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Release 4.14 drivers/input/joystick/walkera0701.c

/*
 *  Parallel port to Walkera WK-0701 TX joystick
 *
 *  Copyright (c) 2008 Peter Popovec
 *
 *  More about driver:  <file:Documentation/input/walkera0701.txt>
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
*/


#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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec78699.12%150.00%
Dmitry Torokhov70.88%150.00%
Total793100.00%2100.00%


static inline int read_ack(struct pardevice *p) { return parport_read_status(p->port) & 0x40; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec22100.00%1100.00%
Total22100.00%1100.00%

/* 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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec26799.26%150.00%
Andrew Morton20.74%150.00%
Total269100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec43100.00%1100.00%
Total43100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec3170.45%150.00%
Dmitry Torokhov1329.55%150.00%
Total44100.00%2100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec3683.72%266.67%
Dmitry Torokhov716.28%133.33%
Total43100.00%3100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec35172.97%225.00%
Sudip Mukherjee7415.38%225.00%
Dmitry Torokhov5611.64%450.00%
Total481100.00%8100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Sudip Mukherjee3154.39%150.00%
Peter Popovec2645.61%150.00%
Total57100.00%2100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec1487.50%150.00%
Sudip Mukherjee212.50%150.00%
Total16100.00%2100.00%


static void __exit walkera0701_exit(void) { parport_unregister_driver(&walkera0701_parport_driver); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec1386.67%150.00%
Sudip Mukherjee213.33%150.00%
Total15100.00%2100.00%

module_init(walkera0701_init); module_exit(walkera0701_exit);

Overall Contributors

PersonTokensPropCommitsCommitProp
Peter Popovec173988.41%222.22%
Sudip Mukherjee1366.91%222.22%
Dmitry Torokhov904.58%444.44%
Andrew Morton20.10%111.11%
Total1967100.00%9100.00%
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