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/*
* HID driver for Cando dual-touch panels
*
* Copyright (c) 2010 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>
MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
MODULE_DESCRIPTION("Cando dual-touch panel");
MODULE_LICENSE("GPL");
#include "hid-ids.h"
struct cando_data {
__u16 x, y;
__u8 id;
__s8 oldest; /* id of the oldest finger in previous frame */
bool valid; /* valid finger data, or just placeholder? */
bool first; /* is this the first finger in this frame? */
__s8 firstid; /* id of the first finger in the frame */
__u16 firstx, firsty; /* (x, y) of the first finger in the frame */
};
static int cando_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_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) {
case HID_DG_TIPSWITCH:
case HID_DG_CONTACTMAX:
return -1;
case HID_DG_INRANGE:
/* 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;
}
return 0;
}
return 0;
}
static int cando_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 finger has been parsed,
* so that it can decide what to send to the input layer.
*/
static void cando_filter_event(struct cando_data *td, struct input_dev *input)
{
td->first = !td->first; /* touchscreen emulation */
if (!td->valid) {
/*
* touchscreen emulation: if this is the second finger and
* the first was valid, the first was the oldest; if the
* first was not valid and there was a valid finger in the
* previous frame, this is a release.
*/
if (td->first) {
td->firstid = -1;
} else if (td->firstid >= 0) {
input_event(input, EV_ABS, ABS_X, td->firstx);
input_event(input, EV_ABS, ABS_Y, td->firsty);
td->oldest = td->firstid;
} else if (td->oldest >= 0) {
input_event(input, EV_KEY, BTN_TOUCH, 0);
td->oldest = -1;
}
return;
}
input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
input_mt_sync(input);
/*
* touchscreen emulation: if there was no touching finger previously,
* emit touch event
*/
if (td->oldest < 0) {
input_event(input, EV_KEY, BTN_TOUCH, 1);
td->oldest = td->id;
}
/*
* touchscreen emulation: if this is the first finger, wait for the
* second; the oldest is then the second if it was the oldest already
* or if there was no first, the first otherwise.
*/
if (td->first) {
td->firstx = td->x;
td->firsty = td->y;
td->firstid = td->id;
} else {
int x, y, oldest;
if (td->id == td->oldest || td->firstid < 0) {
x = td->x;
y = td->y;
oldest = td->id;
} else {
x = td->firstx;
y = td->firsty;
oldest = td->firstid;
}
input_event(input, EV_ABS, ABS_X, x);
input_event(input, EV_ABS, ABS_Y, y);
td->oldest = oldest;
}
}
static int cando_event(struct hid_device *hid, struct hid_field *field,
struct hid_usage *usage, __s32 value)
{
struct cando_data *td = hid_get_drvdata(hid);
if (hid->claimed & HID_CLAIMED_INPUT) {
struct input_dev *input = field->hidinput->input;
switch (usage->hid) {
case HID_DG_INRANGE:
td->valid = value;
break;
case HID_DG_CONTACTID:
td->id = value;
break;
case HID_GD_X:
td->x = value;
break;
case HID_GD_Y:
td->y = value;
cando_filter_event(td, input);
break;
case HID_DG_TIPSWITCH:
/* avoid interference from generic hidinput handling */
break;
default:
/* fallback to the generic hidinput handling */
return 0;
}
}
/* 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 cando_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
int ret;
struct cando_data *td;
td = kmalloc(sizeof(struct cando_data), GFP_KERNEL);
if (!td) {
dev_err(&hdev->dev, "cannot allocate Cando Touch data\n");
return -ENOMEM;
}
hid_set_drvdata(hdev, td);
td->first = false;
td->oldest = -1;
td->valid = false;
ret = hid_parse(hdev);
if (!ret)
ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
if (ret)
kfree(td);
return ret;
}
static void cando_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 cando_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
{ }
};
MODULE_DEVICE_TABLE(hid, cando_devices);
static const struct hid_usage_id cando_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 cando_driver = {
.name = "cando-touch",
.id_table = cando_devices,
.probe = cando_probe,
.remove = cando_remove,
.input_mapping = cando_input_mapping,
.input_mapped = cando_input_mapped,
.usage_table = cando_grabbed_usages,
.event = cando_event,
};
static int __init cando_init(void)
{
return hid_register_driver(&cando_driver);
}
static void __exit cando_exit(void)
{
hid_unregister_driver(&cando_driver);
}
module_init(cando_init);
module_exit(cando_exit);
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