swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: d1abaeb3be7b5fa6d7a1fbbd2e14e3310005c4c1 authored by Linus Torvalds on 18 August 2019, 21:31:08 UTC
Linux 5.3-rc5
Linux 5.3-rc5
Tip revision: d1abaeb
walkera0701.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Parallel port to Walkera WK-0701 TX joystick
*
* Copyright (c) 2008 Peter Popovec
*
* More about driver: <file:Documentation/input/devices/walkera0701.rst>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define RESERVE 20000
#define SYNC_PULSE 1306000
#define BIN0_PULSE 288000
#define BIN1_PULSE 438000
#define ANALOG_MIN_PULSE 318000
#define ANALOG_MAX_PULSE 878000
#define ANALOG_DELTA 80000
#define BIN_SAMPLE ((BIN0_PULSE + BIN1_PULSE) / 2)
#define NO_SYNC 25
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/parport.h>
#include <linux/input.h>
#include <linux/hrtimer.h>
MODULE_AUTHOR("Peter Popovec <popovec@fei.tuke.sk>");
MODULE_DESCRIPTION("Walkera WK-0701 TX as joystick");
MODULE_LICENSE("GPL");
static unsigned int walkera0701_pp_no;
module_param_named(port, walkera0701_pp_no, int, 0);
MODULE_PARM_DESC(port,
"Parallel port adapter for Walkera WK-0701 TX (default is 0)");
/*
* For now, only one device is supported, if somebody need more devices, code
* can be expanded, one struct walkera_dev per device must be allocated and
* set up by walkera0701_connect (release of device by walkera0701_disconnect)
*/
struct walkera_dev {
unsigned char buf[25];
u64 irq_time, irq_lasttime;
int counter;
int ack;
struct input_dev *input_dev;
struct hrtimer timer;
struct parport *parport;
struct pardevice *pardevice;
};
static struct walkera_dev w_dev;
static inline void walkera0701_parse_frame(struct walkera_dev *w)
{
int i;
int val1, val2, val3, val4, val5, val6, val7, val8;
int magic, magic_bit;
int crc1, crc2;
for (crc1 = crc2 = i = 0; i < 10; i++) {
crc1 += w->buf[i] & 7;
crc2 += (w->buf[i] & 8) >> 3;
}
if ((w->buf[10] & 7) != (crc1 & 7))
return;
if (((w->buf[10] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1))
return;
for (crc1 = crc2 = 0, i = 11; i < 23; i++) {
crc1 += w->buf[i] & 7;
crc2 += (w->buf[i] & 8) >> 3;
}
if ((w->buf[23] & 7) != (crc1 & 7))
return;
if (((w->buf[23] & 8) >> 3) != (((crc1 >> 3) + crc2) & 1))
return;
val1 = ((w->buf[0] & 7) * 256 + w->buf[1] * 16 + w->buf[2]) >> 2;
val1 *= ((w->buf[0] >> 2) & 2) - 1; /* sign */
val2 = (w->buf[2] & 1) << 8 | (w->buf[3] << 4) | w->buf[4];
val2 *= (w->buf[2] & 2) - 1; /* sign */
val3 = ((w->buf[5] & 7) * 256 + w->buf[6] * 16 + w->buf[7]) >> 2;
val3 *= ((w->buf[5] >> 2) & 2) - 1; /* sign */
val4 = (w->buf[7] & 1) << 8 | (w->buf[8] << 4) | w->buf[9];
val4 *= (w->buf[7] & 2) - 1; /* sign */
val5 = ((w->buf[11] & 7) * 256 + w->buf[12] * 16 + w->buf[13]) >> 2;
val5 *= ((w->buf[11] >> 2) & 2) - 1; /* sign */
val6 = (w->buf[13] & 1) << 8 | (w->buf[14] << 4) | w->buf[15];
val6 *= (w->buf[13] & 2) - 1; /* sign */
val7 = ((w->buf[16] & 7) * 256 + w->buf[17] * 16 + w->buf[18]) >> 2;
val7 *= ((w->buf[16] >> 2) & 2) - 1; /*sign */
val8 = (w->buf[18] & 1) << 8 | (w->buf[19] << 4) | w->buf[20];
val8 *= (w->buf[18] & 2) - 1; /*sign */
magic = (w->buf[21] << 4) | w->buf[22];
magic_bit = (w->buf[24] & 8) >> 3;
pr_debug("%4d %4d %4d %4d %4d %4d %4d %4d (magic %2x %d)\n",
val1, val2, val3, val4, val5, val6, val7, val8,
magic, magic_bit);
input_report_abs(w->input_dev, ABS_X, val2);
input_report_abs(w->input_dev, ABS_Y, val1);
input_report_abs(w->input_dev, ABS_Z, val6);
input_report_abs(w->input_dev, ABS_THROTTLE, val3);
input_report_abs(w->input_dev, ABS_RUDDER, val4);
input_report_abs(w->input_dev, ABS_MISC, val7);
input_report_key(w->input_dev, BTN_GEAR_DOWN, val5 > 0);
}
static inline int read_ack(struct pardevice *p)
{
return parport_read_status(p->port) & 0x40;
}
/* falling edge, prepare to BIN value calculation */
static void walkera0701_irq_handler(void *handler_data)
{
u64 pulse_time;
struct walkera_dev *w = handler_data;
w->irq_time = ktime_to_ns(ktime_get());
pulse_time = w->irq_time - w->irq_lasttime;
w->irq_lasttime = w->irq_time;
/* cancel timer, if in handler or active do resync */
if (unlikely(0 != hrtimer_try_to_cancel(&w->timer))) {
w->counter = NO_SYNC;
return;
}
if (w->counter < NO_SYNC) {
if (w->ack) {
pulse_time -= BIN1_PULSE;
w->buf[w->counter] = 8;
} else {
