/*
* 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/slab.h>
#include <linux/usb.h>
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");
