swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 0adb32858b0bddf4ada5f364a84ed60b196dbcda authored by Linus Torvalds on 01 April 2018, 21:20:27 UTC
Linux 4.16
Linux 4.16
Tip revision: 0adb328
twidjoy.c
/*
* Copyright (c) 2001 Arndt Schoenewald
* Copyright (c) 2000-2001 Vojtech Pavlik
* Copyright (c) 2000 Mark Fletcher
*
* Sponsored by Quelltext AG (http://www.quelltext-ag.de), Dortmund, Germany
*/
/*
* Driver to use Handykey's Twiddler (the first edition, i.e. the one with
* the RS232 interface) as a joystick under Linux
*
* The Twiddler is a one-handed chording keyboard featuring twelve buttons on
* the front, six buttons on the top, and a built-in tilt sensor. The buttons
* on the front, which are grouped as four rows of three buttons, are pressed
* by the four fingers (this implies only one button per row can be held down
* at the same time) and the buttons on the top are for the thumb. The tilt
* sensor delivers X and Y axis data depending on how the Twiddler is held.
* Additional information can be found at http://www.handykey.com.
*
* This driver does not use the Twiddler for its intended purpose, i.e. as
* a chording keyboard, but as a joystick: pressing and releasing a button
* immediately sends a corresponding button event, and tilting it generates
* corresponding ABS_X and ABS_Y events. This turns the Twiddler into a game
* controller with amazing 18 buttons :-)
*
* Note: The Twiddler2 (the successor of the Twiddler that connects directly
* to the PS/2 keyboard and mouse ports) is NOT supported by this driver!
*
* For questions or feedback regarding this driver module please contact:
* Arndt Schoenewald <arndt@quelltext.com>
*/
/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#define DRIVER_DESC "Handykey Twiddler keyboard as a joystick driver"
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
/*
* Constants.
*/
#define TWIDJOY_MAX_LENGTH 5
static struct twidjoy_button_spec {
int bitshift;
int bitmask;
int buttons[3];
}
twidjoy_buttons[] = {
{ 0, 3, { BTN_A, BTN_B, BTN_C } },
{ 2, 3, { BTN_X, BTN_Y, BTN_Z } },
{ 4, 3, { BTN_TL, BTN_TR, BTN_TR2 } },
{ 6, 3, { BTN_SELECT, BTN_START, BTN_MODE } },
{ 8, 1, { BTN_BASE5 } },
{ 9, 1, { BTN_BASE } },
{ 10, 1, { BTN_BASE3 } },
{ 11, 1, { BTN_BASE4 } },
{ 12, 1, { BTN_BASE2 } },
{ 13, 1, { BTN_BASE6 } },
{ 0, 0, { 0 } }
};
/*
* Per-Twiddler data.
*/
struct twidjoy {
struct input_dev *dev;
int idx;
unsigned char data[TWIDJOY_MAX_LENGTH];
char phys[32];
};
/*
* twidjoy_process_packet() decodes packets the driver receives from the
* Twiddler. It updates the data accordingly.
*/
static void twidjoy_process_packet(struct twidjoy *twidjoy)
{
struct input_dev *dev = twidjoy->dev;
unsigned char *data = twidjoy->data;
struct twidjoy_button_spec *bp;
int button_bits, abs_x, abs_y;
button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f);
for (bp = twidjoy_buttons; bp->bitmask; bp++) {
int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift;
int i;
for (i = 0; i < bp->bitmask; i++)
input_report_key(dev, bp->buttons[i], i+1 == value);
}
abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2);
if (data[4] & 0x08) abs_x -= 256;
abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0);
if (data[3] & 0x02) abs_y -= 256;
input_report_abs(dev, ABS_X, -abs_x);
input_report_abs(dev, ABS_Y, +abs_y);
input_sync(dev);
}
/*
* twidjoy_interrupt() is called by the low level driver when characters
* are ready for us. We then buffer them for further processing, or call the
* packet processing routine.
*/
static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
{
struct twidjoy *twidjoy = serio_get_drvdata(serio);
/* All Twiddler packets are 5 bytes. The fact that the first byte
* has a MSB of 0 and all other bytes have a MSB of 1 can be used
* to check and regain sync. */
if ((data & 0x80) == 0)
twidjoy->idx = 0; /* this byte starts a new packet */
else if (twidjoy->idx == 0)
return IRQ_HANDLED; /* wrong MSB -- ignore this byte */
if (twidjoy->idx < TWIDJOY_MAX_LENGTH)
twidjoy->data[twidjoy->idx++] = data;
if (twidjoy->idx == TWIDJOY_MAX_LENGTH) {
twidjoy_process_packet(twidjoy);
twidjoy->idx = 0;
}
return IRQ_HANDLED;
}
/*
* twidjoy_disconnect() is the opposite of twidjoy_connect()
*/
static void twidjoy_disconnect(struct serio *serio)
{
struct twidjoy *twidjoy = serio_get_drvdata(serio);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_unregister_device(twidjoy->dev);
kfree(twidjoy);
}
/*
* twidjoy_connect() is the routine that is called when someone adds a
* new serio device. It looks for the Twiddler, and if found, registers
* it as an input device.
*/
static int twidjoy_connect(struct serio *serio, struct serio_driver *drv)
{
struct twidjoy_button_spec *bp;
struct twidjoy *twidjoy;
struct input_dev *input_dev;
int err = -ENOMEM;
int i;
twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL);
input_dev = input_allocate_device();
if (!twidjoy || !input_dev)
goto fail1;
twidjoy->dev = input_dev;
snprintf(twidjoy->phys, sizeof(twidjoy->phys), "%s/input0", serio->phys);
input_dev->name = "Handykey Twiddler";
input_dev->phys = twidjoy->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_TWIDJOY;
input_dev->id.product = 0x0001;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4);
input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4);
for (bp = twidjoy_buttons; bp->bitmask; bp++)
for (i = 0; i < bp->bitmask; i++)
set_bit(bp->buttons[i], input_dev->keybit);
serio_set_drvdata(serio, twidjoy);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = input_register_device(twidjoy->dev);
if (err)
goto fail3;
return 0;
fail3: serio_close(serio);
fail2: serio_set_drvdata(serio, NULL);
fail1: input_free_device(input_dev);
kfree(twidjoy);
return err;
}
/*
* The serio driver structure.
*/
static const struct serio_device_id twidjoy_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_TWIDJOY,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids);
static struct serio_driver twidjoy_drv = {
.driver = {
.name = "twidjoy",
},
.description = DRIVER_DESC,
.id_table = twidjoy_serio_ids,
.interrupt = twidjoy_interrupt,
.connect = twidjoy_connect,
.disconnect = twidjoy_disconnect,
};
module_serio_driver(twidjoy_drv);