linux-stable/drivers/input/joystick/zhenhua.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

205 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* derived from "twidjoy.c"
*
* Copyright (c) 2008 Martin Kebert
* Copyright (c) 2001 Arndt Schoenewald
* Copyright (c) 2000-2001 Vojtech Pavlik
* Copyright (c) 2000 Mark Fletcher
*/
/*
* Driver to use 4CH RC transmitter using Zhen Hua 5-byte protocol (Walkera Lama,
* EasyCopter etc.) as a joystick under Linux.
*
* RC transmitters using Zhen Hua 5-byte protocol are cheap four channels
* transmitters for control a RC planes or RC helicopters with possibility to
* connect on a serial port.
* Data coming from transmitter is in this order:
* 1. byte = synchronisation byte
* 2. byte = X axis
* 3. byte = Y axis
* 4. byte = RZ axis
* 5. byte = Z axis
* (and this is repeated)
*
* For questions or feedback regarding this driver module please contact:
* Martin Kebert <gkmarty@gmail.com> - but I am not a C-programmer nor kernel
* coder :-(
*/
/*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/bitrev.h>
#include <linux/input.h>
#include <linux/serio.h>
#define DRIVER_DESC "RC transmitter with 5-byte Zhen Hua protocol joystick driver"
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
/*
* Constants.
*/
#define ZHENHUA_MAX_LENGTH 5
/*
* Zhen Hua data.
*/
struct zhenhua {
struct input_dev *dev;
int idx;
unsigned char data[ZHENHUA_MAX_LENGTH];
char phys[32];
};
/*
* zhenhua_process_packet() decodes packets the driver receives from the
* RC transmitter. It updates the data accordingly.
*/
static void zhenhua_process_packet(struct zhenhua *zhenhua)
{
struct input_dev *dev = zhenhua->dev;
unsigned char *data = zhenhua->data;
input_report_abs(dev, ABS_Y, data[1]);
input_report_abs(dev, ABS_X, data[2]);
input_report_abs(dev, ABS_RZ, data[3]);
input_report_abs(dev, ABS_Z, data[4]);
input_sync(dev);
}
/*
* zhenhua_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 zhenhua_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
{
struct zhenhua *zhenhua = serio_get_drvdata(serio);
/* All Zhen Hua packets are 5 bytes. The fact that the first byte
* is allways 0xf7 and all others are in range 0x32 - 0xc8 (50-200)
* can be used to check and regain sync. */
if (data == 0xef)
zhenhua->idx = 0; /* this byte starts a new packet */
else if (zhenhua->idx == 0)
return IRQ_HANDLED; /* wrong MSB -- ignore this byte */
if (zhenhua->idx < ZHENHUA_MAX_LENGTH)
zhenhua->data[zhenhua->idx++] = bitrev8(data);
if (zhenhua->idx == ZHENHUA_MAX_LENGTH) {
zhenhua_process_packet(zhenhua);
zhenhua->idx = 0;
}
return IRQ_HANDLED;
}
/*
* zhenhua_disconnect() is the opposite of zhenhua_connect()
*/
static void zhenhua_disconnect(struct serio *serio)
{
struct zhenhua *zhenhua = serio_get_drvdata(serio);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_unregister_device(zhenhua->dev);
kfree(zhenhua);
}
/*
* zhenhua_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 zhenhua_connect(struct serio *serio, struct serio_driver *drv)
{
struct zhenhua *zhenhua;
struct input_dev *input_dev;
int err = -ENOMEM;
zhenhua = kzalloc(sizeof(struct zhenhua), GFP_KERNEL);
input_dev = input_allocate_device();
if (!zhenhua || !input_dev)
goto fail1;
zhenhua->dev = input_dev;
snprintf(zhenhua->phys, sizeof(zhenhua->phys), "%s/input0", serio->phys);
input_dev->name = "Zhen Hua 5-byte device";
input_dev->phys = zhenhua->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_ZHENHUA;
input_dev->id.product = 0x0001;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT(EV_ABS);
input_set_abs_params(input_dev, ABS_X, 50, 200, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 50, 200, 0, 0);
input_set_abs_params(input_dev, ABS_Z, 50, 200, 0, 0);
input_set_abs_params(input_dev, ABS_RZ, 50, 200, 0, 0);
serio_set_drvdata(serio, zhenhua);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = input_register_device(zhenhua->dev);
if (err)
goto fail3;
return 0;
fail3: serio_close(serio);
fail2: serio_set_drvdata(serio, NULL);
fail1: input_free_device(input_dev);
kfree(zhenhua);
return err;
}
/*
* The serio driver structure.
*/
static const struct serio_device_id zhenhua_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_ZHENHUA,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, zhenhua_serio_ids);
static struct serio_driver zhenhua_drv = {
.driver = {
.name = "zhenhua",
},
.description = DRIVER_DESC,
.id_table = zhenhua_serio_ids,
.interrupt = zhenhua_interrupt,
.connect = zhenhua_connect,
.disconnect = zhenhua_disconnect,
};
module_serio_driver(zhenhua_drv);