|  | /* | 
|  | *  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 WK0701_DEBUG */ | 
|  |  | 
|  | #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 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 */ | 
|  |  | 
|  | #ifdef WK0701_DEBUG | 
|  | { | 
|  | int magic, magic_bit; | 
|  | magic = (w->buf[21] << 4) | w->buf[22]; | 
|  | magic_bit = (w->buf[24] & 8) >> 3; | 
|  | printk(KERN_DEBUG | 
|  | "walkera0701: %4d %4d %4d %4d  %4d %4d %4d %4d (magic %2x %d)\n", | 
|  | val1, val2, val3, val4, val5, val6, val7, val8, magic, | 
|  | magic_bit); | 
|  | } | 
|  | #endif | 
|  | 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, 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); | 
|  |  | 
|  | 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); | 
|  | } | 
|  |  | 
|  | static int walkera0701_connect(struct walkera_dev *w, int parport) | 
|  | { | 
|  | int err = -ENODEV; | 
|  |  | 
|  | w->parport = parport_find_number(parport); | 
|  | if (w->parport == NULL) | 
|  | return -ENODEV; | 
|  |  | 
|  | if (w->parport->irq == -1) { | 
|  | printk(KERN_ERR "walkera0701: parport without interrupt\n"); | 
|  | goto init_err; | 
|  | } | 
|  |  | 
|  | err = -EBUSY; | 
|  | w->pardevice = parport_register_device(w->parport, "walkera0701", | 
|  | NULL, NULL, walkera0701_irq_handler, | 
|  | PARPORT_DEV_EXCL, w); | 
|  | if (!w->pardevice) | 
|  | goto init_err; | 
|  |  | 
|  | if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) | 
|  | goto init_err1; | 
|  |  | 
|  | if (parport_claim(w->pardevice)) | 
|  | goto init_err1; | 
|  |  | 
|  | w->input_dev = input_allocate_device(); | 
|  | if (!w->input_dev) | 
|  | goto init_err2; | 
|  |  | 
|  | 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->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); | 
|  |  | 
|  | err = input_register_device(w->input_dev); | 
|  | if (err) | 
|  | goto init_err3; | 
|  |  | 
|  | hrtimer_init(&w->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | 
|  | w->timer.function = timer_handler; | 
|  | return 0; | 
|  |  | 
|  | init_err3: | 
|  | input_free_device(w->input_dev); | 
|  | init_err2: | 
|  | parport_release(w->pardevice); | 
|  | init_err1: | 
|  | parport_unregister_device(w->pardevice); | 
|  | init_err: | 
|  | parport_put_port(w->parport); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static void walkera0701_disconnect(struct walkera_dev *w) | 
|  | { | 
|  | hrtimer_cancel(&w->timer); | 
|  | input_unregister_device(w->input_dev); | 
|  | parport_release(w->pardevice); | 
|  | 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); |