| /* |
| * 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); |
| } |
| |
| 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 (abs64(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 (abs64(pulse_time - SYNC_PULSE - BIN0_PULSE) < |
| RESERVE + BIN1_PULSE - BIN0_PULSE) /* frame sync .. */ |
| w->counter = 0; |
| |
| hrtimer_start(&w->timer, ktime_set(0, 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 int walkera0701_connect(struct walkera_dev *w, int parport) |
| { |
| int error; |
| |
| w->parport = parport_find_number(parport); |
| if (!w->parport) { |
| pr_err("parport %d does not exist\n", parport); |
| return -ENODEV; |
| } |
| |
| if (w->parport->irq == -1) { |
| pr_err("parport %d does not have interrupt assigned\n", |
| parport); |
| error = -EINVAL; |
| goto err_put_parport; |
| } |
| |
| w->pardevice = parport_register_device(w->parport, "walkera0701", |
| NULL, NULL, walkera0701_irq_handler, |
| PARPORT_DEV_EXCL, w); |
| if (!w->pardevice) { |
| pr_err("failed to register parport device\n"); |
| error = -EIO; |
| goto err_put_parport; |
| } |
| |
| if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) { |
| pr_err("failed to negotiate parport mode\n"); |
| error = -EIO; |
| 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"); |
| error = -ENOMEM; |
| 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); |
| |
| error = input_register_device(w->input_dev); |
| if (error) { |
| pr_err("failed to register input device\n"); |
| goto err_free_input_dev; |
| } |
| |
| return 0; |
| |
| err_free_input_dev: |
| input_free_device(w->input_dev); |
| err_unregister_device: |
| parport_unregister_device(w->pardevice); |
| err_put_parport: |
| parport_put_port(w->parport); |
| return error; |
| } |
| |
| static void walkera0701_disconnect(struct walkera_dev *w) |
| { |
| input_unregister_device(w->input_dev); |
| parport_unregister_device(w->pardevice); |
| parport_put_port(w->parport); |
| } |
| |
| static int __init walkera0701_init(void) |
| { |
| return walkera0701_connect(&w_dev, walkera0701_pp_no); |
| } |
| |
| static void __exit walkera0701_exit(void) |
| { |
| walkera0701_disconnect(&w_dev); |
| } |
| |
| module_init(walkera0701_init); |
| module_exit(walkera0701_exit); |