pulse_time -= BIN0_PULSE;
w->buf[w->counter] = 0;
}
if (w->counter == 24) { /* full frame */
walkera0701_parse_frame(w);
w->counter = NO_SYNC;
if (abs(pulse_time - SYNC_PULSE) < RESERVE) /* new frame sync */
w->counter = 0;
} else {
if ((pulse_time > (ANALOG_MIN_PULSE - RESERVE)
&& (pulse_time < (ANALOG_MAX_PULSE + RESERVE)))) {
pulse_time -= (ANALOG_MIN_PULSE - RESERVE);
pulse_time = (u32) pulse_time / ANALOG_DELTA; /* overtiping is safe, pulsetime < s32.. */
w->buf[w->counter++] |= (pulse_time & 7);
} else
w->counter = NO_SYNC;
}
} else if (abs(pulse_time - SYNC_PULSE - BIN0_PULSE) <
RESERVE + BIN1_PULSE - BIN0_PULSE) /* frame sync .. */
w->counter = 0;
hrtimer_start(&w->timer, BIN_SAMPLE, HRTIMER_MODE_REL);
}
static enum hrtimer_restart timer_handler(struct hrtimer
*handle)
{
struct walkera_dev *w;
w = container_of(handle, struct walkera_dev, timer);
w->ack = read_ack(w->pardevice);
return HRTIMER_NORESTART;
}
static int walkera0701_open(struct input_dev *dev)
{
struct walkera_dev *w = input_get_drvdata(dev);
if (parport_claim(w->pardevice))
return -EBUSY;
parport_enable_irq(w->parport);
return 0;
}
static void walkera0701_close(struct input_dev *dev)
{
struct walkera_dev *w = input_get_drvdata(dev);
parport_disable_irq(w->parport);
hrtimer_cancel(&w->timer);
parport_release(w->pardevice);
}
static void walkera0701_attach(struct parport *pp)
{
struct pardev_cb walkera0701_parport_cb;
struct walkera_dev *w = &w_dev;
if (pp->number != walkera0701_pp_no) {
pr_debug("Not using parport%d.\n", pp->number);
return;
}
if (pp->irq == -1) {
pr_err("parport %d does not have interrupt assigned\n",
pp->number);
return;
}
w->parport = pp;
memset(&walkera0701_parport_cb, 0, sizeof(walkera0701_parport_cb));
walkera0701_parport_cb.flags = PARPORT_FLAG_EXCL;
walkera0701_parport_cb.irq_func = walkera0701_irq_handler;
walkera0701_parport_cb.private = w;
w->pardevice = parport_register_dev_model(pp, "walkera0701",
&walkera0701_parport_cb, 0);
if (!w->pardevice) {
pr_err("failed to register parport device\n");
return;
}
if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) {
pr_err("failed to negotiate parport mode\n");
goto err_unregister_device;
}
hrtimer_init(&w->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
w->timer.function = timer_handler;
w->input_dev = input_allocate_device();
if (!w->input_dev) {
pr_err("failed to allocate input device\n");
goto err_unregister_device;
}
input_set_drvdata(w->input_dev, w);
w->input_dev->name = "Walkera WK-0701 TX";
w->input_dev->phys = w->parport->name;
w->input_dev->id.bustype = BUS_PARPORT;
/* TODO what id vendor/product/version ? */
w->input_dev->id.vendor = 0x0001;
w->input_dev->id.product = 0x0001;
w->input_dev->id.version = 0x0100;
w->input_dev->dev.parent = w->parport->dev;
w->input_dev->open = walkera0701_open;
w->input_dev->close = walkera0701_close;
w->input_dev->evbit[0] = BIT(EV_ABS) | BIT_MASK(EV_KEY);
w->input_dev->keybit[BIT_WORD(BTN_GEAR_DOWN)] = BIT_MASK(BTN_GEAR_DOWN);
input_set_abs_params(w->input_dev, ABS_X, -512, 512, 0, 0);
input_set_abs_params(w->input_dev, ABS_Y, -512, 512, 0, 0);
input_set_abs_params(w->input_dev, ABS_Z, -512, 512, 0, 0);
input_set_abs_params(w->input_dev, ABS_THROTTLE, -512, 512, 0, 0);
input_set_abs_params(w->input_dev, ABS_RUDDER, -512, 512, 0, 0);
input_set_abs_params(w->input_dev, ABS_MISC, -512, 512, 0, 0);
if (input_register_device(w->input_dev)) {
pr_err("failed to register input device\n");
goto err_free_input_dev;
}
return;
err_free_input_dev:
input_free_device(w->input_dev);
err_unregister_device:
parport_unregister_device(w->pardevice);
}
static void walkera0701_detach(struct parport *port)
{
struct walkera_dev *w = &w_dev;
if (!w->pardevice || w->parport->number != port->number)
return;
input_unregister_device(w->input_dev);
parport_unregister_device(w->pardevice);
w->parport = NULL;
}
static struct parport_driver walkera0701_parport_driver = {
.name = "walkera0701",
.match_port = walkera0701_attach,
.detach = walkera0701_detach,
.devmodel = true,
};
static int __init walkera0701_init(void)
{
return parport_register_driver(&walkera0701_parport_driver);
}
static void __exit walkera0701_exit(void)
{
parport_unregister_driver(&walkera0701_parport_driver);
}
module_init(walkera0701_init);
module_exit(walkera0701_exit);