HID: hid-multitouch: support for PixCir-based panels

Created a driver for PixCir based dual-touch panels, including the one
in the Hanvon tablet.  This is done in a code structure aimed at unifying
support for several existing HID multitouch panels.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Signed-off-by: Stéphane Chatty <chatty@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

5 files changed, 484 insertions, 0 deletions

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 401acecc7f32..511554de526e 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -285,6 +285,15 @@ config HID_MONTEREY
         ---help---
         Support for Monterey Genius KB29E.
 
+config HID_MULTITOUCH
+        tristate "HID Multitouch panels"
+        depends on USB_HID
+        ---help---
+          Generic support for HID multitouch panels.
+
+          Say Y here if you have one of the following devices:
+          - PixCir touchscreen
+
 config HID_NTRIG
         tristate "N-Trig touch screen"
         depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index c335605b9200..ec991d475809 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_HID_MAGICMOUSE)    += hid-magicmouse.o
 obj-$(CONFIG_HID_MICROSOFT)     += hid-microsoft.o
 obj-$(CONFIG_HID_MONTEREY)      += hid-monterey.o
 obj-$(CONFIG_HID_MOSART)        += hid-mosart.o
+obj-$(CONFIG_HID_MULTITOUCH)    += hid-multitouch.o
 obj-$(CONFIG_HID_NTRIG)         += hid-ntrig.o
 obj-$(CONFIG_HID_ORTEK)         += hid-ortek.o
 obj-$(CONFIG_HID_PRODIKEYS)     += hid-prodikeys.o
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 3f9673d94da9..9292eb148ce4 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1286,6 +1286,7 @@ static const struct hid_device_id hid_blacklist[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_BELKIN, USB_DEVICE_ID_FLIP_KVM) },
         { HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE) },
         { HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE_2) },
+        { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CANDO, USB_DEVICE_ID_CANDO_MULTI_TOUCH_15_6) },
@@ -1312,6 +1313,7 @@ static const struct hid_device_id hid_blacklist[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE) },
         { HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE_2) },
         { HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE_3) },
+        { HID_USB_DEVICE(USB_VENDOR_ID_HANVON, USB_DEVICE_ID_HANVON_MULTITOUCH) },
         { HID_USB_DEVICE(USB_VENDOR_ID_KENSINGTON, USB_DEVICE_ID_KS_SLIMBLADE) },
         { HID_USB_DEVICE(USB_VENDOR_ID_KYE, USB_DEVICE_ID_KYE_ERGO_525V) },
         { HID_USB_DEVICE(USB_VENDOR_ID_LABTEC, USB_DEVICE_ID_LABTEC_WIRELESS_KEYBOARD) },
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 8e11af86b014..bd3cd551b4ee 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -134,6 +134,7 @@
 #define USB_DEVICE_ID_BTC_EMPREX_REMOTE_2       0x5577
 
 #define USB_VENDOR_ID_CANDO             0x2087
+#define USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH 0x0703
 #define USB_DEVICE_ID_CANDO_MULTI_TOUCH 0x0a01
 #define USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6 0x0b03
 #define USB_DEVICE_ID_CANDO_MULTI_TOUCH_15_6 0x0f01
@@ -308,6 +309,9 @@
 #define USB_DEVICE_ID_HANWANG_TABLET_FIRST      0x5000
 #define USB_DEVICE_ID_HANWANG_TABLET_LAST       0x8fff
 
+#define USB_VENDOR_ID_HANVON            0x20b3
+#define USB_DEVICE_ID_HANVON_MULTITOUCH 0x0a18
+
 #define USB_VENDOR_ID_HAPP              0x078b
 #define USB_DEVICE_ID_UGCI_DRIVING      0x0010
 #define USB_DEVICE_ID_UGCI_FLYING       0x0020
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
new file mode 100644
index 000000000000..3b05dfe910bc
--- /dev/null
+++ b/drivers/hid/hid-multitouch.c
@@ -0,0 +1,468 @@
+/*
+ *  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);