HID: Support for 3M multitouch panel

Add support for 3M multitouch panels.

Signed-off-by: Stephane Chatty <chatty@enac.fr>
[jkosina@suse.cz: fix build failure because of inconsistent 3M/MMM defines]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 291 insertions, 0 deletions

diff --git a/drivers/hid/hid-3m-pct.c b/drivers/hid/hid-3m-pct.c
new file mode 100644
index 00000000000..6d11e3dbbbf
--- /dev/null
+++ b/drivers/hid/hid-3m-pct.c
@@ -0,0 +1,291 @@
+/*
+ *  HID driver for 3M PCT multitouch panels
+ *
+ *  Copyright (c) 2009 Stephane Chatty <chatty@enac.fr>
+ *
+ */
+
+/*
+ * 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/usb.h>
+
+MODULE_VERSION("0.6");
+MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
+MODULE_DESCRIPTION("3M PCT multitouch panels");
+MODULE_LICENSE("GPL");
+
+#include "hid-ids.h"
+
+struct mmm_finger {
+        __s32 x, y;
+        __u8 rank;
+        bool touch, valid;
+};
+
+struct mmm_data {
+        struct mmm_finger f[10];
+        __u8 curid, num;
+        bool touch, valid;
+};
+
+static int mmm_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+                struct hid_field *field, struct hid_usage *usage,
+                unsigned long **bit, int *max)
+{
+        switch (usage->hid & HID_USAGE_PAGE) {
+
+        case HID_UP_BUTTON:
+                return -1;
+
+        case HID_UP_GENDESK:
+                switch (usage->hid) {
+                case HID_GD_X:
+                        hid_map_usage(hi, usage, bit, max,
+                                        EV_ABS, ABS_MT_POSITION_X);
+                        /* touchscreen emulation */
+                        input_set_abs_params(hi->input, ABS_X,
+                                                field->logical_minimum,
+                                                field->logical_maximum, 0, 0);
+                        return 1;
+                case HID_GD_Y:
+                        hid_map_usage(hi, usage, bit, max,
+                                        EV_ABS, ABS_MT_POSITION_Y);
+                        /* touchscreen emulation */
+                        input_set_abs_params(hi->input, ABS_Y,
+                                                field->logical_minimum,
+                                                field->logical_maximum, 0, 0);
+                        return 1;
+                }
+                return 0;
+
+        case HID_UP_DIGITIZER:
+                switch (usage->hid) {
+                /* we do not want to map these: no input-oriented meaning */
+                case 0x14:
+                case 0x23:
+                case HID_DG_INPUTMODE:
+                case HID_DG_DEVICEINDEX:
+                case HID_DG_CONTACTCOUNT:
+                case HID_DG_CONTACTMAX:
+                case HID_DG_INRANGE:
+                case HID_DG_CONFIDENCE:
+                        return -1;
+                case HID_DG_TIPSWITCH:
+                        /* touchscreen emulation */
+                        hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
+                        return 1;
+                case HID_DG_CONTACTID:
+                        hid_map_usage(hi, usage, bit, max,
+                                        EV_ABS, ABS_MT_TRACKING_ID);
+                        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 mmm_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)
+                clear_bit(usage->code, *bit);
+
+        return 0;
+}
+
+/*
+ * 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 mmm_filter_event(struct mmm_data *md, struct input_dev *input)
+{
+        struct mmm_finger *oldest = 0;
+        bool pressed = false, released = false;
+        int i;
+
+        /*
+         * we need to iterate on all fingers to decide if we have a press
+         * or a release event in our touchscreen emulation.
+         */
+        for (i = 0; i < 10; ++i) {
+                struct mmm_finger *f = &md->f[i];
+                if (!f->valid) {
+                        /* this finger is just placeholder data, ignore */
+                } else if (f->touch) {
+                        /* this finger is on the screen */
+                        input_event(input, EV_ABS, ABS_MT_TRACKING_ID, i);
+                        input_event(input, EV_ABS, ABS_MT_POSITION_X, f->x);
+                        input_event(input, EV_ABS, ABS_MT_POSITION_Y, f->y);
+                        input_mt_sync(input);
+                        /*
+                         * touchscreen emulation: maintain the age rank
+                         * of this finger, decide if we have a press
+                         */
+                        if (f->rank == 0) {
+                                f->rank = ++(md->num);
