/*
* HID driver for 3M PCT multitouch panels
*
* Copyright (c) 2009-2010 Stephane Chatty <chatty@enac.fr>
* Copyright (c) 2010 Henrik Rydberg <rydberg@euromail.se>
* Copyright (c) 2010 Canonical, Ltd.
*
*/
/*
* 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"
#define MAX_SLOTS 60
#define MAX_TRKID USHRT_MAX
#define MAX_EVENTS 360
/* estimated signal-to-noise ratios */
#define SN_MOVE 2048
#define SN_WIDTH 128
struct mmm_finger {
__s32 x, y, w, h;
__u16 id;
bool prev_touch;
bool touch, valid;
};
struct mmm_data {
struct mmm_finger f[MAX_SLOTS];
__u16 id;
__u8 curid;
__u8 nexp, nreal;
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)
{
int f1 = field->logical_minimum;
int f2 = field->logical_maximum;
int df = f2 - f1;
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);
input_set_abs_params(hi->input, ABS_MT_POSITION_X,
f1, f2, df / SN_MOVE, 0);
/* touchscreen emulation */
input_set_abs_params(hi->input, ABS_X,
f1, f2, df / SN_MOVE, 0);
return 1;
case HID_GD_Y:
hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_POSITION_Y);
input_set_abs_params(hi->input, ABS_MT_POSITION_Y,
f1, f2, df / SN_MOVE, 0);
/* touchscreen emulation */
input_set_abs_params(hi->input, ABS_Y,
f1, f2, df / SN_MOVE, 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);
input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
return 1;
case HID_DG_WIDTH:
hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_TOUCH_MAJOR);
input_set_abs_params(hi->input, ABS_MT_TOUCH_MAJOR,
f1, f2, df / SN_WIDTH, 0);
return 1;
case HID_DG_HEIGHT:
hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_TOUCH_MINOR);
input_set_abs_params(hi->input, ABS_MT_TOUCH_MINOR,
f1, f2, df / SN_WIDTH, 0);
input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
0, 1, 0, 0);
return 1;
case HID_DG_CONTACTID:
field->logical_maximum = MAX_TRKID;
hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_TRACKING_ID);
input_set_abs_params(hi->input, ABS_MT_TRACKING_ID,
0, MAX_TRKID, 0, 0);
if (!hi->input->mt)
input_mt_create_slots(hi->input, MAX_SLOTS);
input_set_events_per_packet(hi->input, MAX_EVENTS);
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)
{
/* tell hid-input to skip setup of these event types */
if (usage->type == EV_KEY || usage->type == EV_ABS)
set_bit(usage->type, hi->input->evbit);
return -1;
}
/*
* 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;
int i;
for (i = 0; i < MAX_SLOTS; ++i) {
struct mmm_finger *f = &md->f[i];
if (!f->valid) {
/* this finger is just placeholder data, ignore */
continue;
}
input_mt_slot(input, i);
if (f->touch) {
/* this finger is on the screen */
int wide = (f->w > f->h);
/* divided by two to match visual scale of touch */
int major = max(f->w, f->h) >> 1;
int minor = min(f->w, f->h) >> 1;
if (!f->prev_touch)
f->id = md->id++;
input_event(input, EV_ABS, ABS_MT_TRACKING_ID, f->id);
input_event(input, EV_ABS, ABS_MT_POSITION_X, f->x);
input_event(input, EV_ABS, ABS_MT_POSITION_Y, f->y);
input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
/* touchscreen emulation: pick the oldest contact */
if (!oldest || ((f->id - oldest->id) & (SHRT_MAX + 1)))
oldest = f;
} else {
/* this finger took off the screen */
input_event(input, EV_ABS, ABS_MT_TRACKING_ID, -1);
}
f->prev_touch = f->touch;
f->valid = 0;
}
/* touchscreen emulation */
if (oldest) {
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 {
input_event(input, EV_KEY, BTN_TOUCH, 0);
}
input_sync(input);
}
/*
* 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_WIDTH:
if (md->valid)
md->f[md->curid].w = value;
break;
case HID_DG_HEIGHT:
if (md->valid)
md->f[md->curid].h = value;
break;
case HID_DG_CONTACTID:
value = clamp_val(value, 0, MAX_SLOTS - 1);
if (md->valid) {
md->curid = value;
md->f[value].touch = md->touch;
md->f[value].valid = 1;
md->nreal++;
}
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:
if (value)
md->nexp = value;
if (md->nreal >= md->nexp) {
mmm_filter_event(md, input);
md->nreal = 0;
}
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;
hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
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) },
{ HID_USB_DEVICE(USB_VENDOR_ID_3M, USB_DEVICE_ID_3M2256) },
{ }
};
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);
