPPRESSURE:
+ td->curdata.p = value;
+ break;
+ case HID_GD_X:
+ td->curdata.x = value;
+ break;
+ case HID_GD_Y:
+ td->curdata.y = value;
+ break;
+ case HID_DG_WIDTH:
+ td->curdata.w = value;
+ break;
+ case HID_DG_HEIGHT:
+ td->curdata.h = value;
+ break;
+ case HID_DG_CONTACTCOUNT:
+ /*
+ * We must not overwrite the previous value (some
+ * devices send one sequence splitted over several
+ * messages)
+ */
+ if (value)
+ td->num_expected = value - 1;
+ break;
+
+ default:
+ /* fallback to the generic hidinput handling */
+ return 0;
+ }
+ }
+
+ if (usage->hid == td->last_slot_field)
+ mt_complete_slot(td);
+
+ if (field->index == td->last_field_index
+ && td->num_received > td->num_expected)
+ mt_emit_event(td, field->hidinput->input);
+
+ /* we have handled the hidinput part, now remains hiddev */
+ if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
+ hid->hiddev_hid_event(hid, field, usage, value);
+
+ return 1;
+}
+
+static void mt_set_input_mode(struct hid_device *hdev)
+{
+ struct mt_device *td = hid_get_drvdata(hdev);
+ struct hid_report *r;
+ struct hid_report_enum *re;
+
+ if (td->inputmode < 0)
+ return;
+
+ re = &(hdev->report_enum[HID_FEATURE_REPORT]);
+ r = re->report_id_hash[td->inputmode];
+ if (r) {
+ r->field[0]->value[0] = 0x02;
+ usbhid_submit_report(hdev, r, USB_DIR_OUT);
+ }
+}
+
+static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+ int ret;
+ struct mt_device *td;
+ struct mt_class *mtclass = mt_classes + id->driver_data;
+
+ /* This allows the driver to correctly support devices
+ * that emit events over several HID messages.
+ */
+ hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
+
+ td = kzalloc(sizeof(struct mt_device) +
+ mtclass->maxcontacts * sizeof(struct mt_slot),
+ GFP_KERNEL);
+ if (!td) {
+ dev_err(&hdev->dev, "cannot allocate multitouch data\n");
+ return -ENOMEM;
+ }
+ td->mtclass = mtclass;
+ td->inputmode = -1;
+ hid_set_drvdata(hdev, td);
+
+ ret = hid_parse(hdev);
+ if (ret != 0)
+ goto fail;
+
+ ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+ if (ret != 0)
+ goto fail;
+
+ mt_set_input_mode(hdev);
+
+ return 0;
+
+fail:
+ kfree(td);
+ return ret;
+}
+
+#ifdef CONFIG_PM
+static int mt_reset_resume(struct hid_device *hdev)
+{
+ mt_set_input_mode(hdev);
+ return 0;
+}
+#endif
+
+static void mt_remove(struct hid_device *hdev)
+{
+ struct mt_device *td = hid_get_drvdata(hdev);
+ hid_hw_stop(hdev);
+ kfree(td);
+ hid_set_drvdata(hdev, NULL);
+}
+
+static const struct hid_device_id mt_devices[] = {
+
+ /* PixCir-based panels */
+ { .driver_data = MT_CLS_DUAL1,
+ HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
+ USB_DEVICE_ID_HANVON_MULTITOUCH) },
+ { .driver_data = MT_CLS_DUAL1,
+ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
+ USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
+
+ { }
+};
+MODULE_DEVICE_TABLE(hid, mt_devices);
+
+static const struct hid_usage_id mt_grabbed_usages[] = {
+ { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
+ { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
+};
+
+static struct hid_driver mt_driver = {
+ .name = "hid-multitouch",
+ .id_table = mt_devices,
+ .probe = mt_probe,
+ .remove = mt_remove,
+ .input_mapping = mt_input_mapping,
+ .input_mapped = mt_input_mapped,
+ .feature_mapping = mt_feature_mapping,
+ .usage_table = mt_grabbed_usages,
+ .event = mt_event,
+#ifdef CONFIG_PM
+ .reset_resume = mt_reset_resume,
+#endif
+};
+
+static int __init mt_init(void)
+{
+ return hid_register_driver(&mt_driver);
+}
+
+static void __exit mt_exit(void)
+{
+ hid_unregister_driver(&mt_driver);
+}
+
+module_init(mt_init);
+module_exit(mt_exit);