+                                if (f->rank == 1)
+                                        pressed = true;
+                        }
+                        if (f->rank == 1)
+                                oldest = f;
+                } else {
+                        /* this finger took off the screen */
+                        /* touchscreen emulation: maintain age rank of others */
+                        int j;
+
+                        for (j = 0; j < 10; ++j) {
+                                struct mmm_finger *g = &md->f[j];
+                                if (g->rank > f->rank) {
+                                        g->rank--;
+                                        if (g->rank == 1)
+                                                oldest = g;
+                                }
+                        }
+                        f->rank = 0;
+                        --(md->num);
+                        if (md->num == 0)
+                                released = true;
+                }
+                f->valid = 0;
+        }
+
+        /* touchscreen emulation */
+        if (oldest) {
+                if (pressed)
+                        input_event(input, EV_KEY, BTN_TOUCH, 1);
+                input_event(input, EV_ABS, ABS_X, oldest->x);
+                input_event(input, EV_ABS, ABS_Y, oldest->y);
+        } else if (released) {
+                input_event(input, EV_KEY, BTN_TOUCH, 0);
+        }
+}
+
+/*
+ * this function is called upon all reports
+ * so that we can accumulate contact point information,
+ * and call input_mt_sync after each point.
+ */
+static int mmm_event(struct hid_device *hid, struct hid_field *field,
+                                struct hid_usage *usage, __s32 value)
+{
+        struct mmm_data *md = hid_get_drvdata(hid);
+        /*
+         * strangely, this function can be called before
+         * field->hidinput is initialized!
+         */
+        if (hid->claimed & HID_CLAIMED_INPUT) {
+                struct input_dev *input = field->hidinput->input;
+                switch (usage->hid) {
+                case HID_DG_TIPSWITCH:
+                        md->touch = value;
+                        break;
+                case HID_DG_CONFIDENCE:
+                        md->valid = value;
+                        break;
+                case HID_DG_CONTACTID:
+                        if (md->valid) {
+                                md->curid = value;
+                                md->f[value].touch = md->touch;
+                                md->f[value].valid = 1;
+                        }
+                        break;
+                case HID_GD_X:
+                        if (md->valid)
+                                md->f[md->curid].x = value;
+                        break;
+                case HID_GD_Y:
+                        if (md->valid)
+                                md->f[md->curid].y = value;
+                        break;
+                case HID_DG_CONTACTCOUNT:
+                        mmm_filter_event(md, input);
+                        break;
+                }
+        }
+
+        /* 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 int mmm_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+        int ret;
+        struct mmm_data *md;
+
+        md = kzalloc(sizeof(struct mmm_data), GFP_KERNEL);
+        if (!md) {
+                dev_err(&hdev->dev, "cannot allocate 3M data\n");
+                return -ENOMEM;
+        }
+        hid_set_drvdata(hdev, md);
+
+        ret = hid_parse(hdev);
+        if (!ret)
+                ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+
+        if (ret)
+                kfree(md);
+        return ret;
+}
+
+static void mmm_remove(struct hid_device *hdev)
+{
+        hid_hw_stop(hdev);
+        kfree(hid_get_drvdata(hdev));
+        hid_set_drvdata(hdev, NULL);
+}
+
+static const struct hid_device_id mmm_devices[] = {
+        { HID_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M1968) },
+        { }
+};
+MODULE_DEVICE_TABLE(hid, mmm_devices);
+
+static const struct hid_usage_id mmm_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 mmm_driver = {
+        .name = "3m-pct",
+        .id_table = mmm_devices,
+        .probe = mmm_probe,
+        .remove = mmm_remove,
+        .input_mapping = mmm_input_mapping,
+        .input_mapped = mmm_input_mapped,
+        .usage_table = mmm_grabbed_usages,
+        .event = mmm_event,
+};
+
+static int __init mmm_init(void)
+{
+        return hid_register_driver(&mmm_driver);
+}
+
+static void __exit mmm_exit(void)
+{
+        hid_unregister_driver(&mmm_driver);
+}
+
+module_init(mmm_init);
+module_exit(mmm_exit);
+MODULE_LICENSE("GPL");
+